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  1. Category:Providence, RI | Open Energy Information

    Open Energy Info (EERE)

    Providence, RI Jump to: navigation, search Go Back to PV Economics By Location Media in category "Providence, RI" The following 16 files are in this category, out of 16 total....

  2. LIFE IC | Open Energy Information

    Open Energy Info (EERE)

    Zip: S60 5WG Product: LIFE-IC is a UK national resource centre for the development of all new energy technology innovations. References: LIFE-IC1 This article is a stub. You can...

  3. 2016 IC Virtual Career Fair

    Broader source: Energy.gov [DOE]

    Meet the Intelligence Community Online at the IC Virtual Career Fair on Thursday, March 3, 2016 from 2pm to 8pm. To register, please go to www.ICVirtualFair.com.

  4. IC Green Energy ICG | Open Energy Information

    Open Energy Info (EERE)

    Green Energy ICG Jump to: navigation, search Name: IC Green Energy (ICG) Place: Tel-Aviv, Israel Zip: 61204 Product: IC Green Energy (ICG), a member of Israel Corp. Group, is a new...

  5. Institutional computing (IC) information session

    SciTech Connect (OSTI)

    Koch, Kenneth R; Lally, Bryan R

    2011-01-19

    The LANL Institutional Computing Program (IC) will host an information session about the current state of unclassified Institutional Computing at Los Alamos, exciting plans for the future, and the current call for proposals for science and engineering projects requiring computing. Program representatives will give short presentations and field questions about the call for proposals and future planned machines, and discuss technical support available to existing and future projects. Los Alamos has started making a serious institutional investment in open computing available to our science projects, and that investment is expected to increase even more.

  6. QER- Comment of RI Office of Energy Resources

    Broader source: Energy.gov [DOE]

    Hi Matt, Please find additional materials from the RI Office of Energy Resources for the DOE QER. The documents attached include: 1) A powerpoint providing an overview of the RI State Energy Plan - the plan will be officially released in Fall, 2014; 2) Testimony to the RI Senate which outlines the need for coordinated work on the gas and electric infrastructure in New England; 3) A powerpoint version of the written testimony; 4) The 2013 Annual Report on the RI Energy Efficiency Program.

  7. ORISE: Incident Command System (ICS) Training

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Incident Command System (ICS) Training The Oak Ridge Institute for Science and Education (ORISE) supports the emergency response community by promoting interagency cooperation and...

  8. Instrumentation and Controls, IC, Accelerator Operations and...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Instrumentation and Controls, IC About Us AOT Home Teams Beam Diagnostics Controls Software ECAD Electronics Vacuum CONTACTS Group Leader Fred E. Shelley Office Administrator...

  9. DOE - Office of Legacy Management -- C I Haynes Inc - RI 02

    Office of Legacy Management (LM)

    Evaluation Year: 1994 RI.02-2 RI.02-3 Site Operations: Performed limited scale tests on heat treating uranium in a vacuum cold-wall furnace in 1964 RI.02-1 Site Disposition: ...

  10. I&C Modeling in SPAR Models

    SciTech Connect (OSTI)

    John A. Schroeder

    2012-06-01

    The Standardized Plant Analysis Risk (SPAR) models for the U.S. commercial nuclear power plants currently have very limited instrumentation and control (I&C) modeling [1]. Most of the I&C components in the operating plant SPAR models are related to the reactor protection system. This was identified as a finding during the industry peer review of SPAR models. While the Emergency Safeguard Features (ESF) actuation and control system was incorporated into the Peach Bottom Unit 2 SPAR model in a recent effort [2], various approaches to expend resources for detailed I&C modeling in other SPAR models are investigated.

  11. CE Geothermal | Open Energy Information

    Open Energy Info (EERE)

    Geothermal Jump to: navigation, search Name: CE Geothermal Place: California Sector: Geothermal energy Product: CE Geothermal previously owned the assets of Western States...

  12. 2012 APS-DPP Plasma Science Expo, Providence, RI | Princeton...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    APS-DPP Plasma Science Expo, Providence, RI View larger image IMG 1847 View larger image IMG 1598 View larger image IMG 1608 View larger image IMG 1609 View larger image IMG 1614...

  13. 2015 IC Virtual Career Fair | Department of Energy

    Office of Environmental Management (EM)

    2015 IC Virtual Career Fair 2015 IC Virtual Career Fair Instructions for Applicants Please use the following process to submit an application and resume for DOE's 2015 IC Virtual...

  14. Microsoft Word - S06401_IC.doc

    Office of Legacy Management (LM)

    Photos of T Building Rooms with Special ICs This page intentionally left blank U.S. Department of Energy Annual Assessment of the Effectiveness of Site-Wide Institutional Controls June 2010 Doc. No. S06401 Page D-1 Figure D-1. T Building Rooms with Special ICs Annual Assessment of the Effectiveness of Site-Wide Institutional Controls U.S. Department of Energy Doc. No. S06401 June 2010 Page D-2 Figure D-2. T Bldg. Room 16 View A Figure D-3. T Bldg. Room 16 View B Figure D-4. T Bldg. Room 16 View

  15. Understanding compact object formation and natal kicks. IV. The case of IC 10 X-1

    SciTech Connect (OSTI)

    Wong, Tsing-Wai; Valsecchi, Francesca; Ansari, Asna; Kalogera, Vassiliki; Fragos, Tassos; McClintock, Jeffrey; Glebbeek, Evert E-mail: francesca@u.northwestern.edu E-mail: tfragos@cfa.harvard.edu E-mail: ansari@ldeo.columbia.edu

    2014-08-01

    The extragalactic X-ray binary IC 10 X-1 has attracted attention as it is possibly the host of the most massive stellar-mass black-hole (BH) known to date. Here we consider all available observational constraints and construct its evolutionary history up to the instant just before the formation of the BH. Our analysis accounts for the simplest possible history, which includes three evolutionary phases: binary orbital dynamics at core collapse, common envelope (CE) evolution, and evolution of the BH-helium star binary progenitor of the observed system. We derive the complete set of constraints on the progenitor system at various evolutionary stages. Specifically, right before the core collapse event, we find the mass of the BH immediate progenitor to be ? 31 M{sub ?} (at 95% of confidence, same hereafter). The magnitude of the natal kick imparted to the BH is constrained to be ? 130 km s{sup 1}. Furthermore, we find that the 'enthalpy' formalism recently suggested by Ivanova and Chaichenets is able to explain the existence of IC 10 X-1 without the need to invoke unreasonably high CE efficiencies. With this physically motivated formalism, we find that the CE efficiency required to explain the system is in the range of ? 0.6-1.

  16. Thermoelectric Conversion of Wate Heat to Electricity in an IC...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Wate Heat to Electricity in an IC Engine Powered Vehicle Thermoelectric Conversion of Wate Heat to Electricity in an IC Engine Powered Vehicle Presentation given at the 16th...

  17. PDC IC WELD FAILURE EVALUATION AND RESOLUTION

    SciTech Connect (OSTI)

    Korinko, P.; Howard, S.; Maxwell, D.; Fiscus, J.

    2012-04-16

    During final preparations for start of the PDCF Inner Can (IC) qualification effort, welding was performed on an automated weld system known as the PICN. During the initial weld, using a pedigree canister and plug, a weld defect was observed. The defect resulted in a hole in the sidewall of the canister, and it was observed that the plug sidewall had not been consumed. This was a new type of failure not seen during development and production of legacy Bagless Transfer Cans (FB-Line/Hanford). Therefore, a team was assembled to determine the root cause and to determine if the process could be improved. After several brain storming sessions (MS and T, R and D Engineering, PDC Project), an evaluation matrix was established to direct this effort. The matrix identified numerous activities that could be taken and then prioritized those activities. This effort was limited by both time and resources (the number of canisters and plugs available for testing was limited). A discovery process was initiated to evaluate the Vendor's IC fabrication process relative to legacy processes. There were no significant findings, however, some information regarding forging/anneal processes could not be obtained. Evaluations were conducted to compare mechanical properties of the PDC canisters relative to the legacy canisters. Some differences were identified, but mechanical properties were determined to be consistent with legacy materials. A number of process changes were also evaluated. A heat treatment procedure was established that could reduce the magnetic characteristics to levels similar to the legacy materials. An in-situ arc annealing process was developed that resulted in improved weld characteristics for test articles. Also several tack welds configurations were addressed, it was found that increasing the number of tack welds (and changing the sequence) resulted in decreased can to plug gaps and a more stable weld for test articles. Incorporating all of the process improvements for the actual can welding process, however, did not result in an improved weld geometry. Several possibilities for the lack of positive response exist, some of which are that (1) an insufficient number of test articles were welded under prototypic conditions, (2) the process was not optimized so that significant improvements were observable over the 'noise', and (3) the in-situ arc anneal closed the gap down too much so the can was unable to exhaust pressure ahead of the weld. Several operational and mechanical improvements were identified. The weld clamps were changed to a design consistent with those used in the legacy operations. A helium puff operation was eliminated; it is believed that this operation was the cause of the original weld defect. Also, timing of plug mast movement was found to correspond with weld irregularities. The timing of the movement was changed to occur during weld head travel between tacks. In the end a three sequential tack weld process followed by a pulse weld at the same current and travel speed as was used for the legacy processes was suggested for use during the IC qualification effort. Relative to legacy welds, the PDC IC weld demonstrates greater fluctuation in the region of the weld located between tack welds. However, canister weld response (canister to canister) is consistent and with the aid of the optical mapping system (for targeting the cut position) is considered adequate. DR measurements and METs show the PDC IC welds to have sufficient ligament length to ensure adequate canister pressure/impact capacity and to ensure adequate stub function. The PDC welding process has not been optimized as a result of this effort. Differences remain between the legacy BTC welds and the PDC IC weld, but these differences are not sufficient to prevent resumption of the current PDC IC qualification effort. During the PDC IC qualification effort, a total of 17 cans will be welded and a variety of tests/inspections will be performed. The extensive data collected during that qualification effort should be of a sufficient population to determ

  18. THE UBV(RI){sub C} COLORS OF THE SUN

    SciTech Connect (OSTI)

    Ramirez, I.; Michel, R.; Schuster, W. J.; Sefako, R.; Van Wyk, F.; Tucci Maia, M.; Melendez, J.; Castilho, B. V.

    2012-06-10

    Photometric data in the UBV(RI){sub C} system have been acquired for 80 solar analog stars for which we have previously derived highly precise atmospheric parameters T{sub eff}, log g, and [Fe/H] using high-resolution, high signal-to-noise ratio spectra. UBV and (RI){sub C} data for 46 and 76 of these stars, respectively, are published for the first time. Combining our data with those from the literature, colors in the UBV(RI){sub C} system, with {approx_equal} 0.01 mag precision, are now available for 112 solar analogs. Multiple linear regression is used to derive the solar colors from these photometric data and the spectroscopically derived T{sub eff}, log g, and [Fe/H] values. To minimize the impact of systematic errors in the model-dependent atmospheric parameters, we use only the data for the 10 stars that most closely resemble our Sun, i.e., the solar twins, and derive the following solar colors: (B - V){sub Sun} = 0.653 {+-} 0.005, (U - B){sub Sun} = 0.166 {+-} 0.022, (V - R){sub Sun} = 0.352 {+-} 0.007, and (V - I){sub Sun} = 0.702 {+-} 0.010. These colors are consistent, within the 1{sigma} errors, with those derived using the entire sample of 112 solar analogs. We also derive the solar colors using the relation between spectral-line-depth ratios and observed stellar colors, i.e., with a completely model-independent approach, and without restricting the analysis to solar twins. We find (B - V){sub Sun} = 0.653 {+-} 0.003, (U - B){sub Sun} = 0.158 {+-} 0.009, (V - R){sub Sun} = 0.356 {+-} 0.003, and (V - I){sub Sun} = 0.701 {+-} 0.003, in excellent agreement with the model-dependent analysis.

  19. SwRI's HEDGE Technology for High Efficiency, Low Emissions Gasoline...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Efficiency Engine Technologies and an Introduction to SwRI's Dedicated EGR Concept Development of Dual-Fuel Engine for Class 8 Applications Gasoline Ultra Fuel Efficient Vehicle...

  20. International Refrigeration: Order (2012-CE-1510) | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    International Refrigeration: Order (2012-CE-1510) International Refrigeration: Order (2012-CE-1510) July 20, 2012 DOE ordered International Refrigeration Products to pay an 8,000 ...

  1. Microsoft Word - S07757_2011 Mound IC Report

    Office of Legacy Management (LM)

    Department of Energy Annual Assessment of the Effectiveness of Site-Wide Institutional Controls June 2011 Doc. No. S07757 Page C-1 Figure 1. T Building Rooms with Special ICs Annual Assessment of the Effectiveness of Site-Wide Institutional Controls U.S. Department of Energy Doc. No. S07757 June 2011 Page C-2 T Building Rooms with Special ICs In addition to the ICs for the entire site, T Building has the following additional IC restrictions as described in the Parcel 6, 7, and 8 Record of

  2. CE Solar | Open Energy Information

    Open Energy Info (EERE)

    Czech Republic Zip: 686 01 Product: Czech PV system integrator primarily building plants for Energy 21 in the Czech Republic. References: CE Solar1 This article is a stub....

  3. Prometheus Reactor I&C Software Development Methodology, for Action

    SciTech Connect (OSTI)

    T. Hamilton

    2005-07-30

    The purpose of this letter is to submit the Reactor Instrumentation and Control (I&C) software life cycle, development methodology, and programming language selections and rationale for project Prometheus to NR for approval. This letter also provides the draft Reactor I&C Software Development Process Manual and Reactor Module Software Development Plan to NR for information.

  4. Thermoelectrici Conversion of Waste Heat to Electricity in an IC

    Broader source: Energy.gov (indexed) [DOE]

    Engine-Powered Vehicle | Department of Energy 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters PDF icon 2005_deer_schock.pdf More Documents & Publications Thermoelectric Conversion of Waste Heat to Electricity in an IC Engine Powered Vehicle Thermoelectric Conversion of Waste Heat to Electricity in an IC Engine Powered Vehicle

  5. Portsmouth RI/FS Report for the Process Buildings and Complex Facilities

    Energy Savers [EERE]

    Decontamination and Decommissioning Evaluation Project | Department of Energy Process Buildings and Complex Facilities Decontamination and Decommissioning Evaluation Project Portsmouth RI/FS Report for the Process Buildings and Complex Facilities Decontamination and Decommissioning Evaluation Project This remedial investigation/feasibility study (RI/FS), the Remedial Investigation and Feasibility Study Report for the Process Buildings and Complex Facilities Decontamination and

  6. Microsoft Word - S08846_2012_Annual_IC report

    Office of Legacy Management (LM)

    Department of Energy Annual Assessment of the Effectiveness of Site-Wide Institutional Controls Doc. No. S08846 June 2012 Page C-1 T Building Rooms with Special ICs In addition to the ICs for the entire site, T Building has the following additional IC restrictions as described in the Parcel 6, 7, and 8 Record of Decision. 1. Prohibit the removal of concrete floor material in specified rooms of T Building (Figure 1) to off-site locations without prior approval from EPA, Ohio EPA, and ODH. 2.

  7. Remedial Investigation/Feasibility Study (RI/FS) process, elements and techniques guidance

    SciTech Connect (OSTI)

    Not Available

    1993-12-01

    This manual provides detailed guidance on Remedial Investigation/Feasibility Studies (RI/FSs) conducted pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) at Department of Energy (DOE) facilities. The purpose of the RI/FS, to assess the risk posed by a hazardous waste site and to determine the best way to reduce that risk, and its structure (site characterization, risk assessment, screening and detailed analysis of alternatives, etc.) is defined in the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) and further explained in the Environmental Protection Agency`s (EPA`s) Guidance for Conducting Remedial Investigations and Feasibility Studies Under CERCLA (Interim Final) 540/G-89/004, OSWER Directive 9355.3-01, October 1988. Though issued in 1988, the EPA guidance remains an excellent source of information on the conduct and structure of an RI/FS. This document makes use of supplemental RI/FS-related guidance that EPA has developed since its initial document was issued in 1988, incorporates practical lessons learned in more than 12 years of experience in CERCLA hazardous site remediation, and drawing on those lessons, introduces the Streamlined Approach For Environmental Restoration (SAFER), developed by DOE as a way to proceed quickly and efficiently through the RI/FS process at DOE facilities. Thus as its title implies, this guidance is intended to describe in detail the process and component elements of an RI/FS, as well as techniques to manage the RI/FS effectively.

  8. Interband cascade (IC) photovoltaic (PV) architecture for PV devices

    DOE Patents [OSTI]

    Yang, Rui Q.; Tian, Zhaobing; Mishima, Tetsuya D.; Santos, Michael B.; Johnson, Matthew B.; Klem, John F.

    2015-10-20

    A photovoltaic (PV) device, comprising a PV interband cascade (IC) stage, wherein the IC PV stage comprises an absorption region with a band gap, the absorption region configured to absorb photons, an intraband transport region configured to act as a hole barrier, and an interband tunneling region configured to act as an electron barrier. An IC PV architecture for a photovoltaic device, the IC PV architecture comprising an absorption region, an intraband transport region coupled to the absorption region, and an interband tunneling region coupled to the intraband transport region and to the adjacent absorption region, wherein the absorption region, the intraband transport region, and the interband tunneling region are positioned such that electrons will flow from the absorption region to the intraband transport region to the interband tunneling region.

  9. Idaho - IC 61-516 - Priority Designation for Electric Transmission...

    Open Energy Info (EERE)

    Idaho - IC 61-516 - Priority Designation for Electric Transmission Projects Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- RegulationRegulation:...

  10. Idaho IC 67-6512 | Open Energy Information

    Open Energy Info (EERE)

    12 Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: Idaho IC 67-6512Legal Abstract This section discusses special use permits,...

  11. WA_01_018_IBM_Waiver_of_Governement_US_and_Foreign_Patent_Ri.pdf |

    Energy Savers [EERE]

    Department of Energy 1_018_IBM_Waiver_of_Governement_US_and_Foreign_Patent_Ri.pdf WA_01_018_IBM_Waiver_of_Governement_US_and_Foreign_Patent_Ri.pdf PDF icon WA_01_018_IBM_Waiver_of_Governement_US_and_Foreign_Patent_Ri.pdf More Documents & Publications WA_04_053_IBM_CORP_Waiver_of_the_Government_U.S._and_Foreign.pdf WA_00_015_COMPAQ_FEDERAL_LLC_Waiver_Domestic_and_Foreign_Pat.pdf Advance Patent Waiver W(A)2002-023

  12. Almo: Order (2012-CE-1416) | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    PDF icon 2012-CE-1416AlmoOrder More Documents & Publications Almo: Proposed Penalty (2012-CE-1416) International Refrigeration: Order (2012-CE-1510) Commercial Display Systems: ...

  13. Structure of Fc[gamma]RI in complex with Fc reveals the importance...

    Office of Scientific and Technical Information (OSTI)

    complex with Fc reveals the importance of glycan recognition for high-affinity IgG binding Citation Details In-Document Search Title: Structure of FcgammaRI in complex with Fc ...

  14. Instrumentation and control system (ICS). Training alternatives study

    SciTech Connect (OSTI)

    Lindberg, R.C.

    1997-01-01

    Computer technology today provides tools for producing presentations and training programs that are colorful, effective and comprehensive. For example, the Microsoft package of Word, Excel, Powerpoint, and Visual Basic can be used to produce a multimedia presentation for training WETF ICS operators. This presentation would be segmented into a series of lessons which would lead the prospective operator from a cursory view of facility operations to a detailed knowledge of ICS, process, control room and other systems operations. Using a suitably equipped Personal Computer (PC), a person would be ready for advanced, hands-on experience at the conclusion of such a training sequence.

  15. CE: Proposed Penalty (2013-SE-1429)

    Office of Energy Efficiency and Renewable Energy (EERE)

    DOE alleged in a Notice of Proposed Civil Penalty that CE North America, LLC, privately labeled and distributed noncompliant freezers in the U.S.

  16. CE: Compromise Agreement (2013-SE-1429)

    Broader source: Energy.gov [DOE]

    DOE and CE North America entered into a Compromise Agreement to resolve a case involving the distribution in commerce of noncompliant freezers.

  17. Photoelectron spectra of CeO{sup −} and Ce(OH){sub 2}{sup −}

    SciTech Connect (OSTI)

    Ray, Manisha; Felton, Jeremy A.; Kafader, Jared O.; Topolski, Josey E.; Jarrold, Caroline Chick

    2015-02-14

    The photoelectron spectrum of CeO{sup −} exhibits what appears to be a single predominant electronic transition over an energy range in which numerous close-lying electronic states of CeO neutral are well known. The photoelectron spectrum of Ce(OH){sub 2}{sup −}, a molecule in which the Ce atom shares the same formal oxidation state as the Ce atom in CeO{sup −}, also exhibits what appears to be a single transition. From the spectra, the adiabatic electron affinities of CeO and Ce(OH){sub 2} are determined to be 0.936 ± 0.007 eV and 0.69 ± 0.03 eV, respectively. From the electron affinity of CeO, the CeO{sup −} bond dissociation energy was determined to be 7.7 eV, 0.5 eV lower than the neutral bond dissociation energy. The ground state orbital occupancies of both CeO{sup −} and Ce(OH){sub 2}{sup −} are calculated to have 4f 6s{sup 2} Ce{sup +} superconfigurations, with open-shell states having 4f5d6s superconfiguration predicted to be over 1 eV higher in energy. Low-intensity transitions observed at higher electron binding energies in the spectrum of CeO{sup −} are tentatively assigned to the {sup 1}Σ{sup +} (Ω = 0) state of CeO with the Ce{sup +2}⍰6s{sup 2} superconfiguration.

  18. Structure of Fc[gamma]RI in complex with Fc reveals the importance of

    Office of Scientific and Technical Information (OSTI)

    glycan recognition for high-affinity IgG binding (Journal Article) | SciTech Connect Structure of Fc[gamma]RI in complex with Fc reveals the importance of glycan recognition for high-affinity IgG binding Citation Details In-Document Search Title: Structure of Fc[gamma]RI in complex with Fc reveals the importance of glycan recognition for high-affinity IgG binding Authors: Lu, Jinghua ; Chu, Jonathan ; Zou, Zhongcheng ; Hamacher, Nels B. ; Rixon, Mark W. ; Sun, Peter D. [1] ; BMS) [2] + Show

  19. DOE Zero Energy Ready Home Case Study, Caldwell and Johnson, Exeter, RI,

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Custom Home | Department of Energy Study, Caldwell and Johnson, Exeter, RI, Custom Home DOE Zero Energy Ready Home Case Study, Caldwell and Johnson, Exeter, RI, Custom Home Case study of a DOE Zero Energy Ready Home in Exeter, Rhode Island, that scored HERS 43 without PV. This 2,000 ft2 custom home has a spray- foamed attic and walls, plus rigid foam sheathing, ducted mini-split heat pumps, and an HRV. PDF icon BA_ZeroEnergyReady_CaldwellJohnson_062314.pdf More Documents & Publications

  20. RFI/RI work plan for the Road A Chemical Basin 904-111G

    SciTech Connect (OSTI)

    Kmetz, T.F.

    2000-03-07

    This Resource Conservation and Recovery Act (RCRA) Facility Investigation (RFI)/Remedial Investigation (RI) Work Plan has been prepared for the Road A Chemical Basin Operable Unit (RdACB OU) (904-111G). This unit is subject to the requirements of both RCRA and the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). This Work Plan presents the initial evaluation of existing unit data, applicable background data, the regulatory framework for the unit investigation, and the evaluations and decisions made during the determination of the scope and objectives of the planned Remedial Investigation/Feasibility Study (RI/FS) activities.

  1. Microsoft Word - S07757_2011 Mound IC Report

    Office of Legacy Management (LM)

    IC Assessment Checklist This page intentionally left blank CHECKLIST WORKSHEET - COMBINED - ALL PARCELS Review of Effectiveness of Institutional Controls U.S. Department of Energy Annual Assessment of the Effectiveness of Site-Wide Institutional Controls June 2011 Doc. No. S07757 Page A-1 Scope: Entire Mound Site Preliminary inspections performed on: April 5 and 7, 2011 Physical Inspection Walk around on: April 12, 2011 Review led by: Art Kleinrath, DOE LM Phone #: 937-227-2237 Participants in

  2. DOE Zero Energy Ready Home Case Study: Caldwell and Johnson, Charlestown, RI

    Broader source: Energy.gov [DOE]

    Case study of a DOE Zero Energy Ready affordable home in Charlestown, RI, that achieved a HERS Index of 47 without PV. The 2,244-ft2 two-story home with basement has 2x6 walls filled with 5.5 in. ...

  3. Idaho IC 67-6508, Planning Duties for Local Land Use | Open Energy...

    Open Energy Info (EERE)

    Idaho IC 67-6508, Planning Duties for Local Land Use Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: Idaho IC 67-6508, Planning...

  4. The Role Of IC Engines In Future Energy Use | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Of IC Engines In Future Energy Use The Role Of IC Engines In Future Energy Use Reviews future market trends and forecasts, and future engine challenges and research focus PDF icon ...

  5. I.C. 36-103 - Wildlife Property of State--Preservation | Open...

    Open Energy Info (EERE)

    I.C. 36-103 - Wildlife Property of State--Preservation Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: I.C. 36-103 - Wildlife...

  6. Thermoelectric Couple Demonstration of (In, Ce)-based Skutterudite...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    of (In, Ce)-based Skutterudite Materials for Automotive Energy Recovery Thermoelectric Couple Demonstration of (In, Ce)-based Skutterudite Materials for Automotive...

  7. California Ethanol Power CE P | Open Energy Information

    Open Energy Info (EERE)

    Power CE P Jump to: navigation, search Name: California Ethanol & Power (CE+P) Place: Florida Product: US ethanol project developer. References: California Ethanol & Power...

  8. CeCap LLP | Open Energy Information

    Open Energy Info (EERE)

    Name: CeCap LLP Place: London, United Kingdom Zip: W1S 2LQ Product: London-based investment boutique which provides investment advice to, and invests in, small to mediun size...

  9. Palmetto Clean Energy (PaCE) Program

    Broader source: Energy.gov [DOE]

    PaCE funding comes from the customers of participating utilities who voluntarily choose to support the program through an additional charge on their monthly utility bills. Of the $4, $3.50 goes t...

  10. Portsmouth RI/FS Report for the Site-Wide Waste Disposition Evaluation

    Energy Savers [EERE]

    Project | Department of Energy Site-Wide Waste Disposition Evaluation Project Portsmouth RI/FS Report for the Site-Wide Waste Disposition Evaluation Project This Remedial Investigation and Feasibility Study Report for the Site-Wide Waste Disposition Evaluation Project at the Portsmouth Gaseous Diffusion Plant, Piketon, Ohio, presents the information necessary to select a Site-wide disposal alternative for the waste generated under the Director's Final Findings and Orders (DFF&O) for

  11. A New Path Forward for WTP AL Boldt and RI Smith

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Dick Smith and Al Boldt - thoughts to share with the Tank Waste Committee Not a committee work product A New Path Forward for WTP AL Boldt and RI Smith February 3, 2014 Introduction The "Framework" document, issued by the Department of Energy (DOE) in September of 2013, is purported to show the path forward for completion and operation of the Hanford Waste Treatment Plant (WTP) for treatment of Hanford tank wastes. Construction on two principal facilities (HLW and Pretreatment) was

  12. A revolutionary concept to improve the efficiency of IC antennas

    SciTech Connect (OSTI)

    Milanesio, D.; Maggiora, R.

    2014-02-12

    The successful design of an Ion Cyclotron (IC) antenna mainly relies on the capability of coupling high power to the plasma (MW), feature that is currently reached by allowing rather high voltages (tens of kV) on the unavoidable unmatched part of the feeding lines. This requirement is often responsible of arcs along the transmission lines and other unwanted phenomena that considerably limit the usage of IC launchers. In this work, we suggest and describe a revolutionary approach based on high impedance surfaces, which allows to increase the antenna radiation efficiency and, hence, to highly reduce the imposed voltages to couple the same level of power to the plasma. High-impedance surfaces are periodic metallic structures (patches) displaced usually on top of a dielectric substrate and grounded by means of vertical posts usually embedded inside a dielectric, in a mushroom-like shape. In terms of working properties, high impedance surfaces are electrically thin in-phase reflectors, i.e. they present a high impedance, within a given frequency band, such that the image currents are in-phase with the currents of the antenna itself, thus determining a significant efficiency increase. While the usual design of a high impedance surface requires the presence of a dielectric layer, some alternative solutions can be realized in vacuum, taking advantage of double layers ofmetallic patches. After an introductory part on the properties of high impedance surfaces, this work documents both their design by means of numerical codes and their implementation on a scaled mock-up.

  13. DOE/CE/41035-1-FINAL

    Office of Scientific and Technical Information (OSTI)

    i- , : --) DOE/CE/41035-1-FINAL February 2003 HIGH VALUE SCRAP TIRE RECYCLE 'Project Final Report on VISTAMER~ Polymer Paints By: Bernard D. Bauman Composite Particles, Inc. P.0. Box 218803 Houston, TX 77218-8803 Work Perlbrmed Under Cooperative Agreement No. DE-FCO2-93CE41035 For U.S. Department of Energy Office of Industrial Technologies DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any

  14. Light Element Production in Type Ic Supernovae (Journal Article) | SciTech

    Office of Scientific and Technical Information (OSTI)

    Connect Light Element Production in Type Ic Supernovae Citation Details In-Document Search Title: Light Element Production in Type Ic Supernovae We discuss production of light elements (Li, Be) in energetic type Ic supernovae (SNe Ic) and how newly synthesized light elements are transferred to stars of the next generation. We have pointed out that spallation reactions involving N and He become important in an explosion of a rotating metal-poor star if the progenitor still keeps a fraction of

  15. Microsoft Word - S04030_Ann IC Assmt Rpt final - for printing...

    Office of Legacy Management (LM)

    ... (NESHAPs) requirements are met after ... includes ICs for the land parcel and monitored natural attenuation (MNA) to ... Mechanical Reroute gas piping Advance ...

  16. Attachment method for stacked integrated circuit (IC) chips

    DOE Patents [OSTI]

    Bernhardt, Anthony F. (Berkeley, CA); Malba, Vincent (Livermore, CA)

    1999-01-01

    An attachment method for stacked integrated circuit (IC) chips. The method involves connecting stacked chips, such as DRAM memory chips, to each other and/or to a circuit board. Pads on the individual chips are rerouted to form pads on the side of the chip, after which the chips are stacked on top of each other whereby desired interconnections to other chips or a circuit board can be accomplished via the side-located pads. The pads on the side of a chip are connected to metal lines on a flexible plastic tape (flex) by anisotropically conductive adhesive (ACA). Metal lines on the flex are likewise connected to other pads on chips and/or to pads on a circuit board. In the case of a stack of DRAM chips, pads to corresponding address lines on the various chips may be connected to the same metal line on the flex to form an address bus. This method has the advantage of reducing the number of connections required to be made to the circuit board due to bussing; the flex can accommodate dimensional variation in the alignment of chips in the stack; bonding of the ACA is accomplished at low temperature and is otherwise simpler and less expensive than solder bonding; chips can be bonded to the ACA all at once if the sides of the chips are substantially coplanar, as in the case for stacks of identical chips, such as DRAM.

  17. Attachment method for stacked integrated circuit (IC) chips

    DOE Patents [OSTI]

    Bernhardt, A.F.; Malba, V.

    1999-08-03

    An attachment method for stacked integrated circuit (IC) chips is disclosed. The method involves connecting stacked chips, such as DRAM memory chips, to each other and/or to a circuit board. Pads on the individual chips are rerouted to form pads on the side of the chip, after which the chips are stacked on top of each other whereby desired interconnections to other chips or a circuit board can be accomplished via the side-located pads. The pads on the side of a chip are connected to metal lines on a flexible plastic tape (flex) by anisotropically conductive adhesive (ACA). Metal lines on the flex are likewise connected to other pads on chips and/or to pads on a circuit board. In the case of a stack of DRAM chips, pads to corresponding address lines on the various chips may be connected to the same metal line on the flex to form an address bus. This method has the advantage of reducing the number of connections required to be made to the circuit board due to bussing; the flex can accommodate dimensional variation in the alignment of chips in the stack; bonding of the ACA is accomplished at low temperature and is otherwise simpler and less expensive than solder bonding; chips can be bonded to the ACA all at once if the sides of the chips are substantially coplanar, as in the case for stacks of identical chips, such as DRAM. 12 figs.

  18. Hybridized Nature of Pseudogap in Kondo Insulators CeRhSb and CeRhAs

    SciTech Connect (OSTI)

    Kumigashira, H.; Takahashi, T.; Yoshii, S.; Kasaya, M.

    2001-08-06

    We studied the electronic structure of Kondo insulators CeRhSb and CeRhAs using high-resolution photoemission spectroscopy. We found that the 4f -derived density of states shows a depletion (pseudogap) at E{sub F} in contrast to metallic Kondo materials. It was found that the size of the f pseudogap is smaller than that of conduction electrons (c pseudogap) while both scale well with the Kondo temperature. The present results indicate that the hybridization between 4f and conduction electrons near E{sub F} is essential for the Kondo gap in the Ce-based compounds.

  19. 2012 APS-DPP Plasma Science Expo, Providence, RI | Princeton Plasma Physics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Lab APS-DPP Plasma Science Expo, Providence, RI View larger image IMG 1847 View larger image IMG 1598 View larger image IMG 1608 View larger image IMG 1609 View larger image IMG 1614 View larger image IMG 1647 View larger image IMG 1650 View larger image IMG 1651 View larger image IMG 1657 View larger image IMG 1659 View larger image IMG 1662 View larger image IMG 1663 View larger image IMG 1664 View larger image IMG 1668 View larger image IMG 1672 View larger image IMG 1675 View larger

  20. Goodman Manufacturing: Order (2012-CE-1509) | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    2-CE-1509) Goodman Manufacturing: Order (2012-CE-1509) August 7, 2012 DOE ordered Goodman Manufacturing Company L.P. to pay an 8,000 civil penalty after finding Goodman...

  1. Spin reorientation and Ce-Mn coupling in antiferromagnetic oxypnictide CeMnAsO

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Qiang; Tian, Wei; Peterson, Spencer G.; Dennis, Kevin W.; Vaknin, David

    2015-02-18

    Structure and magnetic properties of high-quality polycrystlline CeMnAsO, a parent compound of the “1111”-type oxypnictides, have been investigated using neutron powder diffraction and magnetization measurements. We find that CeMnAsO undergoes a C-type antiferromagnetic order with Mn2+(S = 5/2) moments pointing along the c axis below a relatively high Néel temperature of TN = 347(1) K. Below TSR = 35 K, two simultaneous transitions occur where the Mn moments reorient from the c axis to the ab plane preserving the C-type magnetic order, and Ce moments undergo long-range AFM ordering with antiparallel moments pointing in the ab plane. Another transition tomore » a noncollinear magnetic structure occurs below 7 K. The ordered moments of Mn and Ce at 2 K are 3.32(4) μB and 0.81(4)μB, respectively. We find that CeMnAsO primarily falls into the category of a local-moment antiferromagnetic insulator in which the nearest-neighbor interaction (J1) is dominant with J2 < J1/2 in the context of J1 – J2 – Jc model. The spin reorientation transition driven by the coupling between Ce and the transition metal seems to be common to Mn, Fe, and Cr ions, but not to Co and Ni ions in the isostructural oxypnictides. As a result, a schematic illustration of magnetic structures in Mn and Ce sublattices in CeMnAsO is presented.« less

  2. Maxlite: Order (2015-CE-27018) | Department of Energy

    Energy Savers [EERE]

    5-CE-27018) Maxlite: Order (2015-CE-27018) May 14, 2015 DOE ordered Maxlite, Inc. to pay a $8,000 civil penalty after finding Maxlite had failed to certify that certain models of general service fluorescent lamps comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Maxlite. PDF icon Maxlite: Order (2015-CE-27018) More Documents & Publications Maxlite: Proposed Penalty (2015-CE-27018) Maxlite:

  3. Utility: Order (2016-CE-42007) | Department of Energy

    Energy Savers [EERE]

    CE-42007) Utility: Order (2016-CE-42007) January 5, 2016 DOE ordered Utility Refrigerator to pay a $8,000 civil penalty after finding Utility had failed to certify that certain models of commercial refrigerator equipment comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Utility. PDF icon Utility: Order (2016-CE-42007) More Documents & Publications Utility: Proposed Penalty (2016-CE-42007)

  4. PQL: Order (2013-CE-27001) | Department of Energy

    Energy Savers [EERE]

    Order (2013-CE-27001) PQL: Order (2013-CE-27001) August 7, 2015 DOE ordered P.Q.L, Inc. to pay a $12,500 civil penalty after finding PQL had failed to certify that certain models of medium base compact fluorescent lamps comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and PQL. PDF icon PQL: Order (2013-CE-27001) More Documents & Publications PQL: Proposed Penalty (2013-CE-27001) PQL: Order

  5. RPI: Order (2015-CE-42065) | Department of Energy

    Energy Savers [EERE]

    Order (2015-CE-42065) RPI: Order (2015-CE-42065) November 6, 2015 DOE ordered RPI Industries, Inc. to pay a $8,000 civil penalty after finding RPI had failed to certify that certain models of commercial refrigeration equipment comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and RPI. PDF icon RPI: Order (2015-CE-42065) More Documents & Publications RPI: Proposed Penalty (2015-CE-42065) Cal Flame:

  6. Role of Ce4+ in the scintillation mechanism of codoped Gd3Ga3Al2O12:Ce

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wu, Yuntao; Meng, Fang; Li, Qi; Koschan, Merry; Melcher, Charles L.

    2014-10-17

    To control the time-response performance of widely used cerium-activated scintillators in cutting-edge medical-imaging devices, such as time-of-flight positron-emission tomography, a comprehensive understanding of the role of Ce valence states, especially stable Ce4+, in the scintillation mechanism is essential. However, despite some progress made recently, an understanding of the physical processes involving Ce4+ is still lacking. The aim of this work is to clarify the role of Ce4+ in scintillators by studying Ca2+ codoped Gd3Ga3Al2O12∶Ce (GGAG∶Ce). By using a combination of optical absorption spectra and x-ray absorption near-edge spectroscopies, the correlation between Ca2+codoping content and the Ce4+ fraction is seen. The energy-levelmore » diagrams of Ce3+ and Ce4+ in the Gd3Ga3Al2O12 host are established by using theoretical and experimental methods, which indicate a higher position of the 5d1 state of Ce4+ in the forbidden gap in comparison to that of Ce3+. Underlying reasons for the decay-time acceleration resulting from Ca2+ codoping are revealed, and the physical processes of the Ce4+-emission model are proposed and further demonstrated by temperature-dependent radioluminescence spectra under x-ray excitation.« less

  7. Role of Ce4+ in the scintillation mechanism of codoped Gd3Ga3Al2O12:Ce

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wu, Yuntao; Meng, Fang; Li, Qi; Koschan, Merry; Melcher, Charles L.

    2014-10-17

    To control the time-response performance of widely used cerium-activated scintillators in cutting-edge medical-imaging devices, such as time-of-flight positron-emission tomography, a comprehensive understanding of the role of Ce valence states, especially stable Ce4+, in the scintillation mechanism is essential. However, despite some progress made recently, an understanding of the physical processes involving Ce4+ is still lacking. The aim of this work is to clarify the role of Ce4+ in scintillators by studying Ca2+ codoped Gd3Ga3Al2O12∶Ce (GGAG∶Ce). By using a combination of optical absorption spectra and x-ray absorption near-edge spectroscopies, the correlation between Ca2+codoping content and the Ce4+ fraction is seen. The energy-levelmore »diagrams of Ce3+ and Ce4+ in the Gd3Ga3Al2O12 host are established by using theoretical and experimental methods, which indicate a higher position of the 5d1 state of Ce4+ in the forbidden gap in comparison to that of Ce3+. Underlying reasons for the decay-time acceleration resulting from Ca2+ codoping are revealed, and the physical processes of the Ce4+-emission model are proposed and further demonstrated by temperature-dependent radioluminescence spectra under x-ray excitation.« less

  8. NEW BV(RI){sub C} PHOTOMETRY FOR PRAESEPE: FURTHER TESTS OF BROADBAND PHOTOMETRIC CONSISTENCY

    SciTech Connect (OSTI)

    Joner, Michael D.; Taylor, Benjamin J.; Laney, C. David; Van Wyk, Francois

    2011-11-15

    New BV(RI){sub C} measurements of Praesepe made at the South African Astronomical Observatory (SAAO) are presented. When those measurements are combined with those reported in previous papers in this series, it is found that they support previously determined V zero points for Praesepe, M67, and the Hyades. Support is also found for joint (V - R){sub C} and (R - I){sub C} zero points established previously for Praesepe and NGC 752. For the SAAO system of standard stars, a B - V correction to the Johnson system of about -9 mmag appears to be reasonably well established. The preferred (though not definitive) V correction is about +7 mmag. For the Landolt V system, zero-point identity with the Johnson system at a 2{sigma} level of 4.8 mmag is found, and no color term as large as 4 mmag (mag){sup -1} is detected. Updated CDS data files for Praesepe are briefly described.

  9. IC 42-104 - Appropriation (of Water) Must be for Beneficial Purpose...

    Open Energy Info (EERE)

    of water must be for beneficial purpose. Published NA Year Signed or Took Effect 1899 Legal Citation I.C. 42-104 DOI Not Provided Check for DOI availability: http:...

  10. I.C. 68-52 - Idaho Administrative Procedure Act | Open Energy...

    Open Energy Info (EERE)

    Act Jump to: navigation, search OpenEI Reference LibraryAdd to library Reference: I.C. 68-52 - Idaho Administrative Procedure Act Published Publisher Not Provided, Date Not...

  11. IC 67-75 - Local Land Use Planning | Open Energy Information

    Open Energy Info (EERE)

    67-75 - Local Land Use Planning Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: IC 67-75 - Local Land Use PlanningLegal Published...

  12. I.C. 39-44 - Idaho Hazardous Waste Management Act | Open Energy...

    Open Energy Info (EERE)

    44 - Idaho Hazardous Waste Management Act Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: I.C. 39-44 - Idaho Hazardous Waste...

  13. I.C. 67-65 - Local Land Use Planning | Open Energy Information

    Open Energy Info (EERE)

    search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: I.C. 67-65 - Local Land Use PlanningLegal Abstract This statute outlines the zoning and...

  14. I.C. 47-1605 - Geothermal Resources - Leases--Rental and Royalty...

    Open Energy Info (EERE)

    search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: I.C. 47-1605 - Geothermal Resources - Leases--Rental and RoyaltyLegal Abstract This code...

  15. I.C. 42-217 - Proof of Application (of Water) to Beneficial Use...

    Open Energy Info (EERE)

    search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: I.C. 42-217 - Proof of Application (of Water) to Beneficial UseLegal Abstract This statute...

  16. I.C. 39-3602 - Water Quality--Definitions | Open Energy Information

    Open Energy Info (EERE)

    search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: I.C. 39-3602 - Water Quality--DefinitionsLegal Abstract This statutory section provides...

  17. I.C. 42-221 - Appropriation of Water Fees | Open Energy Information

    Open Energy Info (EERE)

    search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: I.C. 42-221 - Appropriation of Water FeesLegal Abstract This statutory section provides for...

  18. I.C. 42-203A - Notice Upon Receipt of Application to Appropriate...

    Open Energy Info (EERE)

    search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: I.C. 42-203A - Notice Upon Receipt of Application to AppropriateLegal Abstract This...

  19. I.C. 67-52 - Idaho Administrative Procedure Act | Open Energy...

    Open Energy Info (EERE)

    search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: I.C. 67-52 - Idaho Administrative Procedure ActLegal Abstract This statute governs the...

  20. I.C. 67-80 - Regulatory Takings | Open Energy Information

    Open Energy Info (EERE)

    search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: I.C. 67-80 - Regulatory TakingsLegal Abstract This statute outlines the criteria and...

  1. I.C. 62-6 - Procedure Before Commission and in Courts | Open...

    Open Energy Info (EERE)

    search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: I.C. 62-6 - Procedure Before Commission and in CourtsLegal Abstract This statute governs...

  2. I.C. 27-503 - Protection of Graves, Permitted Acts -- Notice...

    Open Energy Info (EERE)

    search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: I.C. 27-503 - Protection of Graves, Permitted Acts -- NoticeLegal Abstract This statute...

  3. I.C. 39-101 - Idaho Environmental Protection and Health Act ...

    Open Energy Info (EERE)

    search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: I.C. 39-101 - Idaho Environmental Protection and Health ActLegal Published NA Year Signed...

  4. I.C. 61-17 - Siting of Certain Electrical Transmission Facilities...

    Open Energy Info (EERE)

    search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: I.C. 61-17 - Siting of Certain Electrical Transmission FacilitiesLegal Abstract This statute...

  5. CE2 Capital Partners LLC | Open Energy Information

    Open Energy Info (EERE)

    Capital Partners LLC Jump to: navigation, search Name: CE2 Capital Partners LLC Place: Solana Beach, California Zip: 92075 Sector: Carbon, Renewable Energy Product:...

  6. Westinghouse Lighting: Order (2010-CE-09/1001) | Department of...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Westinghouse Lighting: Order (2010-CE-091001) December 9, 2010 DOE ordered Westinghouse Lighting Corporation to pay a 50,000 civil penalty after finding Westinghouse Lighting had ...

  7. Lattice Disorder And Size-Induced Kondo Behavior in CeAl(2) And CePt(2+X)

    SciTech Connect (OSTI)

    Han, S.-W.; Booth, C.H.; Bauer, E.D.; Huang, P.H.; Chen, Y.Y.; Lawrence, J.M.; /LBL, Berkeley /Chonbuk Natl. U. /Los Alamos /Taiwan, Inst. Phys. /UC, Irvine

    2007-07-19

    When the particle size of CeAl{sub 2} and CePt{sub 2+x} samples is reduced to the nanometer scale, antiferromagnetism is suppressed and Kondo behavior dominates. We find that the Kondo temperature T{sub K} can either decrease (CeAl{sub 2}) or increase (CePt{sub 2+x}) in the nanoparticles relative to the bulk. Extended x-ray absorption fine-structure data show that the Ce-Al and Ce-Pt environments are significantly distorted in the nanoparticles. While such distortions should strongly affect magnetic and electronic properties, we find they cannot explain the observed changes in T{sub K}. Changes in the conduction density of states or other parameters must, therefore, play a significant role.

  8. Lattice disorder and size-induced Kondo behavior in CeAl2 andCePt2+x

    SciTech Connect (OSTI)

    Han, S.-W.; Booth, C.H.; Bauer, E.D.; Huang P.H.; Chen, Y.Y.; Lawrence, J.M.

    2006-03-14

    When the particle size of CeAl{sub 2} and CePt{sub 2+x} samples is reduced to the nanometer scale, antiferromagnetism is suppressed and Kondo behavior dominates. We find that the Kondo temperature T{sub K} can either decrease (CeAl{sub 2}) or increase (CePt{sub 2+x}) in the nanoparticles relative to the bulk. Extended x-ray absorption fine-structure data show that the Ce-Al and Ce-Pt environments are significantly distorted in the nanoparticles. While such distortions should strongly affect magnetic and electronic properties, we find they cannot explain the observed changes in T{sub K}. Changes in the conduction density of states or other parameters must, therefore, play a significant role.

  9. Winds of low-metallicity OB-type stars: HST-COS spectroscopy in IC 1613

    SciTech Connect (OSTI)

    Garcia, Miriam; Najarro, Francisco; Herrero, Artemio; Urbaneja, Miguel Alejandro

    2014-06-10

    We present the first quantitative ultraviolet spectroscopic analysis of resolved OB stars in IC 1613. Because of its alleged very low metallicity (?1/10 Z {sub ?}, from H II regions), studies in this Local Group dwarf galaxy could become a significant step forward from the Small Magellanic Cloud (SMC) toward the extremely metal-poor massive stars of the early universe. We present HST-COS data covering the ?1150-1800 wavelength range with resolution R ? 2500. We find that the targets do exhibit wind features, and these are similar in strength to SMC stars. Wind terminal velocities were derived from the observed P Cygni profiles with the Sobolev plus Exact Integration method. The v {sub ?}-Z relationship has been revisited. The terminal velocity of IC 1613 O stars is clearly lower than Milky Way counterparts, but there is no clear difference between IC 1613 and SMC or LMC analog stars. We find no clear segregation with host galaxy in the terminal velocities of B-supergiants, nor in the v {sub ?}/v {sub esc} ratio of the whole OB star sample in any of the studied galaxies. Finally, we present the first evidence that the Fe-abundance of IC 1613 OB stars is similar to the SMC, which is in agreement with previous results on red supergiants. With the confirmed ?1/10 solar oxygen abundances of B-supergiants, our results indicate that IC 1613's ?/Fe ratio is sub-solar.

  10. PTF 12gzkA rapidly declining, high-velocity type Ic radio supernova

    SciTech Connect (OSTI)

    Horesh, Assaf; Kulkarni, Shrinivas R.; Corsi, Alessandra; Frail, Dale A.; Cenko, S. Bradley; Ben-Ami, Sagi; Gal-Yam, Avishay; Yaron, Ofer; Arcavi, Iair; Ofek, Eran O.; Kasliwal, Mansi M.

    2013-11-20

    Only a few cases of Type Ic supernovae (SNe) with high-velocity ejecta (?0.2 c) have been discovered and studied. Here, we present our analysis of radio and X-ray observations of the Type Ic SN PTF 12gzk. The radio emission declined less than 10 days after explosion, suggesting SN ejecta expanding at high velocity (?0.3 c). The radio data also indicate that the density of the circumstellar material (CSM) around the supernova is lower by a factor of ?10 than the CSM around normal Type Ic SNe. PTF 12gzk may therefore be an intermediate event between a 'normal' SN Ic and a gamma-ray-burst-SN-like event. Our observations of this rapidly declining radio SN at a distance of 58 Mpc demonstrates the potential to detect many additional radio SNe, given the new capabilities of the Very Large Array (improved sensitivity and dynamic scheduling), which are currently missed, leading to a biased view of radio SNe Ic. Early optical discovery followed by rapid radio observations would provide a full description of the ejecta velocity distribution and CSM densities around stripped massive star explosions as well as strong clues about the nature of their progenitor stars.

  11. SUPER-LUMINOUS TYPE Ic SUPERNOVAE: CATCHING A MAGNETAR BY THE TAIL

    SciTech Connect (OSTI)

    Inserra, C.; Smartt, S. J.; Jerkstrand, A.; Fraser, M.; Wright, D.; Smith, K.; Chen, T.-W.; Kotak, R.; Nicholl, M.; Valenti, S.; Pastorello, A.; Benetti, S.; Bresolin, F.; Kudritzki, R. P.; Burgett, W. S.; Chambers, K. C.; Flewelling, H.; Botticella, M. T.; Ergon, M.; Fynbo, J. P. U.; and others

    2013-06-20

    We report extensive observational data for five of the lowest redshift Super-Luminous Type Ic Supernovae (SL-SNe Ic) discovered to date, namely, PTF10hgi, SN2011ke, PTF11rks, SN2011kf, and SN2012il. Photometric imaging of the transients at +50 to +230 days after peak combined with host galaxy subtraction reveals a luminous tail phase for four of these SL-SNe. A high-resolution, optical, and near-infrared spectrum from xshooter provides detection of a broad He I {lambda}10830 emission line in the spectrum (+50 days) of SN2012il, revealing that at least some SL-SNe Ic are not completely helium-free. At first sight, the tail luminosity decline rates that we measure are consistent with the radioactive decay of {sup 56}Co, and would require 1-4 M{sub Sun} of {sup 56}Ni to produce the luminosity. These {sup 56}Ni masses cannot be made consistent with the short diffusion times at peak, and indeed are insufficient to power the peak luminosity. We instead favor energy deposition by newborn magnetars as the power source for these objects. A semi-analytical diffusion model with energy input from the spin-down of a magnetar reproduces the extensive light curve data well. The model predictions of ejecta velocities and temperatures which are required are in reasonable agreement with those determined from our observations. We derive magnetar energies of 0.4 {approx}< E(10{sup 51} erg) {approx}< 6.9 and ejecta masses of 2.3 {approx}< M{sub ej}(M{sub Sun }) {approx}< 8.6. The sample of five SL-SNe Ic presented here, combined with SN 2010gx-the best sampled SL-SNe Ic so far-points toward an explosion driven by a magnetar as a viable explanation for all SL-SNe Ic.

  12. Insights Gained for Updating an Analog I&C System to a Digital System

    SciTech Connect (OSTI)

    Adams, A.; Carte, N.; Hardesty, Duane; Hardin, LeRoy A; Wilson, Thomas L

    2012-01-01

    Licensees at both Nuclear Power Plants (NPPs) and Non-Power Reactors (NPRs) are increasing their use of state-of-the-art digital technology in instrumentation and control (I&C) systems because digital systems offer improved reactor control, information processing, and information storage over analog. Digital I&C systems can range from experimental systems for reactor control research (at NPRs), to measurement and display systems, to complete reactor console replacements. Because of the increasing difficulty in finding spare parts for their original analog I&C systems, many licensees have begun or have plans to upgrade, refurbish, or replace their old analog I&C systems with digital systems. The perception is that upgrading to a digital I&C system will solve all of a facility s obsolescence problems. However, licensees need to be aware of several issues associated with upgrading to a digital system including obsolescence of the digital system (hardware and software) because of the short product life cycle and the associated cost to acquire, store, and maintain a long-term supply of spare parts. Configuration management and cyber security are also vitally important for any upgrade. Further, it must be recognized that the introduction of software and microprocessors could create new failure mechanisms, such as software errors and increased susceptibility to electromagnetic interference. In fact, experience has shown that these failure mechanisms may cause the reactor to malfunction in a way not previously considered. Thus, a conversion from analog to digital I&C systems solves some problems while potentially introducing others. Recognition of the additional risks coupled with good design, engineering, review, and testing can identify and minimize these risks.

  13. Measuring the Coronal Properties of IC 4329A with NuSTAR (Journal Article)

    Office of Scientific and Technical Information (OSTI)

    | SciTech Connect Measuring the Coronal Properties of IC 4329A with NuSTAR Citation Details In-Document Search Title: Measuring the Coronal Properties of IC 4329A with NuSTAR Authors: Brenneman, L. W. ; /Harvard-Smithsonian Ctr. Astrophys. ; Madejski, G. ; /KIPAC, Menlo Park /SLAC ; Fuerst, F. ; /Caltech ; Matt, G. ; /Rome III U. ; Elvis, M. ; /Harvard-Smithsonian Ctr. Astrophys. ; Harrison, F. A. ; /Caltech ; Ballantyne, D. R. ; /Georgia Tech ; Boggs, S. E. ; /UC, Berkeley, Space Sci. Dept.

  14. Processing of transparent polycrystalline AlON:Ce3+ scintillators

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chen, Ching -Fong; Yang, Pin; King, Graham; Tegtmeier, Eric L.

    2015-10-23

    A new polycrystalline ceramic scintillator is reported for potential use in radiation detection and medical imaging applications. The goal was to develop cerium-activated aluminum oxynitride (AlON:Ce3+) ceramics, which can be produced using ceramic processes in comparison to the high-cost, low-yield single-crystal growth technique. A phase pure AlON:Ce3+ powder with cubic symmetry was successfully synthesized at high temperature under a reducing atmosphere to convert Ce4+ to Ce3+ in the solid solution. We explored two different activator concentrations (0.5 and 1.0 mol%). Fully dense and transparent AlON:Ce3+ ceramics were produced by a liquid-phase-assisted pressureless sintering. The crystal field splitting around the Ce3+more » activator in the AlON was comparable to the splitting induced by Br₋ and the Cl₋ ligands, which produced an emission spectrum perfectly matching the maximum quantum efficiency range of the photomultiplier tube for radiation detection. Both optical excitation and radiation ionizations in AlON:Ce3+ were demonstrated. Lastly, challenges and mechanisms related to the radioluminescence efficiency are discussed.« less

  15. Evidence of dynamical spin shielding in Ce from spin-resolved...

    Office of Scientific and Technical Information (OSTI)

    Evidence of dynamical spin shielding in Ce from spin-resolved photoelectron spectroscopy Citation Details In-Document Search Title: Evidence of dynamical spin shielding in Ce from ...

  16. Interim Human Factors Guidance for Hybrid and Digital I&C System

    SciTech Connect (OSTI)

    J.Naser, G.Morris

    2003-08-15

    OAK- B135 To help nuclear power plant operators and suppliers plan, specify, design and implement the modernization of control rooms and other HSI in a way that takes advantage of digital systems and HSI technologies, reflects practical constraints associated with modernizing existing control rooms and I&C systems, and addresses issues associated with hybrid control room HSI.

  17. Thermoelectric Conversion of Waste Heat to Electricity in an IC Engine

    Broader source: Energy.gov (indexed) [DOE]

    Powered Vehicle | Department of Energy Determining if a 10% fuel economy improvement is possible using thermoelectrics on a OTR truck PDF icon schock.pdf More Documents & Publications Thermoelectric Conversion of Waste Heat to Electricity in an IC Engine Powered Vehicle Thermoelectric Conversion of Wate

  18. Maxlite: Order (2010-CE-2701) | Department of Energy

    Energy Savers [EERE]

    0-CE-2701) Maxlite: Order (2010-CE-2701) In the Matter of Maxlite, SK America, Inc. (general service flourescent lamps), DOE Case Number 2010-CE-2701, Adopting Order and Compromise Agreement. Order adopting accompanying Compromise Agreement. DOE found that Maxlite failed to submit compliance certifications for its products under 10 C.F.R. Section 430.62, and here assesses a civil penalty of $5,000 (if paid within 30 days) or of $10,000 (if paid between 31-60 days). Maxlite promises to certify

  19. Mitsubishi Electric: Consent Decree (2011-CE-01/0202) | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Mitsubishi Electric: Consent Decree (2011-CE-010202) May 7, 2010 In this consent degree, the Air-Conditioning, Heating and Refrigeration Institute (AHRI) agrees to pay 5,000 on ...

  20. CE2 Carbon Capital LLC | Open Energy Information

    Open Energy Info (EERE)

    Carbon Capital LLC Jump to: navigation, search Name: CE2 Carbon Capital LLC Place: California Sector: Carbon, Renewable Energy Product: US-based carbon trader that looks to take...

  1. Paragon Sales: Order (2012-CE-1417) | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Order (2012-CE-1417) July 30, 2012 DOE ordered Paragon Sales Co., Inc., to pay a 6,000 civil penalty after finding Paragon Sales had failed to certify that certain models of...

  2. Manitowoc Foodservice: Order (2012-CE-5309) | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Order (2012-CE-5309) July 20, 2012 DOE ordered Manitowoc Foodservice to pay an 6,000 civil penalty after finding Manitowoc Foodservice had failed to certify that Manitowoc...

  3. Electrolux: Order (2012-CE-1901) | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Order (2012-CE-1901) July 27, 2012 DOE ordered Electrolux North America to pay a 6,500 civil penalty after finding Electrolux had failed to certify that certain dishwashers comply...

  4. Haier: Order (2011-CE-2104) | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Haier: Order (2011-CE-2104) June 12, 2012 DOE ordered Haier to pay an 20,000 civil penalty after finding Haier had failed to certify that Haier residential clothes...

  5. Danby Products: Order (2012-CE-1415) | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Order (2012-CE-1415) August 9, 2012 DOE ordered Danby Products to pay a 9,900 civil penalty after finding Danby had failed to certify that certain models of refrigerators...

  6. Lochinvar: Order (2016-CE-24001) | Department of Energy

    Energy Savers [EERE]

    Lochinvar: Order (2016-CE-24001) Lochinvar: Order (2016-CE-24001) November 2, 2015 DOE ordered Lochinvar, LLC, to pay a $8,000 civil penalty after finding Lochinvar had failed to certify that certain models of pool heaters comply with the applicable energy conservation standard. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Lochinvar. DOE regulations require a manufacturer (which includes importers) to submit reports certifying that its products have

  7. Fujitsu: Order (2015-CE-16014) | Department of Energy

    Energy Savers [EERE]

    Fujitsu: Order (2015-CE-16014) Fujitsu: Order (2015-CE-16014) October 27, 2015 DOE ordered Fujitsu General America, Inc. to pay a $8,000 civil penalty after finding Fujitsu had failed to certify that certain models of central air conditioners and heat pumps comply with the applicable energy conservation standards prior to distributing them in commerce. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Fujitsu. DOE regulations require a manufacturer (which

  8. Utility: Proposed Penalty (2016-CE-42007) | Department of Energy

    Energy Savers [EERE]

    Proposed Penalty (2016-CE-42007) Utility: Proposed Penalty (2016-CE-42007) November 30, 2015 DOE alleged in a Notice of Proposed Civil Penalty that Utility Refrigerator failed to certify certain commercial refrigerator equipment as compliant with the applicable energy conservation standards. DOE regulations require a manufacturer (which includes importers) to submit reports certifying that its products have been tested and meet the applicable energy conservation standards. This civil penalty

  9. Sanyo Electric: Order (2010-CE-1210) | Department of Energy

    Energy Savers [EERE]

    Sanyo Electric: Order (2010-CE-1210) Sanyo Electric: Order (2010-CE-1210) October 13, 2010 DOE issued an Order and entered into a Compromise Agreement with Sanyo E&E Corp. after finding Sanyo had used an improper method to submit its certification that certain models of residential refrigerators, refrigerator-freezers, and freezers comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Sanyo. PDF

  10. Systemair: Order (2016-CE-43003) | Department of Energy

    Energy Savers [EERE]

    Systemair: Order (2016-CE-43003) Systemair: Order (2016-CE-43003) February 23, 2016 DOE ordered Systemair, Inc., to pay a $8,000 civil penalty after finding Systemair had failed to certify that its single package vertical air conditioning and heating equipment comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Systemair. DOE regulations require a manufacturer (which includes importers) to submit

  11. Atlas Lighting: Proposed Penalty (2015-CE-48001) | Department of Energy

    Energy Savers [EERE]

    Proposed Penalty (2015-CE-48001) Atlas Lighting: Proposed Penalty (2015-CE-48001) June 2, 2015 DOE alleged in a Notice of Proposed Civil Penalty that Atlas Lighting Products failed to certify a variety of illuminated exit sign basic models as compliant with the applicable energy conservation standards. DOE regulations require a manufacturer (which includes importers) to submit reports certifying that its products have been tested and meet the applicable energy conservation standards. This civil

  12. The Broad-band X-ray Spectrum of IC 4329A from a Joint NuSTAR...

    Office of Scientific and Technical Information (OSTI)

    The Broad-band X-ray Spectrum of IC 4329A from a Joint NuSTARSuzaku Observation Citation Details In-Document Search Title: The Broad-band X-ray Spectrum of IC 4329A from a Joint ...

  13. Ca2+-Doped CeBr3 Scintillating Materials

    SciTech Connect (OSTI)

    Guss, Paul; Foster, Michael E.; Wong, Bryan M.; Doty, F. Patrick; Shah, Kanai; Squillante, Michael R.; Shirwadkar, Urmila; Hawrami, Rastgo; Tower, Josh; Yuan, Ding

    2014-01-21

    Despite the outstanding scintillation performance characteristics of cerium tribromide (CeBr3) and cerium-activated lanthanum tribromide, their commercial availability and application are limited due to the difficulties of growing large, crack-free single crystals from these fragile materials. This investigation employed aliovalent doping to increase crystal strength while maintaining the optical properties of the crystal. One divalent dopant (Ca2+) was used as a dopant to strengthen CeBr3 without negatively impacting scintillation performance. Ingots containing nominal concentrations of 1.9% of the Ca2+ dopant were grown. Preliminary scintillation measurements are presented for this aliovalently doped scintillator. Ca2+-doped CeBr3 exhibited little or no change in the peak fluorescence emission for 371 nm optical excitation for CeBr3. The structural, electronic, and optical properties of CeBr3 crystals were studied using the density functional theory within the generalized gradient approximation. The calculated lattice parameters are in good agreement with the experimental data. The energy band structures and density of states were obtained. The optical properties of CeBr3, including the dielectric function, were calculated.

  14. Low-energy RI beam technology and nuclear clusters in the explosive pp-chain breakout process

    SciTech Connect (OSTI)

    Kubono, S. [Institute of Modern Physics, Chinese Academy of Sciences, Nanchang Road 509, Lanzhou 73000 (China); RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Center for Nuclear Study, University of Tokyo, 2-1 Hirosawa, Wako, Saitama 351-0 (Japan); Yamaguchi, H.; Kahl, D. M.; Ohshiro, Y.; Watanabe, S.; Yamazaki, N. [Center for Nuclear Study, University of Tokyo, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Teranishi, T. [Department of Physics, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-858 (Japan); Yanagisawa, Y.; Wakabayashi, Y.; Kase, M. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Hayakawa, S. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, 95125 Catania (Italy); Kwon, Y. K. [Institute for Basic Science, 70, Yuseong-daero 1689-gil, Yuseong-gu, Daejeon 305-81 (Korea, Republic of); Hashimoto, T.; Fukuda, Y. [Research Center for Nuclear Physics, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); He, J. J. [Institute of Modern Physics, Chinese Academy of Sciences, Nanchang Road 509, Lanzhou 73000 (China); Goto, A. [Faculty of Medcine, Yamagata University, Yamagata 990-2331 (Japan); Muto, H. [Center of General Education, Tokyo University of Science at Suwa, Chino, Nagano 391-0292 (Japan)

    2014-05-09

    The lecture includes two parts: One is a discussion on the technology for developing RIB beam facility based on the in-flight method and relevant experimental technology. The second part is a discussion on experimental efforts for studying the breakout process from the pp-chain region based on recent works with low energy RI beams. The discussion of the second part specifically covers the problem of the vp-process in type II supernovae in terms of alpha cluster nature for the reactions.

  15. Comparison of the high-pressure behavior of the cerium oxides Ce2O3 and CeO2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lipp, M. J.; Jeffries, J. R.; Cynn, H.; Park Klepeis, J. -H.; Evans, W. J.; Mortensen, D. R.; Seidler, G. T.; Xiao, Y.; Chow, P.

    2016-02-09

    We studied the high-pressure behavior of Ce2O3 using angle-dispersive x-ray diffraction to 70 GPa and compared with that of CeO2. Up to the highest pressure Ce2O3 remains in the hexagonal phase (space group 164, P ¯32/m1) typical for the lanthanide sesquioxides. We did not observe a theoretically predicted phase instability for 30 GPa. The isothermal bulk modulus and its pressure derivative for the quasihydrostatic case are B0 = 111 ± 2 GPa, B'0 = 4.7 ± 0.3, and for the case without pressure-transmitting medium B0 = 104 ±4 GPa, B'0 = 6.5 ± 0.4. Starting from ambient-pressure magnetic susceptibility measurementsmore » for both oxides in highly purified form,we find that the Ce atom in Ce2O3 behaves like a trivalent Ce3+ ion (2.57μB per Ce atom) in contrast to previously published data. Since x-ray emission spectroscopy of the Lγ (4d3/2 → 2p1/2) transition is sensitive to the 4f -electron occupancy, we also followed the high-pressure dependence of this line for both oxides up to 50 GPa. We observed no change of the respective line shape, indicating that the 4f -electron configuration is stable for both materials. We posit from this data that the 4f electrons do not drive the volume collapse of CeO2 from the high-symmetry, low-pressure fluorite structure to the lower-symmetry orthorhombic phase.« less

  16. Effects of CeO2 Support Facets on VOx/CeO2 Catalysts in Oxidative Dehydrogenation of Methanol

    SciTech Connect (OSTI)

    Li, Yan; Wei, Zhehao; Gao, Feng; Kovarik, Libor; Peden, Charles HF; Wang, Yong

    2014-05-13

    CeO2 supports with dominating facets, i.e., low index (100), (110) and (111) facets, are prepared. The facet effects on the structure and catalytic performance of supported vanadium oxide catalysts are investigated using oxidative dehydrogenation of methanol as a model reaction. In the presence of mixed facets, Infrared and Raman characterizations demonstrate that surface vanadia species preferentially deposit on CeO2 (100) facets, presumably because of its higher surface energy. At the same surface vanadium densities, VOx species on (100) facets show better dispersion, followed by (110) and (111) facets. The VOx species on CeO2 nanorods with (110) and (100) facets display higher activity and lower apparent activation energies compared to that on CeO2 nanopolyhedras with dominating (111) facets and CeO2 nanocubes with dominating (100) facets. The higher activity for VOx/CeO2(110) might be related to the more abundant oxygen vacancies present on the (110) facets, evidenced from Raman spectroscopic measurements.

  17. Streamlined RI/FS planning for the groundwater operable unit at the Weldon Spring Site

    SciTech Connect (OSTI)

    Picel, M.H.; Durham, L.A.; Blunt, D.L.; Hartmann, H.M.

    1995-12-31

    The U.S. Department of Energy (DOE) is conducting cleanup activities at the chemical plant area of the Weldon Spring Site located in St. Charles County, Missouri, about 48 km (30 mi) west of St. Louis and 22 km (14 mi) southwest of the City of St. Charles. The 88-ha (217-acre) chemical plant area is chemically and radioactively contaminated as a result of uranium processing activities conducted by the U.S. Atomic Energy Commission during the 1950s and 1960s. The Army also used the chemical plant area for the production of explosives in the 1940s. The Weldon Spring Site chemical plant area was listed on the National Priorities List (NPL) in 1989. Adjacent to the chemical plant area is another NPL site known as the Weldon Spring Ordnance Works. The ordnance works area is a former explosive production facility that manufactured trinitrotoluene (TNT) and dinitrotoluene (DNT) during World War II. The ordnance works area covers 7,000 ha (17,232 acres); cleanup of this site is managed by the U.S. Army Corps of Engineers (CE).

  18. THE FAST AND FURIOUS DECAY OF THE PECULIAR TYPE Ic SUPERNOVA 2005ek

    SciTech Connect (OSTI)

    Drout, M. R.; Soderberg, A. M.; Margutti, R.; Milisavljevic, D.; Sanders, N. E.; Chornock, R.; Foley, R. J.; Kirshner, R. P.; Chakraborti, S.; Challis, P.; Friedman, A.; Hicken, M.; Jensen, C.; Mazzali, P. A.; Parrent, J. T.; Filippenko, A. V.; Li, W.; Cenko, S. B.; Ganeshalingam, M.; Brown, P. J.; and others

    2013-09-01

    We present extensive multi-wavelength observations of the extremely rapidly declining Type Ic supernova (SN Ic), SN 2005ek. Reaching a peak magnitude of M{sub R} = -17.3 and decaying by {approx}3 mag in the first 15 days post-maximum, SN 2005ek is among the fastest Type I supernovae observed to date. The spectra of SN 2005ek closely resemble those of normal SN Ic, but with an accelerated evolution. There is evidence for the onset of nebular features at only nine days post-maximum. Spectroscopic modeling reveals an ejecta mass of {approx}0.3 M{sub Sun} that is dominated by oxygen ({approx}80%), while the pseudo-bolometric light curve is consistent with an explosion powered by {approx}0.03 M{sub Sun} of radioactive {sup 56}Ni. Although previous rapidly evolving events (e.g., SN 1885A, SN 1939B, SN 2002bj, SN 2010X) were hypothesized to be produced by the detonation of a helium shell on a white dwarf, oxygen-dominated ejecta are difficult to reconcile with this proposed mechanism. We find that the properties of SN 2005ek are consistent with either the edge-lit double detonation of a low-mass white dwarf or the iron-core collapse of a massive star, stripped by binary interaction. However, if we assume that the strong spectroscopic similarity of SN 2005ek to other SNe Ic is an indication of a similar progenitor channel, then a white-dwarf progenitor becomes very improbable. SN 2005ek may be one of the lowest mass stripped-envelope core-collapse explosions ever observed. We find that the rate of such rapidly declining Type I events is at least 1%-3% of the normal SN Ia rate.

  19. A transient supergiant X-ray binary in IC 10: An extragalactic SFXT?

    SciTech Connect (OSTI)

    Laycock, Silas; Cappallo, Rigel; Oram, Kathleen; Balchunas, Andrew

    2014-07-01

    We report the discovery of a large amplitude (factor of ?100) X-ray transient (IC 10 X-2, CXOU J002020.99+591758.6) in the nearby dwarf starburst galaxy IC 10 during our Chandra monitoring project. Based on the X-ray timing and spectral properties, and an optical counterpart observed with Gemini, the system is a high-mass X-ray binary consisting of a luminous blue supergiant and a neutron star. The highest measured luminosity of the source was 1.8 10{sup 37} erg s{sup 1}during an outburst in 2003. Observations before, during, and after a second outburst in 2010 constrain the outburst duration to be less than 3 months (with no lower limit). The X-ray spectrum is a hard power law (? = 0.3) with fitted column density (N{sub H} = 6.3 10{sup 21} atom cm{sup 2}), consistent with the established absorption to sources in IC 10. The optical spectrum shows hydrogen Balmer lines strongly in emission at the correct blueshift (-340 km s{sup 1}) for IC 10. The N III triplet emission feature is seen, accompanied by He II [4686] weakly in emission. Together these features classify the star as a luminous blue supergiant of the OBN subclass, characterized by enhanced nitrogen abundance. Emission lines of He I are seen, at similar strength to H?. A complex of Fe II permitted and forbidden emission lines are seen, as in B[e] stars. The system closely resembles galactic supergiant fast X-ray transients, in terms of its hard spectrum, variability amplitude, and blue supergiant primary.

  20. An Update on NiCE Support for BISON

    SciTech Connect (OSTI)

    McCaskey, Alex; Billings, Jay Jay; Deyton, Jordan H.; Wojtowicz, Anna

    2015-09-01

    The Nuclear Energy Advanced Modeling and Simulation program (NEAMS) from the Department of Energy s Office of Nuclear Energy has funded the development of a modeling and simulation workflow environment to support the various codes in its nuclear energy scientific computing toolkit. This NEAMS Integrated Computational Environment (NiCE) provides extensible tools and services that enable efficient code execution, input generation, pre-processing visualizations, and post-simulation data analysis and visualization for a large portion of the NEAMS Toolkit. A strong focus for the NiCE development team throughout FY 2015 has been support for the Multiphysics Object Oriented Simulation Environment (MOOSE) and the NEAMS nuclear fuel performance modeling application built on that environment, BISON. There is a strong desire in the program to enable and facilitate the use of BISON throughout nuclear energy research and industry. A primary result of this desire is the need for strong support for BISON in NiCE. This report will detail improvements to NiCE support for BISON. We will present a new and improved interface for interacting with BISON simulations in a variety of ways: (1) improved input model generation, (2) embedded mesh and solution data visualizations, and (3) local and remote BISON simulation launch. We will also show how NiCE has been extended to provide support for BISON code development.

  1. Correlation of the ionisation response at selected points of IC sensitive regions with SEE sensitivity parameters under pulsed laser irradiation

    SciTech Connect (OSTI)

    Gordienko, A V; Mavritskii, O B; Egorov, A N; Pechenkin, A A; Savchenkov, D V

    2014-12-31

    The statistics of the ionisation response amplitude measured at selected points and their surroundings within sensitive regions of integrated circuits (ICs) under focused femtosecond laser irradiation is obtained for samples chosen from large batches of two types of ICs. A correlation between these data and the results of full-chip scanning is found for each type. The criteria for express validation of IC single-event effect (SEE) hardness based on ionisation response measurements at selected points are discussed. (laser applications and other topics in quantum electronics)

  2. Homoleptic Ce(III) and Ce(IV) Nitroxide Complexes: Significant Stabilization of the 4+ Oxidation State

    SciTech Connect (OSTI)

    Bogart, Justin A.; Lewis, Andrew J.; Medling, Scott A.; Piro, Nicholas A.; Carroll, Patrick J.; Booth, Corwin H.; Schelter, Eric J.

    2014-06-25

    Electrochemical experiments performed on the complex Ce-IV[2-((BuNO)-Bu-t)py](4), where [2-((BuNO)-Bu-t)py](-) = N-tert-butyl-N-2-pyridylnitroxide, indicate a 2.51 V stabilization of the 4+ oxidation state of Ce compared to [(Bu4N)-Bu-n](2)[Ce(NO3)(6)] in acetonitrile and a 2.95 V stabilization compared to the standard potential for the ion under aqueous conditions. Density functional theory calculations suggest that this preference for the higher oxidation state is a result of the tetrakis(nitroxide) ligand framework at the Ce cation, which allows for effective electron donation into, and partial covalent overlap with, vacant 4f orbitals with delta symmetry. The results speak to the behavior of CeO2 and related solid solutions in oxygen uptake and transport applications, in particular an inherent local character of bonding that stabilizes the 4+ oxidation state. The results indicate a cerium(IV) complex that has been stabilized to an unprecedented degree through tuning of its ligand-field environment.

  3. Vehicle Technologies Office Merit Review 2015: ANL IC3P Research Focus on Diagnostic Studies at BNL

    Broader source: Energy.gov [DOE]

    Presentation given by 3M at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about ANL IC3P research focus on diagnostic...

  4. Infrared tip of the red giant branch and distances to the MAFFEI/IC 342 group

    SciTech Connect (OSTI)

    Wu, Po-Feng; Tully, R. Brent; Jacobs, Bradley A.; Rizzi, Luca; Dolphin, Andrew E.; Karachentsev, Igor D.

    2014-07-01

    In this paper, we extend the use of the tip of the red giant branch (TRGB) method to near-infrared wavelengths from the previously used I-band, using the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3). Upon calibration of a color dependency of the TRGB magnitude, the IR TRGB yields a random uncertainty of ∼5% in relative distance. The IR TRGB methodology has an advantage over the previously used Advance Camera for Surveys F606W and F814W filter set for galaxies that suffer from severe extinction. Using the IR TRGB methodology, we obtain distances toward three principal galaxies in the Maffei/IC 342 complex, which are located at low Galactic latitudes. New distance estimates using the TRGB method are 3.45{sub −0.13}{sup +0.13} Mpc for IC 342, 3.37{sub −0.23}{sup +0.32} Mpc for Maffei 1, and 3.52{sub −0.30}{sup +0.32} Mpc for Maffei 2. The uncertainties are dominated by uncertain extinction, especially for Maffei 1 and Maffei 2. Our IR calibration demonstrates the viability of the TRGB methodology for observations with the James Webb Space Telescope.

  5. DOI-BLM-ID-110-2009-3825-CE | Open Energy Information

    Open Energy Info (EERE)

    110-2009-3825-CE Jump to: navigation, search NEPA Document Collection for: DOI-BLM-ID-110-2009-3825-CE CX at Crane Creek Geothermal Area for GeothermalExploration Crane Creek...

  6. Proactive Design of n-Type (In, Ce) Filled Skutterudites Enabling...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Design of n-Type (In, Ce) Filled Skutterudites Enabling High-Temperature Waste Heat Recovery Proactive Design of n-Type (In, Ce) Filled Skutterudites Enabling High-Temperature ...

  7. SEMI-ANNUAL REPORTS FOR CE FLNG, LLC (CAMBRIDGE) - DK. NO. 12...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    CE FLNG, LLC (CAMBRIDGE) - DK. NO. 12-123-LNG - ORDER 3193 SEMI-ANNUAL REPORTS FOR CE FLNG, LLC (CAMBRIDGE) - DK. NO. 12-123-LNG - ORDER 3193 PDF icon April 2013 PDF icon October...

  8. Angle Resolved Thermal Conductivity of CeCoIn5 along the Nodal...

    Office of Scientific and Technical Information (OSTI)

    Angle Resolved Thermal Conductivity of CeCoIn5 along the Nodal Direction Citation Details In-Document Search Title: Angle Resolved Thermal Conductivity of CeCoIn5 along the Nodal ...

  9. Investigation of the physical properties of the tetragonal CeMAl4Si2...

    Office of Scientific and Technical Information (OSTI)

    the tetragonal CeMAl4Si2 (M Rh, Ir, Pt) compounds Prev Next Title: Investigation of the physical properties of the tetragonal CeMAl4Si2 (M Rh, Ir, Pt) compounds The ...

  10. Neutron scattering of CeNi at the SNS-ORNL: A preliminary report

    SciTech Connect (OSTI)

    Mirmelstein, A. [Russian Federal Nuclear Center VNIITF, Snezhinsk, Russia; Podlesnyak, Andrey A [ORNL; Kolesnikov, Alexander I [ORNL; Saporov, B. [Oak Ridge National Laboratory (ORNL); Sefat, A.S. [Oak Ridge National Laboratory (ORNL); Tobin, J. G. [Lawrence Livermore National Laboratory (LLNL)

    2014-01-01

    This is a preliminary report of a neutron scattering experiment used to investigate 4f electron behavior in Ce.

  11. CO Oxidation mechanism on CeO2-supported Au nanoclusters

    SciTech Connect (OSTI)

    Kim H. Y.; Henkelman, G.

    2013-09-08

    To reveal the richer chemistry of CO oxidation by CeO2 supported Au Nanoclusters(NCs)/Nanoparticles, we design Au13 and Au12 supported on a flat and a stepped-CeO2 model (Au/CeO2) and study various kinds of CO oxidation mechanisms at the Au-CeO2 interface and the Au NC as well.

  12. Advanced Reactor Licensing: Experience with Digital I&C Technology in Evolutionary Plants

    SciTech Connect (OSTI)

    Wood, RT

    2004-09-27

    This report presents the findings from a study of experience with digital instrumentation and controls (I&C) technology in evolutionary nuclear power plants. In particular, this study evaluated regulatory approaches employed by the international nuclear power community for licensing advanced l&C systems and identified lessons learned. The report (1) gives an overview of the modern l&C technologies employed at numerous evolutionary nuclear power plants, (2) identifies performance experience derived from those applications, (3) discusses regulatory processes employed and issues that have arisen, (4) captures lessons learned from performance and regulatory experience, (5) suggests anticipated issues that may arise from international near-term deployment of reactor concepts, and (6) offers conclusions and recommendations for potential activities to support advanced reactor licensing in the United States.

  13. AmeriFlux US-ICs Imnavait Creek Watershed Wet Sedge Tundra

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Bret-Harte, Syndonia [University of Alaska Fairbanks; Euskirchen, Eugenie [University of Alaska Fairbanks; Shaver, Gaius [Marine Biological Laboratory

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-ICs Imnavait Creek Watershed Wet Sedge Tundra. Site Description - The Imnavait Creek Watershed Wet Sedge Tundra (Fen Station) is located near Imnavait Creek in Alaska, north of the Brooks Range in the Kuparuk basin near Lake Toolik and the Toolik Field Station. The Kuparuk River has its headwaters in the Brooks Range and drains through northern Alaska into the Arctic Ocean. Within these headwaters lies the Imnavait basin at an average elevation of 930 m. Water tracks run down the hill in parallel zones with a spacing of approximately 10 m. The Fen Station was deployed at the end of Summer 2007.

  14. The ACS LCID project. X. the star formation history of IC 1613: Revisiting the over-cooling problem

    SciTech Connect (OSTI)

    Skillman, Evan D.; Hidalgo, Sebastian L.; Monelli, Matteo; Gallart, Carme; Aparicio, Antonio E-mail: shidalgo@iac.es E-mail: carme@iac.es [Instituto de Astrofsica de Canarias, Va Lctea s and others

    2014-05-01

    We present an analysis of the star formation history (SFH) of a field near the half-light radius in the Local Group dwarf irregular galaxy IC 1613 based on deep Hubble Space Telescope Advanced Camera for Surveys imaging. Our observations reach the oldest main sequence turn-off, allowing a time resolution at the oldest ages of ?1 Gyr. Our analysis shows that the SFH of the observed field in IC 1613 is consistent with being constant over the entire lifetime of the galaxy. These observations rule out an early dominant episode of star formation in IC 1613. We compare the SFH of IC 1613 with expectations from cosmological models. Since most of the mass is in place at early times for low-mass halos, a naive expectation is that most of the star formation should have taken place at early times. Models in which star formation follows mass accretion result in too many stars formed early and gas mass fractions that are too low today (the 'over-cooling problem'). The depth of the present photometry of IC 1613 shows that, at a resolution of ?1 Gyr, the star formation rate is consistent with being constant, at even the earliest times, which is difficult to achieve in models where star formation follows mass assembly.

  15. Optical observations of the type Ic supernova 2007gr in NGC 1058

    SciTech Connect (OSTI)

    Chen, Juncheng; Wang, Xiaofeng; Li, Junzheng [Physics Department and Tsinghua Center for Astrophysics (THCA), Tsinghua University, Beijing 100084 (China); Ganeshalingam, Mohan; Silverman, Jeffrey M.; Filippenko, Alexei V.; Li, Weidong; Chornock, Ryan; Steele, Thea, E-mail: cjc09@mails.tsinghua.edu.cn, E-mail: wang_xf@mail.tsinghua.edu.cn [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)

    2014-08-01

    We present extensive optical observations of the normal Type Ic supernova (SN) 2007gr, spanning from about one week before maximum light to more than one year thereafter. The optical light and color curves of SN 2007gr are very similar to those of the broad-lined Type Ic SN 2002ap, but the spectra show remarkable differences. The optical spectra of SN 2007gr are characterized by unusually narrow lines, prominent carbon lines, and slow evolution of the line velocity after maximum light. The earliest spectrum (taken at t = 8 days) shows a possible signature of helium (He I ?5876 at a velocity of ?19,000 km s{sup 1}). Moreover, the larger intensity ratio of the [O I] ?6300 and ?6364 lines inferred from the early nebular spectra implies a lower opacity of the ejecta shortly after the explosion. These results indicate that SN 2007gr perhaps underwent a less energetic explosion of a smaller-mass Wolf-Rayet star (?8-9 M{sub ?}) in a binary system, as favored by an analysis of the progenitor environment through pre-explosion and post-explosion Hubble Space Telescope images. In the nebular spectra, asymmetric double-peaked profiles can be seen in the [O I] ?6300 and Mg I] ?4571 lines. We suggest that the two peaks are contributed by the blueshifted and rest-frame components. The similarity in velocity structure and the different evolution of the strength of the two components favor an aspherical explosion with the ejecta distributed in a torus or disk-like geometry, but inside the ejecta the O and Mg have different distributions.

  16. Lattice Disorder and Size-Induced Kondo Behavior in CeAl{sub 2} and CePt{sub 2+x}

    SciTech Connect (OSTI)

    Han, S.-W.; Booth, C. H.; Bauer, E. D.; Huang, P. H.; Chen, Y. Y.; Lawrence, J. M.

    2006-09-01

    When the size of CeAl{sub 2} and CePt{sub 2+x} particles is reduced to the nanometer scale, antiferromagnetism is suppressed and Kondo behavior predominates, with the Kondo temperature T{sub K} either decreasing (CeAl{sub 2}) or increasing (CePt{sub 2+x}) relative to the bulk. Local structure measurements show that these nanoparticles are significantly distorted. While such distortions should strongly affect magnetic and electronic properties, we find they cannot explain the observed changes in T{sub K}. Other size-induced changes to the electronic structure must, therefore, play a significant role.

  17. Comparison of the high-pressure behavior of the cerium oxides Ce[subscript

    Office of Scientific and Technical Information (OSTI)

    2]O[subscript 3] and CeO[subscript 2] (Journal Article) | SciTech Connect Ce[subscript 2]O[subscript 3] and CeO[subscript 2] Citation Details In-Document Search Title: Comparison of the high-pressure behavior of the cerium oxides Ce[subscript 2]O[subscript 3] and CeO[subscript 2] Authors: Lipp, M. J. ; Jeffries, J. R. ; Cynn, H. ; Klepeis, J.-H. Park ; Evans, W. J. ; Mortensen, D. R. ; Seidler, G. T. ; Xiao, Y. ; Chow, P. [1] ; UWASH) [2] ; CIW/GL) [2] + Show Author Affiliations LLNL (

  18. The Broad-band X-ray Spectrum of IC 4329A from a Joint NuSTAR/Suzaku

    Office of Scientific and Technical Information (OSTI)

    Observation (Journal Article) | SciTech Connect The Broad-band X-ray Spectrum of IC 4329A from a Joint NuSTAR/Suzaku Observation Citation Details In-Document Search Title: The Broad-band X-ray Spectrum of IC 4329A from a Joint NuSTAR/Suzaku Observation Authors: Brenneman, L. W. ; /Harvard-Smithsonian Ctr. Astrophys. ; Madejski, G. ; /KIPAC, Menlo Park /SLAC ; Fuerst, F. ; /Caltech ; Matt, G. ; /Rome III U. ; Elvis, M. ; /Harvard-Smithsonian Ctr. Astrophys. ; Harrison, F. A. ; /Caltech ;

  19. The Broad-band X-ray Spectrum of IC 4329A from a Joint NuSTAR/Suzaku

    Office of Scientific and Technical Information (OSTI)

    Observation (Journal Article) | SciTech Connect The Broad-band X-ray Spectrum of IC 4329A from a Joint NuSTAR/Suzaku Observation Citation Details In-Document Search Title: The Broad-band X-ray Spectrum of IC 4329A from a Joint NuSTAR/Suzaku Observation Authors: Brenneman, L. W. ; /Harvard-Smithsonian Ctr. Astrophys. ; Madejski, G. ; /KIPAC, Menlo Park /SLAC ; Fuerst, F. ; /Caltech ; Matt, G. ; /Rome III U. ; Elvis, M. ; /Harvard-Smithsonian Ctr. Astrophys. ; Harrison, F. A. ; /Caltech ;

  20. Preparation and thermochromic properties of Ce-doped VO{sub 2} films

    SciTech Connect (OSTI)

    Song, Linwei; Zhang, Yubo; Huang, Wanxia; Shi, Qiwu; Li, Danxia; Zhang, Yang; Xu, Yuanjie

    2013-06-01

    Graphical abstract: This effect of doping concentration on the phase transition temperature of VO{sub 2} films demonstrates that the phase transition temperature is decreasing along with the increase of the Ce dopant concentrations. After doping Ce, the transition temperature of VO{sub 2} film changes appreciably. Highlights: ► Ce-doped VO{sub 2} films were prepared on muscovite substrate by inorganic sol–gel method for the first time. ► The cerium existing in the VO{sub 2} films in the form of Ce{sup 4+} and Ce{sup 3+} was substituted for part of V atoms in the lattice. ► Ce doping could remarkably reduce the particle size of the Ce-doped films compared with undoped films. ► The phase transition temperature of Ce-doped VO{sub 2} films decreased appreciably with maintaining high-quality phase transition. - Abstract: Mixture of cerium (III) nitrate hexahydrate and vanadium pentaoxide powder were used as precursor to prepare Ce-doped VO{sub 2} films on the muscovite substrate by inorganic sol–gel method. SEM, XRD and XPS were used to investigate the morphologies and structures of VO{sub 2} films. The results show that the VO{sub 2} films grow on the muscovite substrate with preferred orientated (0 1 1) plane and the Ce exists in the form of Ce{sup 4+} and Ce{sup 3+} replacing part of V atoms in the lattice. The infrared transmittance change was measured from room temperature to the temperature above the metal–insulator transition. The films have excellent thermochromic performance. The metal–insulator transition temperature of VO{sub 2} films changes appreciably with Ce doped, which decreases by 4.5 °C per 1 at.% doping. Furthermore, Ce doping could remarkably reduce the particle size of VO{sub 2} films.

  1. On the heat capacity of Ce{sub 3}Al

    SciTech Connect (OSTI)

    Singh, Durgesh Samatham, S. Shanmukharao Venkateshwarlu, D. Gangrade, Mohan Ganesan, V.

    2014-04-24

    Electrical resistivity and heat capacity measurements on Cerium based dense Kondo compound Ce{sub 3}Al have been reported. Clear signatures of first order structural transition at 108K, followed by a Kondo minimum and coherence are clearly seen in resistivity. The structural transition is robust and is not affected by magnetic fields. Heat capacity measurements reveal an anomalous enhancement in the heavy fermion character upon magnetic fields. Vollhardt invariance in specific heat C(T.H) curves have been observed at T=3.7K and at H ≈ 6T.

  2. Magnetic properties and photoabsorption of the Mn-doped CeO{sub 2} nanorods

    SciTech Connect (OSTI)

    Xia, Chuanhui; Science College of Chongqing Jiaotong University, Chongqing 400074 ; Hu, Chenguo; Chen, Peng; Wan, Buyong; He, Xiaoshan; Tian, Yongshu; Chongqing Communication College, Chongqing 400035

    2010-07-15

    Mn-doped CeO{sub 2} nanorods have been prepared from CeO{sub 2} particles through a facile composite-hydroxide-mediated (CHM) approach. The analysis from X-ray photoelectron spectroscopy indicates that the manganese doped in CeO{sub 2} exists as Mn{sup 2+}. The magnetic measurement of the Mn-doped CeO{sub 2} nanorods exhibits an enhanced ferromagnetic property at room temperature with a remanence magnetization (Mr) of 1.36 x 10{sup -3} emu/g and coercivity (Hc) of 22 Oe. Comparative UV-visible spectra reveal the shift of the absorption peak of the CeO{sub 2} from ultraviolet region to visible light region after being doped with Mn. The room temperature ferromagnetic properties and light absorption of the Mn-doped CeO{sub 2} nanorods would have potential applications in photocatalysis and building of photovoltaic devices.

  3. The influence of nano-architectured CeOx supports in RhPd/CeO₂ for the catalytic ethanol steam reforming reaction

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Divins, N. J.; Senanayake, S. D.; Casanovas, A.; Xu, W.; Trovarelli, A.; Llorca, J.

    2015-01-19

    The ethanol steam reforming (ESR) reaction has been tested over RhPd supported on polycrystalline ceria in comparison to structured supports composed of nanoshaped CeO₂ cubes and CeO₂ rods tailored towards the production of hydrogen. At 650-700 K the hydrogen yield follows the trend RhPd/CeO₂-cubes > RhPd/CeO₂ -rods > RhPd/CeO₂- polycrystalline, whereas at temperatures higher than 800 K the catalytic performance of all samples is similar and close to the thermodynamic equilibrium. The improved performance of RhPd/CeO₂-cubes and RhPd/CeO₂ -rods for ESR at low temperature is mainly ascribed to higher water-gas shift activity and a strong interaction between the bimetallic -more » oxide support interaction. STEM analysis shows the existence of RhPd alloyed nanoparticles in all samples, with no apparent relationship between ESR performance and RhPd particle size. X-ray diffraction under operating conditions shows metal reorganization on {100} and {110} ceria crystallographic planes during catalyst activation and ESR, but not on {111} ceria crystallographic planes. The RhPd reconstructing and tuned activation over ceria nanocubes and nanorods is considered the main reason for better catalytic activity with respect to conventional catalysts based on polycrystalline ceria« less

  4. The influence of nano-architectured CeOx supports in RhPd/CeO₂ for the catalytic ethanol steam reforming reaction

    SciTech Connect (OSTI)

    Divins, N. J.; Senanayake, S. D.; Casanovas, A.; Xu, W.; Trovarelli, A.; Llorca, J.

    2015-01-19

    The ethanol steam reforming (ESR) reaction has been tested over RhPd supported on polycrystalline ceria in comparison to structured supports composed of nanoshaped CeO₂ cubes and CeO₂ rods tailored towards the production of hydrogen. At 650-700 K the hydrogen yield follows the trend RhPd/CeO₂-cubes > RhPd/CeO₂ -rods > RhPd/CeO₂- polycrystalline, whereas at temperatures higher than 800 K the catalytic performance of all samples is similar and close to the thermodynamic equilibrium. The improved performance of RhPd/CeO₂-cubes and RhPd/CeO₂ -rods for ESR at low temperature is mainly ascribed to higher water-gas shift activity and a strong interaction between the bimetallic - oxide support interaction. STEM analysis shows the existence of RhPd alloyed nanoparticles in all samples, with no apparent relationship between ESR performance and RhPd particle size. X-ray diffraction under operating conditions shows metal reorganization on {100} and {110} ceria crystallographic planes during catalyst activation and ESR, but not on {111} ceria crystallographic planes. The RhPd reconstructing and tuned activation over ceria nanocubes and nanorods is considered the main reason for better catalytic activity with respect to conventional catalysts based on polycrystalline ceria

  5. Hyperfine field and magnetic structure in the B phase of CeCoIn5

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Conference: Hyperfine field and magnetic structure in the B phase of CeCoIn5 Citation Details In-Document Search Title: Hyperfine field and magnetic structure in the B phase of CeCoIn5 We re-analyze Nuclear Magnetic Resonance (NMR) spectra observed at low temperatures and high magnetic fields in the field-induced B-phase of CeCoIn{sub 5}. The NMR spectra are consistent with incommensurate antiferromagnetic order of the Ce magnetic moments. However, we find that

  6. Luminescence properties of LaF{sub 3}:Ce nanoparticles encapsulated by oleic acid

    SciTech Connect (OSTI)

    Kim, Jaewoo; Lee, Jun-Hyung; An, Hyejin; Lee, Jungkuk; Park, Seong-Hee; Seo, Young-Soo; Miller, William H.

    2014-09-15

    Highlights: In-situ hydrophobization of water dispersible LaF{sub 3}:Ce nanoparticles was achieved. Oleic acid surface modification of the nanoparticles was verified by IR spectra. Quantum yields of LaF{sub 3}:Ce and OA-LaF{sub 3}:Ce nanoparticles were evaluated. Quantum yields of LaF{sub 3}:Ce are strongly dependent on OA surface modification. - Abstract: Cerium ions doped lanthanum fluoride (LaF{sub 3}:Ce) nanopowder as well as LaF{sub 3}:Ce nanopowder whose surfaces was modified by oleic acid (OA) were synthesized by using an in-situ hydrothermal process under the various doping concentrations. Based on the XRD spectra and TEM images, it was confirmed that the crystalline structured hexagonal LaF{sub 3}:Ce nanopowder was synthesized. Oleic acid was efficient for conversion of the water dispersible LaF{sub 3}:Ce nanoparticles to hydrophobic ones. Surface modification was verified by FTIR absorption spectrum as well as TEM images, showing no agglomeration between 5 and 10 nm scaled particles. Photoluminescence based on 5d ? 4f electronic transition of cerium ions excited at ?{sub ex} ?256 nm for both neat and OA encapsulated LaF{sub 3}:Ce nanoparticles decreases as the cerium concentration increases, while the quantum yields of OA encapsulated nanoparticles were much lower than the neat particles due to low photon transmittance of OA at the range longer than ?350 nm.

  7. Capillary electrophoresis-fluorescence line narrowing system (CE-FLNS) for on-line structural characterization

    DOE Patents [OSTI]

    Jankowiak, R.J.; Small, G.J.; Shields, P.A.

    1999-04-27

    Capillary electrophoresis (CE) is interfaced with low temperature fluorescence line-narrowing (FLN) spectroscopy for on-line structural characterization of separated molecular analytes. 21 figs.

  8. Capillary electrophoresis-fluorescence line narrowing system (CE-FLNS) for on-line structural characterization

    DOE Patents [OSTI]

    Jankowiak, Ryszard J.; Small, Gerald J.; Shields, Peter A.

    1999-04-27

    Capillary electrophoresis (CE) is interfaced with low temperature fluorescence line-narrowing (FLN) spectroscopy for on-line structural characterization of separated molecular analytes.

  9. Ethanol Steam Reforming on Co/CeO2: The Effect of ZnO Promoter

    SciTech Connect (OSTI)

    Davidson, Stephen; Sun, Junming; Wang, Yong

    2013-12-02

    A series of ZnO promoted Co/CeO2 catalysts were synthesized and characterized using XRD, TEM, H2-TPR, CO chemisorption, O2-TPO, IR-Py, and CO2-TPD. The effects of ZnO on the catalytic performances of Co/CeO2 were studied in ethanol steam reforming. It was found that the addition of ZnO facilitated the oxidation of Co0 via enhanced oxygen mobility of the CeO2 support which decreased the activity of Co/CeO2 in C–C bond cleavage of ethanol. 3 wt% ZnO promoted Co/CeO2 exhibited minimum CO and CH4 selectivity and maximum CO2 selectivity. This resulted from the combined effects of the following factors with increasing ZnO loading: (1) enhanced oxygen mobility of CeO2 facilitated the oxidation of CHx and CO to form CO2; (2) increased ZnO coverage on CeO2 surface reduced the interaction between CHx/CO and Co/CeO2; and (3) suppressed CO adsorption on Co0 reduced CO oxidation rate to form CO2. In addition, the addition of ZnO also modified the surface acidity and basicity of CeO2, which consequently affected the C2–C4 product distributions.

  10. Thermoelectric Couple Demonstration of (In, Ce)-based Skutterudite Materials for Automotive Energy Recovery

    Broader source: Energy.gov [DOE]

    Presents recent accomplishments and couple test results with these (In, Ce)-based skutterudite TE materials and potential impacts TE power system performance in military and commercial applications

  11. Thermal Variation of Ce Valence in Mixed ValenceKondo Lattice Systems CeT2(Si1-xGex)2 with T= Mn and Ni

    SciTech Connect (OSTI)

    Liang,G.; Croft, M.

    2008-01-01

    The results on the thermal variation of Ce L3-valence in CeT2(Si1-xGex)2 series with 0{le}x{le}1 and T=Mn and Ni are reported. It is observed that for both series, the Ce valence increases with decreasing temperature and has little thermal variation for samples in the nearly trivalent regime. The magnitude of this thermal variation in the T=Mn series is much greater than in the T=Ni series. The results are explained by the degenerate Anderson model and correlated with the specific heat data.

  12. Things to Consider When Upgrading a Non-Power Reactor to a Digital I&C System

    SciTech Connect (OSTI)

    Muhlheim, Michael David; Hardin, LeRoy A; Hardesty, Duane; Wilson, Thomas L

    2011-01-01

    Non-Power Reactor (NPR) licensees are increasing their use of state-of-the-art digital technology in instrumentation and control (I&C) systems because digital systems offer improved reactor control, information processing, and information storage. In Generic Letter GL 95-02, the NRC recognized that the design characteristics specific to the new digital electronics could result in failure modes and system malfunctions that either were not considered during the initial plant design or not evaluated in sufficient detail in the safety analysis report. These concerns include potential common mode failures. A conversion from analog to digital I&C systems in NPRs solves some problems while potentially introducing others. Good design, engineering, review, and testing can identify and minimize these risks.

  13. Statistical circuit simulation with measurement-based active device models: Implications for process control and IC manufacturability

    SciTech Connect (OSTI)

    Root, D.E.; McGinty, D.; Hughes, B.

    1995-12-31

    This paper presents a new approach to statistical active circuit design which unifies device parametric-based process control and non-parametric circuit simulation. Predictions of circuit sensitivity to process variation and yield-loss of circuits fabricated in two different GaAs IC processes are described. The simulations make use of measurement-based active device models which are not formulated in terms of conventional parametric statistical variables. The technique is implemented in commercially available simulation software (HP MDS).

  14. Magnetic structure of the antiferromagnetic Kondo lattice compounds CeRhAl4Si2 and CeIrAl4Si2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ghimire, N. J.; Calder, S.; Janoschek, M.; Bauer, E. D.

    2015-06-01

    In this article, we have investigated the magnetic ground state of the antiferromagnetic Kondo-lattice compounds CeMAl4Si2(M = Rh, Ir) using neutron powder diffraction. Although both of these compounds show two magnetic transitions TN1 and TN2 in the bulk properties measurements, evidence for magnetic long-range order was only found below the lower transition TN2. Analysis of the diffraction profiles reveals a commensurate antiferromagnetic structure with a propagation vector k = (0, 0, 1/2). The magnetic moment in the ordered state of CeRhAl4Si2 and CeIrAl4Si2 were determined to be 1.14(2) and 1.41(3) μB/Ce, respectively, and are parallel to the crystallographic c-axis inmore » agreement with magnetic susceptibility measurements.« less

  15. Inelastic magnetic neutron scattering in CePd{sub 3}.

    SciTech Connect (OSTI)

    Lawrence, J. M.; Fanelli, V. R.; Goremychkin, E. A.; Osborn, R.; Bauer, E. D.; McClellan, K. J.; Christianson, A. D.; Univ. of California at Irvine; LANL; ORNL

    2008-01-01

    We have performed time-of-flight neutron scattering measurements on a single crystal of the intermediate valence compound CePd{sub 3}. At 10 K, a Kondo-esque inelastic magnetic scattering peak occurs near {Delta}E = 60 meV with maximum intensity for momentum transfer Q near the (1/2, 1/2, 0) zone boundary. Spectral weight is transferred to lower energy as Q varies until at zone center the intensity at 60 meV is considerably weaker. These results are in qualitative accord with predictions of the Anderson lattice. The Q-dependence may resolve an older controversy concerning the low-temperature scattering. We discuss the relationship of these results to our recent results in YbAl{sub 3}.

  16. Ternary ceramic alloys of ZR-CE-HF oxides

    DOE Patents [OSTI]

    Becher, Paul F.; Funkenbusch, Eric F.

    1990-01-01

    A ternary ceramic alloy which produces toughening of zirconia and zirconia composites through the stress transformation from tetragonal phase to monoclinic phase. This alloy, having the general formula Ce.sub.x Hf.sub.y Zn.sub.1-x-y O.sub.2, is produced through the addition of appropriate amounts of ceria and hafnia to the zirconia. Typically, improved toughness is achieved with about 5 to about 15 mol % ceria and up to about 40 mol % hafnia. The preparation of alloys of these compositions are given together with data as to the densities, tetragonal phase content, hardness and fracture toughness. The alloys are useful in preparing zirconia bodies as well as reinforcing ceramic composites.

  17. Ternary ceramic alloys of Zr-Ce-Hf oxides

    DOE Patents [OSTI]

    Becher, P.F.; Funkenbusch, E.F.

    1990-11-20

    A ternary ceramic alloy is described which produces toughening of zirconia and zirconia composites through the stress transformation from tetragonal phase to monoclinic phase. This alloy, having the general formula Ce[sub x]Hf[sub y]Zr[sub 1[minus]x[minus]y]O[sub 2], is produced through the addition of appropriate amounts of ceria and hafnia to the zirconia. Typically, improved toughness is achieved with about 5 to about 15 mol % ceria and up to about 40 mol % hafnia. The preparation of alloys of these compositions are given together with data as to the densities, tetragonal phase content, hardness and fracture toughness. The alloys are useful in preparing zirconia bodies as well as reinforcing ceramic composites. 1 fig.

  18. Preparation and properties of ce-doped TiO{sub 2} photocatalyst

    SciTech Connect (OSTI)

    Yan, Ningning; Zhu, Zhongqi; Zhang, Jin; Zhao, Zongyan; Liu, Qingju

    2012-08-15

    Highlights: ? The cerium ion doped TiO{sub 2} (Ce-TiO{sub 2}) powders were prepared and characterized. ? The spectrum absorption region of Ce-TiO{sub 2} is red-shifted to visible light. ? The recombination of photo-generated electron-hole pairs of Ce-TiO{sub 2} is inhibited. ? The photocatalytic activity was effected by Ce ion content and greatly improved. -- Abstract: TiO{sub 2} nanoparticles doped with different content of Ce ion were prepared by solgel method. The samples were characterized by XRD, XPS, TEM, UVVis, and PL, the photocatalytic activity was evaluated by photocatalytic degradation of methylene blue (MB) under the irradiation of fluorescent lamp. The results indicate that Ce ion is incorporated into the lattice of TiO{sub 2}, which can restrain the increase of grain size, broaden the absorption region to visible light, and inhibit the recombination of the photo-generated electron and hole pairs. Moreover, the photocatalytic activity of Ce-TiO{sub 2} in MB degradation is evidently enhanced. The MB degradation rate of the sample with Ce:Ti = 0.33% (molar ratio) in 8 h is 90.03%, which is much higher than that of P25 (68.19%).

  19. CO Oxidation at the Interface of Au Nanoclusters and the Stepped-CeO2(111) Surface

    SciTech Connect (OSTI)

    Kim H. Y.; Henkelman, G.

    2013-01-14

    To reveal the richer chemistry of CO oxidation by CeO2 supported Au Nanoclusters NCs)/Nanoparticles, we design a Au12 supported on a stepped-CeO2 model (Au/CeO2-step) and study various kinds of CO oxidation mechanisms at the interface of the Au/CeO2-step: oxygen spillover from the CeO2 to the Au NCs;2 CO oxidation by the O2 bound to the Au-Ce3+ interface;3 and CO oxidation by the Mars-van Krevelen (M-vK) mechanism.4 DFT+U calculations show that lattice oxygen at the CeO2 step edge oxidizes CO bound to Au NCs by the M-vK mechanism. CO2 desorption determines the rate of CO oxidation and the vacancy formation energy (Evac) is a reactivity descriptor for CO oxidation. The maximum Evac that insures spontaneous CO2 production is higher for the Au/CeO2-step than the Au/CeO2-surface suggesting that the CeO2-step is a better supporting material than the CeO2-surface for CO oxidation by the Au/CeO2. Our results also suggest that for CO oxidation by Au NCs supported on nano- or meso-structured CeO2, which is the case of industrial catalysts, the M-vK mechanism accounts for a large portion of the total activity.

  20. High Curie temperature of Ce-Fe-Si compounds with ThMn12 structure

    SciTech Connect (OSTI)

    Zhou, C; Pinkerton, FE; Herbst, JF

    2015-01-15

    We report the discovery of ternary CeFe(12-x)Si(x)compounds possessing the ThMn12 structure. The samples were prepared by melt spinning followed by annealing. In contrast to other known Ce Fe-based binary and ternary compounds, CeFe12-xSix compounds exhibit exceptionally high Curie temperatures whose values increase with added Si substitution. The highest T. = 583 K in CeFe10Si2 rivals that of the well-established Nd2Fe14B compound. We ascribe the T-c behavior to a combination of Si-induced 3d band structure changes and partial Ce3+ stabilization. (C) 2014 Published by Elsevier Ltd.

  1. Processing of transparent polycrystalline AlON:Ce3+ scintillators

    SciTech Connect (OSTI)

    Chen, Ching -Fong; Yang, Pin; King, Graham; Tegtmeier, Eric L.

    2015-10-23

    A new polycrystalline ceramic scintillator is reported for potential use in radiation detection and medical imaging applications. The goal was to develop cerium-activated aluminum oxynitride (AlON:Ce3+) ceramics, which can be produced using ceramic processes in comparison to the high-cost, low-yield single-crystal growth technique. A phase pure AlON:Ce3+ powder with cubic symmetry was successfully synthesized at high temperature under a reducing atmosphere to convert Ce4+ to Ce3+ in the solid solution. We explored two different activator concentrations (0.5 and 1.0 mol%). Fully dense and transparent AlON:Ce3+ ceramics were produced by a liquid-phase-assisted pressureless sintering. The crystal field splitting around the Ce3+ activator in the AlON was comparable to the splitting induced by Br₋ and the Cl₋ ligands, which produced an emission spectrum perfectly matching the maximum quantum efficiency range of the photomultiplier tube for radiation detection. Both optical excitation and radiation ionizations in AlON:Ce3+ were demonstrated. Lastly, challenges and mechanisms related to the radioluminescence efficiency are discussed.

  2. Studies on Ca2+-Doped CeBr3 Scintillating Materials

    SciTech Connect (OSTI)

    Guss, P. [NSTec; Foster, M. E. [SNL; Wong, B. M. [SNL; Doty, F. P. [SNL; Shah, K. [RMD; Squillante, M. [RMD; Glodo, J. [RMD; Yuan, D. [NSTec

    2013-07-03

    Despite the outstanding scintillation performance characteristics of cerium tribromide (CeBr3) and cerium-activated lanthanum tribromide (LaBr3:Ce), their commercial availability and application is limited due to the difficulties of growing large, crack-free single crystals from these fragile materials. The objective of this investigation was to employ aliovalent doping to increase crystal strength while maintaining the optical properties of the crystal. One divalent dopant (Ca2+) was investigated as a dopant to strengthen CeBr3 without negatively impacting scintillation performance. Ingots containing nominal concentrations of 1.9% of the Ca2+ dopant were grown. Preliminary scintillation measurements are presented for this aliovalently doped scintillator. Ca2+-doped CeBr3 exhibited little or no change in the peak fluorescence emission for 371 nm optical excitation for CeBr3. The structural, electronic, and optical properties of CeBr3 crystals were investigated using the density functional theory within generalized gradient approximation. The calculated lattice parameters are in good agreement with the experimental data. The energy band structures and density of states were obtained. The optical properties of CeBr3, including the dielectric function, were calculated.

  3. Risk-Informed Monitoring, Verification and Accounting (RI-MVA). An NRAP White Paper Documenting Methods and a Demonstration Model for Risk-Informed MVA System Design and Operations in Geologic Carbon Sequestration

    SciTech Connect (OSTI)

    Unwin, Stephen D.; Sadovsky, Artyom; Sullivan, E. C.; Anderson, Richard M.

    2011-09-30

    This white paper accompanies a demonstration model that implements methods for the risk-informed design of monitoring, verification and accounting (RI-MVA) systems in geologic carbon sequestration projects. The intent is that this model will ultimately be integrated with, or interfaced with, the National Risk Assessment Partnership (NRAP) integrated assessment model (IAM). The RI-MVA methods described here apply optimization techniques in the analytical environment of NRAP risk profiles to allow systematic identification and comparison of the risk and cost attributes of MVA design options.

  4. Magnitude of the magnetic exchange interaction in the heavy-fermion antiferromagnet CeRhIn?

    SciTech Connect (OSTI)

    Das, Pinaki [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Lin, S. -Z. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Ghimire, N.? J. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Huang, K. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Univ. of California, San Diego, La Jolla, CA (United States); Ronning, F. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Bauer, E.? D. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Thompson, J.? D. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Batista, C.? D. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Ehlers, G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Janoschek, M. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

    2014-12-01

    We have used high-resolution neutron spectroscopy experiments to determine the complete spin wave spectrum of the heavy-fermion antiferromagnet CeRhIn?. The spin wave dispersion can be quantitatively reproduced with a simple frustrated J??J? model that also naturally explains the magnetic spin-spiral ground state of CeRhIn? and yields a dominant in-plane nearest-neighbor magnetic exchange constant J?=0.74(3)??meV. Our results pave the way to a quantitative understanding of the rich low-temperature phase diagram of the prominent CeTIn? (T = Co, Rh, Ir) class of heavy-fermion materials.

  5. Antiferromagnetic Kondo lattice in the layered compound CePd1-xBi₂ and

    Office of Scientific and Technical Information (OSTI)

    comparison to the superconductor LaPd1-xBi₂ (Journal Article) | SciTech Connect Antiferromagnetic Kondo lattice in the layered compound CePd1-xBi₂ and comparison to the superconductor LaPd1-xBi₂ Citation Details In-Document Search This content will become publicly available on July 12, 2016 Title: Antiferromagnetic Kondo lattice in the layered compound CePd1-xBi₂ and comparison to the superconductor LaPd1-xBi₂ The layered compound CePd1-xBi₂ with the tetragonal ZrCuSi₂-type

  6. Crystal structure of human dynein light chain Dnlc2A: Structural insights into the interaction with IC74

    SciTech Connect (OSTI)

    Liu Junfeng; Wang Zhanxin; Wang Xinquan; Tang Qun; An Xiaomin; Gui Lulu; Liang Dongcai . E-mail: dcliang@sun5.ibp.ac.cn

    2006-10-27

    The human light chain of the motor protein dynein, Dnlc2A, is also a novel TGF-{beta}-signaling component, which is altered with high frequency in epithelial ovarian cancer. It is an important mediator of dynein and the development of cancer, owing to its ability to bind to the dynein intermediate light chain (DIC) IC74 and to regulate TGF-{beta}-dependent transcriptional events. Here we report the 2.1-A crystal structure of Dnlc2A using single anomalous diffraction. The proteins form a homodimer in solution and interact mainly through the helix {alpha}{sub 2}, strand {beta}{sub 3}, and the loop following this strand in each protein to generate a 10-stranded {beta}-sheet core. The surface of the {beta}-sheet core is mainly positively charged and predicted (by software PPI-Pred) to be the site that interacts with other partners. At the same time, the residues 79-82, 88, and 90 of each molecule formed two holes in the core. Residue 89 of each molecule, which is crucial for the DIC binding function of Dnlc2A, is within the holes. On the basis of these observations, we propose that the homodimer is the structural and functional unit maintained by hydrogen bonding interactions and hydrophobic packing, and that the patch of the surface of the {beta}-sheet core is the main area of interaction with other partners. Furthermore, the two holes would be the key sites to interact with IC74.

  7. Lattice instabilities in heavy fermion superconductors. [CeCu/sub 2/Si/sub 2/; CeAl/sub 3/; CeCu/sub 6/; UBe/sub 13/; UPt/sub 3/

    SciTech Connect (OSTI)

    Wohlleben, D.

    1987-01-01

    This paper shows that while in nonsuperconducting HF systems such as CeCu/sub 6/, CeAl/sub 3/ and stoichiometric CeCu/sub 2/Si/sub 2/, the large electronic ..gamma.. is due to a very narrow f band, in the three HF superconductors UBe/sub 13/, UPt/sub 3/ and nonstochiometric CeCu/sub 2/Si/sub 2/, it is not. The f band of these systems, as measured by their response to magnetic fields in three different ways, is much wider than suggested by the large ..gamma... According to their actual f band width, the HF superconductors belong into the Bantam Fermion class. It is argued that most of the large ..gamma.. of the HF superconductors is not of electronic origin and that it is instead caused by the precursor of a martensitic phase transition of the lattice or by a crystallographic phase mixture, i.e., that it is due to the displacive degrees of freedom. This suggests that the superconductivity of all three HF superconductors is caused by some special, low energy phonons rather than by a narrow f band. 52 refs., 4 figs., 3 tabs.

  8. A comparison of the structure and localized magnetism in Ce{sub 2}PdGa{sub 12} with the heavy fermion CePdGa{sub 6}

    SciTech Connect (OSTI)

    Macaluso, Robin T. [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Millican, Jasmine N. [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Nakatsuji, Satoru [Department of Physics, Kyoto University, Kyoto, Japan 606-8502 (Japan); Lee, Han-Oh [Department of Physics, University of California, Davis, CA 95616 (United States); Carter, B. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Moreno, Nelson O. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Fisk, Zachary [Department of Physics, University of California, Davis, CA 95616 (United States); Chan, Julia Y. [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States)]. E-mail: jchan@lsu.edu

    2005-11-15

    Single crystals of Ce{sub 2}PdGa{sub 12} have been synthesized in Ga flux and characterized by X-ray diffraction. This compound crystallizes in the tetragonal P4/nbm space group, Z=2 with lattice parameters of a=6.1040(2)A and c=15.5490(6)A. It shows strongly anisotropic magnetism and orders antiferromagnetically at T{sub N}{approx}11K. A field-induced metamagnetic transition to the ferromagnetic state is observed below T{sub N}. Structure-property relationships with the related heavy-fermion antiferromagnet CePdGa{sub 6} are discussed.

  9. f-electron correlations in nonmagnetic Ce studied by means of...

    Office of Scientific and Technical Information (OSTI)

    f-electron correlations in nonmagnetic Ce studied by means of spin-resolved resonant photoemission Citation Details In-Document Search Title: f-electron correlations in nonmagnetic ...

  10. Pressure-Induced Structural Phase Transition in CeNi: X-ray and...

    Office of Scientific and Technical Information (OSTI)

    Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron Scattering Studies and First-Principles Calculations Citation Details In-Document Search Title: ...

  11. NMR studies of field induced magnetism in CeCoIn5 (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: NMR studies of field induced magnetism in CeCoIn5 Recent Nuclear Magnetic Resonance and elastic neutron scattering experiments have ...

  12. Switching of the Spin-Density-Wave in CeCoIn5 probed by Thermal...

    Office of Scientific and Technical Information (OSTI)

    Title: Switching of the Spin-Density-Wave in CeCoIn5 probed by Thermal Conductivity Authors: Kim, Duk Young 1 ; Lin, Shizeng 1 ; Weickert, Franziska 2 ; Bauer, Eric Dietzgen ...

  13. Determination of the Surface Structure of CeO2(111) by Low-Energy...

    Office of Scientific and Technical Information (OSTI)

    Title: Determination of the Surface Structure of CeO2(111) by Low-Energy Electron Diffraction. Abstract not provided. Authors: McCarty, Kevin F. ; Siegel, David A ; El Gabaly ...

  14. Pressure tuning of competing magnetic interactions in intermetallic CeFe2

    SciTech Connect (OSTI)

    Wang, Jiyang; Feng, Yejun; Jaramillo, R.; van Wezel, Jasper; Canfield, Paul C.; Rosenbaum, T.F.

    2012-07-20

    We use high-pressure magnetic x-ray diffraction and numerical simulation to determine the low-temperature magnetic phase diagram of stoichiometric CeFe2. Near 1.5 GPa we find a transition from ferromagnetism to antiferromagnetism, accompanied by a rhombohedral distortion of the cubic Laves crystal lattice. By comparing pressure and chemical substitution we find that the phase transition is controlled by a shift of magnetic frustration from the Ce-Ce to the Fe-Fe sublattice. Notably the dominant Ce-Fe magnetic interaction, which sets the temperature scale for the onset of long-range order, remains satisfied throughout the phase diagram but does not determine the magnetic ground state. Our results illustrate the complexity of a system with multiple competing magnetic energy scales and lead to a general model for magnetism in cubic Laves phase intermetallic compounds.

  15. ASKO Appliances: Order (2012-CE-19/2004) | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    (2012-CE-192004) July 20, 2012 DOE ordered ASKO Appliances, Inc. to pay a 36,500 civil penalty after finding ASKO had failed to certify that certain models of residential...

  16. Evidence of dynamical spin shielding in Ce from spin-resolved photoelectron

    Office of Scientific and Technical Information (OSTI)

    spectroscopy (Journal Article) | SciTech Connect Evidence of dynamical spin shielding in Ce from spin-resolved photoelectron spectroscopy Citation Details In-Document Search Title: Evidence of dynamical spin shielding in Ce from spin-resolved photoelectron spectroscopy Authors: Tobin, J. G. ; Yu, S. W. ; Komesu, T. ; Chung, B. W. ; Morton, S. A. ; Waddill, G. D. [1] ; MUST) [2] + Show Author Affiliations LLNL ( Publication Date: 2015-10-15 OSTI Identifier: 1223975 Resource Type: Journal

  17. Structure and magnetic properties of LnMnSbO ( Ln=La and Ce)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Qiang; Kumar, C. M. N.; Tian, Wei; Dennis, Kevin W.; Goldman, Alan I.; Vaknin, David

    2016-03-11

    Here, a neutron powder diffraction (NPD) study of LnMnSbO (Ln = La or Ce) reveals differences between the magnetic ground state of the two compounds due to the strong Ce-Mn coupling compared to La-Mn. The two compounds adopt the P4/nmm space group down to 2 K, and whereas magnetization measurements do not show obvious anomaly at high temperatures, NPD reveals a C-type antiferromagnetic (AFM) order below TN = 255K for LaMnSbO and 240 K for CeMnSbO. While the magnetic structure of LaMnSbO is preserved to base temperature, a sharp transition at TSR = 4.5K is observed in CeMnSbO due tomore » a spin-reorientation (SR) transition of the Mn2+ magnetic moments from pointing along the c axis to the ab plane. The SR transition in CeMnSbO is accompanied by a simultaneous long-range AFM ordering of the Ce moments, which indicates that the Mn SR transition is driven by the Ce-Mn coupling. The ordered moments are found to be somewhat smaller than those expected for Mn2+ (S = 5/2) in insulators, but large enough to suggest that these compounds belong to the class of local-moment antiferromagnets. The lower TN found in these two compounds compared to the As-based counterparts (TN = 317 for LaMnAsO, TN = 347K for CeMnAsO) indicates that the Mn-Pn (Pn=As or Sb) hybridization that mediates the superexchange Mn-Pn-Mn coupling is weaker for the Sb-based compounds.« less

  18. Angle Resolved Thermal Conductivity of CeCoIn5 along the Nodal Direction

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Angle Resolved Thermal Conductivity of CeCoIn5 along the Nodal Direction Citation Details In-Document Search Title: Angle Resolved Thermal Conductivity of CeCoIn5 along the Nodal Direction Authors: Movshovich, Roman [1] ; Kim, Duk Young [1] ; Lin, Shizeng [1] ; Weickert, Franziska [2] ; Bauer, Eric Dietzgen [1] ; Ronning, Filip [1] ; Thompson, Joe David [1] + Show Author Affiliations Los Alamos National Laboratory MPA-CMMS: CONDENSED MATTER & MAGNET SCIENCE

  19. Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron

    Office of Scientific and Technical Information (OSTI)

    Scattering Studies and First-Principles Calculations (Journal Article) | SciTech Connect Journal Article: Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron Scattering Studies and First-Principles Calculations Citation Details In-Document Search This content will become publicly available on August 3, 2016 Title: Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron Scattering Studies and First-Principles Calculations The pressure-induced structural

  20. f-electron correlations in nonmagnetic Ce studied by means of spin-resolved

    Office of Scientific and Technical Information (OSTI)

    resonant photoemission (Journal Article) | SciTech Connect f-electron correlations in nonmagnetic Ce studied by means of spin-resolved resonant photoemission Citation Details In-Document Search Title: f-electron correlations in nonmagnetic Ce studied by means of spin-resolved resonant photoemission Authors: Yu, S. -W. ; Komesu, T. ; Chung, B. W. ; Waddill, G. D. ; Morton, S. A. ; Tobin, J. G. [1] ; MUST) [2] + Show Author Affiliations LLNL ( Publication Date: 2015-10-15 OSTI Identifier:

  1. Results for aliovalent doping of CeBr{sub 3} with Ca{sup 2+}

    SciTech Connect (OSTI)

    Guss, Paul; Foster, Michael E.; Wong, Bryan M.; Patrick Doty, F.; Shah, Kanai; Squillante, Michael R.; Shirwadkar, Urmila; Hawrami, Rastgo; Tower, Joshua; Yuan, Ding

    2014-01-21

    Despite the outstanding scintillation performance characteristics of cerium tribromide (CeBr{sub 3}) and cerium-activated lanthanum tribromide, their commercial availability and application are limited due to the difficulties of growing large, crack-free single crystals from these fragile materials. This investigation employed aliovalent doping to increase crystal strength while maintaining the optical properties of the crystal. One divalent dopant (Ca{sup 2+}) was used as a dopant to strengthen CeBr{sub 3} without negatively impacting scintillation performance. Ingots containing nominal concentrations of 1.9% of the Ca{sup 2+} dopant were grown, i.e., 1.9% of the CeBr{sub 3} molecules were replaced by CaBr{sub 2} molecules, to match our target replacement of 1 out of 54 cerium atoms be replaced by a calcium atom. Precisely the mixture was composed of 2.26 g of CaBr{sub 2} added to 222.14 g of CeBr{sub 3}. Preliminary scintillation measurements are presented for this aliovalently doped scintillator. Ca{sup 2+}-doped CeBr{sub 3} exhibited little or no change in the peak fluorescence emission for 371?nm optical excitation for CeBr{sub 3}. The structural, electronic, and optical properties of CeBr{sub 3} crystals were studied using the density functional theory within the generalized gradient approximation. Calculated lattice parameters are in agreement with the experimental data. The energy band structures and density of states were obtained. The optical properties of CeBr{sub 3}, including the dielectric function, were calculated.

  2. An Update on Improvements to NiCE Support for RELAP-7

    SciTech Connect (OSTI)

    McCaskey, Alex; Wojtowicz, Anna; Deyton, Jordan H.; Patterson, Taylor C.; Billings, Jay Jay

    2015-01-01

    The Multiphysics Object-Oriented Simulation Environment (MOOSE) is a framework that facilitates the development of applications that rely on finite-element analysis to solve a coupled, nonlinear system of partial differential equations. RELAP-7 represents an update to the venerable RELAP-5 simulator that is built upon this framework and attempts to model the balance-of-plant concerns in a full nuclear plant. This report details the continued support and integration of RELAP-7 and the NEAMS Integrated Computational Environment (NiCE). RELAP-7 is fully supported by the NiCE due to on-going work to tightly integrate NiCE with the MOOSE framework, and subsequently the applications built upon it. NiCE development throughout the first quarter of FY15 has focused on improvements, bug fixes, and feature additions to existing MOOSE-based application support. Specifically, this report will focus on improvements to the NiCE MOOSE Model Builder, the MOOSE application job launcher, and the 3D Nuclear Plant Viewer. This report also includes a comprehensive tutorial that guides RELAP-7 users through the basic NiCE workflow: from input generation and 3D Plant modeling, to massively parallel job launch and post-simulation data visualization.

  3. Antiferromagnetic ordering in the doped Kondo insulator CeRhSb

    SciTech Connect (OSTI)

    Menon, L.; Malik, S.K.

    1997-06-01

    CeRhSb, the so-called {open_quotes}Kondo insulator,{close_quotes} is a mixed-valent compound showing a gap formation in the electronic density of states. On the other hand, CePdSb is ferromagnetically ordered with a Curie temperature of {approximately}17 K. We have carried out magnetic susceptibility and electrical resistivity measurements on CeRh{sub 1{minus}x}Pd{sub x}Sb (0{le}x{le}1.0), to study the ground-state properties of this system. For small Pd doping in CeRhSb, up to 20{percent}, the gap continually diminishes and no magnetic ordering is observed down to 2 K. In the region 0.3{le}x{le}0.4, as soon as the gap is suppressed, an antiferromagnetic ground state is observed. In the region 0.5{le}x{lt}0.7, the compounds are not single phase. At the CePdSb end, in the region 0.7{le}x{le}1, the ground state is ferromagnetic. The observation of an antiferromagnetic phase in the phase diagram of CeRh{sub 1{minus}x}Pd{sub x}Sb, where neither end is antiferromagnetic, is interesting and is discussed in the light of some recent theoretical models. {copyright} {ital 1997} {ital The American Physical Society}

  4. Structure and scintillation yield of Ce-doped AlGa substituted yttrium garnet

    SciTech Connect (OSTI)

    Sidletskiy, Oleg; Kononets, Valerii; Lebbou, Kheirreddine; Neicheva, Svetlana; Voloshina, Olesya; Bondar, Valerii; Baumer, Vyacheslav; Belikov, Konstantin; Gektin, Alexander; Grinyov, Boris; Joubert, Marie-France

    2012-11-15

    Highlights: ? Range of Y{sub 3}(Al{sub 1?x}Ga{sub x}){sub 5}O{sub 12}:Ce solid solution crystals are grown from melt by the Czochralski method. ? Light yield of mixed crystals reaches 130% of the YAG:Ce value at x ? 0.4. ? ?1% of antisite defects is formed in YGG:Ce, but no evidence of this is obtained for the rest of crystals. -- Abstract: Structure and scintillation yield of Y{sub 3}(Al{sub 1?x}Ga{sub x}){sub 5}O{sub 12}:Ce solid solution crystals are studied. Crystals are grown from melt by the Czochralski method. Distribution of host cations in crystal lattice is determined. Quantity of antisite defects in crystals is evaluated using XRD and atomic emission spectroscopy data. Trend of light output at Al/Ga substitution in Y{sub 3}(Al{sub 1?x}Ga{sub x}){sub 5}O{sub 12}:Ce is determined for the first time. Light output in mixed crystals reaches 130% comparative to Ce-doped yttriumaluminum garnet. Luminescence properties at Al/Ga substitution are evaluated.

  5. Structure and Reactivity of Alkyl Ethers Adsorbed on CeO2(111) Model Catalysts

    SciTech Connect (OSTI)

    F Calaza; T Chen; D Mullins; S Overbury

    2011-12-31

    The effect of surface hydroxyls on the adsorption of ether on ceria was explored. Adsorption of dimethyl ether (DME) and diethyl ether (DEE) on oxidized and reduced CeO{sub 2}(111) films was studied and compared with Ru(0001) using RAIRS and sXPS within a UHV environment. On Ru(0001) the ethers adsorb weakly with the molecular plane close to parallel to the surface plane. On the ceria films, the adsorption of the ethers was stronger than on the metal surface, presumably due to stronger interaction of the ether oxygen lone pair electrons with a cerium cation. This interaction causes the ethers to tilt away from the surface plane compared to the Ru(0001) surface. No pronounced differences were found between oxidized (CeO{sub 2}) and reduced (CeOx) films. The adsorption of the ethers was found to be perturbed by the presence of OH groups on hydroxylated CeOx. In the case of DEE, the geometry of adsorption resembles that found on Ru, and in the case of dimethyl ether DME is in between that one found on clean CeOx and the metal surface. Decomposition of the DEE was observed on the OH/CeOx surface following high DEE exposure at 300 K and higher temperatures. Ethoxides and acetates were identified as adsorbed species on the surface by means of RAIRS and ethoxides and formates by s-XPS. No decomposition of dimethyl ether was observed on the OH/CeOx at these higher temperatures, implying that the dissociation of the C-O bond from ethers requires the presence of {beta}-hydrogen.

  6. Structure and Reactivity of Alkyl Ethers Adsorbed on CeO(2)(111) Model Catalysts

    SciTech Connect (OSTI)

    Calaza, Florencia C; Chen, Tsung-Liang; Mullins, David R; Overbury, Steven {Steve} H

    2011-01-01

    The effect of surface hydroxyls on the adsorption of ether on ceria was explored. Adsorption of dimethyl ether (DME) and diethyl ether (DEE) on oxidized and reduced CeO{sub 2}(111) films was studied and compared with Ru(0001) using RAIRS and sXPS within a UHV environment. On Ru(0001) the ethers adsorb weakly with the molecular plane close to parallel to the surface plane. On the ceria films, the adsorption of the ethers was stronger than on the metal surface, presumably due to stronger interaction of the ether oxygen lone pair electrons with a cerium cation. This interaction causes the ethers to tilt away from the surface plane compared to the Ru(0001) surface. No pronounced differences were found between oxidized (CeO{sub 2}) and reduced (CeOx) films. The adsorption of the ethers was found to be perturbed by the presence of OH groups on hydroxylated CeOx. In the case of DEE, the geometry of adsorption resembles that found on Ru, and in the case of dimethyl ether DME is in between that one found on clean CeOx and the metal surface. Decomposition of the DEE was observed on the OH/CeOx surface following high DEE exposure at 300 K and higher temperatures. Ethoxides and acetates were identified as adsorbed species on the surface by means of RAIRS and ethoxides and formates by s-XPS. No decomposition of dimethyl ether was observed on the OH/CeOx at these higher temperatures, implying that the dissociation of the C-O bond from ethers requires the presence of {beta}-hydrogen.

  7. Reduced graphene oxide/CeO{sub 2} nanocomposite with enhanced photocatalytic performance

    SciTech Connect (OSTI)

    Kaur, Jasmeet Anand, Kanika; Singh, Gurpreet; Hastir, Anita; Virpal,; Singh, Ravi Chand; Anand, Kanica

    2015-05-15

    In this work, reduced graphene oxide /cerium oxide (RGO/CeO{sub 2}) nanocomposite was synthesized by in situ reduction of cerium nitrate Ce(NO{sub 3}){sub 3}6H{sub 2}O in the presence of graphene oxide by hydrazine hydrate (N{sub 2}H{sub 4}.H{sub 2}O). The intrinsic characteristics of as-prepared nanocomposite were studied using powder x-ray diffraction (XRD), Raman spectroscopy and field-emission scanning electron microscopy (FESEM). The photocatalytic degradation of methylene blue (MB) was employed as a model reaction to evaluate the photocatalytic activity of the RGO/CeO{sub 2} nanocomposite. The as-obtained RGO/CeO{sub 2} nanocomposite displays a significantly enhanced photocatalytic degradation of MB dye in comparison with bare CeO{sub 2} nanoparticles under sunlight irradiation, which can be attributed to the improved separation of electron-hole pairs and enhanced adsorption performance due to presence of RGO.

  8. Ionic liquid-assisted sonochemical preparation of CeO2 nanoparticles for CO oxidation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Alammar, Tarek; Noei, Heshmat; Wang, Yuemin; Grünert, Wolfgang; Mudring, Anja -Verena

    2014-10-10

    CeO2 nanoparticles were synthesized via a one-step ultrasound synthesis in different kinds of ionic liquids based on bis(trifluoromethanesulfonylamide, [Tf2N]–, in combination with various cations including 1-butyl-3-methylimidazolium ([C4mim]+), 1-ethyl-2,3-dimethylimidazolium ([Edimim]+), butyl-pyridinium([Py4]+), 1-butyl-1-methyl-pyrrolidinium ([Pyrr14]+), and 2-hydroxyethyl-trimethylammonium ([N1112OH]+). Depending on synthetic parameters, such as ionic liquid, Ce(IV) precursor, heating method, and precipitator, formed ceria exhibits different morphologies, varying from nanospheres, nanorods, nanoribbons, and nanoflowers. The morphology, crystallinity, and chemical composition of the obtained materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy, and N2 adsorption. The structural and electronic propertiesmore » of the as-prepared CeO2 samples were probed by CO adsorption using IR spectroscopy under ultrahigh vacuum conditions. The catalytic activities of CeO2 nanoparticles were investigated in the oxidation of CO. CeO2 nanospheres obtained sonochemically in [C4mim][Tf2N] exhibit the best performance for low-temperature CO oxidation. As a result, the superior catalytic performance of this material can be related to its mesoporous structure, small particle size, large surface area, and high number of surface oxygen vacancy sites.« less

  9. Structural and magnetic phase transitions in CeCu6-xTx (T = Ag,Pd)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Poudel, Lekhanath N.; De la cruz, Clarina; Payzant, E. Andrew; Koehler, Michael R.; May, Andrew F.; Garlea, Vasile O.; Taylor, Alice E.; Parker, David S.; Cao, Huibo B.; McGuire, Michael A.; et al

    2015-12-15

    The structural and the magnetic properties of CeCu6-xAgx (0 ≤ x ≤ 0.85) and CeCu6-xPdx (0 ≤ x ≤ 0.4) have been studied using neutron diffraction, resonant ultrasound spectroscopy (RUS), x-ray diffraction measurements, and first principles calculations. The structural and magnetic phase diagrams of CeCu6-xAgx and CeCu6-xPdx as a function of Ag/Pd composition are reported. The end member, CeCu6, undergoes a structural phase transition from an orthorhombic (Pnma) to a monoclinic (P21/c) phase at 240 K. In CeCu6-xAgx, the structural phase transition temperature (Ts) decreases linearly with Ag concentration and extrapolates to zero at xS ≈ 0.1. The structural transitionmore » in CeCu6-xPdx remains unperturbed with Pd substitution within the range of our study. The lattice constant b slightly decreases with Ag/Pd doping, whereas a and c increase with an overall increase in the unit cell volume. Both systems, CeCu6-xAgx and CeCu6-xPdx, exhibit a magnetic quantum critical point (QCP), at x ≈ 0.2 and x ≈ 0.05, respectively. Near the QCP, long range antiferromagnetic ordering takes place at an incommensurate wave vector (δ1 0 δ2), where δ1 ~ 0.62, δ2 ~ 0.25, x = 0.125 for CeCu6-xPdx and δ1 ~ 0.64, δ2 ~ 0.3, x = 0.3 for CeCu6-xAgx. As a result, the magnetic structure consists of an amplitude modulation of the Ce moments which are aligned along the c axis of the orthorhombic unit cell.« less

  10. Proactive Design of n-Type (In, Ce) Filled Skutterudites Enabling High-Temperature Waste Heat Recovery

    Broader source: Energy.gov [DOE]

    Thermoelectric and structural properties of n-type (In, Ce) filled skutterudites including power factors and ZT as a function of temperature are presented

  11. A Comparative Study of the Water Gas Shift Reaction Over Platinum Catalysts Supported on CeO2, TiO2 and Ce-Modified TiO2

    SciTech Connect (OSTI)

    Gonzalez, I.; Navarro, R; Wen, W; Marinkovic, N; Rodriguez, J; Rosa, F; Fierro, J

    2010-01-01

    WGS reaction has been investigated on catalysts based on platinum supported over CeO{sub 2}, TiO{sub 2} and Ce-modified TiO{sub 2}. XPS and XANES analyses performed on calcined catalysts revealed a close contact between Pt precursors and cerium species on CeO{sub 2} and Ce-modified TiO{sub 2} supports. TPR results corroborate the intimate contact between Pt and cerium entities in the Pt/Ce-TiO{sub 2} catalyst that facilitates the reducibility of the support at low temperatures while the Ce-O-Ti surface interactions established in the Ce-modified TiO{sub 2} support decreases the reduction of TiO{sub 2} at high temperature. The changes in the support reducibility leads to significant differences in the WGS activity of the studied catalysts. Pt supported on Ce-modified TiO{sub 2} support exhibits better activity than those corresponding to individual CeO{sub 2} and TiO{sub 2}-supported catalysts. Additionally, the Ce-TiO{sub 2}-supported catalyst displays better stability at reaction temperatures higher than 573 K that observed on pure TiO{sub 2}-supported counterpart. Activity measurements, when coupled with the physicochemical characterization of catalysts suggest that the modifications in the surface reducibility of the support play an essential role in the enhancement of activity and stability observed when Pt is supported on the Ce-modified TiO{sub 2} substrate.

  12. A COMPREHENSIVE X-RAY AND MULTIWAVELENGTH STUDY OF THE COLLIDING GALAXY PAIR NGC2207/IC 2163

    SciTech Connect (OSTI)

    Mineo, S.; Rappaport, S.; Levine, A.; Homan, J.; Pooley, D.; Steinhorn, B. E-mail: sar@mit.edu E-mail: jeroen@space.mit.edu E-mail: bsteinho@mit.edu

    2014-12-20

    We present a comprehensive study of the total X-ray emission from the colliding galaxy pair NGC2207/IC 2163, based on Chandra, Spitzer, and GALEX data. We detect 28 ultraluminous X-ray sources (ULXs), 7 of which were not detected previously because of X-ray variability. Twelve sources show significant long-term variability, with no correlated spectral changes. Seven sources are transient candidates. One ULX coincides with an extremely blue star cluster (BV = 0.7). We confirm that the global relation between the number and luminosity of ULXs and the integrated star-formation rate (SFR) of the host galaxy also holds on local scales. We investigate the effects of dust extinction and age on the X-ray binary (XRB) population on subgalactic scales. The distributions of N {sub X} and L {sub X} are peaked at L {sub IR}/L {sub NUV} ? 1, which may be associated with an age of ?10Myr for the underlying stellar population. We find that approximately one-third of the XRBs are located in close proximity to young star complexes. The luminosity function of the XRBs is consistent with that typical for high-mass XRBs and appears unaffected by variability. We disentangle and compare the X-ray diffuse spectrum with that of the bright XRBs. The hot interstellar medium dominates the diffuse X-ray emission at E ? 1keV and has a temperature kT=0.28{sub ?0.04}{sup +0.05}keV and intrinsic 0.5-2keV luminosity of 7.910{sup 40} erg s{sup ?1}, a factor of ?2.3 higher than the average thermal luminosity produced per unit SFR in local star-forming galaxies. The total X-ray output of NGC2207/IC 2163 is 1.510{sup 41} erg s{sup ?1}, and the corresponding total integrated SFR is 23.7 M {sub ?} yr{sup 1}.

  13. Hyperfine field and magnetic structure in the B phase of CeCoIn5

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Conference: Hyperfine field and magnetic structure in the B phase of CeCoIn5 Citation Details In-Document Search Title: Hyperfine field and magnetic structure in the B phase of CeCoIn5 × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy

  14. Momentum-space structure of quasielastic spin fluctuations in Ce 3 Pd 20 Si

    Office of Scientific and Technical Information (OSTI)

    6 (Journal Article) | SciTech Connect Momentum-space structure of quasielastic spin fluctuations in Ce 3 Pd 20 Si 6 Citation Details In-Document Search Title: Momentum-space structure of quasielastic spin fluctuations in Ce 3 Pd 20 Si 6 Authors: Portnichenko, P. Y. ; Cameron, A. S. ; Surmach, M. A. ; Deen, P. P. ; Paschen, S. ; Prokofiev, A. ; Mignot, J.-M. ; Strydom, A. M. ; Telling, M. T. F. ; Podlesnyak, A. ; Inosov, D. S. Publication Date: 2015-03-13 OSTI Identifier: 1179978 Type:

  15. NMR studies of field induced magnetism in CeCoIn5 (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Journal Article: NMR studies of field induced magnetism in CeCoIn5 Citation Details In-Document Search Title: NMR studies of field induced magnetism in CeCoIn5 × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy science and technology. A paper copy of this

  16. Angle Resolved Thermal Conductivity of CeCoIn5 along the Nodal Direction

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Angle Resolved Thermal Conductivity of CeCoIn5 along the Nodal Direction Citation Details In-Document Search Title: Angle Resolved Thermal Conductivity of CeCoIn5 along the Nodal Direction × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy

  17. Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron

    Office of Scientific and Technical Information (OSTI)

    Scattering Studies and First-Principles Calculations (Journal Article) | SciTech Connect Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron Scattering Studies and First-Principles Calculations Citation Details In-Document Search Title: Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron Scattering Studies and First-Principles Calculations Authors: Mirmelstein, A ; Podlesnyak, A ; dos Santos, A M ; Ehlers, G ; Kerbel, O ; Matvienko, V ; Sefat, A S ;

  18. Mechanism of Methane Chemical Looping Combustion with Hematite Promoted with CeO2

    SciTech Connect (OSTI)

    Miller, Duane D.; Siriwardane, Ranjani

    2013-08-01

    Chemical looping combustion (CLC) is a promising technology for fossil fuel combustion that produces sequestration-ready CO{sub 2} stream, reducing the energy penalty of CO{sub 2} separation from flue gases. An effective oxygen carrier for CLC will readily react with the fuel gas and will be reoxidized upon contact with oxygen. This study investigated the development of a CeO{sub 2}-promoted Fe{sub 2}O{sub 3}?hematite oxygen carrier suitable for the methane CLC process. Composition of CeO{sub 2} is between 5 and 25 wt % and is lower than what is generally used for supports in Fe{sub 2}O{sub 3} carrier preparations. The incorporation of CeO{sub 2} to the natural ore hematite strongly modifies the reduction behavior in comparison to that of CeO{sub 2} and hematite alone. Temperature-programmed reaction studies revealed that the addition of even 5 wt % CeO{sub 2} enhances the reaction capacity of the Fe{sub 2}O{sub 3} oxygen carrier by promoting the decomposition and partial oxidation of methane. Fixed-bed reactor data showed that the 5 wt % cerium oxides with 95 wt % iron oxide produce 2 times as much carbon dioxide in comparison to the sum of carbon dioxide produced when the oxides were tested separately. This effect is likely due to the reaction of CeO{sub 2} with methane forming intermediates, which are reactive for extracting oxygen from Fe{sub 2}O{sub 3} at a considerably faster rate than the rate of the direct reaction of Fe{sub 2}O{sub 3} with methane. These studies reveal that 5 wt % CeO{sub 2}/Fe{sub 2}O{sub 3} gives stable conversions over 15 reduction/oxidation cycles. Lab-scale reactor studies (pulsed mode) suggest the methane reacts initially with CeO{sub 2} lattice oxygen to form partial oxidation products (CO + H{sub 2}), which continue to react with oxygen from neighboring Fe{sub 2}O{sub 3}, leading to its complete oxidation to form CO{sub 2}. The reduced cerium oxide promotes the methane decomposition reaction to form C + H{sub 2}, which continue to react with Fe{sub 2}O{sub 3}/Fe{sub 3}O{sub 4} to form CO/CO{sub 2} and H{sub 2}O. This mechanism is supported by the characterization studies, which also suggest that the formation of carbonaceous intermediates may affect the reaction rate and selectivity of the oxygen carrier.

  19. Ferromagnetic Kondo lattice CeRuSi{sub 2} with non-Fermi-liquid behavior

    SciTech Connect (OSTI)

    Nikiforov, V. N.; Baran, M.; Irkhin, V. Yu.

    2013-05-15

    The structure, electronic, thermodynamic, and magnetic properties of the CeRuSi{sub 2} Kondo lattice with ferromagnetic ordering characterized by a small moment of the ground state are investigated. Anomalies in the temperature dependences of heat capacity and resistivity (unusual power or logarithmic behavior) observed in the low-temperature range indicate a non-Fermi-liquid behavior. The results are compared with those for other Ce{sub l}Ru{sub n}X{sub m} compounds and anomalous systems based on rare-earth elements and actinides that had been studied earlier.

  20. {ital Ab Initio} Calculation of Crystalline Electric Fields and Kondo Temperatures in Ce Compounds

    SciTech Connect (OSTI)

    Han, J.; Alouani, M.; Cox, D.; Han, J.; Cox, D.; Alouani, M.

    1997-02-01

    We have calculated the band-f hybridizations for Ce{sub x}La{sub 1-x}M{sub 3} compounds (x=1 and x{r_arrow}0; M=Pb,In,Sn,Pd) within the local density approximation and fed this into a noncrossing approximation for the Anderson impurity model applied to both dilute and concentrated limits. Our calculations produce crystalline electric field splittings and Kondo temperatures with trends in good agreement with experiment and demonstrate the need for detailed electronic structure information on hybridization to describe the diverse behaviors of these Ce compounds. {copyright} {ital 1997} {ital The American Physical Society}

  1. Thermodynamic and Transport Properties of YTe3, LaTe3 and CeTe3

    SciTech Connect (OSTI)

    Ru, N.

    2011-08-19

    Measurements of heat capacity, susceptibility, and electrical resistivity are presented for single crystals of the charge density wave compounds YTe{sub 3}, LaTe{sub 3}, and CeTe{sub 3}. The materials are metallic to low temperatures, but have a small density of states due to the charge density wave gapping large portions of the Fermi surface. CeTe{sub 3} is found to be a weak Kondo lattice, with an antiferromagnetic ground state and T{sub N} = 2.8 K. The electrical resistivity of all three compounds is highly anisotropic, confirming the weak dispersion perpendicular to Te planes predicted by band structure calculations.

  2. Optical properties of the Ce and La ditelluride charge density wave compounds

    SciTech Connect (OSTI)

    Lavagnini, M.; Sacchetti, A.; Degiorgi, L.; Shin, K.Y.; Fisher, I.R.; /Stanford U., Geballe Lab. /Stanford U., Appl. Phys. Dept.

    2010-02-15

    The La and Ce di-tellurides LaTe{sub 2} and CeTe{sub 2} are deep in the charge-density-wave (CDW) ground state even at 300 K. We have collected their electrodynamic response over a broad spectral range from the far infrared up to the ultraviolet. We establish the energy scale of the single particle excitation across the CDW gap. Moreover, we find that the CDW collective state gaps a very large portion of the Fermi surface. Similarly to the related rare earth tri-tellurides, we envisage that interactions and Umklapp processes play a role in the onset of the CDW broken symmetry ground state.

  3. (U) Analysis of shock-initiated PBX-9501 through porous CeO2

    SciTech Connect (OSTI)

    Fredenburg, David A.; Dattelbaum, Dana Mcgraw; Dennis-Koller, Darcie

    2015-07-24

    The attenuation properties of an impact initiated PBX-9501 explosive through several thicknesses of CeO2 powder is investigated. The CeO2 is at an initial porous density of 4.0 g/cm3 , roughly 55 % of theoretical maximum density. Measurements of the input (into the powder) and propagated (through the powder) wave profiles are measured using optical velocimetry. Results show a reduction of the average wave speed, CX, and peak steady-state material velocity, uP , with increasing powder thickness from 1.5 - 5.0 mm.

  4. Switching of the Spin-Density-Wave in CeCoIn5 probed by Thermal

    Office of Scientific and Technical Information (OSTI)

    Conductivity (Conference) | SciTech Connect Switching of the Spin-Density-Wave in CeCoIn5 probed by Thermal Conductivity Citation Details In-Document Search Title: Switching of the Spin-Density-Wave in CeCoIn5 probed by Thermal Conductivity Authors: Kim, Duk Young [1] ; Lin, Shizeng [1] ; Weickert, Franziska [2] ; Bauer, Eric Dietzgen [1] ; Ronning, Filip [1] ; Thompson, Joe David [1] ; Movshovich, Roman [1] + Show Author Affiliations Los Alamos National Laboratory MPA-CMMS: CONDENSED MATTER

  5. Switching of the Spin-Density-Wave in CeCoIn5 probed by Thermal

    Office of Scientific and Technical Information (OSTI)

    Conductivity (Conference) | SciTech Connect Switching of the Spin-Density-Wave in CeCoIn5 probed by Thermal Conductivity Citation Details In-Document Search Title: Switching of the Spin-Density-Wave in CeCoIn5 probed by Thermal Conductivity × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information

  6. Magnetic properties of Ce{sup 3+} in Pb{sub 1{minus}x}Ce{sub x}Se: Kondo and crystal-field effect

    SciTech Connect (OSTI)

    Gratens, X.; Charar, S.; Averous, M.; Isber, S.; Deportes, J.; Golacki, Z.

    1997-10-01

    Electron paramagnetic resonance (EPR) experiments were performed on a Pb{sub 1{minus}x}Ce{sub x}Se crystal at liquid-helium temperatures and show very clearly that the doublet {Gamma}{sub 7} is the ground state for cerium ions. The cubic symmetry is shown and the effective Land{acute e} factor for the Ce{sup 3+} is determined to be 1.354{plus_minus}0.003. An orbital reduction factor is introduced to explain the g experimental value. High-field magnetization results are in good agreement with the EPR results. The nominal Ce composition in PbSe deduced from saturation of the magnetization, x=0.0405{plus_minus}0.0003, is very closed to the value determined by microprobe analysis (x=0.04). At 1.5 K, an antiferromagnetic interaction between the nearest-neighbor cerium atoms is found, J{sub ex}/k{sub B}={minus}0.715thinspK. The low-field magnetic-susceptibility results show that the magnetic moment of cerium impurities is strongly temperature dependent, explained by the presence of the crystal-field effect and the Kondo effect. {copyright} {ital 1997} {ital The American Physical Society}

  7. I&C Center

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of services to the office and the general public. These include public information, media relations, congressional, intergovernmental and tribal relations, public...

  8. The synthesis and optical property of solid-state-prepared YAG:Ce phosphor by a spray-drying method

    SciTech Connect (OSTI)

    Lee, H.-M.; Cheng, C.-C.; Huang, C.-Y.

    2009-05-06

    Ce{sup 3+}-activated yttrium aluminum garnet (Y{sub 3}Al{sub 5}O{sub 12}:Ce, YAG:Ce) powder as luminescent phosphor was synthesized by the solid-state reaction method. The phase identification, microstructure and photoluminescent properties of the products were investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), absorption spectrum and photoluminescence (PL) analysis. Spherical phosphor particle is considered better than irregular-shaped particle to improve PL property and application, so this phosphor was granulated into a sphere-like shape by a spray-drying device. After calcinating at 1500 deg. C for 0, 4, and 8 h, the product was identified as YAG and CeO{sub 2} phases. The CeO{sub 2} phase content is decreased by increasing the calcination time or decreasing the Ce{sup 3+} doping content. The product showed higher emission intensity resulted from more Ce{sup 3+} content and larger grain size. The product with CeO{sub 2} was found to have lower emission intensity. This paper presents the crystal structures of Rietveld refinement results of powder XRD data.

  9. Influence of Electron Doping on Magnetic Order in CeRu2Al10

    SciTech Connect (OSTI)

    Kobayashi, Riki; Kaneko, Koji; Saito, Kotaro; Mignot, Jean-Michel; Andre, Gilles; Robert, Julien; Wakimoto, Shuichi; Matsuda, Masaaki; Chi, Songxue; Haga, Yoshinori; Matsuda, Tatsuma; Yamamoto, Etsuji; Nishioka, Takashi; Tanida, Hiroshi; Sera, Masafumi

    2014-01-01

    The effect of electron doping by the substitution of Rh for Ru on unconventional magnetic order in CeRu2Al10 was investigated via neutron powder diffraction. In Ce(Ru1 xRhx)2Al10 with x = 0.05, 0.12, and 0.2, reorientation of the ordered moment from the c-axis as in pure CeRu2Al10 to the a-axis takes place in all samples, while the ordering vector q 0; 1; 0 remains unchanged within this concentration range. The moment reorientation is accompanied by an increase in its size by a factor of 2.4, from = 0.43 B at x = 0 to = 1.06, 1.04, and 1.02 B for x = 0.05, 0.12, and 0.2, respectively. The continuous decrease in the N el temperature T0(TN), despite an abrupt increase in , underlines the strong anisotropy in the exchange interaction in CeRu2Al10 and the fact that this anisotropy is easily suppressed by electron doping. 1.

  10. Phase transition and possible metallization in CeVO{sub 4} under pressure

    SciTech Connect (OSTI)

    Garg, Alka B.; Shanavas, K.V.; Wani, B.N.; Sharma, Surinder M.

    2013-07-15

    Phase stability of CeVO{sub 4} under pressure has been investigated using synchrotron based angle dispersive x-ray diffraction (ADXRD), electrical resistance and first principles calculations. The results indicate that the ambient zircon structure of the compound transforms to a low symmetry monoclinic monazite phase beyond 3.8 GPa with nearly 8.6% volume discontinuity. Beyond 11 GPa, the pattern could be fitted to a similar monazite structure which is about 12.7% denser and has a much larger monoclinic beta angle. On pressure release the first monoclinic phase is recovered. The electrical resistance data show a large drop in resistance with pressure indicating substantial narrowing down of the band gap. Electronic structure calculations support these observations and suggest possible pressure induced metallization in this material. - Pressure induced structural phase transition in CeVO{sub 4} as observed by x- ray diffraction (pressure vs. volume) and possible metallization in CeVO{sub 4} through electrical resistance and first principles electronic structure calculations. - Highlights: Structural and electrical behavior of CeVO{sub 4} under pressure studied using x-ray diffraction and electrical resistance measurements and first principles calculations. Two successive structural transitions confirmed by experiment and theory: zirconmonazite Imonazite II. Band gap collapse and possible metallization is indicated by electrical resistance measurements and electronic structure calculations under pressure. Novel observation of lower bulk modulus in the high pressure phase (both by experiment and calculations) explained through structural analysis.

  11. Charge dynamics of Ce-based compounds: Connection between the mixed valent and Kondo-insulator states

    SciTech Connect (OSTI)

    Bucher, B. [Laboratorium fuer Festkoerperphysik, Eidgenoessische Technische Hochschule Zuerich, 8093 Zuerich (Switzerland)] [Laboratorium fuer Festkoerperphysik, Eidgenoessische Technische Hochschule Zuerich, 8093 Zuerich (Switzerland); Schlesinger, Z. [IBM, Thomas J. Watson Research Center, Yorktown Heights, New York 10958 (United States)] [IBM, Thomas J. Watson Research Center, Yorktown Heights, New York 10958 (United States); Mandrus, D.; Fisk, Z.; Sarrao, J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); DiTusa, J.F.; Oglesby, C.; Aeppli, G.; Bucher, E. [AT& T Bell Laboratories, Murray Hill, New Jersey 07974 (United States)] [AT& T Bell Laboratories, Murray Hill, New Jersey 07974 (United States)

    1996-02-01

    The reflectivities of the mixed-valent compounds CeSn{sub 3} and CePd{sub 3} have been measured to obtain the optical conductivity as a function of temperature. Both compounds show a renormalization of the low-energy Drude conductivity at low temperatures. In addition, for the low-carrier-density compound CePd{sub 3}, but not for high-carrier-density CeSn{sub 3}, substantial spectral weight lost from the conductivity below 1000 cm{sup {minus}1} reappears in the frequency range 2000{endash}10000 cm{sup {minus}1}, indicating that CePd{sub 3} can be considered a lightly doped Kondo insulator. {copyright} {ital 1996 The American Physical Society.}

  12. (U) Equation of State and Compaction Modeling for CeO2

    SciTech Connect (OSTI)

    Fredenburg, David A.; Chisolm, Eric D.

    2014-10-20

    Recent efforts have focused on developing a solid-liquid and three-phase equation of state (EOS) for CeO2, while parallel experimental efforts have focused on obtaining high-fidelity Hugoniot measurements on CeO2 in the porous state. The current work examines the robustness of two CeO2 SESAME equations of state, a solid-liquid EOS, 96170, and a three-phase EOS, 96171, by validating the EOS against a suite of high-pressure shock compression experiments on initially porous CeO2. At lower pressures compaction is considered by incorporating a two-term exponential form of the P-compaction model, using three separate definitions for ?(P). Simulations are executed spanning the partially compacted and fully compacted EOS regimes over the pressure range 0.5 - 109 GPa. Comparison of calculated Hugoniot results with those obtained experimentally indicate good agreement for all definitions of ?(P) with both the solid-liquid and three-phase EOS in the low-pressure compaction regime. At higher pressures the three-phase EOS does a better job at predicting the measured Hugoniot response, though at the highest pressures EOS 96171 predicts a less compliant response than is observed experimentally. Measured material velocity profiles of the shock-wave after it has transmitted through the powder are also compared with those simulated using with solid-liquid and three-phase EOS. Profiles lend insight into limits of the current experimental design, as well as the threshold conditions for the shock-induced phase transition in CeO2.

  13. Synthesis and crystal structure of two new cerium rhodium oxides: Ce{sub 2/3-x}Rh{sup 3+}{sub 2}O{sub 4} (x{approx}0.12) with Ce mixed valency and Ce{sup 4+}Rh{sup 3+}{sub 2}O{sub 5}

    SciTech Connect (OSTI)

    Mizoguchi, Hiroshi; Zakharov, L.N.; Bhuvanesh, N.S.P.; Sleight, A.W.; Subramanian, M.A.

    2011-06-15

    The new compounds Ce{sub 2/3-x}Rh{sub 2}O{sub 4} (x{approx}0.11-0.14) and CeRh{sub 2}O{sub 5} have been prepared. Their structures were determined from single crystal X-ray diffraction data. Electrical and magnetic properties were also evaluated. Based on the structural analysis and physical properties, oxidation states for CeRh{sub 2}O{sub 5} can be assigned as Ce{sup 4+}Rh{sup 3+}{sub 2}O{sub 5}. A small variation in x was detected for Ce{sub 2/3-x}Rh{sub 2}O{sub 4} indicating a formula ranging from Ce{sup 3.64+}{sub 0.55}Rh{sup 3+}{sub 2}O{sub 4} to Ce{sup 3.81+}{sub 0.525}Rh{sup 3+}{sub 2}O{sub 4}. - Graphical abstract: The new compounds Ce{sub 2/3-x}Rh{sub 2}O{sub 4} (x{approx}0.11-0.14) and CeRh{sub 2}O{sub 5} have been prepared and their structures were determined from single crystal X-ray diffraction data. Electrical and magnetic properties were also evaluated. Highlights: > The new compounds CeRh{sub 2}O{sub 5} and Ce{sub 2/3-x}Rh{sub 2}O{sub 4} (x{approx}0.11-0.14) have been prepared. > Their structures were determined from single crystal X-ray diffraction data. > Valence picture is Ce{sup 4+}Rh{sup 3+}{sub 2}O{sub 5} and Ce{sup 3.64+}{sub 0.55}Rh{sup 3+}{sub 2}O{sub 4} to Ce{sup 3.81+}{sub 0.525}Rh{sup 3+}{sub 2}O{sub 4}.

  14. Magnitude of the magnetic exchange interaction in the heavy-fermion antiferromagnet CeRhIn5

    SciTech Connect (OSTI)

    Das, Pinaki; Lin, S. -Z.; Ghimire, N. J.; Huang, K.; Ronning, F.; Bauer, E. D.; Thompson, J. D.; Batista, C. D.; Ehlers, G.; Janoschek, M.

    2014-12-08

    We have used high-resolution neutron spectroscopy experiments to determine the complete spin wave spectrum of the heavy-fermion antiferromagnet CeRhIn?. The spin wave dispersion can be quantitatively reproduced with a simple frustrated J?-J? model that also naturally explains the magnetic spin-spiral ground state of CeRhIn? and yields a dominant in-plane nearest-neighbor magnetic exchange constant J?=0.74(3) meV. Our results lead the way to a quantitative understanding of the rich low-temperature phase diagram of the prominent CeTIn? (T = Co, Rh, Ir) class of heavy-fermion materials.

  15. Magnitude of the magnetic exchange interaction in the heavy-fermion antiferromagnet CeRhIn5

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Das, Pinaki; Lin, S. -Z.; Ghimire, N. J.; Huang, K.; Ronning, F.; Bauer, E. D.; Thompson, J. D.; Batista, C. D.; Ehlers, G.; Janoschek, M.

    2014-12-08

    We have used high-resolution neutron spectroscopy experiments to determine the complete spin wave spectrum of the heavy-fermion antiferromagnet CeRhIn₅. The spin wave dispersion can be quantitatively reproduced with a simple frustrated J₁-J₂ model that also naturally explains the magnetic spin-spiral ground state of CeRhIn₅ and yields a dominant in-plane nearest-neighbor magnetic exchange constant J₀=0.74(3) meV. Our results lead the way to a quantitative understanding of the rich low-temperature phase diagram of the prominent CeTIn₅ (T = Co, Rh, Ir) class of heavy-fermion materials.

  16. 2016 Energy Exchange (Providence, RI)

    Broader source: Energy.gov [DOE]

    The 2016 Energy Exchange in Providence, Rhode Island, will provide training to energy managers and sustainability professionals who are working to improve facility performance, advance the use of renewable energy, and reduce greenhouse gas emissions at federal sites.

  17. Training Session: East Greenwich, RI

    Broader source: Energy.gov [DOE]

    This 3.5-hour training provides builders with a comprehensive review of zero net-energy-ready home construction including the business case, detailed specifications, and opportunities to be...

  18. Reactivity and reaction intermediates for acetic acid adsorbed on CeO2(111)

    SciTech Connect (OSTI)

    Calaza, Florencia; Chen, Tsung-Liang; Mullins, David R; Xu, Ye; Overbury, Steven {Steve} H

    2015-01-01

    Adsorption and reaction of acetic acid on a CeO2(1 1 1) surface was studied by a combination of ultra-highvacuum based methods including temperature desorption spectroscopy (TPD), soft X-ray photoelectronspectroscopy (sXPS), near edge X-ray absorption spectroscopy (NEXAFS) and reflection absorption IRspectroscopy (RAIRS), together with density functional theory (DFT) calculations. TPD shows that thedesorption products are strongly dependent upon the initial oxidation state of the CeO2surface, includingselectivity between acetone and acetaldehyde products. The combination of sXPS and NEXAFS demon-strate that acetate forms upon adsorption at low temperature and is stable to above 500 K, above whichpoint ketene, acetone and acetic acid desorb. DFT and RAIRS show that below 500 K, bridge bondedacetate coexists with a moiety formed by adsorption of an acetate at an oxygen vacancy, formed bywater desorption.

  19. Reactivity and reaction intermediates for acetic acid adsorbed on CeO2(111)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Calaza, Florencia; Chen, Tsung-Liang; Mullins, David R; Xu, Ye; Overbury, Steven

    2015-01-01

    Adsorption and reaction of acetic acid on a CeO2(1 1 1) surface was studied by a combination of ultra-highvacuum based methods including temperature desorption spectroscopy (TPD), soft X-ray photoelectronspectroscopy (sXPS), near edge X-ray absorption spectroscopy (NEXAFS) and reflection absorption IRspectroscopy (RAIRS), together with density functional theory (DFT) calculations. TPD shows that thedesorption products are strongly dependent upon the initial oxidation state of the CeO2surface, includingselectivity between acetone and acetaldehyde products. The combination of sXPS and NEXAFS demon-strate that acetate forms upon adsorption at low temperature and is stable to above 500 K, above whichpoint ketene, acetone and acetic acid desorb.more » DFT and RAIRS show that below 500 K, bridge bondedacetate coexists with a moiety formed by adsorption of an acetate at an oxygen vacancy, formed bywater desorption.« less

  20. Single to Multiquasiparticle Excitations in the Itinerant Helical Magnet CeRhIn5

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Stock, C.; Rodriguez-Rivera, J. A.; Schmalzl, K.; Rodriguez, E. E.; Stunault, A.; Petrovic, C.

    2015-06-19

    Neutron scattering is used to measure the quantum spin fluctuations in CeRhIn5 - the parent material of the eXIn5 superconducting series. Out-of-plane spin fluctuations are gapped and localized in momentum, similar to the spin excitons in CeCoIn5. The in-plane fluctuations consist of sharp spin-wave excitations parameterized by a nearest neighbor exchange JRKKY =0.88 ± 0.05 meV that crossover to a temporally and spatially broad multiparticle spectrum with energies of ~ 2 × JRKKY . This continuum represents composite fluctuations that illustrate the breakdown of single magnons originating from the delicate energy balance between localized 4f and itinerant behavior in amore » heavy metal. The experiment therefore shows how quasiparticle behavior is changed by the close proximity of quantum criticality.« less

  1. Single to Multiquasiparticle Excitations in the Itinerant Helical Magnet CeRhIn5

    SciTech Connect (OSTI)

    Stock, C.; Rodriguez-Rivera, J. A.; Schmalzl, K.; Rodriguez, E. E.; Stunault, A.; Petrovic, C.

    2015-06-19

    Neutron scattering is used to measure the quantum spin fluctuations in CeRhIn5 - the parent material of the eXIn5 superconducting series. Out-of-plane spin fluctuations are gapped and localized in momentum, similar to the spin excitons in CeCoIn5. The in-plane fluctuations consist of sharp spin-wave excitations parameterized by a nearest neighbor exchange JRKKY =0.88 ± 0.05 meV that crossover to a temporally and spatially broad multiparticle spectrum with energies of ~ 2 × JRKKY . This continuum represents composite fluctuations that illustrate the breakdown of single magnons originating from the delicate energy balance between localized 4f and itinerant behavior in a heavy metal. The experiment therefore shows how quasiparticle behavior is changed by the close proximity of quantum criticality.

  2. Momentum-resolved photoemission of the Kondo peak in an ordered Ce-containing alloy

    SciTech Connect (OSTI)

    Garnier, M.; Purdie, D.; Breuer, K.; Hengsberger, M.; Baer, Y.

    1997-11-01

    A comparison of uv-photoemission spectra recorded from the surface alloys Pt(111)({radical}(3){times}{radical}(3))R30{degree}Ce and Pt(111)(2{times}2)La allows the contribution from the 4f electrons to be seen easily. The valence-band structure of these two surfaces is very similar, and the most obvious 4f contribution in high-resolution photoemission spectra of the Ce-containing alloy is the tail of the Kondo peak cut at E{sub F}. Within the limits of our measurement, no dispersion of this feature in the occupied regime is detected. The Kondo peak displays a marked intensity dependence on the emission angle, suggesting that hybridization is present in only a limited part of reciprocal space. The temperature dependence of this near-E{sub F} feature supports this interpretation. {copyright} {ital 1997} {ital The American Physical Society}

  3. Investigation into Nanostructured Lanthanum Halides and CeBr{sub 3} for Nuclear Radiation Detection

    SciTech Connect (OSTI)

    Guss, P., Guise, R., Mukhopadhyay, S., Yuan, D.

    2011-06-22

    This slide-show presents work on radiation detection with nanostructured lanthanum halides and CeBr{sub 3}. The goal is to extend the gamma energy response on both low and high-energy regimes by demonstrating the ability to detect low-energy x-rays and relatively high-energy activation prompt gamma rays simultaneously using the nano-structured lanthanum bromide, lanthanum fluoride, cerium bromide, or other nanocrystal material. Homogeneous and nano structure cases are compared.

  4. Neutron Scattering of CeNi at the Spallation Neutron Source at Oak Ridge

    Office of Scientific and Technical Information (OSTI)

    National Laboratory: A Preliminary Report (Conference) | SciTech Connect Spallation Neutron Source at Oak Ridge National Laboratory: A Preliminary Report Citation Details In-Document Search Title: Neutron Scattering of CeNi at the Spallation Neutron Source at Oak Ridge National Laboratory: A Preliminary Report Authors: Tobin, J G ; Mirmelstein, A V ; Podlesnyak, A ; Kolesnikov, A I Publication Date: 2014-01-16 OSTI Identifier: 1132009 Report Number(s): LLNL-PROC-649216 DOE Contract Number:

  5. Synthesis of Transient Climate Evolution of the last 21-kyr (SynTraCE-21)

    SciTech Connect (OSTI)

    Zhengyu Liu

    2011-05-06

    Climate evolution in the last 21,000 years provides critical observations for testing state-of-the-art climate models on the simulation of climate evolution and abrupt climate changes. Proxy evidences and new modeling activities have led to rapid advances in our understanding of climate change for this past time period. This funding helps to support the first international SynTraCE-21k workshop at Mount Hood, Oregon from 10-13 October, 2010.

  6. Influence of Electron Doping on Magnetic Order in CeRu2Al10

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kobayashi, Riki; Kaneko, Koji; Saito, Kotaro; Mignot, Jean-Michel; André, Gilles; Robert, Julien; Wakimoto, Shuichi; Matsuda, Masaaki; Chi, Songxue; Haga, Yoshinori; et al

    2014-09-17

    The effect of electron doping by the substitution of Rh for Ru on unconventional magnetic order in CeRu2Al10 was investigated via neutron powder diffraction. In Ce(Ru1-xRhx)2Al10 with x = 0.05, 0.12, and 0.2, reorientation of the ordered moment from the c- to the a-axis takes place in all samples, while the ordering vector q=(0 1 0) remains unchanged within this concentration range. The moment reorientation is accompanied by an enhancement in its size by a factor of ~2.4, from μ=0.43 μB at x=0 to μ =1.06, 1.04, and 1.02 μB for x=0.05, 0.12 and 0.2, respectively. The continuous decrease inmore » N´eel temperature T0(TN), despite an abrupt increase in μ , underlines the strong anisotropy in the exchange interaction in CeRu2Al10, and the fact that this anisotropy is easily suppressed by electron doping.« less

  7. Remarkably robust and correlated coherence and antiferromagnetism in (Ce1-x Lax)Cu?Ge?

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hodovanets, H.; Budko, S.? L.; Straszheim, W.? E.; Taufour, V.; Mun, E.? D.; Kim, H.; Flint, R.; Canfield, P.? C.

    2015-06-08

    We present magnetic susceptibility, resistivity, specific heat, and thermoelectric power measurements on (Ce1-x Lax)Cu?Ge? single crystals (0 ? x ? 1). With La substitution, the antiferromagnetic temperature TN is suppressed in an almost linear fashion and moves below 0.36 K, the base temperature of our measurements for x > 0.8. Surprisingly, in addition to robust antiferromagnetism, the system also shows low temperature coherent scattering below Tcoh up to ~ 0.9 of La, indicating a small percolation limit ~ 9% of Ce. Tcoh as a function of magnetic field was found to have different behavior for x more> 0.9. Remarkably, (Tcoh) at H = 0 was found to be linearly proportional to TN. The jump in the magnetic specific heat ?Cm at TN as a function of TK/TN for (Ce1-x Lax)Cu?Ge? follows the theoretical prediction based on the molecular field calculation for the S = 1/2 resonant level model.less

  8. Emission properties and back-bombardment for CeB{sub 6} compared to LaB{sub 6}

    SciTech Connect (OSTI)

    Bakr, Mahmoud; Kawai, M.; Kii, T.; Zen, H.; Masuda, K.; Ohgaki, H.

    2015-02-14

    The emission properties of CeB{sub 6} compared to LaB{sub 6} thermionic cathodes have been measured using an electrostatic DC gun. Obtaining knowledge of the emission properties is the first step in understanding the back-bombardment effect that limits wide usage of thermionic radio-frequency electron guns. The effect of back-bombardment electrons on CeB{sub 6} compared to LaB{sub 6} was studied using a numerical simulation model. The results show that for 6 μs pulse duration with input radio-frequency power of 8 MW, CeB{sub 6} should experience 14% lower temperature increase and 21% lower current density rise compared to LaB{sub 6}. We conclude that CeB{sub 6} has the potential to become the future replacement for LaB{sub 6} thermionic cathodes in radio-frequency electron guns.

  9. Soft chemistry synthesis of high-crystalline orthogermanate CeGeO{sub 4}: A new photocatalyst

    SciTech Connect (OSTI)

    Xing Jun; Yang Chen; Li Weikun; Gong Xueqing; Yang Huagui

    2013-01-15

    A new orthogermanate phase of CeGeO{sub 4} was studied and the corresponding nanocrystals have been successfully synthesized via a facile hydrothermal method without adding any capping agent. The pH value of the solution and the reaction time were also further investigated, respectively. The as-prepared CeGeO{sub 4} nanocrystals with a uniform size of 15 nm have been characterized by using XRD/TEM/TGA/UV-vis techniques, and their electronic structures and band gap were calculated based on a plane wave density function theory (DFT). The promising photocatalytic properties of CeGeO{sub 4} have been confirmed through monitoring reactive oxidative species generated in photocatalytic reactions of terephthalic acid as a fluorescence probe. - Graphical Abstract: A novel photocatalyst CeGeO{sub 4} was prepared. Highlights: Black-Right-Pointing-Pointer CeGeO{sub 4} as a novel photocatalyst was successfully synthesized by a hydrothermal method. Black-Right-Pointing-Pointer Electronic structure and band gap were calculated based on DFT. Black-Right-Pointing-Pointer CeGeO{sub 4} exhibited a promising photocatalytic performance.

  10. Kondo behavior, ferromagnetic correlations, and crystal fields in the heavy Fermion compounds Ce3X (X=In, Sn)

    SciTech Connect (OSTI)

    Wang, C. H.; Lawrence, J. M.; Christianson, Andrew D; Goremychkin, E. A.; Fanelli, V. R.; Gofryk, K.; Bauer, E. D.; Ronning, F.; Thompson, J. D.; De Souza, N. R.; Kolesnikov, Alexander I

    2010-01-01

    We report measuerments of the inelastic neutron scattering, the magnetic susceptibility, the magnetization, and the magnetic field dependence of the specific heat for the heavy Fermion compounds Ce3In and Ce3Sn. The neutron scattering results show that the excited crystal field levels have energies E1=13.2 meV, E2-44.8 meV for Ce3In and E1=18.5 meV, E2=36.1 meV for Ce3Sn. The Kondo temperature deduced from the quasielastic linewidth is 17 K for Ce3In and 40 K for Ce3Sn. The low temperature behavior of teh specific heat, magnetization, and susceptibility can not be well-described by J=1.2 Kondo physics alone, but require calculations that include contributions from the Kondo effect, broadened crystal fields, and ferromagnetic correlations, all of which are known to be important in these compounds. We find that the ferromagnetic fluctuation makes a 10-15% contribution to the ground state entropy and magnetization. The large in this heavy Fermion system thus arises more from the ferromagnetic correlations than from the Kondo behavior.

  11. Effect of oxygen vacancy on half metallicity in Ni-doped CeO{sub 2} diluted magnetic semiconductor

    SciTech Connect (OSTI)

    Saini, Hardev S. Saini, G. S. S.; Singh, Mukhtiyar; Kashyap, Manish K.

    2015-05-15

    The electronic and magnetic properties of Ni-doped CeO{sub 2} diluted amgentic semiconductor (DMS) including the effect of oxygen vacancy (V{sub o}) with doping concentration, x = 0.125 have been calculated using FPLAPW method based on Density Functional Theory (DFT) as implemented in WIEN2k. In the present supercell approach, the XC potential was constructed using GGA+U formalism in which Coulomb correction is applied to standard GGA functional within the parameterization of Perdew-Burke-Ernzerhof (PBE). We have found that the ground state properties of bulk CeO{sub 2} compound have been modified significantly due to the substitution of Ni-dopant at the cation (Ce) site with/without V{sub O} and realized that the ferromagnetism in CeO{sub 2} remarkably depends on the V{sub o} concentrations. The presence of V{sub o}, in Ni-doped CeO{sub 2}, can leads to strong ferromagnetic coupling between the nearest neighboring Ni-ions and induces a HMF in this compound. Such ferromagnetic exchange coupling is mainly attributed to spin splitting of Ni-d states, via electrons trapped in V{sub o}. The HMF characteristics of Ni-doped CeO{sub 2} including V{sub o} makes it an ideal material for spintronic devices.

  12. High thermoelectric performance of In, Yb, Ce multiple filled CoSb{sub 3} based skutterudite compounds

    SciTech Connect (OSTI)

    Ballikaya, Sedat; Department of Physics, University of Michigan, Ann Arbor, MI, 48109 ; Uzar, Neslihan; Yildirim, Saffettin; Salvador, James R.; Uher, Ctirad

    2012-09-15

    Filling voids with rare earth atoms is an effective way to lowering thermal conductivity which necessarily enhances thermoelectric properties of skutterudite compounds. Yb atom is one of the most effective species among the rare earth atoms for filling the voids in the skutterudite structure due to a large atomic mass, radius and it is intermediate valence state. In this work, we aim to find the best filling partners for Yb using different combinations of Ce and In as well as to optimize actual filling fraction in order to achieve high values of ZT. The traditional method of synthesis relying on melting-annealing and followed by spark plasma sintering was used to prepare all samples. The thermoelectric properties of four samples of Yb{sub 0.2}In{sub 0.2}Co{sub 4}Sb{sub 12}, Yb{sub 0.2}Ce{sub 0.15}Co{sub 4}Sb{sub 12}, Yb{sub 0.2}Ce{sub 0.15}In{sub 0.2}Co{sub 4}Sb{sub 12}, and Yb{sub 0.3}Ce{sub 0.15}In{sub 0.2}Co{sub 4}Sb{sub 12} (nominal) were examined based on the Seebeck coefficient, electrical conductivity, thermal conductivity, and Hall coefficient. Hall coefficient and Seebeck coefficient signs confirm that all samples are n-type skutterudite compounds. Carrier density increases with the increasing Yb+Ce content. A high power factor value of 57.7 {mu}W/K{sup 2}/cm for Yb{sub 0.2}Ce{sub 0.15}Co{sub 4}Sb{sub 12} and a lower thermal conductivity value of 2.82 W/m/K for Yb{sub 0.2}Ce{sub 0.15}In{sub 0.2}Co{sub 4}Sb{sub 12} indicate that small quantities of Ce with In may be a good partner to Yb to reduce the thermal conductivity further and thus enhance the thermoelectric performance of skutterudites. The highest ZT value of 1.43 was achieved for Yb{sub 0.2}Ce{sub 0.15}In{sub 0.2}Co{sub 4}Sb{sub 12} triple-filled skutterudite at 800 K. - Graphical abstract: Thermoelectric figure of merit of Yb{sub x}In{sub y}Ce{sub z}Co{sub 4}Sb{sub 12} (0{<=}x,y,z{<=}0.18 actual) compounds versus temperature. Highlights: Black-Right-Pointing-Pointer TE properties of Yb,In,Ce multiple-filled Yb{sub x}In{sub y}Ce{sub z}Co{sub 4}Sb{sub 12} skutterudites were investigated. Black-Right-Pointing-Pointer Thermal conductivity is strongly suppressed by multiple filling of Yb, Ce and In. Black-Right-Pointing-Pointer Small amounts of Ce and In with Yb are beneficial for the enhancement of TE performance. Black-Right-Pointing-Pointer The highest ZT=1.43 was achieved with Yb{sub 0.07}In{sub 0.094}Ce{sub 0.065}Co{sub 4}Sb{sub 11.92} at 800 K.

  13. Lattice, Ce-L{sub 3}valence, transport, and magnetic results on mixed-valent/Kondo system Ce{sub 1{minus}x}La{sub x}Mn{sub 2}Si{sub 2}

    SciTech Connect (OSTI)

    Liang, G.; Xi, H.; Roberts, E.; Binford, T.; Mochizuki, K.; Markert, J.T.; Croft, M.

    1997-04-01

    Lattice, Ce-L{sub 3} edge, resistivity, and magnetic susceptibility measurements have been carried out on the polycrystalline Ce{sub 1{minus}x}La{sub x}Mn{sub 2}Si{sub 2} system (0{le}x{le}1) to study the interplay between Mn 3d-host magnetism and Kondo-type Ce-spin fluctuations. As x increases, the system varies gradually from a Ce mixed-valent system with 3d-host antiferromagnetism (at x=0) to a nearly trivalent system with strong 3d-host ferromagnetism (near x=1). In the antiferromagnetic (AF) phase region (0{le}x{le}0.5), the Neel temperature T{sub N} decreases with the increase of x, manifesting the weakening of the host AF field. Impurity Kondo behavior is observed at x=0.05, indicating that the low-temperature coherence state in CeMn{sub 2}Si{sub 2} can be destroyed by {open_quotes}Kondo holes{close_quotes} which are created by very small substitution of La for Ce. The susceptibility and resistivity results suggest that the impurity Kondo effect in the 0.1{le}x{le}0.5 samples is partially suppressed by a nonvanishing ferromagnetic (FM) field component; whereas the phononlike behavior of the resistivity curves in the Mn-host FM-phase region (0.5{lt}x{le}1.0) supports our previous proposal that the Kondo-type Ce-spin fluctuations can be effectively quenched by a strong 3d-host FM field. {copyright} {ital 1997 American Institute of Physics.}

  14. Optical properties of {gamma}- and {alpha}-Ce by spectroscopic ellipsometry

    SciTech Connect (OSTI)

    Joo Yull, Rhee

    1992-07-20

    A rotating analyzer type ellipsometer with an ultra high vacuum sample chamber was built. The dielectric functions of {gamma}- and {alpha}-Ce were measured in the energy range from 1.5 to 5.4 eV to investigate the role of the 4f electron in the isostructural phase transition. {gamma}- and {alpha}-Ce were made by evaporation of Ce on sapphire substrates at room temperature and 25 K. All measurements were performed inside a UHV chamber at pressures lower than l {times} 10{sup {minus}10}Torr. The measured dielectric functions showed a thickness dependence. The thicker sample has the smaller optical conductivities. Both overlayer thickness and void fraction increase as sample thickness increases. Repeating cooling-heating-cooling or heating-cooling-heating cycles causes the sample surface to become rougher but the relative volume fractions of both phases and the void fraction in the bulk remain unchanged. The optical conductivity increases upon entering the a-phase but the number of electrons per atom, N{sub eff}/N{sub A}, contributing to the optical conductivity does not change. The valence electrons lose oscillator strength in the above energy range due to volume collapse. This reduces N{sub eff}/NA but the increased 4f-sd valence band hybridization exactly compensates the reduced oscillator strength. Therefore the net effects of the {gamma}{yields}{alpha} isostructural phase transition are an increase of optical conductivity and constancy of N{sub eff}/N{sub A}.

  15. Surface-structure sensitivity of CeO2 nanocrystals in photocatalysis and enhancing the reactivity with nanogold

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lei, Wanying; Zhang, Tingting; Gu, Lin; Liu, Ping; Rodriguez, José A.; Liu, Gang; Liu, Minghua

    2015-06-19

    Structure–function correlations are a central theme in heterogeneous (photo)catalysis. In this research, using aberration-corrected scanning transmission electron microscopy (STEM), the atomic surface structures of well-defined one-dimensional (1D) CeO2 nanorods (NRs) and 3D nanocubes (NCs) are directly visualized at subangstrom resolution. CeO2 NCs predominantly expose the {100} facet, with {110} and {111} as minor cutoff facets at the respective edges and corners. Notably, the outermost surface layer of the {100} facet is nearly O-terminated. Neither surface relaxations nor reconstructions on {100} are observed, indicating unusual polarity compensation, which is primarily mediated by near-surface oxygen vacancies. The surface of CeO2 NRs ismore » highly stepped, with the enclosed {110} facet exposing Ce cations and O anions on terraces. On the basis of STEM profile-view imaging and electronic structure analysis, the photoreactivity of CeO2 nanocrystals toward aqueous methyl orange degradation under UV is revealed to be surface-structure-sensitive, following the order: {110} >> {100}. The underlying surface-structure sensitivity can be attributed to the variation in low-coordinate surface cerium cations between {110} and {100} facets. To further enhance light absorption, Au nanoparticles (NPs) are deposited on CeO2 NRs to form Au/CeO2 plasmonic nanocomposites, which dramatically promotes the photoreactivity that is Au particle size- and excitation light wavelength-dependent. The mechanisms responsible for the enhancement of photocatalytic activity are discussed, highlighting the crucial role of photoexcited charge carrier transfer.« less

  16. Kondo-lattice behavior and multiple characteristic temperatures in CeIr{sub 2}Ge{sub 2}

    SciTech Connect (OSTI)

    Mallik, R.; Sampathkumaran, E.V.; Paulose, P.L.; Dumschat, J.; Wortmann, G.

    1997-02-01

    The results of electrical-resistivity {rho} measurements (1.4{endash}300 K) on the alloys, Ce{sub 1{minus}x}La{sub x}Ir{sub 2}Ge{sub 2} (0{le}x{le}1), CeIr{sub 2{minus}x}(Rh,Pt){sub x}Ge{sub 2} (x=0.2 and 0.4), and CeIr{sub 2}Ge{sub 2{minus}x}(Si,Sn){sub x} (x=0.2 and 0.4), are reported in order to understand the Kondo effect in CeIr{sub 2}Ge{sub 2}. There is a significant decrease in {rho} as the temperature is lowered from 100 to 4.2 K for x = 0.0. This feature disappears for a small replacement of Ce by La (x = 0.3), thereby resulting in a single-ion Kondo effect for higher values of x. This finding establishes that the temperature T{sub coh}, characterizing the coherent scattering among the Kondo centers for x=0 is as large as about 100 K. The coherent scattering is not destroyed by small substitutions at the Ir or Ge site. The observed sensitivity of this coherence effect to a small disruption of Ce sublattice periodicity alone by La substitution is uncommon among trivalent Ce alloys. Such a large T{sub coh} value enables us to emphasize the need to invoke three characteristic temperatures for nonmagnetic Kondo lattices. {copyright} {ital 1997} {ital The American Physical Society}

  17. Surface-structure sensitivity of CeO2 nanocrystals in photocatalysis and enhancing the reactivity with nanogold

    SciTech Connect (OSTI)

    Lei, Wanying; Zhang, Tingting; Gu, Lin; Liu, Ping; Rodriguez, José A.; Liu, Gang; Liu, Minghua

    2015-06-19

    Structure–function correlations are a central theme in heterogeneous (photo)catalysis. In this research, using aberration-corrected scanning transmission electron microscopy (STEM), the atomic surface structures of well-defined one-dimensional (1D) CeO2 nanorods (NRs) and 3D nanocubes (NCs) are directly visualized at subangstrom resolution. CeO2 NCs predominantly expose the {100} facet, with {110} and {111} as minor cutoff facets at the respective edges and corners. Notably, the outermost surface layer of the {100} facet is nearly O-terminated. Neither surface relaxations nor reconstructions on {100} are observed, indicating unusual polarity compensation, which is primarily mediated by near-surface oxygen vacancies. The surface of CeO2 NRs is highly stepped, with the enclosed {110} facet exposing Ce cations and O anions on terraces. On the basis of STEM profile-view imaging and electronic structure analysis, the photoreactivity of CeO2 nanocrystals toward aqueous methyl orange degradation under UV is revealed to be surface-structure-sensitive, following the order: {110} >> {100}. The underlying surface-structure sensitivity can be attributed to the variation in low-coordinate surface cerium cations between {110} and {100} facets. To further enhance light absorption, Au nanoparticles (NPs) are deposited on CeO2 NRs to form Au/CeO2 plasmonic nanocomposites, which dramatically promotes the photoreactivity that is Au particle size- and excitation light wavelength-dependent. The mechanisms responsible for the enhancement of photocatalytic activity are discussed, highlighting the crucial role of photoexcited charge carrier transfer.

  18. Structure and magnetic properties of Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15}, a new 10H-polytype in the Ba-Ce-Mn-O system

    SciTech Connect (OSTI)

    Macias, Mario A.; Mentre, Olivier; Cuello, Gabriel J.; Gauthier, Gilles H.

    2013-02-15

    Based on the peculiar magnetic properties that are observed in pseudo one-dimensional manganites, we decided to synthesize the new Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15} compound. The preparation was performed by solid state reaction in air at about 1350 Degree-Sign C, for which we found that the compound crystallizes in a hexagonal symmetry with space group P6{sub 3}/mmc (No-194) and cell parameters a=b=5.7861(2) A and c=23.902(1) A. The structural description was correlated with neutron diffraction and bond valence calculations, confirming the presence of Ce{sup 4+} and Mn{sup 4+} segregated in the different crystallographic positions. Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15} displays evidence for strong AFM couplings already set at room temperature. The main arrangement of Mn{sup 4+} in magnetically isolated tetramers of face-sharing octahedra is responsible for a metamagnetic-like transition around 50 K. - Graphical abstract: The new Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15} polytype shows strong AFM couplings in magnetically isolated [Ce{sub 0.25}Mn{sub 3.75}O{sub 15}] tetramers of face-sharing octahedral, resulting in a metamagnetic-like transition around 50 K. Highlights: Black-Right-Pointing-Pointer Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15}, a new 10H polytype, has been prepared in the Ba-Ce-Mn-O system. Black-Right-Pointing-Pointer The compound crystallizes in the P6{sub 3}/mmc space group with (cchhh){sub 2} stacking sequence. Black-Right-Pointing-Pointer [Ce{sub 0.25}Mn{sub 3.75}O{sub 15}] tetramers are separated by [CeO{sub 6}] octahedra in the structure. Black-Right-Pointing-Pointer Instead of robust AFM ordering, a metamagnetic-like transition is found around 50 K.

  19. Microsoft Word - Ce-CH3X ms-revised.doc

    Office of Scientific and Technical Information (OSTI)

    
 1
 Hydrogen for X-group exchange in CH 3 X, X = Cl, Br, I, OMe and NMe 2 by Monomeric [1,2,4-(Me 3 C) 3 C 5 H 2 ] 2 CeH: Experimental and Computational Support for a Carbenoid Mechanism Evan L. Werkema a , Richard A. Andersen* a , Ahmed Yahia b , Laurent Maron* b and Odile Eisenstein* c a) Department of Chemistry, University of California, Berkeley, California 94720- 1460, b) Université de Toulouse, INSA, UPS, LPCNO, 135 avenue de Rangueil, 31077 Toulouse, France, and CNRS, 31077

  20. Disorder and size effects on Kondo interactions and magneticcorrelations in CePt2 nanoscrystals

    SciTech Connect (OSTI)

    Chen, Y.Y.; Huang, P.H.; Ou, M.N.; Wang, C.R.; Yao, Y.D.; Lee,T.K.; Ho, M.Y.; Lawrence, J.M.; Booth, C.H.

    2006-12-12

    The evolution of the Kondo effect and magnetic correlations with size reduction in CePt{sub 2} nanoparticles (3.1-26 nm) is studied by analysis of the temperature-dependent specific heat and magnetic susceptibility. The antiferromagnetic correlations diminish with size reduction. The Kondo effect predominates at small particle size with trivalent, small Kondo temperature (T{sub K}) magnetic regions coexisting with strongly mixed valent, large T{sub K} nonmagnetic regions. We discuss the role of structural disorder, background density of states and the electronic quantum size effect on the results.

  1. Nanostructured LaF{sub 3}:Ce Quantum Dot Nuclear Radiation Detector

    SciTech Connect (OSTI)

    Guss, P., Guise, R., Reed, M., Mukhopadhyay, S., Yuan, D.

    2010-11-01

    Many radioactive isotopes have low energy X-rays and high energy gamma rays of interest for detection. The goal of the work presented was to demonstrate the possibility of measuring both low-energy X-rays and relatively high-energy gamma rays simultaneously using the nano-structured lanthanum bromide, lanthanum fluoride, or cerium bromide. The key accomplishments of the project was the building and acquisition of the LaF3:Ce nanocomposite detectors. Nanocomposite detectors are sensitive to {gamma}s as well as ns and X-rays.

  2. Analysis of FEL-based CeC amplification at high gain limit

    SciTech Connect (OSTI)

    Wang, G.; Litvinenko, V.; Jing, Y.

    2015-05-03

    An analysis of Coherent electron Cooling (CeC) amplifier based on 1D Free Electron Laser (FEL) theory was previously performed with exact solution of the dispersion relation, assuming electrons having Lorentzian energy distribution. At high gain limit, the asymptotic behavior of the FEL amplifier can be better understood by Taylor expanding the exact solution of the dispersion relation with respect to the detuning parameter. In this work, we make quadratic expansion of the dispersion relation for Lorentzian energy distribution and investigate how longitudinal space charge and electrons’ energy spread affect the FEL amplification process.

  3. Digital I&C systems in nuclear power plants. Risk-screening of environmental stressors and a comparison of hardware unavailability with an existing analog system

    SciTech Connect (OSTI)

    Hassan, M.; Vesely, W.E.

    1998-01-01

    In this report, we present a screening study to identify environmental stressors for digital instrumentation and control (I&C) systems in a nuclear power plant (NPP) which can be potentially risk-significant, and compare the hardware unavailability of such a system with that of its existing analog counterpart. The stressors evaluated are temperature, humidity, vibration, radiation, electro-magnetic interference (EMI), and smoke. The results of risk-screening for an example plant, subject to some bounding assumptions and based on relative changes in plant risk (core damage frequency impacts of the stressors), indicate that humidity, EMI from lightning, and smoke can be potentially risk-significant. Risk from other sources of EMI could not be evaluated for a lack of data. Risk from temperature appears to be insignificant as that from the assumed levels of vibrations. A comparison of the hardware unavailability of the existing analog Safety Injection Actuation System (SIAS) in the example plant with that of an assumed digital upgrade of the system indicates that system unavailability may be more sensitive to the level of redundancy in elements of the digital system than to the environmental and operational variations involved. The findings of this study can be used to focus activities relating to the regulatory basis for digital I&C upgrades in NPPs, including identification of dominant stressors, data-gathering, equipment qualification, and requirements to limit the effects of environmental stressors. 30 refs., 8 figs., 26 tabs.

  4. Pulse studies to decipher the role of surface morphology in CuO/CeO₂ nanocatalysts for the water gas shift reaction

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rodriguez, Jose A.; Zhao, Fuzhen; Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Si, Rui; Johnston-Peck, Aaron C.; Martinez-Arias, Arturo; Hanson, Jonathan C.; Senanayake, Sanjaya D.

    2015-01-23

    The water-gas shift reaction (WGS, CO + H₂O → CO₂) was studied over CuO/CeO₂ catalysts with two different ceria particle morphohologies, in the form of nanospheres (ns) and nanocubes (nc). To understand the strong dependence of the WGS reaction activity on the ceria nanoshapes, pulses of CO (without and with water vapor) were employed during in situ X-ray diffraction (XRD) and X-ray absoprtion near edge structure (XANES) measurements done to characterize the catalysts. The results showed that CuO/CeO₂ (ns) exhibited a substantially better activity than CuO/CeO₂ (nc). The higher activity was associated with the unique properties of CuO/CeO₂ (ns), suchmore » as the easier reduction of highly dispersed CuO to metallic Cu, the stability of metallic Cu and a larger concentration Ce³⁺ in CeO₂ (ns).« less

  5. Pulse studies to decipher the role of surface morphology in CuO/CeO₂ nanocatalysts for the water gas shift reaction

    SciTech Connect (OSTI)

    Rodriguez, Jose A.; Zhao, Fuzhen; Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Si, Rui; Johnston-Peck, Aaron C.; Martinez-Arias, Arturo; Hanson, Jonathan C.; Senanayake, Sanjaya D.

    2015-01-23

    The water-gas shift reaction (WGS, CO + H₂O → CO₂) was studied over CuO/CeO₂ catalysts with two different ceria particle morphohologies, in the form of nanospheres (ns) and nanocubes (nc). To understand the strong dependence of the WGS reaction activity on the ceria nanoshapes, pulses of CO (without and with water vapor) were employed during in situ X-ray diffraction (XRD) and X-ray absoprtion near edge structure (XANES) measurements done to characterize the catalysts. The results showed that CuO/CeO₂ (ns) exhibited a substantially better activity than CuO/CeO₂ (nc). The higher activity was associated with the unique properties of CuO/CeO₂ (ns), such as the easier reduction of highly dispersed CuO to metallic Cu, the stability of metallic Cu and a larger concentration Ce³⁺ in CeO₂ (ns).

  6. Nickel deficiency in RENi2-xP2 (RE=La, Ce, Pr). Combined crystallographic and physical property studies

    SciTech Connect (OSTI)

    Bauer, Eric D; Ronning, Filip; Thompson, Joe D; Sarrao, John L; Bobev, S; Xia, S

    2008-01-01

    Large single crystals from RENi{sub 2-x}P{sub 2} (RE = La, Ce, Pr) were synthesized from the pure elements using Sn as a metal flux, and their structures were established by X-ray crystallography. The title compounds were confirmed to crystallize in the body-centered tetragonal ThCr{sub 2}Si{sub 2} structure type (space group I4/mmm (No. 139); Pearson's symbol tI10), but with a significant stoichiometry breadth with respect to the transition metal. Systematic synthetic work, coupled with accurate structure refinements indicated strong correlation between the degree of Ni-deficiency and the reaction conditions. For four different PrNi{sub 2-x}P{sub 2} (x {le} 0.5) samples, temperature dependent dc magnetization measurements indicated typical local moment 4f-magnetism and a stable Pr{sup 3+} ground state. Field-dependent heat capacity data confirmed a ferromagnetic order at low temperature, and the variations of T{sub c} with the concentration of Ni defects are discussed. LaNi{sub 2-x}P{sub 2}, as expected was found to be Pauli-like paramagnetic in the studied temperature regime, while the Ce-analog CeNi{sub 2-x}P{sub 2} (x = 0.28(1)) showed the characteristics of a mixed valent Ce{sup 3+}/Ce{sup 4+} system with a possible Kondo temperature on the order of 230 K.

  7. High thermal stability of La2O3 and CeO2-stabilized tetragonal ZrO2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wang, Shichao; Xie, Hong; Lin, Yuyuan; Poeppelmeier, Kenneth R.; Li, Tao; Winans, Randall E.; Cui, Yanran; Ribeiro, Fabio H.; Canlas, Christian P.; Elam, Jeffrey W.; et al

    2016-02-15

    Catalyst support materials of tetragonal ZrO2, stabilized by either La2O3 (La2O3-ZrO2) or CeO2 (CeO2-ZrO2), were synthesized under hydrothermal conditions at 200 °C with NH4OH or tetramethylammonium hydroxide as the mineralizer. From In Situ synchrotron powder X-ray diffraction and small-angle X-ray scattering measurements, the calcined La2O3-ZrO2 and CeO2-ZrO2 supports were nonporous nanocrystallites that exhibited rectangular shapes with thermal stability up to 1000 °C in air. These supports had an average size of ~10 nm and a surface area of 59-97 m2/g. The catalysts Pt/La2O3-ZrO2 and Pt/CeO2-ZrO2 were prepared by using atomic layer deposition with varying Pt loadings from 6.3-12.4 wt %.more » Mono-dispersed Pt nanoparticles of ~3 nm were obtained for these catalysts. As a result, the incorporation of La2O3 and CeO2 into the t-ZrO2 structure did not affect the nature of the active sites for the Pt/ZrO2 catalysts for the water-gas-shift (WGS) reaction.« less

  8. Theoretical Study of Trimethylacetic Acid Adsorption on CeO 2 (111) Surface

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wang, Weina; Thevuthasan, S.; Wang, Wenliang; Yang, Ping

    2016-01-11

    We investigated trimethylacetic acid (TMAA) adsorption on stoichiometric and oxygen-deficient CeO2(111) surfaces using density functional theory that accounts for the on-site Coulomb interaction via a Hubbard term (DFT+U) and long-range dispersion correction. Both the molecular state and dissociative state (TMAA → TMA– + H+) were identified on stoichiometric and oxygen-deficient CeO2(111) surfaces. For the stoichiometric surface, two thermodynamically favorable configurations with adsorption energies of the order of -30 kcal/mol are identified; one is a molecule adsorption state, and the other one is a dissociative state. For the oxygen-deficient surface, dissociative states are more favorable than molecular states. Moreover, the mostmore » favorable configuration is the dissociative adsorption of TMAA with the adsorption energy of the order of -77 kcal/mol. The dissociated TMA moiety takes the position of oxygen vacancy, forming three Ce–O bonds. The signature vibrational frequencies for these thermodynamically stable structures are reported as well as their electronic structures. The effects of long-range dispersion interactions are found to be negligible for geometries but important for adsorption energies.« less

  9. Hydrogenation of CO2 to methanol on CeOx/Cu(111) and ZnO/Cu(111) catalysts: Role of the metal-oxide interface and importance of Ce3+ sites

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sanjaya D. Senanayake; Ramirez, Pedro J.; Waluyo, Iradwikanari; Kundu, Shankhamala; Mudiyanselage, Kumudu; Liu, Zongyuan; Liu, Zhi; Axnanda, Stephanus; Stacchiola, Dario J.; Evans, Jaime; et al

    2016-01-06

    The role of the interface between a metal and oxide (CeOx–Cu and ZnO–Cu) is critical to the production of methanol through the hydrogenation of CO2 (CO2 + 3H2 → CH3OH + H2O). The deposition of nanoparticles of CeOx or ZnO on Cu(111), θoxi < 0.3 monolayer, produces highly active catalysts for methanol synthesis. The catalytic activity of these systems increases in the sequence: Cu(111) < ZnO/Cu(111) < CeOx/Cu(111). The apparent activation energy for the CO2 → CH3OH conversion decreases from 25 kcal/mol on Cu(111) to 16 kcal/mol on ZnO/Cu(111) and 13 kcal/mol on CeOx/Cu(111). The surface chemistry of the highlymore » active CeOx–Cu(111) interface was investigated using ambient pressure X-ray photoemission spectroscopy (AP-XPS) and infrared reflection absorption spectroscopy (AP-IRRAS). Both techniques point to the formation of formates (HCOO–) and carboxylates (CO2δ–) during the reaction. Our results show an active state of the catalyst rich in Ce3+ sites which stabilize a CO2δ– species that is an essential intermediate for the production of methanol. Furthermore, the inverse oxide/metal configuration favors strong metal–oxide interactions and makes possible reaction channels not seen in conventional metal/oxide catalysts.« less

  10. Electronic structure of the heavy-fermion caged compound Ce?Pd??X? (X = Si, Ge) studied by density functional theory and photoelectron spectroscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yamaoka, Hitoshi; Jarrige, Ignace; Schwier, Eike F.; Arita, Masashi; Shimada, Kenya; Tsujii, Naohito; Jiang, Jian; Hayashi, Hirokazu; Iwasawa, Hideaki; Namatame, Hirofumi; et al

    2015-03-30

    The electronic structure of Ce?Pd??X? (X = Si, Ge) has been studied using detailed density functional theory (DFT) calculations and high-resolution photoelectron spectroscopy (PES) measurements. The orbital decomposition of the electronic structure by DFT calculations indicates that Ce atoms at the (8c) site surrounded by 16 Pd atoms have a more localized nature and a tendency to be magnetic. Ce atoms in the (4a) site surrounded by 12 Pd and 6 X atoms, on the other, show only a negligible magnetic moment. In the photoemission valence-band spectra we observe a strong f? (Ce??) component with a small fraction of fmore(Ce?) component. The spectral weight of f component near the Fermi level Ce?Pd??Si? is stronger than that for Ce?Pd??Ge? at the 4d-4f resonance, suggesting stronger c-f hybridization in the former. This may hint to the origin of the large electronic specific coefficient of Ce?Pd??Si? compared to Ce?Pd??Ge?.less

  11. Influence of solvent on the morphology and photocatalytic properties of ZnS decorated CeO{sub 2} nanoparticles

    SciTech Connect (OSTI)

    Raubach, Cristiane W. Polastro, Lisnias; Ferrer, Mateus M.; Perrin, Andre; Perrin, Christiane; Albuquerque, Anderson R.; Buzolin, Prescila G. C.; Sambrano, Julio R.; Santana, Yuri B. V. de; Varela, Jos A.; Longo, Elson

    2014-06-07

    Herein, we report a theoretical and experimental study on the photocatalytic activity of CeO{sub 2} ZnS, and ZnS decorated CeO{sub 2} nanoparticles prepared by a microwave-assisted solvothermal method. Theoretical models were established to analyze electron transitions primarily at the interface between CeO{sub 2} and ZnS. As observed, the particle morphology strongly influenced the photocatalytic degradation of organic dye Rhodamine B. A model was proposed to rationalize the photocatalytic behavior of the prepared decorated systems taking into account different extrinsic and intrinsic defect distributions, including order-disorder effects at interfacial and intra-facial regions, and vacancy concentration.

  12. Temperature Dependence of the Kondo Resonance and Its Satellites in CeCu{sub 2}Si{sub 2}

    SciTech Connect (OSTI)

    Reinert, F.; Ehm, D.; Schmidt, S.; Nicolay, G.; Huefner, S.; Kroha, J.; Trovarelli, O.; Geibel, C.

    2001-09-03

    We present high-resolution photoemission spectroscopy studies on the Kondo resonance of the strongly correlated Ce system CeCu{sub 2}Si {sub 2} . By exploiting the thermal broadening of the Fermi edge we analyze position, spectral weight, and temperature dependence of the low-energy 4f spectral features, whose major weight lies above the Fermi level E{sub F} . We also present theoretical predictions based on the single-impurity Anderson model using an extended noncrossing approximation, including all spin-orbit and crystal field splittings of the 4f states. The excellent agreement between theory and experiment provides strong evidence that the spectral properties of CeCu{sub 2}Si {sub 2} can be described by single-impurity Kondo physics down to T{approx}5 K .

  13. Update on the CeC PoP 704 MHz 5-cell cavity cryomodule design and fabrication

    SciTech Connect (OSTI)

    Brutus, J. C.; Belomestnykh, S.; Ben-Zvi, I.; Grimm, T.; Huang, Y.; Jecks, R.; Kelly, M.; Litvinenko, V.; Pinayev, I.; Reid, T.; Skaritka, J.; Snydstrup, L.; Than, R.; Tuozzolo, J.; Xu, W.; Yancey, J.; Gerbick, S.

    2015-05-03

    A 5-cell SRF cavity operating at 704 MHz will be used for the Coherent Electron Cooling Proof of Principle (CeC PoP) system under development for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The CeC PoP experiment will demonstrate the new technique of cooling proton and ion beams that may increase the beam luminosity in certain cases, by as much as tenfold. The 704 MHz cavity will accelerate 2 MeV electrons from a 112 MHz SRF gun up to 22MeV. This paper provides an overview of the design, the project status and schedule of the 704 MHz 5-cell SRF for CeC PoP experiment.

  14. Magnetic Hardening of CeFe11Ti and the Effect of TiC Addition (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Magnetic Hardening of CeFe11Ti and the Effect of TiC Addition Citation Details In-Document Search Title: Magnetic Hardening of CeFe11Ti and the Effect of TiC Addition Authors: Zhou, Chen ; Haddad, Daad ; Kukreja, Ratandeep S. ; Pinkerton, Frederick E. ; Sun, Kewei ; Kramer, M. J. Publication Date: 2015-04-01 OSTI Identifier: 1221660 Report Number(s): IS-J 8423 Journal ID: ISSN 0018-9464 DOE Contract Number: AC02-07CH11358; 0472-1526 Resource Type: Journal Article

  15. Determination of the Surface Structure of CeO2(111) by Low-Energy Electron

    Office of Scientific and Technical Information (OSTI)

    Diffraction. (Journal Article) | SciTech Connect Determination of the Surface Structure of CeO2(111) by Low-Energy Electron Diffraction. Citation Details In-Document Search Title: Determination of the Surface Structure of CeO2(111) by Low-Energy Electron Diffraction. Abstract not provided. Authors: McCarty, Kevin F. ; Siegel, David A ; El Gabaly Marquez, Farid ; Chueh, William ; de la Figuera, Juan ; Blanco-Rey, Maria Publication Date: 2013-06-01 OSTI Identifier: 1113313 Report Number(s):

  16. Implementation of the National Incident Management System (NIMS)/Incident Command System (ICS) in the Federal Radiological Monitoring and Assessment Center(FRMAC) - Emergency Phase

    SciTech Connect (OSTI)

    NSTec Environmental Restoration

    2007-04-01

    Homeland Security Presidential Directive HSPD-5 requires all federal departments and agencies to adopt a National Incident Management System (NIMS)/Incident Command System (ICS) and use it in their individual domestic incident management and emergency prevention, preparedness, response, recovery, and mitigation programs and activities, as well as in support of those actions taken to assist state and local entities. This system provides a consistent nationwide template to enable federal, state, local, and tribal governments, private-sector, and nongovernmental organizations to work together effectively and efficiently to prepare for, prevent, respond to, and recover from domestic incidents, regardless of cause, size, or complexity, including acts of catastrophic terrorism. This document identifies the operational concepts of the Federal Radiological Monitoring and Assessment Center's (FRMAC) implementation of the NIMS/ICS response structure under the National Response Plan (NRP). The construct identified here defines the basic response template to be tailored to the incident-specific response requirements. FRMAC's mission to facilitate interagency environmental data management, monitoring, sampling, analysis, and assessment and link this information to the planning and decision staff clearly places the FRMAC in the Planning Section. FRMAC is not a mitigating resource for radiological contamination but is present to conduct radiological impact assessment for public dose avoidance. Field monitoring is a fact-finding mission to support this effort directly. Decisions based on the assessed data will drive public protection and operational requirements. This organizational structure under NIMS is focused by the mission responsibilities and interface requirements following the premise to provide emergency responders with a flexible yet standardized structure for incident response activities. The coordination responsibilities outlined in the NRP are based on the NIMS/ICS construct and Unified Command (UC) for management of a domestic incident. The NRP Nuclear/Radiological Incident Annex (NUC) further provides requirements and protocols for coordinating federal government capabilities to respond to nuclear/radiological Incidents of National Significance (INS) and other radiological incidents. When a FRMAC is established, it operates under the parameters of NIMS as defined in the NRP. FRMAC and its operations have been modified to reflect NIMS/ICS concepts and principles and to facilitate working in a Unified Command structure. FRMAC is established at or near the scene of the incident to coordinate radiological monitoring and assessment and is established in coordination with the U.S. Department of Homeland Security (DHS); the coordinating agency; other federal agencies; and state, local, and tribal authorities. However, regardless of the coordinating agency designation, U.S. Department of Energy (DOE) coordinates radiological monitoring and assessment activities for the initial phases of the offsite federal incident response through the Radiological Assistance Program (RAP) and FRMAC assets. Monitoring and assessment data are managed by FRMAC in an accountable, secure, and retrievable format. Monitoring data interpretations, including exposure rate contours, dose projections, and any requested radiological assessments are to be provided to the DHS; to the coordinating agency; and to state, local, and tribal government agencies.

  17. Magnetic structure of the antiferromagnetic Kondo lattice compounds CeRhAl4Si2 and CeIrAl4Si2

    SciTech Connect (OSTI)

    Ghimire, N. J.; Calder, S.; Janoschek, M.; Bauer, E. D.

    2015-06-01

    In this article, we have investigated the magnetic ground state of the antiferromagnetic Kondo-lattice compounds CeMAl4Si2(M = Rh, Ir) using neutron powder diffraction. Although both of these compounds show two magnetic transitions TN1 and TN2 in the bulk properties measurements, evidence for magnetic long-range order was only found below the lower transition TN2. Analysis of the diffraction profiles reveals a commensurate antiferromagnetic structure with a propagation vector k = (0, 0, 1/2). The magnetic moment in the ordered state of CeRhAl4Si2 and CeIrAl4Si2 were determined to be 1.14(2) and 1.41(3) ?B/Ce, respectively, and are parallel to the crystallographic c-axis in agreement with magnetic susceptibility measurements.

  18. Vortex Lattice Studies in CeCoIn₅ with H⊥c

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Das, P.; White, J. S.; Holmes, A. T.; Gerber, S.; Forgan, E. M.; Bianchi, A. D.; Kenzelmann, M.; Zolliker, M.; Gavilano, J. L.; Bauer, E. D.; et al

    2012-02-23

    We present small angle neutron scattering studies of the vortex lattice (VL) in CeCoIn₅ with magnetic fields applied parallel (H) to the antinodal [100] and nodal [110] directions. For H II 100], a single VL orientation is observed, while a 90° reorientation transition is found for H II [110]. For both field orientations and VL configurations we find a distorted hexagonal VL with an anisotropy, Γ=2.0±0.05. The VL form factor shows strong Pauli paramagnetic effects similar to what have previously been reported for H II [001]. At high fields, above which the upper critical field (Hc2) becomes a first-order transition,more » an increased disordering of the VL is observed.« less

  19. Nanostructured Lanthanum Halides and CeBr3 for Nuclear Radiation and Detection

    SciTech Connect (OSTI)

    Paul Guss, Sanjoy Mukhopadhyay, Ron Guise, Ding Yuan

    2010-06-09

    Scintillator materials are used to detect, and in some cases identify, gamma rays. Higher performance scintillators are expensive, hard to manufacture, fragile, and sometimes require liquid nitrogen or cooling engines. But whereas lower-quality scintillators are cheap, easy to manufacture, and more rugged, their performance is lower. At issue: can the desirable qualities of high-and low-performance scintillators be combined to achieve better performance at lower cost? Preliminary experiments show that a LaF{sub 3}:Ce oleic acid-based nanocomposite exhibits a photopeak when exposed to {sup 137}Cs source gamma-radiation. The chemical synthesis of the cerium-doped lanthanum halide nanoparticles are scalable and large quantities of material can be produced at a time, unlike typical crystal growth processes such as the Bridgeman process. Using a polymer composite (Figure 1), produced by LANL, initial measurements of the unloaded and 8% LaF{sub 3}:Ce-loaded sample have been made using {sup 137}Cs sources. Figure 2 shows an energy spectrum acquired for CeF{sub 3}. The lighter plot is the measured polymer-only spectrum and the black plot is the spectrum from the nanocomposite scintillator. As the development of this material continues, the energy resolution is expected to improve and the photopeak-to-Compton ratio will become greater at higher loadings. These measurements show the expected Compton edge in the polymer-only sample, and the Compton edge and photo-peak expected in the nanophosphor composites that LANL has produced. Using a porous VYCORR with CdSe/ZnS core shell quantum dots, Letant has demonstrated that he has obtained signatures of the 241Am photopeak with energy resolution as good at NaI (Figure 3). We begin with the fact that CeBr{sub 3} crystals do not have a self-activity component as strong as the lanthanum halides. The radioactive 0.090% {sup 138}La component of lanthanum leads to significant self-activity, which will be a problem for very large detector volumes. Yet a significant strength of the nanostructure detector concept is the ability to create extremely large detector volumes by mixing nanoparticles into a transparent matrix. This would argue for use of nanoparticles other than lanthanum halides. Nanocomposites are easy to prepare; it is much less costly to use nanocomposites than to grow large whole crystals of these materials. The material can be fabricated at an industrial scale, further reducing cost. This material potentially offers the performance of $300/cc material (e.g., lanthanum bromide) at a cost of $1/cc. Because the material acts as a plastic, it is rugged and flexible, and can be made in large sheets, increasing the sensitivity of a detector using it. It would operate at ambient temperatures. Very large volumes of detector may be produced at greatly reduced cost, enhancing the non-proliferation posture of the nation for the same dollar value.

  20. Theoretical studies of Ir5Th and Ir5Ce nanoscale precipitates in Ir

    SciTech Connect (OSTI)

    Morris, James R; Averill, Frank; Cooper, Valentino R

    2014-01-01

    Experimentally, it is known that very small amounts of thorium and/or cerium added to iridium metal form a precipitate, Ir5Th / Ir5Ce, which improves the high temperature mechanical properties of the resulting alloys. We demonstrate that there are low-energy configurations for nano-scale precipitates of these phases in Ir, and that these coherent arrangements may assist in producing improved mechanical properties. One precipitate/matrix orientation gives a particularly low interfacial energy, and a low lattice misfit. Nanolayer precipitates with this orientation are found to be likely to form, with little driving force to coarsen. The predicted morphology of the precipitates and their orientation with the matrix phase provide a potential experiment that could be used to test these predictions.

  1. Differential conductance and defect states in the heavy-fermion superconductor CeCoIn5

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    John S. Van Dyke; Davis, James C.; Morr, Dirk K.

    2016-01-22

    We demonstrate that the electronic band structure extracted from quasiparticle interference spectroscopy [Nat. Phys. 9, 468 (2013)] and the theoretically computed form of the superconducting gaps [Proc. Natl. Acad. Sci. USA 111, 11663 (2014)] can be used to understand the dI/dV line shape measured in the normal and superconducting state of CeCoIn5 [Nat. Phys. 9, 474 (2013)]. In particular, the dI/dV line shape, and the spatial structure of defect-induced impurity states, reflects the existence of multiple superconducting gaps of dx2–y2 symmetry. As a result, these results strongly support a recently proposed microscopic origin of the unconventional superconducting state.

  2. Transport properties of Ce{sub 2}Ni{sub 2}Sn and Ce{sub 2}Pd{sub 2.05}Sn{sub 0.95} Kondo lattice systems

    SciTech Connect (OSTI)

    Pinto, R.P.; Amado, M.M.; Braga, M.E.; de Azevedo, M.M.; Sousa, J.B.; Chevalier, B.; Etourneau, J.

    1997-04-01

    We report experimental data on thermoelectric power S, electrical resistivity {rho}, and the magnetoresistivity of the antiferromagnet Kondo stannides Ce{sub 2}Ni{sub 2}Sn (T{sub N}=4.7 K) and Ce{sub 2}Pd{sub 2.05}Sn{sub 0.95} (T{sub N}=4.7 K). The essential features of the S(T) curves resemble those of heavy fermion systems such as CeCu{sub 2}Si{sub 2}: a broad and positive maximum at intermediate temperatures, followed by a sharper negative minimum at lower temperatures. S values are is considerably smaller in Ce{sub 2}Pd{sub 2.05}Sn{sub 0.95} than in Ce{sub 2}Ni{sub 2}Sn. The positive peak originates from the incoherent Kondo scattering by the excited crystal field levels of the Ce ion ground state. The negative peak might be related to the shape of the density of states associated with the Abrikosov{endash}Suhl resonance. The change of sign in S(T) between its minimum and maximum at T{sup {asterisk}} can be assigned to the fact that the Fermi level sinks below the upper band at T{gt}T{sup {asterisk}}. This behavior and the maximum observed in the {rho}(T) curve at this temperature can be discussed in terms of the electron polaron model, although one must also take into account the crystal field effect. The role played by the crystal field effect, which is more important in Ce{sub 2}Pd{sub 2.05}Sn{sub 0.95}, is analyzed for this compound, providing the magnitude of the crystal field splitting. Magnetoresistivity was also measured in both compounds. The results are consistent with the important role of the Kondo effect at low temperatures and suggest the splitting of the double degenerate bands at T{gt}T{sup {asterisk}}. {copyright} {ital 1997 American Institute of Physics.}

  3. Improved thermoelectric performance of n-type Ca and Ca-Ce filled skutterudites

    SciTech Connect (OSTI)

    Thompson, Daniel R.; Liu, Chang; Ellison, Nicole D.; Salvador, James R.; Meyer, Martin S.; Haddad, Daad B.; Wang, Hsin; Cai, W.

    2014-12-28

    Thermoelectric (TE) technology for use in automotive waste heat recovery is being advanced by General Motors with support from the US Department of Energy. Skutterudites are a very promising material for this application of TE technology due to their superior mechanical properties and good TE performance. Double-filled Yb{sub x}Ba{sub y}Co{sub 4}Sb{sub 12} with ZT values around 1.1 at 750?K are the best performing n-type skutterudites produced on a large scale using an economically viable approach of melt spinning (MS) in conjunction with spark plasma sintering (SPS). Another economical production method on the tons scale, the melt quench annealing (MQA) technique, has been recently claimed by Treibacher Industrie AG, further information is available [G. Rogl et al., Acta Mater. 76, 434448 (2014)]. A possible hurdle to commercial implementation of these materials is the use of rare earths as the fillers to reduce thermal conductivity and improve the electrical transport properties. It will be shown herein that skutterudites double-filled with Ca and Ce, both of which are lower-cost fillers, display markedly different TE properties depending on whether they are produced by MQA or MS + SPS synthesis techniques. Ca and Ce double-filled skutterudites prepared by MS + SPS have TE properties that are superior to the same compositions prepared by MQA and that are comparable to the best performing Yb and Ba filled materials. Furthermore, the results of this study suggest that the unusually poor transport properties of MQA Ca-filled skutterudites can be ascribed to deleterious secondary phases, which is contrary to reports in the literature attempting to explain these irregularities via band structure features.

  4. The effect of Au and Ni doping on the heavy fermion state of the Kondo lattice antiferromagnet CePtZn

    SciTech Connect (OSTI)

    Dhar, S. K.; Aoki, Y.; Suemitsu, B.; Miyazaki, R.; Provino, A.; Manfrinetti, P.

    2014-05-07

    We have probed the effect of doping CePtZn with Au and Ni and also investigated in detail the magnetic behavior of the iso-structural CeAuZn. A magnetic ground state is observed in both CePt{sub 0.9}Au{sub 0.1}Zn and CePt{sub 0.9}Ni{sub 0.1}Zn with T{sub N}?=?2.1 and 1.1?K and the coefficient of the linear term of electronic heat capacity ??=?0.34 and 0.9?J/mol K{sup 2}, respectively. The corresponding values for CePtZn are 1.7?K and 0.6?J/mol K{sup 2}. The altered values of T{sub N} and ? show that the electronic correlations in CePtZn are affected by doping with Au and Ni. CeAuZn orders magnetically near 1.7?K and its electrical resistivity shows a normal metallic behavior. Together with a ? of 0.022?J/mol K{sup 2} the data indicate a weak 4f-conduction electron hybridization in CeAuZn characteristic of normal trivalent cerium based systems.

  5. Investigation of the physical properties of the tetragonal CeMAl4Si2 (M = Rh, Ir, Pt) compounds

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ghimire, N. J.; Ronning, F.; Williams, D. J.; Scott, B. L.; Luo, Yongkang; Thompson, J. D.; Bauer, E. D.

    2014-12-15

    The synthesis, crystal structure and physical properties studied by means of x-ray diffraction, magnetic, thermal and transport measurements of CeMAl4Si2 (M = Rh, Ir, Pt) are reported, along with the electronic structure calculations for LaMAl4Si2 (M = Rh, Ir, Pt). These materials adopt a tetragonal crystal structure (space group P4/mmm) comprised of BaAl4 blocks, separated by MAl2 units, stacked along the c-axis. Both CeRhAl4Si2 and CeIrAl4Si2 order antiferromagnetically below TN1 = 14 and 16 K, respectively, and undergo a second antiferromagnetic transitition at lower temperature (TN2 = 9 and 14 K, respectively). CePtAl4Si2 orders ferromagnetically below TC = 3 Kmore » with an ordered moment of μsat = 0.8 μB for a magnetic field applied perpendicular to the c-axis. Electronic structure calculations reveal quasi-2D character of the Fermi surface.« less

  6. The effect of Ce{sup 4+} incorporation on structural, morphological and photocatalytic characters of ZnO nanoparticles

    SciTech Connect (OSTI)

    Kannadasan, N.; Shanmugam, N. Cholan, S.; Sathishkumar, K.; Viruthagiri, G.; Poonguzhali, R.

    2014-11-15

    We report a simple chemical precipitation method for the preparation of undoped and cerium doped ZnO nanocrystals. The concentration of cerium in the products can be controlled in the range of 0.0250.125 mol. The structure and chemical compositions of the products were characterized by X-ray diffraction, X-ray photoelectron spectroscopy; energy dispersive spectrum and Fourier transform infrared spectroscopy. The results demonstrate that Ce{sup 4+} ions were successfully incorporated into the lattice position of Zn{sup 2+} ions in ZnO. The morphology of the products was analyzed by field emission scanning electron microscopy and confirmed by high resolution transmission electron microscope analysis. The optical properties of the products were studied by ultravioletvisible and room temperature photoluminescence measurements. The photoluminescence emission spectra of Ce-doped ZnO showed enhanced visible emissions as a result of 5d ? 4f transition of cerium. In particular, a novel photocatalytic activity of the products was assessed using methylene blue. The obtained result reveals that Ce-doped products show higher reduction efficiency for methylene blue than the undoped ZnO. - Highlights: Nanocrystals of ZnO and ZnO:Ce{sup 4+} were grown. XPS results confirmed the incorporated cerium in tetravalence. PL emission exhibited 5d ? 4f transition on cerium doping. Doped ZnO decolorizes MB faster than undoped ZnO.

  7. Kondo lattice and antiferromagnetic behavior in quaternary CeTAl4Si2 (T = Rh, Ir) single crystals

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Maurya, Arvind; Kulkarni, Ruta; Thamizhavel, Arumugam; Paudyal, Durga; Dhar, Sudesh Kumar

    2016-02-26

    Here, we have explored in detail the anisotropic magnetic properties of CeRhAl4Si2 and CeIrAl4Si2, which undergo two antiferromagnetic transitions, at TN1 = 12.6 and 15.5 K, followed by a second transition at TN2 = 9.4 and 13.8 K, respectively, with the [001]-axis as the relatively easy axis of magnetization. The electrical resistivity at ambient and applied pressure provides evidence of Kondo interaction in both compounds, further supported by a reduced value of the entropy associated with the magnetic ordering. The Sommerfeld coefficient γ is inferred to be 195.6 and 49.4 mJ/(mol K2) for CeRhAl4Si2 and CeIrAl4Si2, respectively, classifying these materialsmore » as moderate heavy-fermion compounds. The crystal electric field energy levels are derived from the peak seen in the Schottky heat capacity. Furthermore, we have also performed electronic structure calculations by using the local spin density approximation + U [LSDA+U] approach, which provide physical insights on the observed magnetic behavior of these two compounds.« less

  8. Reactions of Monomeric [1,2,4-(Me3C)3C5H2]2CeH and CO with orwithout H2:An

    Office of Scientific and Technical Information (OSTI)

    Experimental and Computational Study (Journal Article) | SciTech Connect Reactions of Monomeric [1,2,4-(Me3C)3C5H2]2CeH and CO with orwithout H2:An Experimental and Computational Study Citation Details In-Document Search Title: Reactions of Monomeric [1,2,4-(Me3C)3C5H2]2CeH and CO with orwithout H2:An Experimental and Computational Study Addition of CO to [1,2,4-(Me3C)3C5H2]2CeH, Cp'2CeH, intoluene yields the cis (Cp'2Ce)2(mu-OCHCHO), in which the cis enediolategroup bridges the two

  9. Superior performance of Ni-W-Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rodriguez, Jose A.; Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Johnson-Peck, Aaron C.; Zhao, Fuzhen; Michorczyk, Piotr; Kubacka, Anna; Stach, Eric A.; Fernandez-Garica, Marcos; et al

    2014-11-26

    The ethanol steam reforming (ESR) reaction was studied over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO? lattice, with the remaining Ni forming highly dispersed nano NiO (moreThe Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.less

  10. Synthesis, Structures, and Magnetic Properties of Rare-Earth Cobalt Arsenides, RCo2As2 (R = La, Ce, Pr, Nd)

    SciTech Connect (OSTI)

    Thompson, Corey; Tan, Xiaoyan; Kovnir, Kirill; Garlea, Vasile O; Shatruk, Michael

    2014-01-01

    Four rare-earth cobalt arsenides, RCo2As2 (R = La, Ce, Pr, Nd), were obtained by reactions of constituent elements in molten Bi. The use of Bi flux also allowed the growth of representative single crystals. All compounds are isostructural and belong to the ThCr2Si2 structure type (space group I4/mmm). The formation of Co vacancies is observed in all structures, while the structures of La- and Ce-containing compounds also show incorporation of minor Bi defects next to the R crystallographic site. Correspondingly, the general formula of these materials can be written as R1 xBixCo2 As2, with x/ = 0.03/0.1, 0.05/0.15, 0/0.2, and 0/0.3 for R = La, Ce, Pr, and Nd, respectively. All compounds exhibit high-temperature ferromagnetic ordering of Co magnetic moments in the range of 150-200 K. Electronic band structure calculations revealed a high peak in the density of states at the Fermi level, thus supporting the itinerant nature of magnetism in the Co sublattice. The magnetic ordering in the lanthanide sublattice takes place at lower temperatures, with the R moments aligning antiparallel to the Co moments to give a ferrimagnetic ground state. The measurements on oriented single crystals demonstrated significant magnetic anisotropy in the ferrimagnetic state, with the preferred moment alignment along the c axis of the tetragonal lattice. Neutron powder diffraction failed to reveal the structure of magnetically ordered states, but confirmed the presence of Co vacancies. X-ray absorption near-edge structure spectroscopy on Ce1.95Bi0.05Co1.85As2 showed the average oxidation state of Ce to be +3.06. Solid state NMR spectroscopy revealed a substantially reduced hyperfine field on the Co atoms in the vicinity of Bi defects.

  11. Ionic liquid-assisted sonochemical preparation of CeO2 nanoparticles for CO oxidation

    SciTech Connect (OSTI)

    Alammar, Tarek; Noei, Heshmat; Wang, Yuemin; Grnert, Wolfgang; Mudring, Anja -Verena

    2014-10-10

    CeO2 nanoparticles were synthesized via a one-step ultrasound synthesis in different kinds of ionic liquids based on bis(trifluoromethanesulfonylamide, [Tf2N], in combination with various cations including 1-butyl-3-methylimidazolium ([C4mim]+), 1-ethyl-2,3-dimethylimidazolium ([Edimim]+), butyl-pyridinium([Py4]+), 1-butyl-1-methyl-pyrrolidinium ([Pyrr14]+), and 2-hydroxyethyl-trimethylammonium ([N1112OH]+). Depending on synthetic parameters, such as ionic liquid, Ce(IV) precursor, heating method, and precipitator, formed ceria exhibits different morphologies, varying from nanospheres, nanorods, nanoribbons, and nanoflowers. The morphology, crystallinity, and chemical composition of the obtained materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy, and N2 adsorption. The structural and electronic properties of the as-prepared CeO2 samples were probed by CO adsorption using IR spectroscopy under ultrahigh vacuum conditions. The catalytic activities of CeO2 nanoparticles were investigated in the oxidation of CO. CeO2 nanospheres obtained sonochemically in [C4mim][Tf2N] exhibit the best performance for low-temperature CO oxidation. As a result, the superior catalytic performance of this material can be related to its mesoporous structure, small particle size, large surface area, and high number of surface oxygen vacancy sites.

  12. Reverse micelles directed synthesis of TiO{sub 2}-CeO{sub 2} mixed oxides and investigation of their crystal structure and morphology

    SciTech Connect (OSTI)

    Matejova, Lenka; Vales, Vaclav; Fajgar, Radek; Matej, Zdenek; Holy, Vaclav; Solcova, Olga

    2013-02-15

    The synthesis of TiO{sub 2}-CeO{sub 2} mixed oxides based on the sol-gel process controlled within reverse micelles of non-ionic surfactant Triton X-114 in cyclohexane is reported. The crystallization, phase composition, trends in nanoparticles growth and porous structure properties are studied as a function of Ti:Ce molar composition and annealing temperature by in-situ X-ray diffraction, Raman spectroscopy and physisorption. The brannerite-type CeTi{sub 2}O{sub 6} crystallizes as a single crystalline phase at Ti:Ce molar composition of 70:30 and in the mixture with cubic CeO{sub 2} and anatase TiO{sub 2} for composition 50:50. At Ti:Ce molar ratios 90:10 and 30:70 the mixtures of TiO{sub 2} anatase, rutile and cubic CeO{sub 2} appear. In these mixtures TiO{sub 2} rutile is formed at higher temperatures than conventionally. Additionally, the amount of a present amorphous phase in individual mixtures was estimated from diffraction data. The porous structure morphology depends both on molar composition and annealing temperature. This is correlated with the presence of carbon impurities of different character. - Graphical abstract: The phase composition of Ti90--Ce10 and Ti50--Ce50 oxide mixtures as a function of annealing temperature. The amount of the amorphous phase was estimated and attributed to TiO{sub 2}. Highlights: Black-Right-Pointing-Pointer Ti/Ce oxides were prepared using reverse micelles of Triton X-114. Black-Right-Pointing-Pointer Crystallization of TiO{sub 2}, CeO{sub 2} or CeTi{sub 2}O{sub 6} depends on Ti:Ce molar ratio. Black-Right-Pointing-Pointer Amorphous phase attributed to TiO{sub 2} was identified. Black-Right-Pointing-Pointer Metal oxides surface area is influenced by the character of present carbon impurities.

  13. SUZAKU VIEW OF THE SWIFT/BAT ACTIVE GALACTIC NUCLEI. IV. NATURE OF TWO NARROW-LINE RADIO GALAXIES (3C 403 AND IC 5063)

    SciTech Connect (OSTI)

    Tazaki, Fumie; Ueda, Yoshihiro; Terashima, Yuichi; Mushotzky, Richard F.

    2011-09-01

    We report the results of Suzaku broadband X-ray observations of the two narrow-line radio galaxies, 3C 403 and IC 5063. Combined with the Swift/Burst Alert Telescope (BAT) spectra averaged for 58 months, we are able to accurately constrain their spectral properties over the 0.5-200 keV band. The spectra of both nuclei are well represented with an absorbed cutoff power law, an absorbed reflection component from cold matter with an iron-K emission line, and an unabsorbed soft component, which gives a firm upper limit for the scattered emission. The reflection strength normalized to the averaged BAT flux is R {identical_to} {Omega}/2{pi} {approx} 0.6 in both targets, implying that their tori have a sufficiently large solid angle to produce the reprocessed emission. A numerical torus model with an opening angle of {approx}50{sup 0} well reproduces the observed spectra. We discuss the possibility that the amount of the normal gas responsible for Thomson scattering is systematically smaller in radio galaxies compared with Seyfert galaxies.

  14. OC_IC_DIGITAL.indd

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    463-9076 Physical Chemistry Chemical Physics www.rsc.orgpccp Volume 14 | Number 5 | 7 ... RSC Books Defining Chemical Science Content New Series - Coming Soon Polymer Chemistry, ...

  15. LES Modeling for IC Engines

    Broader source: Energy.gov [DOE]

    Large eddy simulation offers better accuracy and sensitivity to study cyclic variability, mode transition and mixing effects in engine design and operation

  16. 2011 Annual IC Assessment Report

    Office of Legacy Management (LM)

    ... and this report follow requirements in three documents that ... and Ohio EPA to approve land uses, soil removal, ... of the Ohio Department of Natural Resources website and the ...

  17. 2011 Annual IC Assessment Report

    Office of Legacy Management (LM)

    ... report follow requirements in three documents that ... and Ohio EPA to approve land uses, soil removal, ... of the Ohio Department of Natural Resources website and the ...

  18. GENERAL@ELECTtiIC COMPINY

    Office of Legacy Management (LM)

    FOR GENERAL ED&'RIC - APED The Atoinic Power Equipment Depart++ of the The uranium ... We propose to fabricate the pellets in by the Atomic Power Equipment Department, ...

  19. Magnetic hardening of Ce1+xFe11-yCoyTi with ThMn12 structure by melt

    Office of Scientific and Technical Information (OSTI)

    spinning (Journal Article) | SciTech Connect hardening of Ce1+xFe11-yCoyTi with ThMn12 structure by melt spinning Citation Details In-Document Search Title: Magnetic hardening of Ce1+xFe11-yCoyTi with ThMn12 structure by melt spinning A recent study on the intrinsic magnetic properties of CeFe11-yCoyTi has revealed that substituting one Co for Fe retains the favorable magnetocrystalline anisotropy Ha found in the ternary Fe end member, while enhancing the Curie temperature Tc and saturation

  20. Structural and magnetic phase transitions in CeCu6-xTx (T = Ag,Pd)

    SciTech Connect (OSTI)

    Poudel, Lekhanath N.; De la cruz, Clarina; Payzant, E. Andrew; Koehler, Michael R.; May, Andrew F.; Garlea, Vasile O.; Taylor, Alice E.; Parker, David S.; Cao, Huibo B.; McGuire, Michael A.; Tian, Wei; Matsuda, Masaaki; Jeen, Hyoung Jeen; Lee, Ho Nyung; Hong, Tao; Calder, Stuart A.; Lumsden, Mark D.; Zhou, Haidong; Keppens, Veerle; Mandrus, D.; Christianson, Andrew D.

    2015-12-15

    The structural and the magnetic properties of CeCu6-xAgx (0 ≤ x ≤ 0.85) and CeCu6-xPdx (0 ≤ x ≤ 0.4) have been studied using neutron diffraction, resonant ultrasound spectroscopy (RUS), x-ray diffraction measurements, and first principles calculations. The structural and magnetic phase diagrams of CeCu6-xAgx and CeCu6-xPdx as a function of Ag/Pd composition are reported. The end member, CeCu6, undergoes a structural phase transition from an orthorhombic (Pnma) to a monoclinic (P21/c) phase at 240 K. In CeCu6-xAgx, the structural phase transition temperature (Ts) decreases linearly with Ag concentration and extrapolates to zero at xS ≈ 0.1. The structural transition in CeCu6-xPdx remains unperturbed with Pd substitution within the range of our study. The lattice constant b slightly decreases with Ag/Pd doping, whereas a and c increase with an overall increase in the unit cell volume. Both systems, CeCu6-xAgx and CeCu6-xPdx, exhibit a magnetic quantum critical point (QCP), at x ≈ 0.2 and x ≈ 0.05, respectively. Near the QCP, long range antiferromagnetic ordering takes place at an incommensurate wave vector (δ1 0 δ2), where δ1 ~ 0.62, δ2 ~ 0.25, x = 0.125 for CeCu6-xPdx and δ1 ~ 0.64, δ2 ~ 0.3, x = 0.3 for CeCu6-xAgx. As a result, the magnetic structure consists of an amplitude modulation of the Ce moments which are aligned along the c axis of the orthorhombic unit cell.

  1. Kondo hole behavior in Ce{sub 0.97} La{sub 0.03}Pd{sub 3}

    SciTech Connect (OSTI)

    Lawrence, J.M.; Graf, T.; Hundley, M.F.; Mandrus, D.; Thompson, J.D. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Lacerda, A.; Torikachvili, M.S. [National High Magnetic Field Laboratory, Pulse Facility, Los Alamos, New Mexico 87545 (United States)] [National High Magnetic Field Laboratory, Pulse Facility, Los Alamos, New Mexico 87545 (United States); Sarrao, J.L.; Fisk, Z. [National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306 (United States)] [National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306 (United States)

    1996-05-01

    We present results for the resistivity, the magnetoresistance, and the specific heat of Ce{sub 0.97}La{sub 0.03}Pd{sub 3} and CePd{sub 3}. The impurity contributions to these measurements follow the predictions of the single-impurity Kondo model for a Kondo temperature {ital T}{sub {ital L}}{approx_equal}65 K, assuming that the impurity behaves as a crystal-field split ({Gamma}{sub 7}) doublet. Assuming a {ital J}=5/2 impurity, the value of {ital T}{sub {ital L}} needed to fit these experiments varies from 65 to 125 K. The contribution to the susceptibility may be too small to be explained by the model. These results address whether the nonmagnetic impurity behaves as a Kondo hole. {copyright} {ital 1996 The American Physical Society.}

  2. Influence of Electron Doping on Magnetic Order in CeRu2Al10

    SciTech Connect (OSTI)

    Kobayashi, Riki; Kaneko, Koji; Saito, Kotaro; Mignot, Jean-Michel; André, Gilles; Robert, Julien; Wakimoto, Shuichi; Matsuda, Masaaki; Chi, Songxue; Haga, Yoshinori; Matsuda, Tatsuma D.; Yamamoto, Etsuji; Nishioka, Takashi; Matsumura, Masahiro; Tanida, Hiroshi; Sera, Masafumi

    2014-09-17

    The effect of electron doping by the substitution of Rh for Ru on unconventional magnetic order in CeRu2Al10 was investigated via neutron powder diffraction. In Ce(Ru1-xRhx)2Al10 with x = 0.05, 0.12, and 0.2, reorientation of the ordered moment from the c- to the a-axis takes place in all samples, while the ordering vector q=(0 1 0) remains unchanged within this concentration range. The moment reorientation is accompanied by an enhancement in its size by a factor of ~2.4, from μ=0.43 μB at x=0 to μ =1.06, 1.04, and 1.02 μB for x=0.05, 0.12 and 0.2, respectively. The continuous decrease in N´eel temperature T0(TN), despite an abrupt increase in μ , underlines the strong anisotropy in the exchange interaction in CeRu2Al10, and the fact that this anisotropy is easily suppressed by electron doping.

  3. Strongly enhanced oxygen ion transport through samarium-doped CeO2 nanopillars in nanocomposite films

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yang, Sangmo; Lee, Shinbuhm; Jian, Jie; Zhang, Wenrui; Lu, Ping; Jia, Quanxi; Wang, Haiyan; Noh, Tae Won; Kalinin, Sergei V.; MacManus-Driscoll, Judith L.

    2015-10-08

    Enhancement of oxygen ion conductivity in oxides is important for low-temperature (<500 °C) operation of solid oxide fuel cells, sensors and other ionotronic devices. While huge ion conductivity has been demonstrated in planar heterostructure films, there has been considerable debate over the origin of the conductivity enhancement, in part because of the difficulties of probing buried ion transport channels. Here we create a practical geometry for device miniaturization, consisting of highly crystalline micrometre-thick vertical nanocolumns of Sm-doped CeO2 embedded in supporting matrices of SrTiO3. The ionic conductivity is higher by one order of magnitude than plain Sm-doped CeO2 films. Bymore » using scanning probe microscopy, we show that the fast ion-conducting channels are not exclusively restricted to the interface but also are localized at the Sm-doped CeO2 nanopillars. This work offers a pathway to realize spatially localized fast ion transport in oxides of micrometre thickness.« less

  4. Strongly enhanced oxygen ion transport through samarium-doped CeO2 nanopillars in nanocomposite films

    SciTech Connect (OSTI)

    Yang, Sang Mo; Lee, Shinbuhm; Jian, Jie; Zhang, Wenrui; Lu, Ping; Jia, Quanxi; Wang, Haiyan; Won Noh, Tae; Kalinin, Sergei V.; MacManus?Driscoll, Judith L.

    2015-10-08

    Enhancement of oxygen ion conductivity in oxides is important for low-temperature (<500 C) operation of solid oxide fuel cells, sensors and other ionotronic devices. While huge ion conductivity has been demonstrated in planar heterostructure films, there has been considerable debate over the origin of the conductivity enhancement, in part because of the difficulties of probing buried ion transport channels. Here we create a practical geometry for device miniaturization, consisting of highly crystalline micrometre-thick vertical nanocolumns of Sm-doped CeO2 embedded in supporting matrices of SrTiO3. The ionic conductivity is higher by one order of magnitude than plain Sm-doped CeO2films. Then by using scanning probe microscopy, we show that the fast ion-conducting channels are not exclusively restricted to the interface but also are localized at the Sm-doped CeO2 nanopillars. Furthermore, this work offers a pathway to realize spatially localized fast ion transport in oxides of micrometre thickness.

  5. One-, two-, and three-channel Kondo effects for a model Ce{sup 3+} impurity in a metal

    SciTech Connect (OSTI)

    Kim, T.; Cox, D.L.

    1997-05-01

    We present studies of a simple Anderson model Hamiltonian for Ce{sup 3+} ions in cubic symmetry with three configurations (f{sup 0},f{sup 1},f{sup 2}). In different parameter regimes, our model Hamiltonian maps to the one-, two-, and three-channel spin-1/2 Kondo models. Using third-order scaling (perturbative renormalization group) analysis, we study the stability of the non-Fermi-liquid fixed point of the two-channel Kondo model for Ce{sup 3+} ions in cubic symmetry against the one-channel Kondo interaction. Using the noncrossing approximation (NCA), we also report detailed studies for our simplified model of the competition between the Fermi-liquid fixed point of the one-channel Kondo model and the non-Fermi fixed points of the two- and three-channel Kondo models. We provide the phase diagram in the model parameter space and study the thermodynamics and the transport properties of our simplified model Hamiltonian. Thermodynamics and transport coefficients show distinct behaviors for different numbers of channels. We confirm in detail that the NCA is a valid numerical method for the overcompensated multichannel S{sub I}=1/2 Anderson models. Our model study might be relevant to the non-Fermi-liquid alloy Ce{sub 1{minus}x}La{sub x}Cu{sub 2.2}Si{sub 2}. {copyright} {ital 1997} {ital The American Physical Society}

  6. Strongly enhanced oxygen ion transport through samarium-doped CeO2 nanopillars in nanocomposite films

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yang, Sang Mo; Lee, Shinbuhm; Jian, Jie; Zhang, Wenrui; Lu, Ping; Jia, Quanxi; Wang, Haiyan; Won Noh, Tae; Kalinin, Sergei V.; MacManus‐Driscoll, Judith L.

    2015-10-08

    Enhancement of oxygen ion conductivity in oxides is important for low-temperature (<500 °C) operation of solid oxide fuel cells, sensors and other ionotronic devices. While huge ion conductivity has been demonstrated in planar heterostructure films, there has been considerable debate over the origin of the conductivity enhancement, in part because of the difficulties of probing buried ion transport channels. Here we create a practical geometry for device miniaturization, consisting of highly crystalline micrometre-thick vertical nanocolumns of Sm-doped CeO2 embedded in supporting matrices of SrTiO3. The ionic conductivity is higher by one order of magnitude than plain Sm-doped CeO2films. Then bymore » using scanning probe microscopy, we show that the fast ion-conducting channels are not exclusively restricted to the interface but also are localized at the Sm-doped CeO2 nanopillars. Furthermore, this work offers a pathway to realize spatially localized fast ion transport in oxides of micrometre thickness.« less

  7. Effect of Oxygen Defects on the Catalytic Performance of VOx/CeO2 Catalysts for Oxidative Dehydrogenation of Methanol

    SciTech Connect (OSTI)

    Li, Yan; Wei, Zhehao; Gao, Feng; Kovarik, Libor; Baylon, Rebecca A.; Peden, Charles HF; Wang, Yong

    2015-05-01

    In this work, CeO2 nanocubes with controlled particle size and dominating (100) facets are synthesized as supports for VOx catalysts. Combined TEM, SEM, XRD, and Raman study reveals that the oxygen vacancy density of CeO2 supports can be tuned by tailoring the particle sizes without altering the dominating facets, where smaller particle sizes result in larger oxygen vacancy densities. At the same vanadium coverage, the VOx catalysts supported on small-sized CeO2 supports with higher oxygen defect densities exhibit promoted redox property and lower activation energy for methoxyl group decomposition, as evidenced by H2-TPR and methanol TPD study. These results further confirm that the presence of oxygen vacancies plays an important role in promoting the activity of VOx species in methanol oxidation. We gratefully acknowledge financial support from the U.S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. Part of this work was conducted in the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is a multiprogram national laboratory operated for the DOE by Battelle.

  8. Remarkably robust and correlated coherence and antiferromagnetism in (Ce1-xLax)Cu2Ge2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hodovanets, H.; Bud’ko, S. L.; Straszheim, W. E.; Taufour, V.; Mun, E. D.; Kim, H.; Flint, R.; Canfield, P. C.

    2015-06-08

    We present magnetic susceptibility, resistivity, specific heat, and thermoelectric power measurements on (Ce1-xLax)Cu2Ge2 single crystals (0 ≤ x ≤ 1). With La-substitution, the antiferromagnetic temperature TN is suppressed in an almost linear fashion and moves below 0.36 K, the base temperature of our measurements for x > 0.8. Surprisingly, in addition to robust antiferromagnetism, the system also shows low temperature coherent scattering below Tcoh up to ~0.9 of La, indicating a small percolation limit ~9% of Ce. Tcoh as a function of magnetic field was found to have different behavior for x < 0.9 and x > 0.9. Remarkably, (Tcoh)2more » at H = 0 was found to be linearly proportional to TN. In conclusion, the jump in the magnetic specific heat δCm at TN as a function of TK/TN for (Ce1-xLax)Cu2Ge2 follows the theoretical prediction based on the molecular field calculation for the S = 1/2 resonant level model.« less

  9. SESAME 96170, a solid-liquid equation of state for CeO2

    SciTech Connect (OSTI)

    Chisolm, Eric D.

    2014-05-02

    I describe an equation of state (EOS) for the low-pressure solid phase and liquid phase of cerium (IV) oxide, CeO2. The models and parameters used to calculate the EOS are presented in detail, and I compare with data for the full-density crystal. Hugoniot data are available only for high-porosity powders, and I discuss difficulties in comparing with such data. I have constructed SESAME 96170, an EOS for cerium (IV) oxide that includes the ambient solid and liquid phases. The EOS extends over the full standard SESAME range, but should not be used at low temperatures and high densities because of the lack of a high-pressure solid phase. I have described the models used to compute the three terms of the EOS (cold curve, nuclear, and thermal electronic), and I have given the parameters used in the models. They were determined by comparison with experimental data at P = 1 atm, including the constant-pressure specific heat, coefficient of thermal expansion, and melting and boiling points. The EOS compares well with data in its intended range of validity, but the presence of high-frequency optical modes in its phonon spectrum limits the agreement of our models with thermal data. The next step is to construct a multiphase EOS that includes the low- and high-pressure solid phases and the liquid. The DAC data from Duclos will most strongly constrain the parameters of the high-pressure solid. A remaining issue is the comparison of the crystal-density EOS with experimental Hugoniot data, which are taken at much lower initial data because the samples are porous powders. A satisfactory means of modeling porosity, allowing comparison of theory and experiment, has not yet been produced.

  10. Structural characterization of the CeO{sub 2}/Gd{sub 2}O{sub 3} mixed system by synchrotron X-ray diffraction

    SciTech Connect (OSTI)

    Artini, Cristina; Costa, Giorgio A.; Pani, Marcella; Lausi, Andrea; Plaisier, Jasper

    2012-06-15

    The structural determination of the CeO{sub 2}/Gd{sub 2}O{sub 3} mixed system is a non-trivial problem because of the close resemblance between the ionic sizes of Ce{sup 4+} and Gd{sup 3+} and between the crystal structures of CeO{sub 2} and Gd{sub 2}O{sub 3}. (Ce{sub 1-x}Gd{sub x})O{sub 2-x/2} powder samples with x ranging between 0 and 1 have been synthesized by coprecipitation of mixed oxalates and subsequent thermal decomposition in air at 1200 Degree-Sign C followed by slow cooling. Synchrotron powder X-ray diffraction data were collected and refined by the Rietveld method. Lattice parameters do not follow Vegard's law and no peak splitting has been observed for any composition, meaning that no biphasic regions exist over the whole compositional range. The same hybrid structural model - a proper mixture of the structures of the two pure oxides - was used for the refinements, allowing to account for the data observed. - graphical abstract: Substituting Ce{sup 4+} by Gd{sup 3+}, a gradual transition from the F structure (typical of CeO{sub 2}) to the C structure (typical of Gd{sub 2}O{sub 3}) takes place. The lattice parameters do not follow Vegard's law. Highlights: Black-Right-Pointing-Pointer A structural study of Ce-Gd mixed oxides has been performed. Black-Right-Pointing-Pointer In (Ce{sub 1-x}Gd{sub x})O{sub 2-x/2} a solid solution forms for 0{<=}x{<=}0.3. Black-Right-Pointing-Pointer For x>0.3 a gradual transition from the C to the F structure is observed. Black-Right-Pointing-Pointer Lattice parameters do not follow Vegard's law.

  11. Methanol conversion to light olefins over nanostructured CeAPSO-34 catalyst: Thermodynamic analysis of overall reactions and effect of template type on catalytic properties and performance

    SciTech Connect (OSTI)

    Aghamohammadi, Sogand; Haghighi, Mohammad; Charghand, Mojtaba

    2014-02-01

    Graphical abstract: In this research nanostructured CeAPSO-34 was synthesized to explore the effect of TEAOH and morpholine on its physiochemical properties and MTO performance. Prepared catalysts were characterized with XRD, FESEM, BET, FTIR and NH3-TPD techniques. The results indicated that the nature of the template determines the physiochemical properties of CeAPSO-34 due to different rate of crystal growth. The catalyst obtained by using morpholine showed longer life time as well as sustaining light olefins selectivity at higher values. Furthermore, a comprehensive thermodynamic analysis of overall reactions network was carried out to address the major channels of methanol to olefins conversion. - Highlights: Introduction of Ce into SAPO-34 framework. Comparison of CeAPSO-34 synthesized using morpholine and TEAOH. The nature of the template determines the physiochemical properties of CeAPSO-34. Morpholine enhances catalyst lifetime in MTO process. Presenting a complete reaction network for MTO process. - Abstract: TEAOH and morpholine were employed in synthesis of nanostructured CeAPSO-34 molecular sieve and used in methanol to olefins conversion. Prepared samples were characterized by XRD, FESEM, EDX, BET, FTIR and NH{sub 3}-TPD techniques. XRD patterns reflected the higher crystallinity of the catalyst synthesized with morpholine. The FESEM results indicated that the nature of the template determines the morphology of nanostructured CeAPSO-34 due to different rate of crystal growth. There was a meaningful difference in the strength of both strong and weak acid sites for CeAPSO-34 catalysts synthesized with TEAOH and morpholine templates. The catalyst synthesized with morpholine showed higher desorption temperature of both weak and strong acid sites evidenced by NH{sub 3}-TPD characterization. The catalyst obtained using morpholine template had the longer lifetime and sustained desired light olefins at higher values. A comprehensive thermodynamic analysis of overall reactions network was carried out to address the major channels of methanol to olefins conversion.

  12. Superior performance of Ni–W–Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Johnson-Peck, Aaron C.; Zhao, Fuzhen; Michorczyk, Piotr; Kubacka, Anna; Stach, Eric A.; Fernández-García, Marcos; Senanayake, Sanjaya D.; et al

    2014-11-26

    In this study, the ethanol steam reforming (ESR) reaction was examined over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO₂ lattice, with the remaining Ni forming highly dispersed nano NiO (< 2 nm) outside the Ni-W-Ce oxide structure. The nano NiO was reduced to Nimore » under ESR conditions. The Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.« less

  13. Superior performance of Ni-W-Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

    SciTech Connect (OSTI)

    Rodriguez, Jose A.; Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Johnson-Peck, Aaron C.; Zhao, Fuzhen; Michorczyk, Piotr; Kubacka, Anna; Stach, Eric A.; Fernandez-Garica, Marcos; Senanayake, Sanjaya D.

    2014-11-26

    The ethanol steam reforming (ESR) reaction was studied over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO? lattice, with the remaining Ni forming highly dispersed nano NiO (< 2 nm) outside the Ni-W-Ce oxide structure. The nano NiO was reduced to Ni under ESR conditions. The Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.

  14. A ferromagnetic quantum critical point in heavy-fermion iron oxypnictide CeFe{sub 1?x}Cr{sub x}PO

    SciTech Connect (OSTI)

    Okano, T.; Matoba, M.; Kamihara, Y.; Kitao, S.; Seto, M.; Atou, T.; Itoh, M.

    2015-05-07

    We report crystallographic and magnetic properties of layered iron oxypnictide CeFe{sub 1?x}Cr{sub x}PO (x?=?0.0000.692). Interlayer distances between Ce{sub 2}O{sub 2} and (Fe{sub 1?x}Cr{sub x}){sub 2}P{sub 2} layers increase as a function of x, suggesting suppression of Kondo coupling among hybridized conducting orbitals and localized Ce 4f orbitals. CeFe{sub 1?x}Cr{sub x}PO (x?=?0.1000.384) exhibits finite ferromagnetic transition temperatures (T{sub curie}) obtained by Arrott plots, although {sup 57}Fe Mssbauer spectra reveal paramagnetic Fe sublattice at T???4.2?K. These results indicate that the ferromagnetic phase transitions of samples are mainly due to Ce sublattice. For the samples with x???0.500, no ferromagnetic order is observed down to 2?K. These results verify that ferromagnetic quantum critical points of CeFe{sub 1?x}Cr{sub x}PO appear at 0.045???x???0.100 and 0.384???x???0.500.

  15. Superior performance of Ni–W–Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

    SciTech Connect (OSTI)

    Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Johnson-Peck, Aaron C.; Zhao, Fuzhen; Michorczyk, Piotr; Kubacka, Anna; Stach, Eric A.; Fernández-García, Marcos; Senanayake, Sanjaya D.; Rodriguez, José A.

    2014-11-26

    In this study, the ethanol steam reforming (ESR) reaction was examined over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO₂ lattice, with the remaining Ni forming highly dispersed nano NiO (< 2 nm) outside the Ni-W-Ce oxide structure. The nano NiO was reduced to Ni under ESR conditions. The Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.

  16. Crystalline Electric Field as a Probe for Long-Range Antiferromagnetic Order and Superconducting State of CeFeAsO1-xFx

    SciTech Connect (OSTI)

    Chi, Songxue; Adroja, D. T.; GUIDI, T.; Bewley, Robert I.; Li, Shiliang; Zhao, Jun; Lynn, J. W.; Brown, C. M.; Qiu, Y.; Chen, G. F,; Luo, J. L.; Wang, N. L.; Dai, Pengcheng

    2008-01-01

    We use inelastic neutron scattering to study the crystalline electric field (CEF) excitations of Ce{sup 3+} in CeFeAsO{sub 1-x}F{sub x} (x=0, 0.16). For nonsuperconducting CeFeAsO, the Ce CEF levels have three magnetic doublets in the paramagnetic state, but these doublets split into six singlets when the Fe ions order antiferromagnetically. For superconducting CeFeAsO{sub 0.84}F{sub 0.16} (T{sub c} = 41 K), where the static antiferromagnetic order is suppressed, the Ce CEF levels have three magnetic doublets at {h_bar}{sub {omega}} = 0, 18.7, 58.4 meV at all temperatures. Careful measurements of the intrinsic linewidth {Lambda} and the peak position of the 18.7 meV mode reveal a clear anomaly at T{sub c}, consistent with a strong enhancement of local magnetic susceptibility {chi}{double_prime}({h_bar}{sub {omega}}) below T{sub c}. These results suggest that CEF excitations in the rare-earth oxypnictides can be used as a probe of spin dynamics in the nearby FeAs planes.

  17. Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+}: A novel blue emitting phosphor for white LEDs

    SciTech Connect (OSTI)

    Li, Panlai Wang, Zhijun Yang, Zhiping; Guo, Qinglin

    2014-12-15

    Graphical abstract: Under the 350 nm radiation excitation, Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} has a broad blue emission band. When the temperature turned up to 150 C, the emission intensity of Ba{sub 1.97}B{sub 2}O{sub 5}:0.03Ce{sup 3+} is 63.4% of the initial value at room temperature. The activation energy ?E is calculated to be 0.25 eV, which prove the good thermal stability of Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+}. All the properties indicate that Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} may have potential application in white LEDs. - Highlights: Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} has a broad blue emission band under the 350 nm radiation excitation. Emission intensity of Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} is 63.4% (150 C) of the initial value (30 C). The activation energy ?E for thermal quenching is 0.25 eV. - Abstract: A novel blue emitting phosphor Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} is synthesized by a high temperature solid state method. The luminescent property and the thermal stability of Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} are investigated. Under the 350 nm radiation excitation, Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} has a broad blue emission band, and the peak locates at 417 nm which is assigned to the 5d{sup 1}4f{sup 1} transition of Ce{sup 3+}. It is further proved that the dipoledipole interaction results in the concentration quenching of Ce{sup 3+} in Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+}. When the temperature turned up to 150 C, the emission intensity of Ba{sub 1.97}B{sub 2}O{sub 5}:0.03Ce{sup 3+} is 63.4% of the initial value at room temperature. The activation energy ?E is calculated to be 0.25 eV, which prove the good thermal stability of Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+}. All the properties indicate that Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} may have potential application in white LEDs.

  18. Hierarchical heterogeneity at the CeOx-TiO? interface: Electronic and geometric structural influence on the photocatalytic activity of oxide on oxide nanostructures

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    None

    2015-01-13

    Mixed oxide interfaces are critical for delivering active components of demanding catalytic processes such as the photo-catalytic splitting of water. We have studied CeOxTiO? catalysts with low ceria loadings of 1 wt%, 3 wt% and 6 wt% that were prepared with wet impregnation methods to favor a strong interaction between CeOx and TiO?. In these materials the interfaces between CeOx-TiO? have been sequentially loaded (1%, 3% and 6%), with and without Pt (0.5 wt%). The structure and properties of the catalysts were characterized using several X-ray and electron based techniques including XRD, XPS, UPS, NEXAFS, UV-Vis and HR-STEM/STEM-EELS, to unravelmorethe local morphology, bulk structure, surface states and electronic structure. The combination of all these techniques allow us to analyze in a systematic way the complete structural and electronic properties that prevail at the CeOx-TiO? interface. Fluorite structured nano crystallites of ceria on anatase-structured titania were identified by both XRD and NEXAFS. A sequential increasing of the CeOx loading led to the formation of clusters, then plates and finally nano particles in a hierarchical manner on the TiO? support. The electronic structures of these catalysts indicate that the interaction between TiO? and CeO? is closely related to the local morphology of nanostructured CeO?. Ce? cations were detected at the surface of CeO? and at the interface of the two oxides. In addition, the titania is perturbed by the interaction with ceria and also with Pt. The photocatalytic activity for the splitting of H?O using UV light was measured for these materials and correlated with our understanding of the electronic and structural properties. Optimal catalytic performance and photo response results were found for the 1 wt% CeOx-TiO? catalyst where low dimensional geometry of the ceria provided ideal electronic and geometrical properties. The structural and electronic properties of the interface were critical for the photocatalytic performance of this mixed-oxide nanocatalyst system.less

  19. Hierarchical Heterogeneity at the CeO x –TiO 2 Interface: Electronic and Geometric Structural Influence on the Photocatalytic Activity of Oxide on Oxide Nanostructures

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Luo, Si; Nguyen-Phan, Thuy-Duong; Johnston-Peck, Aaron C.; Barrio, Laura; Sallis, Shawn; Arena, Dario A.; Kundu, Shankhamala; Xu, Wenqian; Piper, Louis F. J.; Stach, Eric A.; et al

    2015-01-13

    Mixed oxide interfaces are critical for delivering active components of demanding catalytic processes such as the photo-catalytic splitting of water. We have studied CeOxTiO₂ catalysts with low ceria loadings of 1 wt%, 3 wt% and 6 wt% that were prepared with wet impregnation methods to favor a strong interaction between CeOx and TiO₂. In these materials the interfaces between CeOx-TiO₂ have been sequentially loaded (1%, 3% and 6%), with and without Pt (0.5 wt%). The structure and properties of the catalysts were characterized using several X-ray and electron based techniques including XRD, XPS, UPS, NEXAFS, UV-Vis and HR-STEM/STEM-EELS, to unravelmore » the local morphology, bulk structure, surface states and electronic structure. The combination of all these techniques allow us to analyze in a systematic way the complete structural and electronic properties that prevail at the CeOx-TiO₂ interface. Fluorite structured nano crystallites of ceria on anatase-structured titania were identified by both XRD and NEXAFS. A sequential increasing of the CeOx loading led to the formation of clusters, then plates and finally nano particles in a hierarchical manner on the TiO₂ support. The electronic structures of these catalysts indicate that the interaction between TiO₂ and CeO₂ is closely related to the local morphology of nanostructured CeO₂. Ce³⁺ cations were detected at the surface of CeO₂ and at the interface of the two oxides. In addition, the titania is perturbed by the interaction with ceria and also with Pt. The photocatalytic activity for the splitting of H₂O using UV light was measured for these materials and correlated with our understanding of the electronic and structural properties. Optimal catalytic performance and photo response results were found for the 1 wt% CeOx-TiO₂ catalyst where low dimensional geometry of the ceria provided ideal electronic and geometrical properties. The structural and electronic properties of the interface were critical for the photocatalytic performance of this mixed-oxide nanocatalyst system.« less

  20. Comparative Gamma Spectroscopy with SrI2(Eu), GYGAG(Ce) and Bi-loaded Plastic Scintillators

    SciTech Connect (OSTI)

    Cherepy, N J

    2010-11-19

    We are developing new scintillator materials that offer potential for high resolution gamma ray spectroscopy at low cost. Single crystal SrI{sub 2}(Eu) offers {approx}3% resolution at 662 keV, in sizes of {approx}1 in{sup 3}. We have developed ceramics processing technology allowing us to achieve cubic inch scale transparent ceramic scintillators offering gamma spectroscopy performance superior to NaI(Tl). We fabricated a bismuth-loaded plastic scintillator that demonstrates energy resolution of {approx}8% at 662 keV in small sizes. Gamma ray spectroscopy can be used to identify the presence of weak radioactive sources within natural background. The ability to discriminate close-lying spectral lines is strongly dependent upon the energy resolution of the detector. In addition to excellent energy resolution, large volume detectors are needed to acquire sufficient events, for example, to identify a radioactive anomaly moving past a detector. We have employed a 'directed search' methodology for identifying potential scintillator materials candidates, resulting in the discovery of Europium-doped Strontium Iodide, SrI{sub 2}(Eu), Cerium-doped Gadolinium Garnet, GYGAG(Ce), and Bismuth-loaded Polymers. These scintillators possess very low self-radioactivity, offer energy resolution of 3-8% at 662 keV, and have potential to be grown cost-effectively to sizes similar to the most widely deployed gamma spectroscopy scintillator, Thallium-doped Sodium Iodide, NaI(Tl). In this study, gamma ray spectra of a variety of sources, were obtained employing SrI{sub 2}(Eu), GYGAG(Ce), Bi-loaded polymers, LaBr{sub 3}(Ce), and NaI(Tl). The effects of detector size, energy resolution, and background radioactivity (including self-radioactivity) on the ability to distinguish weak sources is quantified, based on a simple model, and qualitatively compared to laboratory data.

  1. Heavy fermion Ce{sub 3}Co{sub 4}Sn{sub 13} compound under pressure

    SciTech Connect (OSTI)

    Collave, J. R.; Borges, H. A.; Ramos, S. M.; Hering, E. N.; Mendona-Ferreira, L.; Pagliuso, P. G.

    2015-05-07

    The non-magnetic heavy fermion compound Ce{sub 3}Co{sub 4}Sn{sub 13} was studied under pressure. We report single crystalline measurements of electrical resistivity as a function of temperature ?(T) under pressure. Some characteristic features related to a structural transition (T{sub S}), crystalline field effects (T{sub CEF}), and a low temperature maximum (T{sub max}), possibly connected simultaneously to the onset of Kondo lattice coherence and short range magnetic correlations, were identified in the ?(T) data. A pressure-temperature phase diagram with T{sub S} and T{sub max} was constructed by mapping these features. Like for most Ce-based heavy fermion compounds, T{sub max} moves to higher temperatures with pressure, indicating that it is related to the Kondo energy scale, due to the increase of hybridization induced by pressure. On the other hand, T{sub S}, associated to a superlattice distortion and probably combined with a charge density wave transition, decreases as a function of pressure. However, differently from the Sr{sub 3?x}Ca{sub x}Ir{sub 4}Sn{sub 13} system, where a superlattice quantum phase transition is observed [L. E. Klintberg et al., Phys. Rev. Lett. 109, 237?008 (2012)], in Ce{sub 3}Co{sub 4}Sn{sub 13} T{sub S}???154?K, at ambient pressure (P?=?0), seems to stabilize at around 143?K for P???19 kilobars. We also investigated ?(T) in external magnetic fields, at P?=?0. Negative magnetoresistance and increase of T{sub max} are observed, suggesting suppression of low temperature short range magnetic correlations.

  2. Synthesis of mesoporous Bi{sub 2}O{sub 3}/CeO{sub 2} microsphere for photocatalytic degradation of Orange II dye

    SciTech Connect (OSTI)

    Hsieh, Shu-Han; Manivel, Arumugam; Lee, Gang-Juan; Wu, Jerry J.

    2013-10-15

    Graphical abstract: - Highlights: Bi{sub 2}O{sub 3}/CeO{sub 2} microspheres were successfully synthesized by a hydrothermal procedure. Bi{sub 2}O{sub 3}/CeO{sub 2} microspheres were used to remove wastewater pollutant containing azo dye. The activity of Bi{sub 2}O{sub 3}/CeO{sub 2} is synergically enhanced compared to its pristine forms. - Abstract: We report on the visible-light responsive porous assembly of Bi{sub 2}O{sub 3}/CeO{sub 2} microspheres, which were synthesized via a simple hydrothermal reaction between Bi(NO{sub 3}){sub 3}5H{sub 2}O and Ce(NO{sub 3}){sub 3}6H{sub 2}O in the presence of ethylene glycol and ethanol. Systematic structural (X-ray diffraction (XRD)), morphological (field emission scanning electron microscopy (FE-SEM) and transmission electron microscopic (TEM)), BET surface area and diffuse reflectance spectral (DRS) analyses were carried out to characterize the formed product. The effects of experimental parameters on the microstructural and morphological behavior of Bi{sub 2}O{sub 3}/CeO{sub 2} composites were discussed. The semiconductor material as obtained was evaluated as a heterogeneous photocatalyst for the photolytic degradation of an azo dye in water and the degradation was found to follow pseudo-first-order rate kinetics. The study compares the rate constants of the new hybrid catalyst to a pristine Bi{sub 2}O{sub 3} and CeO{sub 2}, which has excellent catalytic properties under visible light irradiation for the degradation of Orange II dye.

  3. Fabrication and microstructure of cerium doped lutetium aluminum garnet (Ce:LuAG) transparent ceramics by solid-state reaction method

    SciTech Connect (OSTI)

    Li, Junlang; Xu, Jian; Shi, Ying; Qi, Hongfang; Xie, Jianjun; Lei, Fang

    2014-07-01

    Highlights: We fabricate Ce doped lutetium aluminum garnet ceramics by solid-state method. The raw materials include Lu{sub 2}O{sub 3} nanopowders synthesized by co-precipitation method. The density of the transparent ceramics reach 99.7% of the theoretical value. The optical transmittance of the bulk ceramic at 550 nm was 57.48%. Some scattering centers decrease the optical characteristic of the ceramic. - Abstract: Polycrystalline Ce{sup 3+} doped lutetium aluminum garnet (Ce:LuAG) transparent ceramics fabricated by one step solid-state reaction method using synthetic nano-sized Lu{sub 2}O{sub 3}, commercial ?-Al{sub 2}O{sub 3} and CeO{sub 2} powders were investigated in this paper. The green compacts shaped by the mixed powders were successfully densified into Ce:LuAG transparent ceramics after vacuum sintering at 1750 C for 10 h. The in-line optical transmittance of the Ce:LuAG ceramic made by home-made Lu{sub 2}O{sub 3} powders could reach 57.48% at 550 nm, which was higher than that of the ceramic made by commercial Lu{sub 2}O{sub 3} powders (22.96%). The microstructure observation showed that light scattering centers caused by micro-pores, aluminum segregation and refraction index inhomogeneities induced the decrease of optical transparency of the Ce:LuAG ceramics, which should be removed and optimized in the future work.

  4. Response of LaBr{sub 3}(Ce) scintillators to 2.5 MeV fusion neutrons

    SciTech Connect (OSTI)

    Cazzaniga, C.; Nocente, M.; Gorini, G.; Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Via Roberto Cozzi 53, Milano 20125 ; Tardocchi, M.; Croci, G.; Giacomelli, L.; Angelone, M.; Pillon, M.; Villari, S.; Weller, A.; Petrizzi, L.; Collaboration: ASDEX Upgrade Team; JET-EFDA Contributors

    2013-12-15

    Measurements of the response of LaBr{sub 3}(Ce) to 2.5 MeV neutrons have been carried out at the Frascati Neutron Generator and at tokamak facilities with deuterium plasmas. The observed spectrum has been interpreted by means of a Monte Carlo model. It is found that the main contributor to the measured response is neutron inelastic scattering on {sup 79}Br, {sup 81}Br, and {sup 139}La. An extrapolation of the count rate response to 14 MeV neutrons from deuterium-tritium plasmas is also presented. The results are of relevance for the design of ?-ray diagnostics of fusion burning plasmas.

  5. Effect of magnetic fields on the Kondo insulator CeRhSb: Magnetoresistance and high-field heat capacity measurements

    SciTech Connect (OSTI)

    Malik, S.K.; Menon, L.; Pecharsky, V.K.; Gschneidner, K.A. Jr.

    1997-05-01

    The compound CeRhSb is a mixed valent Ce-based compound which shows a gap in the electronic density of states at low temperatures. The gap manifests by a rise in electrical resistivity{emdash}below about 8 K from which the gap energy is estimated to be about 4 K. We have carried out heat capacity measurements on this compound in various applied fields up to 9.85 T. The magnetic contribution to the heat capacity, {Delta}C, is found to have a maximum in {Delta}C/T vs T at 10 K, below which {Delta}C/T is linear with T. This is attributed to the fact that below this temperature, in the gapped state, the electronic density of states decreases linearly with decreasing temperature. On application of a magnetic field, the electronic specific heat coefficient {gamma} in the gapped state increases by {approximately}4mJ/molK{sup 2}. The maximum in {Delta}C/T vs T is observed in all fields, which shifts to lower temperatures {approximately}1K at 5.32 T and raises again at 9.85 T to about the same values as at H=0T. This suggests that the gap exists for all fields up to 9.85 T. Above 10 K, in the mixed-valent state, {Delta}C/T vs T decreases with increasing temperature in zero field. There is hardly any effect of application of field in the mixed-valent state. We have also carried out magnetoresistance measurements on CeRhSb up to fields of 5.5 T at 2, 4.5, 10, 20, and 30 K. The magnetoresistance in CeRhSb is positive at temperatures of 4.5 K and above, in applied fields up to 5.5 T. At 5.5 T, the magnetoresistance is maximum at 4.5 K (6{percent}) and decreases with increasing temperature. The observation of the maximum is consistent with the observation of a maximum in {Delta}C/T vs T and is due to a change in the density of states. At a temperature of 2 K, a negative magnetoresistance is observed for magnetic fields greater than {approximately}3.5T which suggests reduction in the gap. {copyright} {ital 1997} {ital The American Physical Society}

  6. Generation and reactivity of putative support systems, Ce-Al neutral binary oxide nanoclusters: CO oxidation and CH bond activation

    SciTech Connect (OSTI)

    Wang, Zhe-Chen; Yin, Shi; Bernstein, Elliot R.

    2013-11-21

    Both ceria (CeO{sub 2}) and alumina (Al{sub 2}O{sub 3}) are very important catalyst support materials. Neutral binary oxide nanoclusters (NBONCs), Ce{sub x}Al{sub y}O{sub z}, are generated and detected in the gas phase and their reactivity with carbon monoxide (CO) and butane (C{sub 4}H{sub 10}) is studied. The very active species CeAlO{sub 4}{sup } can react with CO and butane via O atom transfer (OAT) and H atom transfer (HAT), respectively. Other Ce{sub x}Al{sub y}O{sub z} NBONCs do not show reactivities toward CO and C{sub 4}H{sub 10}. The structures, as well as the reactivities, of Ce{sub x}Al{sub y}O{sub z} NBONCs are studied theoretically employing density functional theory (DFT) calculations. The ground state CeAlO{sub 4}{sup } NBONC possesses a kite-shaped structure with an O{sub t}CeO{sub b}O{sub b}AlO{sub t} configuration (O{sub t}, terminal oxygen; O{sub b}, bridging oxygen). An unpaired electron is localized on the O{sub t} atom of the AlO{sub t} moiety rather than the CeO{sub t} moiety: this O{sub t} centered radical moiety plays a very important role for the reactivity of the CeAlO{sub 4}{sup } NBONC. The reactivities of Ce{sub 2}O{sub 4}, CeAlO{sub 4}{sup }, and Al{sub 2}O{sub 4} toward CO are compared, emphasizing the importance of a spin-localized terminal oxygen for these reactions. Intramolecular charge distributions do not appear to play a role in the reactivities of these neutral clusters, but could be important for charged isoelectronic BONCs. DFT studies show that the reaction of CeAlO{sub 4}{sup } with C{sub 4}H{sub 10} to form the CeAlO{sub 4}HC{sub 4}H{sub 9}{sup } encounter complex is barrierless. While HAT processes have been previously characterized for cationic and anionic oxide clusters, the reported study is the first observation of a HAT process supported by a ground state neutral oxide cluster. Mechanisms for catalytic oxidation of CO over surfaces of Al{sub x}O{sub y}/M{sub m}O{sub n} or M{sub m}O{sub n}/Al{sub x}O{sub y} materials are proposed consistent with the presented experimental and theoretical results.

  7. Electronic and optical properties of layered RE{sub 2}Ti{sub 2}O{sub 7} (RE = Ce and Pr) from first principles

    SciTech Connect (OSTI)

    Sayede, A.; Khenata, R.; Chahed, A.; Benhelal, O.

    2013-05-07

    We have studied the structural and electronic properties of Ce{sub 2}Ti{sub 2}O{sub 7} (CeTO) and Pr{sub 2}Ti{sub 2}O{sub 7} (PrTO) by first-principles density functional theory calculations. The computed structural parameters are in fairly good agreement with the available experimental findings. Band structure calculations using the GGA+U approach predict an insulating ground state for the herein studied compounds. The insulating band gaps of 2.00 eV and 2.83 eV are found for CeTO and PrTO, respectively. The analysis of the density of states reveals that the strongly localized RE 4f levels act as charge-trapping sites, predicting a lower photocatalytic activity for CeTO. We have also calculated the optical properties for both CeTO and PrTO. Based on these properties, it is predicted that these titanates are insensitive to ultra-violet radiation, while they are more sensitive to frequencies of the radiation in visible and early UV regions.

  8. Universal heat conduction in Ce1-xYbxCoIn5: Evidence for robust nodal d-wave superconducting gap

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Xu, Y.; Petrovic, C.; Dong, J. K.; Lum, I. K.; Zhang, J.; Hong, X. C.; He, L. P.; Wang, K. F.; Ma, Y. C.; Maple, M. B.; et al

    2016-02-01

    In the heavy-fermion superconductor Ce1-xYbxCoIn5, Yb doping was reported to cause a possible change from nodal d-wave superconductivity to a fully gapped d-wave molecular superfluid of composite pairs near x ≈ 0.07 (nominal value xnom = 0.2). Here we present systematic thermal conductivity measurements on Ce1-xYbxCoIn5 (x = 0.013, 0.084, and 0.163) single crystals. The observed finite residual linear term κ0/T is insensitive to Yb doping, verifying the universal heat conduction of the nodal d-wave superconducting gap in Ce1-xYbxCoIn5. Similar universal heat conduction is also observed in the CeCo(In1–yCdy)5 system. Furthermore, these results reveal a robust nodal d-wave gap inmore » CeCoIn5 upon Yb or Cd doping.« less

  9. Antiferromagnetic Kondo lattice in the layered compound CePd1–xBi₂ and comparison to the superconductor LaPd1–xBi₂

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Han, Fei; Wan, Xiangang; Phelan, Daniel; Stoumpos, Constantinos C.; Sturza, Mihai; Malliakas, Christos D.; Li, Qing'an; Han, Tian-Heng; Zhao, Qingbiao; Chung, Duck Young; et al

    2015-07-13

    The layered compound CePd1–xBi₂ with the tetragonal ZrCuSi₂-type structure was obtained from excess Bi flux. Magnetic susceptibility data of CePd1–xBi₂ show an antiferromagnetic ordering below 6 K and are anisotropic along the c axis and the ab plane. The anisotropy is attributed to crystal-electric-field (CEF) effects and a CEF model which is able to describe the susceptibility data is given. An enhanced Sommerfeld coefficient γ of 0.191 J mol Ce⁻¹ K⁻² obtained from specific-heat measurement suggests a moderate Kondo effect in CePd1–xBi₂. Other than the antiferromagnetic peak at 6 K, the resistivity curve shows a shoulderlike behavior around 75 Kmore » which could be attributed to the interplay between Kondo and CEF effects. Magnetoresistance and Hall-effect measurements suggest that the interplay reconstructs the Fermi-surface topology of CePd1–xBi₂ around 75 K. Electronic structure calculations reveal that the Pd vacancies are important to the magnetic structure and enhance the CEF effects which quench the orbital moment of Ce at low temperatures.« less

  10. Small-Scale Solar Grants (Commerce RI)

    Broader source: Energy.gov [DOE]

    Commerce RI provides incentives for renewable-energy projects. Incentive programs are funded by the Rhode Island Renewable Energy Fund (REF) and alternative compliance payments (ACPs) from the...

  11. Rapid Microwave Preparation of Highly Efficient Ce[superscript 3+]-Substituted Garnet Phosphors for Solid State White Lighting

    SciTech Connect (OSTI)

    Birkel, Alexander; Denault, Kristin A.; George, Nathan C.; Doll, Courtney E.; Hry, Bathylle; Mikhailovsky, Alexander A.; Birkel, Christina S.; Hong, Byung-Chul; Seshadri, Ram (UCSB); (Mitsubishi)

    2012-04-30

    Ce{sup 3+}-substituted aluminum garnet compounds of yttrium (Y{sub 3}Al{sub 5}O{sub 12}) and lutetium (Lu{sub 3}Al{sub 5}O{sub 12}) - both important compounds in the generation of (In,Ga)N-based solid state white lighting - have been prepared using a simple microwave heating technique involving the use of a microwave susceptor to provide the initial heat source. Carbon used as the susceptor additionally creates a reducing atmosphere around the sample that helps stabilize the desired luminescent compound. High quality, phase-pure materials are prepared within a fraction of the time and using a fraction of the energy required in a conventional ceramic preparation; the microwave technique allows for a reduction of about 95% in preparation time, making it possible to obtain phase pure, Ce{sup 3+}-substituted garnet compounds in under 20 min of reaction time. It is estimated that the overall reduction in energy compared with ceramic routes as practiced in the lab is close to 99%. Conventionally prepared material is compared with material prepared using microwave heating in terms of structure, morphology, and optical properties, including quantum yield and thermal quenching of luminescence. Finally, the microwave-prepared compounds have been incorporated into light-emitting diode 'caps' to test their performance characteristics in a real device, in terms of their photon efficiency and color coordinates.

  12. Pressure-tuned quantum criticality in the antiferromagnetic Kondo semimetal CeNi2–δAs2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Luo, Yongkang; Ronning, F.; Wakeham, N.; Lu, Xin; Park, Tuson; Xu, Z. -A.; Thompson, J. D.

    2015-10-19

    The easily tuned balance among competing interactions in Kondo-lattice metals allows access to a zero-temperature, continuous transition between magnetically ordered and disordered phases, a quantum-critical point (QCP). Indeed, these highly correlated electron materials are prototypes for discovering and exploring quantum-critical states. Theoretical models proposed to account for the strange thermodynamic and electrical transport properties that emerge around the QCP of a Kondo lattice assume the presence of an indefinitely large number of itinerant charge carriers. Here, we report a systematic transport and thermodynamic investigation of the Kondo-lattice system CeNi2–δAs2 (δ ≈ 0.28) as its antiferromagnetic order is tuned by pressuremore » and magnetic field to zero-temperature boundaries. These experiments show that the very small but finite carrier density of ~0.032 e–/formular unit in CeNi2–δAs2 leads to unexpected transport signatures of quantum criticality and the delayed development of a fully coherent Kondo-lattice state with decreasing temperature. Here, the small carrier density and associated semimetallicity of this Kondo-lattice material favor an unconventional, local-moment type of quantum criticality and raises the specter of the Nozières exhaustion idea that an insufficient number of conduction-electron spins to separately screen local moments requires collective Kondo screening.« less

  13. Effect of Doping on Surface Reactivity and Conduction Mechanism in Sm-doped CeO2 Thin Films

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yang, Nan; Belianinov, Alex; Strelcov, Evgheni; Tebano, Antonello; Daniele, Dr. Di Castro; Schlueter, Dr. Christoph; Lee, Dr. Tien-Lin; Baddorf, Arthur P; Wisinger, Nina; Jesse, Stephen; et al

    2014-01-01

    Scanning probe microscopy measurements show irreversible surface electrochemistry in Sm-doped CeO2 thin films, which depends on humidity, temperature and doping concentration. A systematic study by electrochemical strain microscopy (ESM) in samples with two different Sm content and in several working conditions allows disclosing the microscopic mechanism underlying the difference in water adsorption and splitting with subsequent proton liberation. We measure the behavior of the hysteresis loops by changing temperature and humidity, both in standard ESM configuration and using the first order reversal curve (FORC) method. Complementing our study with spectroscopic measurements by hard x-ray photoemission spectroscopy we find that watermore » incorporation is favored until the doping with Sm is too high to allow the presence of Ce3+. The influence of doping on the surface reactivity and conduction mechanism clearly emerges from all of our experimental results. We find that at lower Sm concentration proton conduction is prevalent, featured by lower activation energy and higher mobility. Defect concentrations determine the type of the prevalent charge carrier in a doping dependent manner.« less

  14. Chemical Reduction of Nd1.85Ce0.15CuO4??Powders in Supercritical Sodium Ammonia Solutions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dias, Yasmin; Wang, Hui; Zhou, Haiqing; Lin, Feng; Lan, Yucheng

    2015-01-01

    Nd1.85Ce0.15CuO4??powders are chemically reduced in supercritical sodium ammonia solutions from room temperature to 350C. The crystallographic structure of the reduced powders is investigated from Rietveld refinement of X-ray powder diffraction. The atomic positions are maintained constant within experimental errors while temperature factors of all atoms increase significantly after the chemical treatments, especially of Nd/Ce atoms. The ammonothermally reduced Nd1.85Ce0.15CuO4??powders show diamagnetic below 24?K which is contributed to the lower oxygen content and higher temperature factors of atoms in the treated compound. The ammonothermal method paves a new way to reduce oxides in supercritical solutions near room temperature.

  15. Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron Scattering Studies and First-Principles Calculations

    SciTech Connect (OSTI)

    Mirmelstein, A.; Podlesnyak, Andrey A.; dos Santos, Antonio M.; Ehlers, Georg; Kerbel, O.; Matvienko, V.; Sefat, A. S.; Saporov, B.; Halder, G. J.; Tobin, J. G.

    2015-08-03

    The pressure-induced structural phase transition in the intermediate-valence compound CeNi has been investigated by x-ray and neutron powder diffraction techniques. It is shown that the structure of the pressure-induced CeNi phase (phases) can be described in terms of the Pnma space group. Equations of state for CeNi on both sides of the phase transition are derived and an approximate P-T phase diagram is suggested for P<8 GPa and T<300 K. The observed Cmcm→Pnma structural transition is then analyzed using density functional theory calculations, which successfully reproduce the ground state volume, the phase transition pressure, and the volume collapse associated with the phase transition.

  16. Chemical Reduction of Nd 1.85 Ce 0.15 CuO 4− δ Powders in Supercritical Sodium Ammonia Solutions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dias, Yasmin; Wang, Hui; Zhou, Haiqing; Lin, Feng; Lan, Yucheng

    2015-01-01

    Nd 1.85 Ce 0.15 CuO 4− δ powders are chemically reduced in supercritical sodium ammonia solutions from room temperature to 350°C. The crystallographic structure of the reduced powders is investigated from Rietveld refinement of X-ray powder diffraction. The atomic positions are maintained constant within experimental errors while temperature factors of all atoms increase significantly after the chemical treatments, especially of Nd/Ce atoms. The ammonothermally reduced Nd 1.85 Ce 0.15 CuO 4− δ powders show diamagnetic below 24 K which is contributed to the lower oxygen content and higher temperature factors of atoms in the treated compound.more » The ammonothermal method paves a new way to reduce oxides in supercritical solutions near room temperature.« less

  17. Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron Scattering Studies and First-Principles Calculations

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mirmelstein, A.; Podlesnyak, Andrey A.; dos Santos, Antonio M.; Ehlers, Georg; Kerbel, O.; Matvienko, V.; Sefat, A. S.; Saporov, B.; Halder, G. J.; Tobin, J. G.

    2015-08-03

    The pressure-induced structural phase transition in the intermediate-valence compound CeNi has been investigated by x-ray and neutron powder diffraction techniques. It is shown that the structure of the pressure-induced CeNi phase (phases) can be described in terms of the Pnma space group. Equations of state for CeNi on both sides of the phase transition are derived and an approximate P-T phase diagram is suggested for P<8 GPa and T<300 K. The observed Cmcm→Pnma structural transition is then analyzed using density functional theory calculations, which successfully reproduce the ground state volume, the phase transition pressure, and the volume collapse associated withmore » the phase transition.« less

  18. Magnetic hardening of Ce1+xFe11–yCoyTi with ThMn12 structure by melt spinning

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhou, Chen; Sun, Kewei; Pinkerton, Frederick E.; Kramer, M. J.

    2015-04-15

    A recent study on the intrinsic magnetic properties of CeFe11–yCoyTi has revealed that substituting one Co for Fe retains the favorable magnetocrystalline anisotropy Ha found in the ternary Fe end member, while enhancing the Curie temperature Tc and saturation magnetization 4πMs. These findings warrant further optimization around Co substitution y = 1 to try to exploit the hard magnetic properties of these Ce-based magnets. Both Ce and Co concentrations in Ce1+xFe11–yCoyTi have been optimized in the range of x = 0 – 0.2 and y = 0 –1.5. It was found that Co substitution effectively enhances all hard magnetic properties,more » although the values are still lower than those predicted from the intrinsic magnetic properties. Specifically, Tc increases from 210 °C to 285 – 350 °C; 4πM19 (magnetization at 19 kOe) from 8.9 kG to 10.5 – 11.5 kG, remanence Br from 3.1 kG to 4.1 – 4.5 kG, and most importantly, Hci from 1.1 kOe to 1.5 kOe. As a result, the room temperature energy product (BH)max has been increased by over 100% from 0.7 MGOe in Ce1.1Fe11Ti to 1.5 MGOe in Ce1.05Fe9.75Co1.25Ti. Microscopy analysis indicates that the addition of Co refines the grain size and promotes chemical homogeneity at the microscopic scale. As a result, the beneficial effect of Co on the microstructure contributes to the improved hard magnetic properties.« less

  19. Magnetic hardening of Ce1+xFe11–yCoyTi with ThMn12 structure by melt spinning

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhou, Chen; Sun, Kewei; Pinkerton, Frederick E.; Kramer, M. J.

    2015-04-15

    A recent study on the intrinsic magnetic properties of CeFe11–yCoyTi has revealed that substituting one Co for Fe retains the favorable magnetocrystalline anisotropy Ha found in the ternary Fe end member, while enhancing the Curie temperature Tc and saturation magnetization 4πMs. These findings warrant further optimization around Co substitution y = 1 to try to exploit the hard magnetic properties of these Ce-based magnets. Both Ce and Co concentrations in Ce1+xFe11–yCoyTi have been optimized in the range of x = 0 – 0.2 and y = 0 –1.5. It was found that Co substitution effectively enhances all hard magnetic properties,more »although the values are still lower than those predicted from the intrinsic magnetic properties. Specifically, Tc increases from 210 °C to 285 – 350 °C; 4πM19 (magnetization at 19 kOe) from 8.9 kG to 10.5 – 11.5 kG, remanence Br from 3.1 kG to 4.1 – 4.5 kG, and most importantly, Hci from 1.1 kOe to 1.5 kOe. As a result, the room temperature energy product (BH)max has been increased by over 100% from 0.7 MGOe in Ce1.1Fe11Ti to 1.5 MGOe in Ce1.05Fe9.75Co1.25Ti. Microscopy analysis indicates that the addition of Co refines the grain size and promotes chemical homogeneity at the microscopic scale. As a result, the beneficial effect of Co on the microstructure contributes to the improved hard magnetic properties.« less

  20. Reactivity of pulverized coals during combustion catalyzed by CeO{sub 2} and Fe{sub 2}O{sub 3}

    SciTech Connect (OSTI)

    Gong, Xuzhong; Guo, Zhancheng; Wang, Zhi

    2010-02-15

    Effects of CeO{sub 2} and Fe{sub 2}O{sub 3} on combustion reactivity of several fuels, including three ranks of coals, graphite and anthracite chars, were investigated using thermo-gravimetric analyzer. The results indicated that the combustion reactivity of all the samples except lignite was improved with CeO{sub 2} or Fe{sub 2}O{sub 3} addition. It was interesting to note that the ignition temperatures of anthracite were decreased by 50 C and 53 C, respectively, with CeO{sub 2} and Fe{sub 2}O{sub 3} addition and that its combustion rates were increased to 15.4%/min and 12.2%/min. Ignition temperatures of lignite with CeO{sub 2} and Fe{sub 2}O{sub 3} addition were 250 C and 226 C, and the combustion rates were 12.8% and 19.3%/min, respectively. When compared with those of lignite without catalysts, no obvious catalytic effects of the two catalysts on its combustion reactivity were revealed. The results from the combustion of the three rank pulverized coals catalyzed by CeO{sub 2} and Fe{sub 2}O{sub 3} indicated significant effects of the two catalysts on fixed carbon combustion. And it was found that the higher the fuel rank, the better the catalytic effect. The results of combustion from two kinds of anthracite chars showed obvious effects of anthracite pyrolysis catalyzed by CeO{sub 2} and Fe{sub 2}O{sub 3} on its combustion reactivity. (author)

  1. Lu.sub.1-xI.sub.3:Ce.sub.x-a scintillator for gamma-ray spectroscopy and time-of-flight pet

    DOE Patents [OSTI]

    Shah, Kanai S.

    2008-02-12

    The present invention includes very fast scintillator materials including lutetium iodide doped with Cerium (Lu.sub.1-xI.sub.3:Ce.sub.x; LuI.sub.3:Ce). The LuI.sub.3 scintillator material has surprisingly good characteristics including high light output, high gamma-ray stopping efficiency, fast response, low cost, good proportionality, and minimal afterglow that the material is useful for gamma-ray spectroscopy, medical imaging, nuclear and high energy physics research, diffraction, non-destructive testing, nuclear treaty verification and safeguards, and geological exploration.

  2. Coadsorbed species explain the mechanism of methanol temperature-desorption on CeO2(111)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sutton, Jonathan E.; Steven H. Overbury; Beste, Ariana

    2016-03-24

    Here, we have used density functional theory calculations to investigate the temperature-programmed desorption (TPD) of methanol from CeO2(111). For the first time, low-temperature water formation and high-temperature methanol desorption are explained by our calculations. High coverages of methanol, which correspond to experimental conditions, are required to properly describe these features of the TPD spectrum. We identify a mechanism for the low-temperature formation of water involving the dissociation of two methanol molecules on the same surface O atom and filling of the resulting surface vacancy with one of the methoxy products. After water desorption, methoxy groups are stabilized on the surfacemore » and react at higher temperatures to form methanol and formaldehyde by a disproportionation mechanism. Alternatively, the stabilized methoxy groups undergo sequential C–H scission reactions to produce formaldehyde. Calculated energy requirements and methanol/formaldehyde selectivity agree with the experimental data.« less

  3. Low pressure CO₂ hydrogenation to methanol over gold nanoparticles activated on a CeOx/TiO₂ interface

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yang, Xiaofang; Boscoboinik, J. Anibal; Kattel, Shyam; Senanayake, Sanjaya D.; Nie, Xiaowa; Graciani, Jesus; Rodriguez, Jose A.; Liu, Ping; Stacchiola, Dario J.; Chen, Jingguang G.

    2015-07-28

    Capture and recycling of CO₂ into valuable chemicals such as alcohols could help mitigate its emissions into the atmosphere. Due to its inert nature, the activation of CO₂ is a critical step in improving the overall reaction kinetics during its chemical conversion. Although pure gold is an inert noble metal and cannot catalyze hydrogenation reactions, it can be activated when deposited as nanoparticles on the appropriate oxide support. In this combined experimental and theoretical study, it is shown that an electronic polarization at the metal–oxide interface of Au nanoparticles anchored and stabilized on a CeOx/TiO₂ substrate generates active centers formore » CO₂ adsorption and its low pressure hydrogenation, leading to a higher selectivity toward methanol. In conclusion, this study illustrates the importance of localized electronic properties and structure in catalysis for achieving higher alcohol selectivity from CO₂ hydrogenation.« less

  4. High pressures and the Kondo gap in Ce{sub 3}Bi{sub 4}Pt{sub 3}

    SciTech Connect (OSTI)

    Cooley, J.C.; Aronson, M.C.; Canfield, P.C.

    1997-03-01

    We have measured the electrical resistivity {rho}(T) of single crystals of Ce{sub 3}Bi{sub 4}Pt{sub 3} for temperatures from 1.2 to 300 K, and pressures from 1 bar to 145 kbar. The transport is dominated at high temperatures by excitations across a small activation gap {Delta}, which increases rapidly with pressure. The low-temperature transport involves variable range hopping among extrinsic states in the gap. The spatial extent of the in-gap states reflects coupling to conduction-electron states, and is strongly modified as pressure enhances {Delta}. Despite the strong pressure dependence of {Delta}, a direct correspondence between single-ion energetics and the measured gap is maintained, and the role of valence fluctuations is minimal even at the highest pressures. {copyright} {ital 1997} {ital The American Physical Society}

  5. Magnetic properties of CeFe11-xCoxTi with ThMn12 structure

    SciTech Connect (OSTI)

    Zhou, C; Pinkerton, FE; Herbst, JF

    2014-05-07

    A series of novel alloys CeFe11-xCoxTi (0 <= x <= 11) with ThMn12 structure has been successfully prepared by melt-spinning. The Curie temperature T-c increases with Co content x, reaching a maximum of 689 degrees C at x = 9 and declining to 664 degrees C at complete Co filling (x = 11). The room temperature saturation magnetization 4 pi M-s and magnetocrystalline anisotropy H-a have been estimated by fitting the first quadrant demagnetization curve with the Stoner-Wohlfarth model. 4 pi M-s first increases with increasing Co up to x = 3, then decrease. H-a has a complex dependence on Co content, which is indicative of a change in the easy magnetization direction from axis to plane and back as the Co content increases. (C) 2014 AIP Publishing LLC.

  6. Crystal Chemistry and Luminescence of Ce3+ -Doped Lu2CaMg2(Si,Ge)3O12 and Its Use in LED Based Lighting

    SciTech Connect (OSTI)

    Setlur,A.; Heward, W.; Gao, Y.; Srivastava, A.; Chandron, R.; Shankar, M.

    2006-01-01

    In this paper, we describe the formation and luminescence of a new garnet phosphor for light emitting diode (LED) based lighting, Lu{sub 2}CaMg{sub 2}(Si,Ge){sub 3}O{sub 12}:Ce{sup 3+}.The regions for garnet phase formation are initially described with respect to larger rare earth substitution and show reasonable correlation to previous crystal chemistry studies for the garnet parent structure. While the pure silicate phosphor also has apatite second phases, a significant amount of Ce{sup 3+} enters the garnet phase, giving Ce{sup 3+} luminescence that is significantly redder when compared to typical Al{sup 3+} garnet phosphors with quantum efficiencies comparable to commercial Ce{sup 3+} garnet phosphors. Potential reasons for the emission red shift and the high quantum efficiency are discussed. Finally, the performance of these new phosphors is tested within LED based lamps. Lamps using these phosphors can reach color temperatures required for general illumination lighting and also have comparable phosphor conversion efficiencies when compared to lamps using typical garnet phosphors.

  7. Data:F3d511d9-6321-49ce-b5b2-a0d21fd28d52 | Open Energy Information

    Open Energy Info (EERE)

    d9-6321-49ce-b5b2-a0d21fd28d52 No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1....

  8. Inverse magnetocaloric effect in Ce(Fe{sub 0.96}Ru{sub 0.04}){sub 2}: Effect of fast neutron irradiation

    SciTech Connect (OSTI)

    Dube, V.; Mishra, P. K.; Prajapat, C. L.; Singh, M. R.; Ravikumar, G.; Rajarajan, A. K.; Sastry, P. U.; Thakare, S. V.

    2013-02-05

    We have shown the effect of fast neutron irradiation on the magnetic phase transition and magnetocaloric effect (MCE) in a doped Ce(Fe{sub 0.96}Ru{sub 0.04}){sub 2}, intermettalic. We show that this leads to suppression of MCE and a to a disordered ferromagnetic phase.

  9. High Catalytic Activity of Au/CeOx/TiO2(110) Controlled by the Nature of the Mixed Metal Oxide at the Nanometer Level

    SciTech Connect (OSTI)

    Park, J.; Graciani, J; Evans, J; Stacchiola, D; Ma, S; Liu, P; Nambu, A; Sanz, J; Hrbek, J; et. al.

    2009-01-01

    Mixed-metal oxides play a very important role in many areas of chemistry, physics, materials science, and geochemistry. Recently, there has been a strong interest in understanding phenomena associated with the deposition of oxide nanoparticles on the surface of a second (host) oxide. Here, scanning tunneling microscopy, photoemission, and density-functional calculations are used to study the behavior of ceria nanoparticles deposited on a TiO2(110) surface. The titania substrate imposes nontypical coordination modes on the ceria nanoparticles. In the CeOx/TiO2(110) systems, the Ce cations adopt an structural geometry and an oxidation state (+3) that are quite different from those seen in bulk ceria or for ceria nanoparticles deposited on metal substrates. The increase in the stability of the Ce3+ oxidation state leads to an enhancement in the chemical and catalytic activity of the ceria nanoparticles. The codeposition of ceria and gold nanoparticles on a TiO2(110) substrate generates catalysts with an extremely high activity for the production of hydrogen through the water-gas shift reaction (H2O + CO ? H2 + CO2) or for the oxidation of carbon monoxide (2CO + O2 ? 2CO2). The enhanced stability of the Ce3+ state is an example of structural promotion in catalysis described here on the atomic level. The exploration of mixed-metal oxides at the nanometer level may open avenues for optimizing catalysts through stabilization of unconventional surface structures with special chemical activity.

  10. Mechanistic insights of ethanol steam reforming over Ni-CeOx(111): The importance of hydroxyl groups for suppressing coke formation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Zongyuan; Senanayake, Sanjaya D.; Duchon, Tomas; Wang, Huanru; Peterson, Erik W.; Zhou, Yinghui; Luo, Si; Zhou, Jing; Matolin, Vladimir; Stacchiola, Dario J.; et al

    2015-07-10

    We have studied the reaction of ethanol and water over NiCeO2-x(111) model surfaces to elucidate the mechanistic steps associated with the ethanol steam reforming (ESR) reaction. Our results provide insights about the importance of hydroxyl groups to the ESR reaction over Ni-based catalysts. Systematically, we have investigated the reaction of ethanol on NiCeO2-x(111) at varying Ce? concentrations (CeO1.82.0) with absence/presence of water using a combination of soft X-ray photoelectron spectroscopy (sXPS) and temperature-programmed desorption (TPD). Consistent with previous reports, upon annealing, metallic Ni formed on reduced ceria while NiO was the main component on fully oxidized ceria. Ni? is themoreactive phase leading to both the CC and CH cleavage of ethanol but is also responsible for carbon accumulation or coking. We have identified a Ni?C phase that formed prior to the formation of coke. At temperatures above 600K, the lattice oxygen from ceria and the hydroxyl groups from water interact cooperatively in the removal of coke, likely through a strong metalsupport interaction between nickel and ceria that facilitates oxygen transfer.less

  11. Mechanistic Insights of Ethanol Steam Reforming over Ni–CeO x (111): The Importance of Hydroxyl Groups for Suppressing Coke Formation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Zongyuan; Duchoň, Tomáš; Wang, Huanru; Peterson, Erik W.; Zhou, Yinghui; Luo, Si; Zhou, Jing; Matolín, Vladimir; Stacchiola, Dario J.; Rodriguez, José A.; et al

    2015-07-30

    We have studied the reaction of ethanol and water over Ni–CeO2-x(111) model surfaces to elucidate the mechanistic steps associated with the ethanol steam reforming (ESR) reaction. Our results provide insights about the importance of hydroxyl groups to the ESR reaction over Ni-based catalysts. Systematically, we have investigated the reaction of ethanol on Ni–CeO2-x(111) at varying Ce³⁺ concentrations (CeO1.8–2.0) with absence/presence of water using a combination of soft X-ray photoelectron spectroscopy (sXPS) and temperature-programmed desorption (TPD). Consistent with previous reports, upon annealing, metallic Ni formed on reduced ceria while NiO was the main component on fully oxidized ceria. Ni⁰ is themore » active phase leading to both the C–C and C–H cleavage of ethanol but is also responsible for carbon accumulation or coking. We have identified a Ni₃C phase that formed prior to the formation of coke. At temperatures above 600K, the lattice oxygen from ceria and the hydroxyl groups from water interact cooperatively in the removal of coke, likely through a strong metal–support interaction between nickel and ceria that facilitates oxygen transfer.« less

  12. Mechanistic Insights of Ethanol Steam Reforming over Ni–CeO x (111): The Importance of Hydroxyl Groups for Suppressing Coke Formation

    SciTech Connect (OSTI)

    Liu, Zongyuan; Duchoň, Tomáš; Wang, Huanru; Peterson, Erik W.; Zhou, Yinghui; Luo, Si; Zhou, Jing; Matolín, Vladimir; Stacchiola, Dario J.; Rodriguez, José A.; Senanayake, Sanjaya D.

    2015-07-30

    We have studied the reaction of ethanol and water over Ni–CeO2-x(111) model surfaces to elucidate the mechanistic steps associated with the ethanol steam reforming (ESR) reaction. Our results provide insights about the importance of hydroxyl groups to the ESR reaction over Ni-based catalysts. Systematically, we have investigated the reaction of ethanol on Ni–CeO2-x(111) at varying Ce³⁺ concentrations (CeO1.8–2.0) with absence/presence of water using a combination of soft X-ray photoelectron spectroscopy (sXPS) and temperature-programmed desorption (TPD). Consistent with previous reports, upon annealing, metallic Ni formed on reduced ceria while NiO was the main component on fully oxidized ceria. Ni⁰ is the active phase leading to both the C–C and C–H cleavage of ethanol but is also responsible for carbon accumulation or coking. We have identified a Ni₃C phase that formed prior to the formation of coke. At temperatures above 600K, the lattice oxygen from ceria and the hydroxyl groups from water interact cooperatively in the removal of coke, likely through a strong metal–support interaction between nickel and ceria that facilitates oxygen transfer.

  13. Investigation of the hydrothermal crystallisation of the perovskite solid solution NaCe{sub 1?x}La{sub x}Ti{sub 2}O{sub 6} and its defect chemistry

    SciTech Connect (OSTI)

    Harunsani, Mohammad H.; Woodward, David I.; Peel, Martin D.; Ashbrook, Sharon E.; Walton, Richard I.

    2013-11-15

    Perovskites of nominal composition NaCe{sub 1?x}La{sub x}Ti{sub 2}O{sub 6} (0?x?1) crystallise directly under hydrothermal conditions at 240 C. Raman spectroscopy shows distortion from the ideal cubic structure and Rietveld analysis of powder X-ray and neutron diffraction reveals that the materials represent a continuous series in rhombohedral space group R3-bar c. Ce L{sub III}-edge X-ray absorption near edge structure spectroscopy shows that while the majority of cerium is present as Ce{sup 3+} there is evidence for Ce{sup 4+}. The paramagnetic Ce{sup 3+} affects the chemical shift and line width of {sup 23}Na MAS NMR spectra, which also show with no evidence for A-site ordering. {sup 2}H MAS NMR of samples prepared in D{sub 2}O shows the inclusion of deuterium, which IR spectroscopy shows is most likely to be as D{sub 2}O. The deuterium content is highest for the cerium-rich materials, consistent with oxidation of some cerium to Ce{sup 4+} to provide charge balance of A-site water. - Graphical abstract: A multi-element A-site perovskite crystallises directly from aqueous, basic solutions at 240 C; while the paramagnetic effect of Ce{sup 3+} on the {sup 23}Na NMR shows a homogeneous solid-solution, the incorporation of A-site water is also found from {sup 2}H NMR and IR, with oxidation of some cerium to charge balance proved by XANES spectroscopy. Display Omitted - Highlights: Direct hydrothermal synthesis allows crystallisation of a perovskite solid-solution. XANES spectroscopy shows some oxidation of Ce{sup 3+} to Ce{sup 4+}. The paramagnetism of Ce{sup 3+} shifts and broadens the {sup 23}Na solid-state NMR. The perovskite materials incorporate water as an A-site defect.

  14. Substitution effect on the magnetic and transport properties of CeNi{sub 0.8−x}Mn{sub x}Bi{sub 2}

    SciTech Connect (OSTI)

    Kim, Soo-Whan; Lee, Kyujoon; Jung, Myung-Hwa; Adroja, D. T.; Demmel, F.; Taylor, J. W.

    2014-08-21

    We report the results of Mn substitution for Ni in CeNi{sub 0.8}Bi{sub 2} (i.e., CeNi{sub 0.8−x}Mn{sub x}Bi{sub 2}). All the samples have an antiferromagnetic ordered state below T{sub N} = 5.0 K due to localized 4f-magnetic moment on the Ce ions. Besides this antiferromagnetic ordering caused by Ce, the magnetic and transport properties are abruptly changed with increasing Mn contents at the boundary composition of x = 0.4. The magnetic state is changed into a ferromagnetic state around 200 K for x > 0.4, where the electrical resistivity is strongly suppressed to become simple metallic. These results of ferromagnetism and metallicity can be explained by the double exchange mechanism, rather than the simple picture of Doniach phase diagram. The mixed valence states of Ni and Mn ions are confirmed by X-ray photoelectron spectroscopy. For x ≤ 0.4, the initial Ni{sup 3+} state gradually changes to the Ni{sup 2+} state with increasing x up to 0.4. On further increase of x > 0.4, the Ni{sup 2+} state is replaced by the Mn{sup 2+} state, which gradually changes to the final Mn{sup 3+} state. We also present an inelastic neutron scattering (INS) measurements on CeNi{sub 0.8}Bi{sub 2} (i.e., x = 0) between 1.2 and 12 K. The high energy INS study reveals the presence of two well-defined crystal electric field (CEF) excitations near 9 meV and 19 meV at 1.2 K and 6 K, while the low energy INS study reveals the presence of quasielastic scattering above 4 K. We will discuss our INS results of CeNi{sub 0.8}Bi{sub 2} based on the CEF model.

  15. Low temperature specific heat of the Kondo-semimetal CeNiSn in zero and applied magnetic fields

    SciTech Connect (OSTI)

    Brueckl, A.; Neumaier, K.; Einzel, D.; Andres, K.; Flaschin, S.; Kalvius, G.M.; Nakamoto, G.; Takabatake, T.

    1999-06-01

    The specific heat of several CeNiSn single crystals of various purity has been measured in the temperature range from 25 mK to 5 K and in magnetic fields from zero to 7 Tesla. At very low temperatures (below {approximately} 200 mK) the specific heat is found to vary linearly with temperature (C = {gamma}T), the coefficient {gamma} decreasing with increasing purity. Above 200 mK, the specific heat is well described as the sum of a linear and a quadratic term. An applied magnetic field affects mostly the linear term, which first slightly decreases, then strongly increases with field. In magnetic fields, a nuclear hyperfine specific heat contribution is superimposed, which is due mostly to the bare Zeeman-splitting of the {sup 115}Sn, {sup 117}Sn, {sup 119}Sn nuclei (all with spin I = 1/2 and with abundances of 0.35, 7.61, and 8.58% respectively) in the externally applied field. The results on the specific heat at very low temperatures in applied fields fit into the model of an enhanced (heavy-fermion type) density of states which is modified by coherent antiferromagnetic fluctuations into a V-shaped density of states at the Fermi energy.

  16. Electrochemical Study on the Electrodeposition of U, Nd, Ce, La and Y on a Liquid Cadmium Cathode in a LiCl-KCl Eutectic Salt

    SciTech Connect (OSTI)

    Sung Bin Park; Jong Hyeon Lee; Sung Chan Hwang; Young Ho Kang; Joon Bo Shim; Han Soo Lee; Eung Ho Kim; Seong Won Park

    2007-07-01

    Electro-depositions of U, Nd, Ce, La and Y on a liquid cadmium cathode in a LiCl-KCl eutectic salt were studied by using an electrolytic cell. For the LiCl-KCl-UCl{sub 3}- NdCl{sub 3}-CeCl{sub 3}-LaCl{sub 3}-YCl{sub 3}/Cd system, cyclic voltammograms and polarization curves were measured and the electrochemical properties of the system were discussed. From the results of the electro-depositions of U and rare earth metals on the LCC, separation factors and recovery ratios of U and REs were obtained and co-electro-depositions of U and REs were investigated. (authors)

  17. Nodal to nodeless superconducting energy gap structure change concomitant with Fermi surface reconstruction in the heavy-fermion CeCoIn?

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kim, Hyunsoo; Petrovic, C.; Tanatar, M. A.; Flint, R.; Hu, Rongwei; White, B. D.; Lum, I. K.; Maple, M. B.; Prozorov, R.

    2015-01-15

    The London penetration depth ?(T) was measured in single crystals of Ce1xRxCoIn?, R=La, Nd, and Yb down to Tmin ? 50 mK (Tc/Tmin ~50) using a tunnel-diode resonator. In the cleanest samples ??(T) is best described by the power law, ??(T) ? Tn, with n ~ 1, consistent with line nodes. Substitutions of Ce with La, Nd, and Yb lead to similar monotonic suppressions of Tc, however, the effects on ??(T) differ. While La and Nd dopings lead to increase of the exponent n and saturation at n ~ 2, as expected for a dirty nodal superconductor, Yb doping leadsmoreto n > 3, suggesting a change from nodal to nodeless superconductivity. This superconducting gap structure change happens in the same doping range where changes of the Fermi surface topology were reported, implying that the nodal structure and Fermi surface topology are closely linked.less

  18. Lu.sub.1-xI.sub.3:Ce.sub.x--a scintillator for gamma ray spectroscopy and time-of-flight PET

    DOE Patents [OSTI]

    Shah, Kanai S.

    2007-02-06

    The present invention concerns very fast scintillator materials comprising lutetium iodide doped with Cerium (Lu.sub.1-xI.sub.3:Ce.sub.x; LuI.sub.3:Ce). The LuI.sub.3 scintillator material has surprisingly good characteristics including high light output, high gamma ray stopping efficiency, fast response, low cost, good proportionality, and minimal afterglow that the material is useful for gamma ray spectroscopy, medical imaging, nuclear and high energy physics research, diffraction, non-destructive testing, nuclear treaty verification and safeguards, and geological exploration. The timing resolution of the scintillators of the present invention provide compositions capable of resolving the position of an annihilation event within a portion of a human body cross-section.

  19. Commissioning of the 112 MHz SRF Gun and 500 MHz bunching cavities for the CeC PoP Linac

    SciTech Connect (OSTI)

    Belomestnykh, S.; Ben-Zvi, I.; Brutus, J. C.; Litvinenko, V.; McIntosh, P.; Moss, A.; Narayan, G.; Orfin, P.; Pinayev, I.; Rao, T.; Skaritka, J.; Smith, K.; Than, R.; Tuozzolo, J.; Wang, E.; Wheelhouse, A.; Wu, Q.; Xiao, B.; Xin, T.; Xu, W.; Zaltsman, A.

    2015-05-03

    The Coherent electron Cooling Proof-of-Principle (CeC PoP) experiment at BNL includes a short electron linac. During Phase 1, a 112 MHz superconducting RF photo-emission gun and two 500 MHz normal conducting bunching cavities were installed and are under commissioning. The paper describes the Phase1 linac layout and presents commissioning results for the cavities and associated RF, cryogenic and other sub-systems

  20. High Activity of Ce1-xNixO2-y for H2 Production through Ethanol Steam Reforming: Tuning Catalytic Performance through Metal-Oxide Interactions

    SciTech Connect (OSTI)

    G Zhou; L Barrio; S Agnoli; S Senanayake; J Evans; A Kubacka; M Estrella; J Hanson; A Martinez-Arias; et al.

    2011-12-31

    The importance of the oxide: Ce{sub 0.8}Ni{sub 0.2}O{sub 2-y} is an excellent catalyst for ethanol steam reforming. Metal-oxide interactions perturb the electronic properties of the small particles of metallic nickel present in the catalyst under the reaction conditions and thus suppress any methanation activity. The nickel embedded in ceria induces the formation of O vacancies, which facilitate cleavage of the OH bonds in ethanol and water.

  1. Remarkably robust and correlated coherence and antiferromagnetism in (Ce1-xLax)Cu2Ge2

    SciTech Connect (OSTI)

    Hodovanets, H.; Budko, S. L.; Straszheim, W. E.; Taufour, V.; Mun, E. D.; Kim, H.; Flint, R.; Canfield, P. C.

    2015-06-08

    We present magnetic susceptibility, resistivity, specific heat, and thermoelectric power measurements on (Ce1-xLax)Cu2Ge2 single crystals (0 ? x ? 1). With La-substitution, the antiferromagnetic temperature TN is suppressed in an almost linear fashion and moves below 0.36 K, the base temperature of our measurements for x > 0.8. Surprisingly, in addition to robust antiferromagnetism, the system also shows low temperature coherent scattering below Tcoh up to ~0.9 of La, indicating a small percolation limit ~9% of Ce. Tcoh as a function of magnetic field was found to have different behavior for x < 0.9 and x > 0.9. Remarkably, (Tcoh)2 at H = 0 was found to be linearly proportional to TN. In conclusion, the jump in the magnetic specific heat ?Cm at TN as a function of TK/TN for (Ce1-xLax)Cu2Ge2 follows the theoretical prediction based on the molecular field calculation for the S = 1/2 resonant level model.

  2. Spin-glass freezing above the ordering temperature for the Kondo ferromagnet CeNi{sub 0.4}Cu{sub 0.6}

    SciTech Connect (OSTI)

    Gomez Sal, J.C.; Garcia Soldevilla, J.; Blanco, J.A.; Espeso, J.I.; Rodriguez Fernandez, J.; Luis, F.; Bartolome, F.; Bartolome, J.

    1997-11-01

    The low-temperature magnetic and transport properties of the orthorhombic CeNi{sub 0.4}Cu{sub 0.6} compound have been determined from the analysis of specific heat, ac magnetic susceptibility, electrical resistivity, elastic and inelastic neutron scattering. These measurements present intriguing experimental results that could not be explained within the usual phenomenology of Ce-based compounds. C{sub p} and {chi}{sub ac} present anomalies around 1 K corresponding to ferromagnetic order as confirmed by neutron diffraction. The magnetic structure is collinear with very reduced moments, 0.6{mu}{sub B}/Ce lying in the b direction. Additionally, a clear Kondo behavior is observed with a Kondo temperature T{sub K}=1.9K estimated from quasielastic neutron scattering. Above the ordering temperature, further anomalies are observed in C{sub p} and {chi}{sub ac} that could not be explained as originating from crystal electric field or Kondo effects. From the frequency and field dependence of the {chi}{sub ac}, above T{sub c}, a spin-glass state with a freezing temperature T{sub f}=2K is proposed for this compound. This unusual magnetic behavior is discussed in terms of mixed (positive and negative) Ruderman-Kittel-Kasuya-Yosida interactions, randomness (structural disorder), large hybridization (Kondo effect), and strong magnetocrystalline anisotropy (crystal electric field effects). {copyright} {ital 1997} {ital The American Physical Society}

  3. Resolution of the discrepancy between the variation of the physical properties of Ce1-xYbxCoIn5 single crystals and thin films with Yb composition

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jang, S.; White, B. D.; Lum, I. K.; Kim, H.; Tanatar, M. A.; Straszheim, W. E.; Prozorov, R.; Keiber, T.; Bridges, F.; Shu, L.; et al

    2014-11-18

    The extraordinary electronic phenomena including an Yb valence transition, a change in Fermi surface topology, and suppression of the heavy fermion quantum critical field at a nominal concentration x≈0.2 have been found in the Ce1-xYbxCoIn5 system. These phenomena have no discernable effect on the unconventional superconductivity and normal-state non-Fermi liquid behaviour that occur over a broad range of x up to ~0.8. However, the variation of the coherence temperature T* and the superconducting critical temperature Tc with nominal Yb concentration x for bulk single crystals is much weaker than that of thin films. To determine whether differences in the actualmore » Yb concentration of bulk single crystals and thin film samples might be responsible for these discrepancies, we employed Vegard’s law and the spectroscopically determined values of the valences of Ce and Yb as a function of x to determine the actual composition xact of bulk single crystals. This analysis is supported by energy-dispersive X-ray spectroscopy, wavelength-dispersive X-ray spectroscopy, and transmission X-ray absorption edge spectroscopy measurements. The actual composition xact is found to be about one-third of the nominal concentration x up to x~0.5, and resolves the discrepancy between the variation of the physical properties of Ce1-xYbxCoIn5 single crystals and thin films with Yb concentration.« less

  4. Magnetic order and heavy fermion behavior in CePd{sub 1+x}Al{sub 6-x}: Synthesis, structure, and physical properties

    SciTech Connect (OSTI)

    Tobash, Paul H., E-mail: ptobash@lanl.go [Materials Physics and Application Division, MPA-10, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716 (United States); Ronning, Filip; Thompson, J.D. [Materials Physics and Application Division, MPA-10, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Bobev, Svilen [Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716 (United States); Bauer, Eric D. [Materials Physics and Application Division, MPA-10, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2010-03-15

    The physical properties including magnetic susceptibility, specific heat, and electrical resistivity of single crystals are reported for the compound CePd{sub 1+x}Al{sub 6-x} (x=0.5) which crystallizes in the tetragonal SrAu{sub 2}Ga{sub 5}-type structure (space group P4/mmm). The compound was grown from an excess of molten Al flux from the respective elements and the crystal structure was established from single-crystal X-ray diffraction. Anomalies in the low temperature specific heat C{sub p}(T) and electrical resistivity rho(T) show that the compound undergoes ferromagnetic order at T{sub C}=2.8 K. In the ordered state, CePd{sub 1.5}Al{sub 5.5} displays heavy fermion behavior with a Sommerfeld coefficient of ca. 500 mJ/mol-K{sup 2}. - Graphical abstract: The compound CePd{sub 1+x}Al{sub 6-x} (x=0.5) has been synthesized and structurally characterized by single-crystal X-ray diffraction. The measured physical properties of temperature and field dependent magnetic susceptibility, specific heat, and electrical resistivity suggests that the compound undergoes ferromagnetic order at ca. 2.8 K and further exhibits relatively heavy fermion behavior with a Sommerfeld coefficient of 500 mJ/mol-K2.

  5. Electronic structure of the heavy-fermion caged compound Ce3Pd20X6(X=Si,Ge) studied by density functional theory and photoelectron spectroscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yamaoka, Hitoshi; Schwier, Eike F.; Arita, Masashi; Shimada, Kenya; Tsujii, Naohito; Jarrige, Ignace; Jiang, Jian; Hayashi, Hirokazu; Iwasawa, Hideaki; Namatame, Hirofumi; et al

    2015-03-30

    The electronic structure of Ce₃Pd₂₀X₆ (X = Si, Ge) has been studied using detailed density functional theory (DFT) calculations and high-resolution photoelectron spectroscopy (PES) measurements. The orbital decomposition of the electronic structure by DFT calculations indicates that Ce atoms at the (8c) site surrounded by 16 Pd atoms have a more localized nature and a tendency to be magnetic. Ce atoms in the (4a) site surrounded by 12 Pd and 6 X atoms, on the other, show only a negligible magnetic moment. In the photoemission valence-band spectra we observe a strong f⁰ (Ce⁴⁺) component with a small fraction of f¹more » (Ce³⁺) component. The spectral weight of f¹ component near the Fermi level Ce₃Pd₂₀Si₆ is stronger than that for Ce₃Pd₂₀Ge₆ at the 4d-4f resonance, suggesting stronger c-f hybridization in the former. This may hint to the origin of the large electronic specific coefficient of Ce₃Pd₂₀Si₆ compared to Ce₃Pd₂₀Ge₆.« less

  6. The rare earth silicon phosphides LnSi{sub 2}P{sub 6} (Ln = La, Ce, Pr, and Nd)

    SciTech Connect (OSTI)

    Kaiser, P.; Jeitschko, W.

    1996-07-01

    The title compounds were prepared in well-crystallized form from a tin flux and their crystal structure was determined from single-crystal diffractometer data of LaSi{sub 2}P{sub 6}: Cmc2{sub 1}, a = 1012.9(3) pm, b = 2817.5(7) pm, c = 1037.4(5) pm, Z = 16, R = 0.034 for 3303 structure factors and 181 variable parameters. The structure of the isotypic compound CeSi{sub 2}P{sub 6} was also refined from single-crystal X-ray data: a = 1011.8(4) pm, b = 2803.1(8) pm, c = 1031.1(4) pm, R = 0.035 for 2132 F values and 181 variables. The silicon and the phosphorus atoms could be distinguished by comparing their occupancy parameters obtained from both structure refinements. The assignments agree with those deduced by structure-chemical arguments. These atoms form a three-dimensionally infinite framework polyanion, which accommodates four different kinds of rare earth atoms: three with nine and one with ten phosphorus neighbors. The silicon atoms are all in tetrahedral phosphorus coordination. There are phosphorus atoms which have only two rare earth and two silicon neighbors, but most phosphorus atoms have--in addition to the rare earth and silicon atoms--phosphorus neighbors, thus forming P{sub 3}, P{sub 4}, P{sub 5}, and P{sub 6} units. Using oxidation numbers, the compounds can be rationalized with the formulas Ln{sup 3+}(Si{sub 2}P{sub 6}){sub 3-} and Ln{sup 3+}(Si{sup 4+}){sub 2}(P{sub 6}){sup 11-}, where the octet rule is obeyed for the silicon and phosphorus atoms and two electrons are counted for each Si-P and P-P interaction.

  7. Magnetic properties of bulk, and rapidly solidified nanostructured (Nd1-xCex)2Fe14-yCoyB ribbons

    SciTech Connect (OSTI)

    Pathak, Arjun K.; Khan, M.; Gschneidner, Jr., K. A.; McCallum, R. W.; Zhou, L.; Sun, K.; Kramer, M. J.; Pecharsky, V. K.

    2015-11-06

    Magnetic properties of Ce and Co co-doped (Nd1-xCex)2Fe14-yCoyB compounds have been investigated both in bulk polycrystalline and rapidly solidified nanostructured ribbon forms. For certain Ce concentrations the materials exhibit spin re-orientation transitions below 140 K. The Curie temperatures, saturation magnetizations, and other magnetic properties relevant for applications as permanent magnets are controlled by Ce and Co substitutions for Nd and Fe, respectively. Most importantly, the results show that Ce, Co co-doped compounds are excellent replacements for several Dy-based high performance permanent magnets (dysprosium is one of the critical elements and is, therefore, in short supply). As a result, the high temperature (>375 K) magnetic properties for Nd–Ce–Fe–Co–B based alloys show promise not only as a replacement for Dy-doped Nd2Fe14B permanent magnets, but the new alloys also require significantly lower amounts of Nd, which too is the critical element that can be replaced by a more abundant Ce.

  8. Antiferromagnetic Kondo lattice in the layered compound CePd1xBi? and comparison to the superconductor LaPd1xBi?

    SciTech Connect (OSTI)

    Han, Fei; Wan, Xiangang; Phelan, Daniel; Stoumpos, Constantinos C.; Sturza, Mihai; Malliakas, Christos D.; Li, Qing'an; Han, Tian-Heng; Zhao, Qingbiao; Chung, Duck Young; Kanatzidis, Mercouri G.

    2015-07-13

    The layered compound CePd1xBi? with the tetragonal ZrCuSi?-type structure was obtained from excess Bi flux. Magnetic susceptibility data of CePd1xBi? show an antiferromagnetic ordering below 6 K and are anisotropic along the c axis and the ab plane. The anisotropy is attributed to crystal-electric-field (CEF) effects and a CEF model which is able to describe the susceptibility data is given. An enhanced Sommerfeld coefficient ? of 0.191 J mol Ce? K? obtained from specific-heat measurement suggests a moderate Kondo effect in CePd1xBi?. Other than the antiferromagnetic peak at 6 K, the resistivity curve shows a shoulderlike behavior around 75 K which could be attributed to the interplay between Kondo and CEF effects. Magnetoresistance and Hall-effect measurements suggest that the interplay reconstructs the Fermi-surface topology of CePd1xBi? around 75 K. Electronic structure calculations reveal that the Pd vacancies are important to the magnetic structure and enhance the CEF effects which quench the orbital moment of Ce at low temperatures.

  9. Role of Ce4+ in the scintillation mechanism of codoped Gd3Ga3Al2O12:Ce

    SciTech Connect (OSTI)

    Wu, Yuntao; Meng, Fang; Li, Qi; Koschan, Merry; Melcher, Charles L.

    2014-10-17

    To control the time-response performance of widely used cerium-activated scintillators in cutting-edge medical-imaging devices, such as time-of-flight positron-emission tomography, a comprehensive understanding of the role of Ce valence states, especially stable Ce4+, in the scintillation mechanism is essential. However, despite some progress made recently, an understanding of the physical processes involving Ce4+ is still lacking. The aim of this work is to clarify the role of Ce4+ in scintillators by studying Ca2+ codoped Gd3Ga3Al2O12?Ce?(GGAG?Ce). By using a combination of optical absorption spectra and x-ray absorption near-edge spectroscopies, the correlation between Ca2+codoping content and the Ce4+ fraction is seen. The energy-level diagrams of Ce3+ and Ce4+ in the Gd3Ga3Al2O12 host are established by using theoretical and experimental methods, which indicate a higher position of the 5d1 state of Ce4+ in the forbidden gap in comparison to that of Ce3+. Underlying reasons for the decay-time acceleration resulting from Ca2+ codoping are revealed, and the physical processes of the Ce4+-emission model are proposed and further demonstrated by temperature-dependent radioluminescence spectra under x-ray excitation.

  10. Hierarchical Heterogeneity at the CeO x TiO 2 Interface: Electronic and Geometric Structural Influence on the Photocatalytic Activity of Oxide on Oxide Nanostructures

    SciTech Connect (OSTI)

    Luo, Si; Nguyen-Phan, Thuy-Duong; Johnston-Peck, Aaron C.; Barrio, Laura; Sallis, Shawn; Arena, Dario A.; Kundu, Shankhamala; Xu, Wenqian; Piper, Louis F. J.; Stach, Eric A.; Polyanskiy, Dmitry E.; Fujita, Etsuko; Rodriguez, Jos A.; Senanayake, Sanjaya D.

    2015-01-13

    Mixed oxide interfaces are critical for delivering active components of demanding catalytic processes such as the photo-catalytic splitting of water. We have studied CeOxTiO? catalysts with low ceria loadings of 1 wt%, 3 wt% and 6 wt% that were prepared with wet impregnation methods to favor a strong interaction between CeOx and TiO?. In these materials the interfaces between CeOx-TiO? have been sequentially loaded (1%, 3% and 6%), with and without Pt (0.5 wt%). The structure and properties of the catalysts were characterized using several X-ray and electron based techniques including XRD, XPS, UPS, NEXAFS, UV-Vis and HR-STEM/STEM-EELS, to unravel the local morphology, bulk structure, surface states and electronic structure. The combination of all these techniques allow us to analyze in a systematic way the complete structural and electronic properties that prevail at the CeOx-TiO? interface. Fluorite structured nano crystallites of ceria on anatase-structured titania were identified by both XRD and NEXAFS. A sequential increasing of the CeOx loading led to the formation of clusters, then plates and finally nano particles in a hierarchical manner on the TiO? support. The electronic structures of these catalysts indicate that the interaction between TiO? and CeO? is closely related to the local morphology of nanostructured CeO?. Ce? cations were detected at the surface of CeO? and at the interface of the two oxides. In addition, the titania is perturbed by the interaction with ceria and also with Pt. The photocatalytic activity for the splitting of H?O using UV light was measured for these materials and correlated with our understanding of the electronic and structural properties. Optimal catalytic performance and photo response results were found for the 1 wt% CeOx-TiO? catalyst where low dimensional geometry of the ceria provided ideal electronic and geometrical properties. The structural and electronic properties of the interface were critical for the photocatalytic performance of this mixed-oxide nanocatalyst system.

  11. IC-Compatible Technologies for Optical MEMS

    SciTech Connect (OSTI)

    Krygowski, T.W.; Sniegowski, J.J.

    1999-04-30

    Optical Micro Electro Mechanical Systems (Optical MEMS) Technology holds the promise of one-day producing highly integrated optical systems on a common, monolithic substrate. The choice of fabrication technology used to manufacture Optical MEMS will play a pivotal role in the size, functionality and ultimately the cost of optical Microsystems. By leveraging the technology base developed for silicon integrated circuits, large batches of routers, emitters, detectors and amplifiers will soon be fabricated for literally pennies per part. In this article we review the current status of technologies used for Optical MEMS, as well as fabrication technologies of the future, emphasizing manufacturable surface micromachining approaches to producing reliable, low-cost devices for optical communications applications.

  12. Microsoft Word - S06401_IC.doc

    Office of Legacy Management (LM)

    Effectiveness of Site-Wide Institutional Controls Applied to the Former DOE Mound Site Property June 2010 LMS/MND/S06401 This page intentionally left blank LMS/MND/S06401 Annual Assessment of the Effectiveness of Site-Wide Institutional Controls Applied to the Former DOE Mound Site Property June 2010 This page intentionally left blank U.S. Department of Energy Annual Assessment of the Effectiveness of Site-Wide Institutional Controls June 2010 Doc. No. S06401 Page i Contents

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    Office of Legacy Management (LM)

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  14. Microsoft Word - S06401_IC.doc

    Office of Legacy Management (LM)

    Annual Assessment Checklists For Parcels D, H, 4, and 3 and Phase I Land Parcel (Physical Walkover Conducted on April 14, 2009) This page intentionally left blank CHECKLIST WORKSHEET - COMBINED - ALL PARCELS Review of Effectiveness of Institutional Controls U.S. Department of Energy Annual Assessment of the Effectiveness of Site-Wide Institutional Controls June 2010 Doc. No. S06401 Page A-1 Parcels reviewed: D, H, 3, 4, 6, 7, 8, and Phase I (A, B, and C) Preliminary inspections performed on:

  15. Microsoft Word - S06401_IC.doc

    Office of Legacy Management (LM)

    0 Doc. No. S06401 Page B-1 Annual Assessment of the Effectiveness of Site-Wide Institutional Controls U.S. Department of Energy Doc. No. S06401 June 2010 Page B-2 U.S. Department of Energy Annual Assessment of the Effectiveness of Site-Wide Institutional Controls June 2010 Doc. No. S06401 Page B-3 Annual Assessment of the Effectiveness of Site-Wide Institutional Controls U.S. Department of Energy Doc. No. S06401 June 2010

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    Office of Legacy Management (LM)

    Institutional Controls: A Citizen's Guide to Understanding Institutional Controls at Superfund, Brownfields, Federal Facilities, Underground Storage Tank, and Resource Conservation and Recovery Act Cleanups This page intentionally left blank U.S. Department of Energy Annual Assessment of the Effectiveness of Site-Wide Institutional Controls June 2010 Doc. No. S06401 Page C-1 Annual Assessment of the Effectiveness of Site-Wide Institutional Controls U.S. Department of Energy Doc. No. S06401 June

  17. Itinerant electrons, local moments, and magnetic correlations in the pnictide superconductors CeFeAsO₁₋xFxand Sr(Fe₁₋xCox)₂As₂

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Vilmercati, Paolo; Fedorov, Alexei; Bondino, Federica; Offi, Francesco; Panaccione, Giancarlo; Lacovig, Paolo; Simonelli, Laura; McGuire, Michael A.; Sefat, Athena S. M.; Mandrus, David; et al

    2012-06-15

    A direct and element-specific measurement of the local Fe spin moment has been provided by analyzing the Fe 3s core level photoemission spectra in the parent and optimally doped CeFeAsO₁₋xFx (x = 0, 0.11) and Sr(Fe₁₋xCox)2As2 (x = 0, 0.10) pnictides. The rapid time scales of the photoemission process allowed the detection of large local spin moments fluctuating on a 10⁻¹⁵ s time scale in the paramagnetic, antiferromagnetic, and superconducting phases, indicative of the occurrence of ubiquitous strong Hund's magnetic correlations. The magnitude of the spin moment is found to vary significantly among different families, 1.3μB in CeFeAsO and 2.1μBmore » in SrFe₂As₂. Surprisingly, the spin moment is found to decrease considerably in the optimally doped samples, 0.9μB in CeFeAsO₀.₈₉F₀.₁₁ and 1.3μB in Sr(Fe₀.₉Co₀.₁)₂As₂. The strong variation of the spin moment against doping and material type indicates that the spin moments and the motion of itinerant electrons are influenced reciprocally in a self-consistent fashion, reflecting the strong competition between the antiferromagnetic superexchange interaction among the spin moments and the kinetic energy gain of the itinerant electrons in the presence of a strong Hund's coupling. By describing the evolution of the magnetic correlations concomitant with the appearance of superconductivity, these results constitute a fundamental step toward attaining a correct description of the microscopic mechanisms shaping the electronic properties in the pnictides, including magnetism and high-temperature superconductivity.« less

  18. Structure and Magnetic Properties of Ce3(Ni/Al/Ga)11„A New Phase with the La3Al11 Structure Type

    Office of Scientific and Technical Information (OSTI)

    Crystals 2015, 5, 1-8; doi:10.3390/cryst5010001 crystals ISSN 2073-4352 www.mdpi.com/journal/crystals Article Structure and Magnetic Properties of Ce 3 (Ni/Al/Ga) 11 -A New Phase with the La 3 Al 11 Structure Type Oliver Janka 1,2,†, *, Tian Shang 3,4,† , Ryan E. Baumbach 3,5,† , Eric D. Bauer 3,† , Joe D. Thompson 3,† and Susan M. Kauzlarich 1,†, * 1 Department of Chemistry, University of California, Davis, CA 95616, USA 2 Institut für Anorganische und Analytische Chemie,

  19. Synthesis and crystal structure of the isotypic rare earth thioborates Ce[BS{sub 3}], Pr[BS{sub 3}], and Nd[BS{sub 3}

    SciTech Connect (OSTI)

    Hunger, Jens; Borna, Marija [Max Planck Institute for Chemical Physics of Solids, Noethnitzer Strasse 40, D-01187 Dresden (Germany); Kniep, Ruediger, E-mail: kniep@cpfs.mpg.d [Max Planck Institute for Chemical Physics of Solids, Noethnitzer Strasse 40, D-01187 Dresden (Germany)

    2010-03-15

    The orthothioborates Ce[BS{sub 3}], Pr[BS{sub 3}] and Nd[BS{sub 3}] were prepared from mixtures of the rare earth (RE) metals together with amorphous boron and sulfur summing up to the compositions CeB{sub 3}S{sub 6}, PrB{sub 5}S{sub 9} and NdB{sub 3}S{sub 6}. The following preparation routes were used: solid state reactions with maximum temperatures of 1323 K and high-pressure high-temperature syntheses at 1173 K and 3 GPa. Pr[BS{sub 3}] and Nd[BS{sub 3}] were also obtained from rare earth chlorides RECl{sub 3} and sodium thioborate Na{sub 2}B{sub 2}S{sub 5} by metathesis type reactions at maximum temperatures of 1073 K. The crystal structure of the title compounds was determined from X-ray powder diffraction data. The thioborates are isotypic and crystallize in the orthorhombic spacegroup Pna2{sub 1} (No. 33; Z=4; Ce: a=7.60738(6)A, b=6.01720(4)A, c=8.93016(6)A; Pr: a=7.56223(4)A, b=6.00876(2)A, c=8.89747(4)A; Nd: a=7.49180(3)A, b=6.00823(2)A, c=8.86197(3)A) . The crystal structures contain isolated [BS{sub 3}]{sup 3-} groups with boron in trigonal-planar coordination. The sulfur atoms form the vertices of undulated kagome nets, which are stacked along [100] according to the sequence ABAB. Within these nets every second triangle is occupied by boron and the large hexagons are centered by rare earth ions, which are surrounded by overall nine sulfur species. - Abstract: Graphical Abstract Legend (TOC Figure): Table of Contents Figure The isotypic orthothioborates Ce[BS{sub 3}], Pr[BS{sub 3}] and Nd[BS{sub 3}] were prepared using different preparation routes. The crystal structure of the title compounds was determined from X-ray powder diffraction data. The crystal structures contain isolated [BS{sub 3}]{sup 3-} groups with boron in trigonal-planar coordination. The sulfur atoms form the vertices of corrugated kagome nets (sketched with blue dotted lines), which are stacked along [100] according to the sequence ABAB. Within these nets every second triangle is occupied by boron and the large hexagons are centered by rare earth ions, which are surrounded by overall nine sulfur species.

  20. Magnetic correlations and the anisotropic kondo effect in Ce{sub 1-x}La{sub x}Al{sub 3}.

    SciTech Connect (OSTI)

    Goremychkin, E. A.; Osborn, R.; Rainford, B. D.; Costi, T. A.; Murani, A. P.; Scott, C. A.; King, P. J. C.; Materials Science Division; Univ. of Southhampton; Univ. Karlsruhe; Inst. laue Langevin; Rutherford Appleton Lab.

    2002-09-30

    By combining the results of muon spin relaxation and inelastic neutron scattering in the heavy fermion compounds Ce{sub 1-x}La{sub x}Al{sub 3} (0.0 {le} x {le} 0.2), we show that static magnetic correlations are suppressed above a characteristic temperature, T*, by electronic dissipation rather than by thermal disorder. Below T*, an energy gap opens in the single-ion magnetic response in agreement with the predictions of the anisotropic Kondo model. Scaling arguments suggest that similar behavior may underlie the 'hidden order' in URu{sub 2}Si{sub 2}.

  1. Evidence for Anisotropic Kondo Behavior in Ce{sub 0.8}La{sub 0.2}Al{sub 3}

    SciTech Connect (OSTI)

    Goremychkin, E. A.; Osborn, R.; Rainford, B. D.; Murani, A. P.

    2000-03-06

    We have performed an inelastic neutron scattering study of the low energy spin dynamics of the heavy fermion compound Ce{sub 0.8}La {sub 0.2}Al{sub 3} as a function of temperature and external pressure up to 5 kbar. At temperatures below 3 K, the magnetic response transforms from a quasielastic form, common to many heavy fermion systems, to a single well-defined inelastic peak, which is extremely sensitive to external pressure. The scaling of the spin dynamics and the thermodynamic properties are in agreement with the predictions of the anisotropic Kondo model. (c) 2000 The American Physical Society.

  2. Neutron diffraction study of magnetic field induced behavior in the heavy Fermion Ce3Co4Sn13

    SciTech Connect (OSTI)

    Christianson, Andrew D; Goremychkin, E. A.; Gardner, J. S.; Kang, H. J.; Chung, J.-H.; Manuel, P.; Thompson, J. D.; Sarrao, J. L.; Lawrence, J. M.

    2008-01-01

    The specific heat of Ce3Co4Sn13 exhibits a crossover from heavy Fermion behavior with antiferromagnetic correlations at low field to single impurity Kondo behavior above 2 T. We have performed neutron diffraction measurements in magnetic fields up to 6 Tesla on single crystal samples. The (001) position shows a dramatic increase in intensity in field which appears to arise from static polarization of the 4f level and which at 0.14 K also exhibits an anomaly near 2T reflecting the crossover to single impurity behavior.

  3. A novel yellow-emitting SrAlSi{sub 4}N{sub 7}:Ce{sup 3+} phosphor for solid state lighting: Synthesis, electronic structure and photoluminescence properties

    SciTech Connect (OSTI)

    Ruan, Jian; Xie, Rong-Jun; Funahashi, Shiro; Tanaka, Yoshinori; Takeda, Takashi; Suehiro, Takayuki; Hirosaki, Naoto; Li, Yuan-Qiang

    2013-12-15

    Ce{sup 3+}-doped and Ce{sup 3+}/Li{sup +}-codoped SrAlSi{sub 4}N{sub 7} phosphors were synthesized by gas pressure sintering of powder mixtures of Sr{sub 3}N{sub 2}, AlN, ?-Si{sub 3}N{sub 4}, CeN and Li{sub 3}N. The phase purity, electronic crystal structure, photoluminescence properties of SrAlSi{sub 4}N{sub 7}:Ce{sup 3+}(Ce{sup 3+}/Li{sup +}) were investigated in this work. The band structure calculated by the DMol{sup 3} code shows that SrAlSi{sub 4}N{sub 7} has a direct band gap of 3.87 eV. The single crystal analysis of Ce{sup 3+}-doped SrAlSi{sub 4}N{sub 7} indicates a disordered Si/Al distribution and nitrogen vacnacy defects. SrAlSi{sub 4}N{sub 7} was identified as a major phase of the fired powders, and Sr{sub 5}Al{sub 5}Si{sub 21}N{sub 35}O{sub 2} and AlN as minor phases. Both Ce{sup 3+} and Ce{sup 3+}/Li{sup +} doped SrAlSi{sub 4}N{sub 7} phosphors can be efficiently excited by near-UV or blue light and show a broadband yellow emission peaking around 565 nm. A highest external quantum efficiency of 38.3% under the 450 nm excitation was observed for the Ce{sup 3+}/Li{sup +}-doped SrAlSi{sub 4}N{sub 7} (5 mol%). A white light LED lamp with color temperature of 6300 K and color rendering index of Ra=78 was achieved by combining Sr{sub 0.97}Al{sub 1.03}Si{sub 3.997}N/94/maccounttest14=t0005{sub 1}8193 {sub 7}:Ce{sup 3+}{sub 0.03} with a commercial blue InGaN chip. It indicates that SrAlSi{sub 4}N{sub 7}:Ce{sup 3+} is a promising yellow emitting down-conversion phosphor for white LEDs. - Graphical abstract: One-phosphor converted white light-emitting diode (LED) was fabricated by combining a blue LED chip and a yellow-emitting SrAlSi4N7:Ce{sup 3+} phosphor (see inset), which has the color rendering index of 78 and color temperature of 6300 K. - Highlights: We reported a new yellow nitride phosphor suitable for solid state lighting. We solved the crystal structure and evidenced a disordered Si/Al distribution. We fabricated a high color rendering white LEDs by using a single SrAlSi4N7:Ce.

  4. Structural and magnetic properties of La{sub 1−x}Ce{sub x}Fe{sub 1−x}Cr{sub x}O{sub 3} orthoferrite prepared by co-precipitation method

    SciTech Connect (OSTI)

    Azab, A.A.; Helmy, N.; Albaaj, Sukrat

    2015-06-15

    Graphical abstract: TEM micrographs of La{sub 1−x}Ce{sub x}Fe{sub 1−x}Cr{sub x}O{sub 3} for x = 0.0. - Highlights: • The composition of La{sub 1−x}Ce{sub x}Fe{sub 1−x} Cr{sub x}O{sub 3} was prepared by co-precipitation method. • X-ray diffraction showed orthorhombic structure with space group Pnma. • With increasing Ce and Cr content, a decrease of the unit cell volume. • Enhancement in the coercivity (H{sub c}) with increasing Ce and Cr content. • Reduction of M{sub s} and M{sub r} up to x = 0.15 and increases with further increases of x. - Abstract: Nanocrystalline orthoferrites with the composition of La{sub 1−x}Ce{sub x}Fe{sub 1−x} Cr{sub x}O{sub 3} where (x = 0, 0.1, 0.15 and 0.2) were prepared by co-precipitation method. The structural and magnetic properties of the La{sub 1−x}Ce{sub x}Fe{sub 1−x}Cr{sub x}O{sub 3} system have been investigated. X-ray diffraction showed the formation of orthorhombic structure with space group Pnma for different compositions. With increasing Ce and Cr content, lattice parameters a and c were found to decrease while b increases, resulting in a decrease of the unit cell volume. The crystallite size was calculated from XRD data and compared with that obtained from TEM micrographs. Vibrating sample magnetometer measurements reveal an enhancement in the coercivity (H{sub c}) with increasing Ce and Cr content and reduction of saturation magnetization (M{sub s}) and remnant magnetization (M{sub r}) up to x = 0.15 and increases with further increases of x. The magnetic susceptibility measurements vs. temperature showed canted-antiferromagnetic (AFM) in which the Neel temperature is increasing with Ce and Cr content.

  5. Effect of Tb{sup 3+} concentration on the optical and vibrational properties of YBO{sub 3} tri-doped with Eu{sup 3+}, Ce{sup 3+}, and Tb{sup 3+}

    SciTech Connect (OSTI)

    Sohal, S.; Hassanzadeh, E.; Huang, J. Y. [Department of Physics, Texas Tech University and Nano Tech Center, Lubbock, Texas 79409 (United States); Nazari, M.; Holtz, M., E-mail: mark.holtz@txstate.edu [Department of Physics, Texas State University, San Marcos, Texas 78666 (United States); Zhang, X.; Chaudhuri, J. [Department of Mechanical Engineering, Texas Tech University, Lubbock, Texas 79409 (United States); Kuryatkov, V. V. [Department of Electrical and Computer Engineering and Nano Tech Center, Texas Tech University, Lubbock, Texas 79409 (United States); Hope-Weeks, L. J. [Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409 (United States)

    2014-05-14

    Structural and optical studies are reported of yttrium orthoborate YBO{sub 3} when tri-doped with Eu{sup 3+}, Ce{sup 3+}, and Tb{sup 3+}, focusing on the role of terbium concentration. Incorporation of Tb{sup 3+} affects emission properties for photoluminescence (PL) excited by near ultraviolet light. For constant cerium and europium concentrations, increasing the Tb{sup 3+} results in diminished PL from the Ce{sup 3+} and Tb{sup 3+} color centers. Simultaneously, the PL excitation bands related to both Ce{sup 3+} and Tb{sup 3+} increase in intensity for red emission from the Eu{sup 3+}. Results are consistent with a Ce{sup 3+}???(Tb{sup 3+}){sub n}???Eu{sup 3+} energy transfer scheme, where (Tb{sup 3+}){sub n} denotes a chain incorporating n terbium ions. A high red to orange PL intensity ratio is obtained, ranging from 1.34 to 2.09. Raman vibrational bands show a systematic change, with Tb{sup 3+} concentration, in the B{sub 3}O{sub 9} ring terminal oxygen bending mode coordinated with the yttrium site where dopant ions substitute. The structural changes are interpreted as variations in the local neighborhood of these sites in the YBO{sub 3}:Ce{sup 3+},Tb{sup 3+},Eu{sup 3+} crystal structure.

  6. BPA-2013-00088-FOIA Request

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Kirk Brown Sent: Thursday, October 18, 2012 2:13 PM To: Winn,Kim S (BPA) - DK-7 Ri CE VEt) flY BPA Subject: FOIA Request- BPA FOLA OFFICE Tftf I DATE: 'Ci, To Whom it May...

  7. National Center for Photovoltaics NCPV | Open Energy Information

    Open Energy Info (EERE)

    Center for Photovoltaics NCPV Jump to: navigation, search Name: National Center for Photovoltaics (NCPV) Product: String representation "The National Ce ... ics community.'" is too...

  8. Pressure-tuned quantum criticality in the antiferromagnetic Kondo semimetal CeNi2–δAs2

    SciTech Connect (OSTI)

    Luo, Yongkang; Ronning, F.; Wakeham, N.; Lu, Xin; Park, Tuson; Xu, Z. -A.; Thompson, J. D.

    2015-10-19

    The easily tuned balance among competing interactions in Kondo-lattice metals allows access to a zero-temperature, continuous transition between magnetically ordered and disordered phases, a quantum-critical point (QCP). Indeed, these highly correlated electron materials are prototypes for discovering and exploring quantum-critical states. Theoretical models proposed to account for the strange thermodynamic and electrical transport properties that emerge around the QCP of a Kondo lattice assume the presence of an indefinitely large number of itinerant charge carriers. Here, we report a systematic transport and thermodynamic investigation of the Kondo-lattice system CeNi2–δAs2 (δ ≈ 0.28) as its antiferromagnetic order is tuned by pressure and magnetic field to zero-temperature boundaries. These experiments show that the very small but finite carrier density of ~0.032 e/formular unit in CeNi2–δAs2 leads to unexpected transport signatures of quantum criticality and the delayed development of a fully coherent Kondo-lattice state with decreasing temperature. Here, the small carrier density and associated semimetallicity of this Kondo-lattice material favor an unconventional, local-moment type of quantum criticality and raises the specter of the Nozières exhaustion idea that an insufficient number of conduction-electron spins to separately screen local moments requires collective Kondo screening.

  9. Nodal to nodeless superconducting energy-gap structure change concomitant with Fermi-surface reconstruction in the heavy-fermion compound CeCoIn5

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kim, Hyunsoo; Tanatar, M. A.; Flint, R.; Petrovic, C.; Hu, Rongwei; White, B. D.; Lum, I. K.; Maple, M. B.; Prozorov, R.

    2015-01-15

    The London penetration depth λ(T) was measured in single crystals of Ce1–xRxCoIn₅, R=La, Nd, and Yb down to Tmin ≈ 50 mK (Tc/Tmin ~50) using a tunnel-diode resonator. In the cleanest samples Δλ(T) is best described by the power law, Δλ(T) ∝ Tn, with n ~ 1, consistent with line nodes. Substitutions of Ce with La, Nd, and Yb lead to similar monotonic suppressions of Tc, however, the effects on Δλ(T) differ. While La and Nd dopings lead to increase of the exponent n and saturation at n ~ 2, as expected for a dirty nodal superconductor, Yb doping leadsmore » to n > 3, suggesting a change from nodal to nodeless superconductivity. As a result, this superconducting gap structure change happens in the same doping range where changes of the Fermi surface topology were reported, implying that the nodal structure and Fermi surface topology are closely linked.« less

  10. Luminescence of Ce 3+ -Doped MB2Si2O8 (M = Sr, Ba): A Deeper Insight into the Effects of Electronic Structure and Stokes Shift

    SciTech Connect (OSTI)

    Peng, Qi; Liu, Chunmeng; Hou, Dejian; Zhou, Weijie; Ma, Chong-Geng; Liu, Guokui; Brik, Mikhail G.; Tao, Ye; Liang, Hongbin

    2015-12-18

    A series of Sr 1 -2x CexNaxB2Si2O8 and Ba 1-2x CexKxB2Si2O8 (x = 0.005, 0.01, 0.02, 0.04, 0.06, 0.08) samples were synthesized by a high-temperature solid-state reaction. The low temperature excitation, emission, and fluorescence decay spectra together demonstrated that all spectral bands arise from the Ce 3+ ions located at only one kind of lattice site. The first-principles calculations of the structural and electronic properties of pure and Ce 3+2Si2O8 (M = Sr, Ba) were performed, and the obtained results were used for understanding the structural changes after doping and identification of the observed position of the host absorption bands. The measured 4f-5d excitation and emission spectra of Ce3+ ions doped in MB2Si2O8 were analyzed and simulated in the framework of the crystal-field (CF) theory. The electron-phonon coupling effect generally ignored in most studies published so far was also taken into account by applying the configurational coordinate model. The validity of such a combined insight into the 5d CF energy level positions and the Stokes shift has been confirmed by analyzing the dependence of the Ce 3+

  11. Energy efficient microwave synthesis of mesoporous Ce0.5M0.5O2 (Ti, Zr, Hf) nanoparticles for low temperature CO oxidation in an ionic liquid – a comparative study

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Alammar, Tarek; Chow, Ying -Kit; Mudring, Anja -Verena

    2014-11-19

    Ce0.5M0.5O2 (M = Ti, Zr, Hf) nanoparticles have been successfully synthesized by microwave irradiation in the ionic liquid [C4mim][Tf2N] (1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide). The morphology, crystallinity, and chemical composition of the obtained materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy, and N2–adsorption measurements. XRD and Raman spectroscopy analyses confirmed the formation of solid solutions with cubic fluorite structure. The catalytic activities of the Ce0.5M0.5O2 (M = Ti, Zr, Hf) nanoparticles were investigated in the low-temperature oxidation of CO. Ce0.5Zr0.5O2 nanospheres exhibit the best performance (100% conversion at 350 °C), followed by Ce0.5Hf0.5O2more » (55% conversion at 360 °C) and Ce0.5Ti0.5O2 (11% conversion at 350 °C). Heating the as-prepared Ce0.5Zr0.5O2 to 600 °C for extended time leads to a decrease in surface area and, as expected decreased catalytic activity. Depending on the ionic liquid the obtained Ce0.5Zr0.5O2 exhibits different morphologies, varying from nano-spheres in [C4mim][Tf2N] and [P66614][Tf2N] (P66614 = trishexyltetradecylphosphonium) to sheet-like assemblies in [C3mimOH][Tf2N] (C3mimOH = 1-(3-hydroxypropyl)-3-methylimidazolium). As a result, the microwave synthesis superiority to other heating methods like sonochemical synthesis and conventional heating was proven by comparative experiments where the catalytic activity of Ce0.5Zr0.5O2 obtained by alternate methods such as conventional heating was found to be poorer than that of the microwave-synthesised material.« less

  12. Sub-nanosecond Half-life Measurement of the Yrast I{sup π}=5{sup −} State in the N=78 Nucleus {sup 136}{sub 58}Ce using Fast-timing Coincident Gamma-ray Spectroscopy

    SciTech Connect (OSTI)

    Alharbi, T.; Regan, P.H.; Mărginean, N.; Podolyák, Zs.; Bajoga, A.; Britton, R.; Bucurescu, D.; Deleanu, D.; Filipescu, D.; Ghită, D.; Glodariu, T.; Mihai, C.; Mulholland, K.; Mărginean, R.; Negret, A.; Nita, C.R.; Patel, Z.; Roberts, O.J.; Stroe, L.; Sava, T.; and others

    2014-06-15

    We report on the measurement of the half-life of the yrast I{sup π}=5{sup −} state in the transitional nucleus {sup 136}Ce using a combined HPGe-LaBr3(Ce) scintillator gamma-ray detection array. The measured value for the E1 decay is approximately half a nanosecond, which corresponds to an E1 decay strength of approximately 2×10{sup −6} Wu. This value is in line with single-particle type E1 decays in this mass region and suggests no sign of additional K-hindrance associated with axially symmetric quadrupole deformations observed for lighter cerium isotopes.

  13. Electronic structure of Ce?RhIn?: A two-dimensional heavy-fermion system studied by angle-resolved photoemission spectroscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jiang, Rui; Petrovic, C.; Mou, Daixing; Liu, Chang; Zhao, Xin; Yao, Yongxin; Ryu, Hyejin; Ho, Kai -Ming; Kaminski, Adam

    2015-04-01

    We use angle-resolved photoemission spectroscopy (ARPES) to study the 2D heavy fermion superconductor, Ce?RhIn?. The Fermi surface is rather complicated and consists of several hole and electron pockets with one of the sheets displaying strong nesting properties with a q-vector of (0.32, 0.32) ?/a. We do not observe kz dispersion of the Fermi sheets, which is consistent with the expected 2D character of the electronic structure. Comparison of the ARPES data to band structure calculations suggests that a localized picture of the f-electrons works best. While there is some agreement in the overall band dispersion and location of the Fermimoresheets, the model does not reproduce all observed bands and is not completely accurate for those it does. Our data paves the way for improving the band structure calculations and the general understanding of the transport and thermodynamical properties of this material.less

  14. Influence of the Electronic Structure and Optical Properties of CeO2 and UO2 for Characterization with UV-Laser Assisted Atom Probe Tomography

    SciTech Connect (OSTI)

    Billy Valderrama; H.B. Henderson; C. Yablinsky; J. Gan; T.R. Allen; M.V. Manuel

    2015-09-01

    Oxide materials are used in numerous applications such as thermal barrier coatings, nuclear fuels, and electrical conductors and sensors, all applications where nanometer-scale stoichiometric changes can affect functional properties. Atom probe tomography can be used to characterize the precise chemical distribution of individual species and spatially quantify the oxygen to metal ratio at the nanometer scale. However, atom probe analysis of oxides can be accompanied by measurement artifacts caused by laser-material interactions. In this investigation, two technologically relevant oxide materials with the same crystal structure and an anion to cation ratio of 2.00, pure cerium oxide (CeO2) and uranium oxide (UO2) are studied. It was determined that electronic structure, optical properties, heat transfer properties, and oxide stability strongly affect their evaporation behavior, thus altering their measured stoichiometry, with thermal conductance and thermodynamic stability being strong factors.

  15. 15N2 formation and fast oxygen isotope exchange during pulsed 15N18O exposure of MnOx/CeO2

    SciTech Connect (OSTI)

    Kwak, Ja Hun; Szanyi, Janos

    2014-12-23

    Pulsing 15N18O onto an annealed 1% Mn16Ox/Ce16O2 catalyst resulted in very fast oxygen isotope exchange and 15N2 formation at 295 K. In the 1st 15N18O pulse, due to the presence of large number of surface oxygen defects, extensive 15N218O and 15N2 formations were observed. In subsequent pulses oxygen isotope exchange dominated as a result of highly labile oxygen in the oxide. We gratefully acknowledge the US Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy/Vehicle Technologies Program for the support of this work. The research described in this paper was performed at the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the DOEs Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is operated for the US DOE by Battelle.

  16. Study of the thermodynamic properties of CeO{sub 2} from ab initio calculations: The effect of phonon-phonon interaction

    SciTech Connect (OSTI)

    Niu, Zhen-Wei; Zeng, Zhao-Yi; Hu, Cui-E; Cai, Ling-Cang; Chen, Xiang-Rong

    2015-01-07

    The thermodynamic properties of CeO{sub 2} have been reevaluated by a simple but accurate scheme. All our calculations are based on the self-consistent ab initio lattice dynamical (SCAILD) method that goes beyond the quasiharmonic approximation. Through this method, the effects of phonon-phonon interactions are included. The obtained thermodynamic properties and phonon dispersion relations are in good agreement with experimental data when considering the correction of phonon-phonon interaction. We find that the correction of phonon-phonon interaction is equally important and should not be neglected. At last, by comparing with quasiharmonic approximation, the present scheme based on SCAILD method is probably more suitable for high temperature systems.

  17. Phases in ceria-zirconia binary oxide (1-x)CeO2-xZrO2 nanoparticles: the size effects

    SciTech Connect (OSTI)

    Zhang,F.; Chen, C.; Hanson, J.; Herman, I.; Chan, S.

    2006-01-01

    The phases of ceria-zirconia nanoparticles observed in air are studied as a function of particle size and composition by X-ray diffraction, transmission electron microscopy, and Raman spectroscopy. The emergence of two tetragonal phases t{prime}{prime} and t monotonically moves toward higher zirconia concentrations with decreasing particle size. A smaller particle size increases the solubility of zirconia in cubic ceria, while higher zirconia content in ceria stabilizes against coarsening. In particular, the cubic Ce{sub 1-x}Zr{sub x}O{sub 2-y} is persistent and is 8% in phase amount even at 90% zirconia with 33 nm crystal size. Neither the monoclinic phase m nor the tetragonal phase t{prime} is observed in the present nanoparticles (<40 nm). The effectiveness of these nanoparticles as oxygen source-and-sink in catalytic support is largely due to the persistence of the cubic and the t{prime}{prime} phases.

  18. Low pressure CO? hydrogenation to methanol over gold nanoparticles activated on a CeOx/TiO? interface

    SciTech Connect (OSTI)

    Yang, Xiaofang; Boscoboinik, J. Anibal; Kattel, Shyam; Senanayake, Sanjaya D.; Nie, Xiaowa; Graciani, Jesus; Rodriguez, Jose A.; Liu, Ping; Stacchiola, Dario J.; Chen, Jingguang G.

    2015-07-28

    Capture and recycling of CO? into valuable chemicals such as alcohols could help mitigate its emissions into the atmosphere. Due to its inert nature, the activation of CO? is a critical step in improving the overall reaction kinetics during its chemical conversion. Although pure gold is an inert noble metal and cannot catalyze hydrogenation reactions, it can be activated when deposited as nanoparticles on the appropriate oxide support. In this combined experimental and theoretical study, it is shown that an electronic polarization at the metaloxide interface of Au nanoparticles anchored and stabilized on a CeOx/TiO? substrate generates active centers for CO? adsorption and its low pressure hydrogenation, leading to a higher selectivity toward methanol. In conclusion, this study illustrates the importance of localized electronic properties and structure in catalysis for achieving higher alcohol selectivity from CO? hydrogenation.

  19. Structure and physical properties of single crystal PrCr{sub 2}Al{sub 20} and CeM{sub 2}Al{sub 20} (M=V, Cr): A comparison of compounds adopting the CeCr{sub 2}Al{sub 20} structure type

    SciTech Connect (OSTI)

    Kangas, Michael J.; Schmitt, Devin C.; Sakai, Akito; Nakatsuji, Satoru; Institute of Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 ; Chan, Julia Y.

    2012-12-15

    Crystal growth and full structure determination of compounds adopting the CeCr{sub 2}Al{sub 20} structure type, LnTi{sub 2}Al{sub 20} (Ln=La-Pr, Sm, and Yb), LnV{sub 2}Al{sub 20} (Ln=La-Pr, and Sm), and LnCr{sub 2}Al{sub 20} (Ln=La-Pr, Sm, and Yb), are reported. Resistivity, magnetic susceptibility, and heat capacity of flux grown single crystals of the nonmagnetic CeM{sub 2}Al{sub 20} (Ln=Ce, Yb; M=Ti, V) compounds are compared to PrCr{sub 2}Al{sub 20}. Of particular interest is PrCr{sub 2}Al{sub 20} which does not show any phase transition down to the lowest temperature of the measurement (400 mK in resistivity measurement and 1.8 K for magnetic susceptibility measurements) and exhibits Kondo behavior at low temperatures. - Graphical abstract: Crystal structure of SmV{sub 2}Al{sub 20} showing the interpenetrating diamond-like samarium network and pyrochlore-like vanadium network. Highlights: Black-Right-Pointing-Pointer Single crystals of LnM{sub 2}Al{sub 20} were grown from a molten aluminum flux. Black-Right-Pointing-Pointer Magnetic, electrical, and specific heat of single crystal LnM{sub 2}Al{sub 20} are presented. Black-Right-Pointing-Pointer PrCr{sub 2}Al{sub 20} exhibits evidence of Kondo effect.

  20. Structure and magnetic properties of RE{sub 2}CuIn{sub 3} (RE=Ce, Pr, Nd, Sm and Gd)

    SciTech Connect (OSTI)

    Tyvanchuk, Yuriy B. Szytula, Andrzej; Zarzycki, Arkadiusz; Rodewald, Ute Ch.; Kalychak, Yaroslav M.; Poettgen, Rainer

    2008-12-15

    The ternary copper indides RE{sub 2}CuIn{sub 3}{identical_to}RECu{sub 0.5}In{sub 1.5} (RE=Ce, Pr, Nd, Sm and Gd) were synthesized from the elements in sealed tantalum tubes in an induction furnace. They crystallize with the CaIn{sub 2}-type structure, space group P6{sub 3}/mmc, with a statistical occupancy of copper and indium on the tetrahedral substructure. These indides show homogeneity ranges RECu{sub x}In{sub 2-x}. Single crystal structure refinements were performed for five crystals: CeCu{sub 0.66}In{sub 1.34} (a=479.90(7) pm, c=768.12(15) pm), PrCu{sub 0.52}In{sub 1.48} (a=480.23(7) pm, c=759.23(15) pm), NdCu{sub 0.53}In{sub 1.47} (a=477.51(7) pm, c=756.37(15) pm), SmCu{sub 0.46}In{sub 1.54} (a=475.31(7) pm, c=744.77(15) pm), and GdCu{sub 0.33}In{sub 1.67} (a=474.19(7), c=737.67(15) pm). Temperature-dependent susceptibility measurements show antiferromagnetic ordering at T{sub N}=4.7 K for Pr{sub 2}CuIn{sub 3} and Nd{sub 2}CuIn{sub 3} and 15 K for Sm{sub 2}CuIn{sub 3}. Fitting of the susceptibility data of the samarium compound revealed an energy gap {delta}E=39.7(7) K between the ground and the first excited levels. - Graphical abstract: The CaIn{sub 2}-type structure of Sm{sub 2}CuIn{sub 3}.

  1. Precipitate size refinement by CeO{sub 2} and Y{sub 2}BaCuO{sub 5} additions in directionally solidified YBa{sub 2}Cu{sub 3}O{sub 7}

    SciTech Connect (OSTI)

    Vilalta, N.; Sandiumenge, F.; Pinol, S.; Obradors, X.

    1997-01-01

    Directional solidification of YBa{sub 2}Cu{sub 3}O{sub 7} has been carried out through a Bridgman technique, and the influence of Y{sub 2}BaCuO{sub 5} and CeO{sub 2} additives on the size of Y{sub 2}BaCuO{sub 5} precipitates has been investigated. It is demonstrated in this work that the most efficient procedure to reduce the size of the Y{sub 2}BaCuO{sub 5} precipitates is to increase the concentration of nucleation centers present in the peritectic decomposition of YBa{sub 2}Cu{sub 3}O{sub 7{minus}x}. A small concentration (0.3{endash}1 wt.{percent}) of CeO{sub 2} has a strong influence on the solidification process and on the size of Y{sub 2}BaCuO{sub 5} precipitates. It is shown that when CeO{sub 2} is added, further refinement of the size of precipitates results from the formation of nanometric Y{sub 2}O{sub 3} particles which further enhance the multinucleation effect. We have also observed that coarsening effects are avoided with CeO{sub 2} additives. {copyright} {ital 1997 Materials Research Society.}

  2. Charge-coupled Substituted Garnets (Y3-xCa0.5xM0.5x)Fe5O12 (M = Ce, Th): Structure and Stability as Crystalline Nuclear Waste Forms

    SciTech Connect (OSTI)

    Guo, Xiaofeng; Kukkadapu, Ravi K.; Lanzirotti, Anthony; Newville, Mathew; Engelhard, Mark H.; Sutton , Steven R.; Navrotsky, Alexandra

    2015-04-20

    The garnet structure has been proposed as a potential crystalline nuclear waste form for accommodation of actinide elements, especially uranium (U). In this study, yttrium iron garnet (YIG) as a model garnet host was studied for the incorporation of U analogs, cerium (Ce), and thorium (Th), incorporated by a charge-coupled substitution with calci-um (Ca) for yttrium (Y) in YIG, namely 2Y3+ = Ca2+ + M4+, where M4+ = Ce4+ or Th4+. Single phase garnets Y3-xCa0.5xM0.5xFe5O12, synthesized by the citrate-nitrate combustion method, were obtained up to x = 0.7. Ce was confirmed to be tetravalent by X-ray absorption spectroscopy and X-ray photoelectron spectroscopy. X-ray diffraction and 57Fe-Mössbauer spectroscopy indicated that the samples are single phase, M4+ and Ca2+ cations are restricted to the c-site, the nature of M4+ has only a minor effect on the structure, and the local environments of both the tetrahedral and octahedral Fe3+ are systematically affected by the extent of substitution, especially on the tetrahedral sublattice. The charge coupled substitution has advantages in incorporating Ce/Th and in stabilizing the substituted phases, compared to a single substitution strategy. Enthalpies of formation of garnets were obtained by high temperature oxide melt solution calorimetry, and the enthalpies of substitution of Ce and Th were determined. The thermodynamic analysis demonstrates that the substituted garnets are entropically rather than energetically stabilized. This suggests that such garnets may form and persist in repositories at high temperature but might decompose near room temperature. These structural and thermodynamic findings shed light on possible incorporation of U in this garnet system.

  3. On phase equilibria and crystal structures in the systems Ce-Pd-B and Yb-Pd-B. Physical properties of R{sub 2}Pd{sub 13.6}B{sub 5} (R=Yb, Lu)

    SciTech Connect (OSTI)

    Sologub, Oksana; Rogl, Peter; Salamakha, Leonid; Bauer, Ernst; Hilscher, Gerfried; Michor, Herwig; Giester, Gerald

    2010-05-15

    Phase equilibria and crystal structures of ternary compounds were determined in the systems Ce-Pd-B and Yb-Pd-B at 850 deg. C in the concentration ranges up to 45 and 33 at% of Ce and Yb, respectively, employing X-ray single crystal and powder diffraction. Phase relations in the Ce-Pd-B system at 850 deg. C are governed by formation of extended homogeneity fields, tau{sub 2}-CePd{sub 8}B{sub 2-x} (0.10Ce{sub 3}Pd{sub 25-x}B{sub 8-y} (1.06CePd{sub 3}B{sub x} (0CePd{sub 3}. Crystallographic parameters for the new structure type tau{sub 2}-CePd{sub 8}B{sub 2-x} (space group C2/c, a=1.78104(4) nm, b=1.03723(3) nm, c=1.16314(3), beta=118.515(1){sup o} for x=0.46) were established from X-ray single crystal diffraction. The crystal structures of tau{sub 2}-CePd{sub 8}B{sub 2-x} and tau{sub 3}-Ce{sub 3}Pd{sub 25-x}B{sub 3-y} are connected in a crystallographic group-subgroup relationship. Due to the lack of suitable single crystals, the novel structure of tau{sub 1}-Ce{sub 6}Pd{sub 47-x}B{sub 6} (x=0.2, C2/m space group, a=1.03594(2) nm, b=1.80782(3) nm, c=1.01997(2) nm, beta=108.321(1){sup o}) was determined from Rietveld refinement of X-ray powder diffraction data applying the structural model obtained from single crystals of homologous La{sub 6}Pd{sub 47-x}B{sub 6} (x=0.19) (X-ray single crystal diffraction, new structure type, space group C2/m, a=1.03988(2) nm, b=1.81941(5) nm, c=1.02418(2) nm, beta=108.168(1){sup o}). The Yb-Pd-B system is characterized by one ternary compound, tau{sub 1}-Yb{sub 2}Pd{sub 14}B{sub 5}, forming equilibria with extended solution YbPd{sub 3}B{sub x}, YbB{sub 6}, Pd{sub 5}B{sub 2} and Pd{sub 3}B. The crystal structures of both Yb{sub 2}Pd{sub 14}B{sub 5} and isotypic Lu{sub 2}Pd{sub 14}B{sub 5} were determined from X-ray Rietveld refinements and found to be closely related to the Y{sub 2}Pd{sub 14}B{sub 5}-type (I4{sub 1}/amd). The crystal structure of binary Yb{sub 5}Pd{sub 2-x} (Mn{sub 5}C{sub 2}-type) was confirmed from X-ray single crystal data and a slight defect on the Pd site (x=0.06) was established. The three structures tau{sub 1}-Ce{sub 6}Pd{sub 47-x}B{sub 6}, tau{sub 2}-CePd{sub 8}B{sub 2-x} and tau{sub 3}-Ce{sub 3}Pd{sub 25-x}B{sub 8-y} are related and can be considered as the packings of fragments observed in Nd{sub 2}Fe{sub 14}B structure with different stacking of common structural blocks. Physical properties for Yb{sub 2}Pd{sub 13.6}B{sub 5} (temperature dependent specific heat, electrical resistivity and magnetization) yielded a predominantly Yb-4f{sup 13} electronic configuration, presumably related with a magnetic instability below 2 K. Kondo interaction and crystalline electric field effects control the paramagnetic temperature domain. - Graphical Abstract: Crystal structure of CePd{sub 8}B{sub 2-x}.

  4. Ch 13 RI Print Ready 4-27-16

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    Energy Savers [EERE]

    legacies resulting from more than 60 years of nuclear weapons development and ... at the former K-25 site in the next 5-7 years, DOE will continue with cleanup at Y-12 ...

  7. Magnetic hardening of Ce1+xFe11yCoyTi with ThMn12 structure by melt spinning

    SciTech Connect (OSTI)

    Zhou, Chen; Sun, Kewei; Pinkerton, Frederick E.; Kramer, M. J.

    2015-04-15

    A recent study on the intrinsic magnetic properties of CeFe11yCoyTi has revealed that substituting one Co for Fe retains the favorable magnetocrystalline anisotropy Ha found in the ternary Fe end member, while enhancing the Curie temperature Tc and saturation magnetization 4?Ms. These findings warrant further optimization around Co substitution y = 1 to try to exploit the hard magnetic properties of these Ce-based magnets. Both Ce and Co concentrations in Ce1+xFe11yCoyTi have been optimized in the range of x = 0 0.2 and y = 0 1.5. It was found that Co substitution effectively enhances all hard magnetic properties, although the values are still lower than those predicted from the intrinsic magnetic properties. Specifically, Tc increases from 210 C to 285 350 C; 4?M19 (magnetization at 19 kOe) from 8.9 kG to 10.5 11.5 kG, remanence Br from 3.1 kG to 4.1 4.5 kG, and most importantly, Hci from 1.1 kOe to 1.5 kOe. As a result, the room temperature energy product (BH)max has been increased by over 100% from 0.7 MGOe in Ce1.1Fe11Ti to 1.5 MGOe in Ce1.05Fe9.75Co1.25Ti. Microscopy analysis indicates that the addition of Co refines the grain size and promotes chemical homogeneity at the microscopic scale. As a result, the beneficial effect of Co on the microstructure contributes to the improved hard magnetic properties.

  8. Splitting of the pygmy dipole resonance in {sup 138}Ba and {sup 140}Ce observed in the ({alpha},{alpha}{sup '}{gamma}) reaction

    SciTech Connect (OSTI)

    Endres, J.; Hasper, J.; Zilges, A.; Savran, D.; Berg, A. M. van den; Dendooven, P.; Woertche, H. J.; Fritzsche, M.; Harakeh, M. N.

    2009-09-15

    The N=82 nuclei {sup 140}Ce and {sup 138}Ba have been investigated by means of the ({alpha},{alpha}{sup '}{gamma}) coincidence method to study the pygmy dipole resonance (PDR). The experiments have been performed at the AGOR cyclotron at KVI, Groningen, at a primary beam energy of E{sub {alpha}}=136 MeV. The Big-Bite Spectrometer and seven large-volume high-purity germanium detectors were used in coincidence to perform a simultaneous spectroscopy of the scattered {alpha} particles and the {gamma} decay. The comparison with results of nuclear resonance fluorescence experiments reveals a splitting of the PDR into two components. Up to about 6 MeV the same states that could be observed in ({gamma},{gamma}{sup '}) are also excited in {alpha}-scattering experiments, whereas the higher-lying states are missing in the ({alpha},{alpha}{sup '}{gamma}) reaction. This indicates a structural splitting of the PDR into two modes with different underlying structure.

  9. Performance of Ni-Fe/gadolinium-doped CeO{sub2} anode supported tubular solid oxide fuel cells using steam reforming of methane

    SciTech Connect (OSTI)

    Liang, B.; Suzuki, T.; Hamamoto, K.; Yamaguchi, T.; Sumi, H.; Fujishiro, Y.; Ingram, B. J.; Carter, J. D.

    2012-03-15

    Iron nanoparticles (Fe{sub 2}O{sub 3}) were added to NiO/gadolinium-doped CeO{sub 2} (GDC) anode supported solid oxide fuel cell (SOFC) for the direct methane-water fuel operation. The cell was co-sintered at 1400 C, and the anode porosity is 31.8%. The main size corresponding to peak volume is around 1.5 {mu}m. When steam and methane directly fed to the cell, the power density is about 0.57 W cm{sup -2} at 650 C. It is the familiar performance for H{sub 2} operation (4 times of flow rate) with same fuel utilization. Compare with the testing temperature of 600 and 650 C, there is almost no carbon fiber deposition at 700 C with steam/methane (S/C) of 5. At the same time, fuel operation of high value of S/C (=3.3) resulted in fiber-like deposition and degradation of power performance based on loading test results.

  10. An In-Situ XAS Study of the Structural Changes in a CuO-CeO2/Al2O3 Catalyst during Total Oxidation of Propane

    SciTech Connect (OSTI)

    Silversmith, Geert; Poelman, Hilde; Poelman, Dirk; Gryse, Roger de; Olea, Maria; Balcaen, Veerle; Heynderickx, Philippe; Marin, Guy B.

    2007-02-02

    A CuOx-CeOx/Al2O3 catalyst was studied with in-situ transmission Cu K XAS for the total oxidation of propane as model reaction for the catalytic elimination of volatile organic compounds. The local Cu structure was determined for the catalyst as such, after pre-oxidation and after reduction with propane. The catalyst as such has a local CuO structure. No structural effect was observed upon heating in He up to 600 deg. C or after pre-oxidation at 150 deg. C. A full reduction of the Cu2+ towards metallic Cu0 occurred, when propane was fed to the catalyst. The change in local Cu structure during propane reduction was followed with a time resolution of 1 min. The {chi}(k) scans appeared as linear combinations of start and end spectra, CuO and Cu structure, respectively. However, careful examination of the XANES edge spectra indicates the presence of a small amount of additional Cu1+ species.

  11. Effect of 8 MeV electron beam irradiation on the structural and optical properties of CeO{sub 2} nanoparticles

    SciTech Connect (OSTI)

    Babitha, K.K.; Priyanka, K.P.; Sreedevi, A.; Ganesh, S.; Varghese, Thomas

    2014-12-15

    The effect of 8 MeV electron beam irradiation on the structural and optical properties of cerium oxide nanoparticles was investigated. Ceria nanoparticles were synthesized by chemical precipitation method, and characterized by X-ray diffraction, transmission electron microscopy, ultravioletvisible, photoluminescence and Raman spectroscopy. Ultravioletvisible absorption spectra, photoluminescence and Raman spectra of beam irradiated samples were modified, and shifted to blue region, which were attributed to quantum size effect. Systematic observations found that nonstoichiometry, defects and size reduction caused by beam irradiation have great influence on optical band gap, blue shift, photoluminescence and Raman band modifications. Moreover, electron beam irradiation is a suitable technique to enhance the structural and optical properties of nanoceria by controlling the particle size, which may lead to potentially useful technological applications. - Highlights: Investigated effect of beam irradiation on CeO{sub 2} nanoparticles Beam irradiation caused size reduction and surface modification. It increases microstrain, decreases d-spacing and broadens XRD peaks. It also modifies optical band gap, absorption, PL and Raman bands.

  12. Electronic structure of Ce2 RhIn8: A two-dimensional heavy-fermion system studied by angle-resolved photoemission spectroscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jiang, Rui; Mou, Daixing; Liu, Chang; Zhao, Xin; Yao, Yongxin; Ryu, Hyejin; Petrovic, C.; Ho, Kai -Ming; Kaminski, Adam

    2015-04-01

    In this study, we use angle-resolved photoemission spectroscopy (ARPES) to study the two-dimensional (2D) heavy-fermion superconductor, Ce2 RhIn8. The Fermi surface is rather complicated and consists of several hole and electron pockets with one of the sheets displaying strong nesting properties with a q vector of (0.32, 0.32) π/a. We do not observe kz dispersion of the Fermi sheets, which is consistent with the expected 2D character of the electronic structure. Comparison of the ARPES data to band-structure calculations suggests that a localized picture of the f electrons works best. While there is some agreement in the overall band dispersionmore » and location of the Fermi sheets, the model does not reproduce all observed bands and is not completely accurate for those it does. Our data paves the way for improving the band-structure calculations and the general understanding of the transport and thermodynamical properties of this material.« less

  13. Crystal structure, magnetism and transport properties of Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}Al{sub 4.1}B{sub 10}

    SciTech Connect (OSTI)

    Janka, Oliver; Baumbach, Ryan E.; Thompson, Joe D.; Bauer, Eric D.; Kauzlarich, Susan M.

    2013-09-15

    Single crystals of Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}Al{sub 4.1}B{sub 10} were obtained from a process in which a polycrystalline sample of CeRu{sub 2}Al{sub 2}B was annealed in an excess of a NiIn flux. The initial phase, CeRu{sub 2}Al{sub 2}B, does not recrystallize, instead, crystals of a new phase, Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}Al{sub 4.1}B{sub 10}, could be isolated once the flux was removed. The title compound crystallizes in the tetragonal space group P4/nmm (No. 129) with a=1139.02(8), c=801.68(6) pm (c/a=0.70) in the Nd{sub 3}Ni{sub 29}Si{sub 4}B{sub 10} structure type. Electrical resistivity measurements reveal metallic behavior with a minimum of 700 ? cm and a small residual resistivity ratio of RRR=1.4 indicating a large amount of disorder scattering. The cerium atoms are either in the 4+ or an intermediate valence state with a valence fluctuation temperature far above room temperature. - Graphical abstract: Single crystals of Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}A{sub l4.1}B{sub 10} were obtained using a process in which a polycrystalline sample of CeRu{sub 2}Al{sub 2}B was annealed in an excess of a NiIn flux. Electrical resistivity measurements reveal metallic behavior with a minimum of 700 ?? cm and a small residual resistivity ratio of RRR=1.4 indicating a large amount of disorder scattering. The cerium atoms are either in the 4+ or an intermediate valence state with a valence fluctuation temperature far above room temperature. Display Omitted - Highlights: Flux synthesis of high quality single crystals of Ce{sub 3}Ni{sub 25.75}Ru{sub 3.16}Al{sub 4.1}B{sub 10} is presented along with the crystal structure, magnetic and transport properties. The compound is isostructural to Nd{sub 3}Ni{sub 29}Si{sub 4}B{sub 10} but is first of this structure type showing mixed occupancies of d-elements. This is an intermetallic phase with Ce in either the 4+ or an intermediate valence state. The fact that this structure with mixed occupied transition metal sites exists suggests that more compounds of this type should be accessible and the physical properties tuned.

  14. Improvement of {gamma}-ray energy resolution of LaBr{sub 3}:Ce{sup 3+} scintillation detectors by Sr{sup 2+} and Ca{sup 2+} co-doping

    SciTech Connect (OSTI)

    Alekhin, M. S.; Haas, J. T. M. de; Khodyuk, I. V.; Dorenbos, P.; Kraemer, K. W.; Menge, P. R.; Ouspenski, V.

    2013-04-22

    Commercially available LaBr{sub 3}:5% Ce{sup 3+} scintillators show with photomultiplier tube readout about 2.7% energy resolution for the detection of 662 keV {gamma}-rays. Here we will show that by co-doping LaBr{sub 3}:Ce{sup 3+} with Sr{sup 2+} or Ca{sup 2+} the resolution is improved to 2.0%. Such an improvement is attributed to a strong reduction of the scintillation light losses that are due to radiationless recombination of free electrons and holes during the earliest stages (1-10 ps) inside the high free charge carrier density parts of the ionization track.

  15. UFe/sub 4/P/sub 12/ and CeFe/sub 4/P/sub 12/: non-metallic isotypes of superconducting LaFe/sub 4/P/sub 12/

    SciTech Connect (OSTI)

    Meisner, G.P.; Torikachvili, M.S.; Yang, K.N.; Maple, M.B.; Guertin, R.P.

    1984-01-01

    The new compound UFe/sub 4/P/sub 12/, which was found to be isostructural to superconducting LaFe/sub 4/P/sub 12/ and with a lattive constant of 7.7729 A, is a semiconductor and shows ferromagnetic order below 3.15 K. CeFe/sub 4/P/sub 12/ is also a semiconductor and its magnetic susceptibility is unusually small in comparison to LaFe/sub 4/P/sub 12/. The semiconducting behaviors of both UFe/sub 4/P/sub 12/ and CeFe/sub 4/P/sub 12/ seem anomalous and may arise from strong f-electron hybridization.

  16. UFe/sub 4/P/sub 12/ and CeFe/sub 4/P/sub 12/: Nonmetallic isotypes of superconducting LaFe/sub 4/P/sub 12/

    SciTech Connect (OSTI)

    Meisner, G.P.; Torikachvili, M.S.; Yang, K.N.; Maple, M.B.; Guertin, R.P.

    1985-04-15

    The new compound UFe/sub 4/P/sub 12/, which was found to be isostructural to superconducting LaFe/sub 4/P/sub 12/ and have a lattice constant of 7.7729 A, is a semiconductor and shows ferromagnetic order below 3.15 K. CeFe/sub 4/P/sub 12/ is also a semiconductor, and its magnetic susceptibility is unusually small in comparison to LaFe/sub 4/P/sub 12/. The semiconducting behaviors of both UFe/sub 4/P/sub 12/ and CeFe/sub 4/P/sub 12/ seem anomalous and may arise from strong f-electron hybridization.

  17. Charge-coupled substituted garnets (Y 3–x Ca 0.5x M 0.5x )Fe₅O₁₂ (M = Ce, Th): Structure and stability as crystalline nuclear waste forms

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Guo, Xiaofeng; Kukkadapu, Ravi K.; Lanzirotti, Antonio; Newville, Matthew; Engelhard, Mark H.; Sutton, Stephen R.; Navrotsky, Alexandra

    2015-04-20

    The garnet structure has been proposed as a potential crystalline nuclear waste form for accommodation of actinide elements, especially uranium (U). In this study, yttrium iron garnet (YIG) as a model garnet host was studied for the incorporation of U analogs, cerium (Ce) and thorium (Th), incorporated by a charge-coupled substitution with calcium (Ca) for yttrium (Y) in YIG, namely, 2Y³⁺ = Ca²⁺ + M⁴⁺, where M⁴⁺ = Ce⁴⁺ or Th⁴⁺. Single-phase garnets Y3–xCa0.5xM0.5xFe₅O₁₂ (x = 0.1–0.7) were synthesized by the citrate–nitrate combustion method. Ce was confirmed to be tetravalent by X-ray absorption spectroscopy and X-ray photoelectron spectroscopy. X-ray diffractionmore » and ⁵⁷Fe–Mössbauer spectroscopy indicated that M⁴⁺ and Ca²⁺ cations are restricted to the c site, and the local environments of both the tetrahedral and the octahedral Fe³⁺ are systematically affected by the extent of substitution. The charge-coupled substitution has advantages in incorporating Ce/Th and in stabilizing the substituted phases compared to a single substitution strategy. Enthalpies of formation of garnets were obtained by high-temperature oxide melt solution calorimetry, and the enthalpies of substitution of Ce and Th were determined. The thermodynamic analysis demonstrates that the substituted garnets are entropically rather than energetically stabilized. This suggests that such garnets may form and persist in repositories at high temperature but might decompose near room temperature.« less

  18. Magnetic and electrical properties of LaC/sub 2/, CeC/sub 2/, PrC/sub 2/, NdC/sub 2/, and SmC/sub 2/

    SciTech Connect (OSTI)

    Sakai, T.; Adachi, G.; Yoshida, T.; Shiokawa, J.

    1981-09-15

    The electrical resistivities of the tetragonal CaC/sub 2/-type rare-earth dicarbides RC/sub 2/ (R = La, Ce, Pr, Nd, and Sm) and the magnetic susceptibilities of RC/sub 2/ (R = Pr, Nd, and Sm) are reported. The dicarbide LaC/sub 2/ becomes a superconductor at 1.6 K, which is in good agreement with literature values. The resistivity vs temperature curve of CeC/sub 2/ indicates a small hump at 30 K, and those of PrC/sub 2/ and NdC/sub 2/ show a sharp change in slope at 18 and 25 K, respectively, all verifying the antiferromagnetic transitions found by neutron diffraction. The temperature dependence of resistivity of CeC/sub 2/ was explained on the basis of the GAMMA/sub 7/ components of Ce/sup 3 +/. The compound PrC/sub 2/ becomes ferromagnetic at a zero-field Curie temperature of 7 K. This magnetic behavior differs significantly from that reported previously, suggesting an antiferromagnetic-to-ferromagnetic transition in the field of less than 700 Oe. The susceptibility of NdC/sub 2/ shows a field-independent antiferromagnetic transition at 24 K. An antiferromagnetic transition in SmC/sub 2/ was found anew at 21 K in both the resistivity and susceptibility data, exhibiting Van Vleck's Sm/sup 3 +/ characteristics. The Sm/sup 3 +/ ion in SmC/sub 2/ appears to be largely confined in the J = 5/2 ground state at about 21 K, since the paramagnetic Curie temperature reduced thereby and those of the other dicarbides can be correlated reasonably in the de Gennes factor plot.

  19. In-situ and theoretical studies for the dissociation of water on an active Ni/CeO? catalyst: Importance of strong metal-support interactions for the cleavage of O-H bonds

    SciTech Connect (OSTI)

    Carrasco, Javier; Rodriguez, Jose A.; Lopez-Duran, David; Liu, Zongyuan; Duchon, Tomas; Evans, Jaime; Senanayake, Sanjaya D.; Crumlin, Ethan J.; Matolin, Vladimir; Ganduglia-Pirovano, M. Veronica

    2015-03-23

    Water dissociation is crucial in many catalytic reactions on oxide-supported transition-metal catalysts. Here, supported by experimental and density-functional theory results, we elucidate the effect of the support on O-H bond cleavage activity for nickel/ceria systems. Ambient-pressure O1s photoemission spectra at low Ni loadings on CeO?(111) reveal a substantially larger amount of OH groups as compared to the bare support. Our computed activation energy barriers for water dissociation show an enhanced reactivity of Ni adatoms on CeO?(111) compared with pyramidal Ni? particles with one Ni atom not in contact with the support, and extended Ni(111) surfaces. At the origin of this support effect is the ability of ceria to stabilize oxidized Ni? species by accommodating electrons in localized f-states. The fast dissociation of water on Ni/CeO? has a dramatic effect on the activity and stability of this system as a catalyst for the water-gas shift and ethanol steam reforming reactions.

  20. In-situ and theoretical studies for the dissociation of water on an active Ni/CeO₂ catalyst: Importance of strong metal-support interactions for the cleavage of O-H bonds

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Carrasco, Javier; Rodriguez, Jose A.; Lopez-Duran, David; Liu, Zongyuan; Duchon, Tomas; Evans, Jaime; Senanayake, Sanjaya D.; Crumlin, Ethan J.; Matolin, Vladimir; Ganduglia-Pirovano, M. Veronica

    2015-03-23

    Water dissociation is crucial in many catalytic reactions on oxide-supported transition-metal catalysts. Here, supported by experimental and density-functional theory results, we elucidate the effect of the support on O-H bond cleavage activity for nickel/ceria systems. Ambient-pressure O1s photoemission spectra at low Ni loadings on CeO₂(111) reveal a substantially larger amount of OH groups as compared to the bare support. Our computed activation energy barriers for water dissociation show an enhanced reactivity of Ni adatoms on CeO₂(111) compared with pyramidal Ni₄ particles with one Ni atom not in contact with the support, and extended Ni(111) surfaces. At the origin of thismore » support effect is the ability of ceria to stabilize oxidized Ni²⁺ species by accommodating electrons in localized f-states. The fast dissociation of water on Ni/CeO₂ has a dramatic effect on the activity and stability of this system as a catalyst for the water-gas shift and ethanol steam reforming reactions.« less

  1. Preparation and thermophysical properties of (Sm{sub 1?x}Er{sub x}){sub 2}Ce{sub 2}O{sub 7} oxides for thermal barrier coatings

    SciTech Connect (OSTI)

    Xiaoge, Chen; Shusen, Yang; Hongsong, Zhang; Gang, Li; Zhenjun, Li.; Bo, Ren; Xudan, Dang; Haoming, Zhang; An, Tang

    2014-03-01

    Graphical abstract: - Highlights: These ceramic materials with fluorite structure were synthesized. Defect points lead to their lower thermal conductivities. The lower ionic radius of Er{sup 3+} ion leads to the reduction of thermal expansion coefficient of (Sm{sub 1?x}Er{sub x}){sub 2}Ce{sub 2}O{sub 7} oxides. - Abstract: (Sm{sub 1?x}Er{sub x}){sub 2}Ce{sub 2}O{sub 7} ceramics were synthesized by solgel method and sintered at 1600 C for 10 h in air. The influence of Er{sub 2}O{sub 3}-substitution on the phase structure and thermophysical properties of Sm{sub 2}Ce{sub 2}O{sub 7} was investigated. The phase structures of these ceramics were identified by X-ray diffraction showing that all synthesized ceramics have fluorite-type structure. The measurements for thermophysical properties of these ceramics show that their thermal conductivities and thermal expansion coefficients remarkably decreased through Er-substitution. However, the thermal expansion coefficients were higher than that of YSZ and their thermal conductivities were much lower than that of 8YSZ. The excellent thermophysical property implies that these solid solutions are potential materials for the ceramics layer in thermal barrier coatings.

  2. A Brief Review of Past INL Work Assessing Radionuclide Content in TMI-2 Melted Fuel Debris: The Use of 144Ce as a Surrogate for Pu Accountancy

    SciTech Connect (OSTI)

    D. L. Chichester; S. J. Thompson

    2013-09-01

    This report serves as a literature review of prior work performed at Idaho National Laboratory, and its predecessor organizations Idaho National Engineering Laboratory (INEL) and Idaho National Engineering and Environmental Laboratory (INEEL), studying radionuclide partitioning within the melted fuel debris of the reactor of the Three Mile Island 2 (TMI-2) nuclear power plant. The purpose of this review is to document prior published work that provides supporting evidence of the utility of using 144Ce as a surrogate for plutonium within melted fuel debris. When the TMI-2 accident occurred no quantitative nondestructive analysis (NDA) techniques existed that could assay plutonium in the unconventional wastes from the reactor. However, unpublished work performed at INL by D. W. Akers in the late 1980s through the 1990s demonstrated that passive gamma-ray spectrometry of 144Ce could potentially be used to develop a semi-quantitative correlation for estimating plutonium content in these materials. The fate and transport of radioisotopes in fuel from different regions of the core, including uranium, fission products, and actinides, appear to be well characterized based on the maximum temperature reached by fuel in different parts of the core and the melting point, boiling point, and volatility of those radioisotopes. Also, the chemical interactions between fuel, fuel cladding, control elements, and core structural components appears to have played a large role in determining when and how fuel relocation occurred in the core; perhaps the most important of these reaction appears to be related to the formation of mixed-material alloys, eutectics, in the fuel cladding. Because of its high melting point, low volatility, and similar chemical behavior to plutonium, the element cerium appears to have behaved similarly to plutonium during the evolution of the TMI-2 accident. Anecdotal evidence extrapolated from open-source literature strengthens this logical feasibility for using cerium, which is rather easy to analyze using passive nondestructive analysis gamma-ray spectrometry, as a surrogate for plutonium in the final analysis of TMI-2 melted fuel debris. The generation of this report is motivated by the need to perform nuclear material accountancy measurements on the melted fuel debris that will be excavated from the damaged nuclear reactors at the Fukushima Daiichi nuclear power plant in Japan, which were destroyed by the Tohoku earthquake and tsunami on March 11, 2011. Lessons may be taken from prior U.S. work related to the study of the TMI-2 core debris to support the development of new assay methods for use at Fukushima Daiichi. While significant differences exist between the two reactor systems (pressurized water reactor (TMI-2) versus boiling water reactor (FD), fresh water post-accident cooing (TMI-2) versus salt water (FD), maintained containment (TMI-2) versus loss of containment (FD)) there remain sufficient similarities to motivate these comparisons.

  3. Quantum Critical Behavior in the Heavy Fermion Single Crystal Ce(Ni0.935Pd0.065)2Ge2

    SciTech Connect (OSTI)

    Wang, Cuihuan [ORNL; Lawrence, J M [University of California, Irvine; Christianson, Andrew D [ORNL; Chang, S [NIST Center for Neutron Research (NCRN), Gaithersburg, MD; Bauer, E D [Los Alamos National Laboratory (LANL); Gofryk, K [Los Alamos National Laboratory (LANL); Ronning, F [Los Alamos National Laboratory (LANL); Thompson, J D [Los Alamos National Laboratory (LANL); McClellan, K J [Los Alamos National Laboratory (LANL); Rodriguez-Rivera, J A [NCNR and University of Maryland; Lynn, J W [NIST Center for Neutron Research (NCRN), Gaithersburg, MD

    2011-01-01

    We have performed magnetic susceptibility, specific heat, resistivity, and inelastic neutron scattering measurements on a single crystal of the heavy Fermion compound Ce(Ni{sub 0.935}Pd{sup 0.065}){sub 2}Ge{sub 2}, which is believed to be close to a quantum critical point (QCP) at T = 0. At lowest temperature (1.8--3.5 K), the magnetic susceptibility behaves as {chi}(T)-{chi} (0) {proportional_to} T{sup -1/6} with {chi} (0) = 0.032 x 10{sup -6} m{sup 3}/mole (0.0025 emu/mole). For T < 1 K, the specific heat can be fit to the formula {Delta} C/T = {gamma}{sub 0} - T{sup 1/2} with {gamma}{sub 0} of order 700 mJ/mole-K{sup 2}. The resistivity behaves as {rho} = {rho}{sub 0} + AT{sup 3/2} for temperatures below 2 K. This low temperature behavior for {gamma} (T) and {rho} (T) is in accord with the SCR theory of Moriya and Takimoto. The inelastic neutron scattering spectra show a broad peak near 1.5 meV that appears to be independent of Q; we interpret this as Kondo scattering with T{sub K} = 17 K. In addition, the scattering is enhanced near Q=(1/2, 1/2, 0) with maximum scattering at {Delta} E = 0.45 meV{sup -}; we interpret this as scattering from antiferromagnetic fluctuations near the antiferromagnetic QCP.

  4. Quorum: Order (2014-CE-32013)

    Broader source: Energy.gov [DOE]

    DOE ordered Davoil, Inc. d/b/a Quorum International, Inc. to pay a $8,000 civil penalty after finding Quorum had failed to certify that certain models of ceiling fans comply with the applicable energy conservation standards.

  5. Amerikooler: Order (2013-CE-5307)

    Broader source: Energy.gov [DOE]

    DOE ordered Amerikooler, Inc. to pay a $8,000 civil penalty after finding Amerikooler had failed to certify that certain models of walk-in cooler and freezer components comply with the applicable energy conservation standards.

  6. Trastar: Order (2013-CE-49003)

    Broader source: Energy.gov [DOE]

    DOE ordered Trastar Inc. to pay a $8,000 civil penalty after finding Trastar had failed to certify that certain basic models of traffic signal modules and pedestrian modules comply with the applicable energy conservation standards.

  7. Almo: Order (2012-CE-1416)

    Broader source: Energy.gov [DOE]

    DOE ordered Almo Corporation to pay a $6,500 civil penalty after finding Almo had failed to certify that certain models of residential refrigerators comply with the applicable energy conservation standards.

  8. Versonel: Order (2014-CE-21009)

    Broader source: Energy.gov [DOE]

    DOE ordered Smart Surplus, Inc. d/b/a Versonel to pay a $8,000 civil penalty after finding Versonel had failed to certify that certain models of refrigerators and residential clothes dryers comply with the applicable energy conservation standards.

  9. Curtis: Order (2015-CE-14021)

    Broader source: Energy.gov [DOE]

    DOE ordered Curtis International, Ltd. to pay a $5,800 civil penalty after finding Curtis had failed to certify that refrigerator-freezer basic model FR9211 complies with the applicable energy conservation standards.

  10. Electrolux: Order (2014-CE-23015)

    Broader source: Energy.gov [DOE]

    DOE ordered Electrolux North America, Inc. to pay a $16,000 civil penalty after finding Electrolux had failed to certify that certain models of cooking products comply with the applicable energy conservation standards.

  11. Sunpentown: Order (2012-CE-1505)

    Broader source: Energy.gov [DOE]

    DOE ordered Sunpentown International Inc. to pay a $12,160 civil penalty after finding Sunpentown had failed to certify that certain models of room air conditioners comply with the applicable energy conservation standards.

  12. Sears: Order (2012-CE-3606)

    Broader source: Energy.gov [DOE]

    DOE ordered Sears, Roebuck & Co. to pay an $8,000 civil penalty after finding Sears had failed to certify that Sears dehumidifiers comply with the applicable energy conservation standard.

  13. Electrolux: Order (2015-CE-14020)

    Broader source: Energy.gov [DOE]

    DOE ordered Electrolux North America, Inc. to pay a $20,000 civil penalty after finding Electrolux had failed to certify that certain models of refrigerator-freezers comply with the applicable energy conservation standards.

  14. Topaz: Order (2014-CE-35005)

    Broader source: Energy.gov [DOE]

    DOE ordered Topaz Lighting Corp. to pay a $8,000 civil penalty after finding Topaz had failed to certify that certain basic models of medium base compact fluorescent lamps, general service fluorescent lamps, and illuminated exit signs comply with the applicable energy conservation standards.

  15. Electrolux: Order (2012-CE-1901)

    Broader source: Energy.gov [DOE]

    DOE ordered Electrolux North America to pay a $6,500 civil penalty after finding Electrolux had failed to certify that certain dishwashers comply with the applicable energy conservation standard.

  16. TCP: Order (2011-CE-3501)

    Broader source: Energy.gov [DOE]

    DOE ordered Technical Consumer Products, Inc. to pay a $3,000 civil penalty after finding TCP had failed to certify that a certain model of medium base compact fluorescent lamp (CFL) complies with the applicable energy conservation standards.

  17. Legacy: Order (2015-CE-14025)

    Broader source: Energy.gov [DOE]

    DOE ordered The Legacy Companies to pay a $8,000 civil penalty after finding Legacy had failed to certify that refrigerator Maxx-Ice brand basic model MCR3U complies with the applicable energy conservation standards.

  18. Eurodib: Order (2014-CE-45001)

    Broader source: Energy.gov [DOE]

    DOE ordered Eurodib Inc. to pay a $8,000 civil penalty after finding Eurodib had failed to certify that certain models of automatic commercial ice makers comply with the applicable energy conservation standards.

  19. Winix: Order (2012-CE-3607)

    Broader source: Energy.gov [DOE]

    DOE ordered Cloud 9 Marketing, Inc. d/b/a Winix, Inc., to pay a $8,000 civil penalty after finding Winix had failed to certify that certain models of dehumidifiers comply with the applicable energy conservation standards.

  20. Aircooler: Order (2013-CE-5338)

    Broader source: Energy.gov [DOE]

    DOE ordered Aircooler Corporation to pay a $8,000 civil penalty after finding Aircooler had failed to certify that certain models of walk-in cooler and freezer components comply with the applicable energy conservation standards.

  1. Satco: Order (2013-CE-2702)

    Broader source: Energy.gov [DOE]

    DOE ordered Satco Products, Inc. to pay a $8,000 civil penalty after finding Satco had failed to certify that certain models of general service fluorescent lamps comply with the applicable energy conservation standards.

  2. PQL: Order (2013-CE-27001)

    Broader source: Energy.gov [DOE]

    DOE ordered P.Q.L., Inc. to pay a $8,000 civil penalty after finding PQL had failed to certify that various basic models of medium base compact fluorescent lamps, general service fluorescent lamps, fluorescent lamp ballasts, and illuminated exit signs comply with the applicable energy conservation standards.

  3. NCBECS C&E 1979

    U.S. Energy Information Administration (EIA) Indexed Site

    U9UJU;9AOO "S'D 0098-393 (303) S9903 'O'Q 'uoi6urysBM 6uip|ing J0| peso|6ua si LLIJOJ 02-13' Moiaq iB8

  4. Smeg: Order (2014-CE-23003)

    Broader source: Energy.gov [DOE]

    DOE ordered Smeg USA, Inc. to pay a $16,000 civil penalty after finding Smeg had failed to certify that certain models of refrigerators/refrigerator-freezers/freezers, dishwashers, and cooking products comply with the applicable energy conservation standards.

  5. Leotek: Order (2013-CE-4903)

    Broader source: Energy.gov [DOE]

    DOE ordered Leotek Electronics USA Corp. to pay a $8,000 civil penalty after finding Leotek had failed to certify that certain models of traffic signal modules and pedestrian modules comply with the applicable energy conservation standards.

  6. Litex: Order (2014-CE-32011)

    Broader source: Energy.gov [DOE]

    DOE ordered Litex Industries, Limited to pay a $8,000 civil penalty after finding Litex had failed to certify that certain models of ceiling fans comply with the applicable energy conservation standards.

  7. TMP: Order (2013-CE-5334)

    Broader source: Energy.gov [DOE]

    DOE ordered TMP Manufacturing Company, Inc. to pay a $8,000 civil penalty after finding TMP had failed to certify that certain models of walk-in cooler and freezer components comply with the applicable energy conservation standards.

  8. Sylvane: Order (2013-CE-36005)

    Broader source: Energy.gov [DOE]

    DOE ordered Sylvane, Inc. to pay a $4,000 civil penalty after finding Sylvane had failed to certify that certain models of dehumidifiers comply with the applicable energy conservation standards.

  9. Northland: Order (2014-CE-23002)

    Broader source: Energy.gov [DOE]

    DOE ordered Northland Corporation d/b/a AGA Marvel to pay a $16,000 civil penalty after finding Northland had failed to certify that certain models of cooking products comply with the applicable energy conservation standards.

  10. Keystone: Order (2013-CE-2601)

    Broader source: Energy.gov [DOE]

    DOE ordered Keystone Technologies, LLC to pay a $8,000 civil penalty after finding Keystone had failed to certify that certain models of fluorescent lamp ballasts comply with the applicable energy conservation standards.

  11. Emerson: Order (2014-CE-54001)

    Broader source: Energy.gov [DOE]

    DOE ordered Emerson Electric Co. to pay a $8,000 civil penalty after finding Emerson had failed to certify that certain models of metal halide lamp fixtures comply with the applicable energy conservation standards.

  12. Kichler: Order (2014-CE-32007)

    Office of Energy Efficiency and Renewable Energy (EERE)

    DOE ordered The L.D. Kichler Co. d/b/a Kichler Lighting to pay a $8,000 civil penalty after finding Kichler had failed to certify that certain models of ceiling fans comply with the applicable energy conservation standards.

  13. Dacor: Order (2014-CE-23010)

    Broader source: Energy.gov [DOE]

    DOE ordered Dacor to pay a $8,000 civil penalty after finding Dacor had failed to certify that certain models of cooking products comply with the applicable energy conservation standards.

  14. Yosemite: Order (2014-CE-32015)

    Office of Energy Efficiency and Renewable Energy (EERE)

    DOE ordered Northern Central Distributing, Inc. d/b/a Yosemite Home Dcor to pay a $8,000 civil penalty after finding Yosemite had failed to certify that certain models of ceiling fans comply with the applicable energy conservation standards.

  15. Whirlpool: Order (2014-CE-21010)

    Office of Energy Efficiency and Renewable Energy (EERE)

    DOE ordered Whirlpool Corporation to pay a $8,000 civil penalty after finding Whirlpool had failed to certify that certain models of residential clothes dryers comply with the applicable energy conservation standards.

  16. DHI: Order (2014-CE-32004)

    Office of Energy Efficiency and Renewable Energy (EERE)

    DOE ordered DHI Corp. to pay a $8,000 civil penalty after finding DHI had failed to certify that certain models of ceiling fans comply with the applicable energy conservation standards.

  17. Vaxcel: Order (2014-CE-32006)

    Office of Energy Efficiency and Renewable Energy (EERE)

    DOE ordered Vaxcel International Co., Ltd. to pay a $8,000 civil penalty after finding Vaxcel had failed to certify that certain models of ceiling fans comply with the applicable energy conservation standards.

  18. Leer: Order (2013-CE-5325)

    Broader source: Energy.gov [DOE]

    DOE ordered Leer, Inc. to pay a $8,000 civil penalty after finding Leer had failed to certify that certain models of walk-in cooler and freezer (WICF) components comply with the applicable energy conservation standards.

  19. Daewoo: Order (2010-CE-0410)

    Broader source: Energy.gov [DOE]

    DOE ordered Daewoo International, Inc. to pay a $5,000 civil penalty after finding Daewoo had failed to certify that certain models of residential clothes dryers comply with the applicable energy conservation standards.

  20. LG: Order (2015-CE-14022)

    Broader source: Energy.gov [DOE]

    DOE ordered LG Electronics USA, Inc. to pay a $8,000 civil penalty after finding LG had failed to certify that various refrigerator-freezer basic models comply with the applicable energy conservation standards.

  1. Atosa: Order (2015-CE-42037)

    Broader source: Energy.gov [DOE]

    DOE ordered Atosa Catering Equipment, Inc. to pay a $8,000 civil penalty after finding Atosa had failed to certify that certain models of self-contained commercial refrigeration equipment with doors comply with the applicable energy conservation standards.

  2. Barron: Order (2013-CE-48004)

    Broader source: Energy.gov [DOE]

    DOE ordered Barron Lighting Group, Inc. to pay a $8,000 civil penalty after finding Barron had failed to certify that certain models of illuminated exit signs comply with the applicable energy conservation standards.

  3. Avanti: Order (2013-CE-2105)

    Broader source: Energy.gov [DOE]

    DOE ordered Avanti Products, LLC to pay a $8,000 civil penalty after finding Avanti had failed to certify that certain models of residential clothes dryers comply with the applicable energy conservation standards.

  4. Acuity: Order (2013-CE-4802)

    Broader source: Energy.gov [DOE]

    DOE ordered Acuity Brands Lighting to pay a $8,000 civil penalty after finding Acuity had failed to certify that certain models of illuminated exit signs comply with the applicable energy conservation standards.

  5. Haier: Order (2011-CE-2104)

    Broader source: Energy.gov [DOE]

    DOE ordered Haier to pay an $20,000 civil penalty after finding Haier had failed to certify that Haier residential clothes dryers comply with the applicable energy conservation standard.

  6. Nicor: Order (2014-CE-32016)

    Broader source: Energy.gov [DOE]

    DOE ordered Nicor, Inc. to pay a $8,000 civil penalty after finding Nicor had failed to certify that certain models of ceiling fans comply with the applicable energy conservation standards.

  7. BSH: Order (2013-CE-2001)

    Broader source: Energy.gov [DOE]

    DOE ordered BSH Home Appliances Corp. to pay a $8,000 civil penalty after finding BSH had failed to certify that certain models of residential clothes washers comply with the applicable energy/water conservation standards.

  8. Resolution of the discrepancy between the variation of the physical properties of Ce1-xYbxCoIn5 single crystals and thin films with Yb composition

    SciTech Connect (OSTI)

    Jang, S.; White, B. D.; Lum, I. K.; Kim, H.; Tanatar, M. A.; Straszheim, W. E.; Prozorov, R.; Keiber, T.; Bridges, F.; Shu, L.; Baumbach, R. E.; Janoschek, M.; Maple, M. B.

    2014-11-18

    The extraordinary electronic phenomena including an Yb valence transition, a change in Fermi surface topology, and suppression of the heavy fermion quantum critical field at a nominal concentration x≈0.2 have been found in the Ce1-xYbxCoIn5 system. These phenomena have no discernable effect on the unconventional superconductivity and normal-state non-Fermi liquid behaviour that occur over a broad range of x up to ~0.8. However, the variation of the coherence temperature T* and the superconducting critical temperature Tc with nominal Yb concentration x for bulk single crystals is much weaker than that of thin films. To determine whether differences in the actual Yb concentration of bulk single crystals and thin film samples might be responsible for these discrepancies, we employed Vegard’s law and the spectroscopically determined values of the valences of Ce and Yb as a function of x to determine the actual composition xact of bulk single crystals. This analysis is supported by energy-dispersive X-ray spectroscopy, wavelength-dispersive X-ray spectroscopy, and transmission X-ray absorption edge spectroscopy measurements. The actual composition xact is found to be about one-third of the nominal concentration x up to x~0.5, and resolves the discrepancy between the variation of the physical properties of Ce1-xYbxCoIn5 single crystals and thin films with Yb concentration.

  9. Crystal structures and luminescence properties of novel compounds K{sub 4}M{sub 2}[Al{sub 2}Si{sub 8}O{sub 24}] (M = Ce, Gd)

    SciTech Connect (OSTI)

    Aksenov, S. M., E-mail: aks.crys@gmail.com [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Rassulov, V. A. [Russian Academy of Sciences, Fedorovsky All-Russian Research Institute of Mineral Resources (Russian Federation)] [Russian Academy of Sciences, Fedorovsky All-Russian Research Institute of Mineral Resources (Russian Federation); Rastsvetaeva, R. K. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)] [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Taroev, V. K. [Russian Academy of Sciences, Institute of Geochemistry, Siberian Branch (Russian Federation)] [Russian Academy of Sciences, Institute of Geochemistry, Siberian Branch (Russian Federation)

    2013-11-15

    Two novel potassium rare earth silicates, obtained by hydrothermal synthesis, have been investigated by X-ray diffraction and described by the general formula K{sub 4}M{sub 2}[Al{sub 2}Si{sub 8}O{sub 24}] (M = Ce, Gd). The parameters of the monoclinic K{sub 4}Ce{sub 2}[Al{sub 2}Si{sub 8}O{sub 24}] and K{sub 4}Gd{sub 2}[Al{sub 2}Si{sub 8}O{sub 24}] cells are, respectively, as follows: a = 26.867(1), 26.6520(2) A; b = 7.4150(2), 7.2854(1) A; c = 14.910(1), 14.8182(1) A; {beta} = 123.52(1) Degree-Sign , 123.46(1) Degree-Sign ; and sp. gr. P2{sub 1}/n. The structures are solved by the charge flipping method and refined in the anisotropic approximation of thermal vibrations for atoms to R = 5.2 and 2.5%, respectively. The compounds under study are crystallized into a new structural type, which is based on two-level [Al{sub 2}Si{sub 8}O{sub 24}] layers, combined into a three-dimensional framework by columns of edge-sharing seven-vertex REE polyhedra. Potassium atoms are located in the framework channels. The spectral luminescence characteristics are determined. The luminescence bands are typical of Gd{sup 3+} and Ce{sup 3+} ions. Upon excitation by light with {lambda}{sub exc} = 246 nm, a band due to the {sup 2}D {yields} {sup 8}F{sub 5/2} transition with {lambda}{sub max} = 430 nm is observed in the spectrum of K{sub 4}Ce{sub 2}[Al{sub 2}Si{sub 8}O{sub 24}] and a band related to the {sup 6}P{sub 7/2} {yields} {sup 8}S{sub 7/2} transition with {lambda}{sub max} = 311 nm is observed in the spectrum of K{sub 4}Gd{sub 2}[Al{sub 2}Si{sub 8}O{sub 24}].

  10. Combined effect of chemical pressure and valence electron concentration through the electron-deficient Li substitution on the RE{sub 4}LiGe{sub 4} (RE=La, Ce, Pr, and Sm) system

    SciTech Connect (OSTI)

    Nam, Gnu; Jeon, Jieun; Kim, Youngjo; Kwon Kang, Sung; Ahn, Kyunghan; You, Tae-Soo

    2013-09-15

    Four members of the RE{sub 4}LiGe{sub 4} (RE=La, Ce, Pr, and Sm) system have been prepared by high-temperature reaction method and characterized by X-ray diffractions. All compounds crystallize in the orthorhombic Gd{sub 5}Si{sub 4}-type structure (space group Pnma, Pearson code oP16) with bonding interactions for interslab Ge{sub 2} dimers. The Li substitution for rare-earth elements in the RE{sub 4}LiGe{sub 4} system leads to a combined effect of the increased chemical pressure and the decreased valance electron concentration (VEC), which eventually results in the structure transformation from the Sm{sub 5}Ge{sub 4}-type with all broken interslab Ge–Ge bond for the parental RE{sub 5}Ge{sub 4} to the Gd{sub 5}Si{sub 4}-type structure for the ternary RE{sub 4}LiGe{sub 4} (RE=La, Ce, Pr, and Sm) system. Site-preference between rare-earth metals and Li is proven to generate energetically the most favorable atomic arrangements according to coloring-problem, and the rationale is provided using both the size-factor and the electronic-factor related, respectively, to site-volume and electronegativity as well as QVAL values. Tight-binding, linear-muffin-tin-orbital (TB-LMTO) calculations are performed to investigate electronic densities of states (DOS) and crystal orbital Hamilton population (COHP) curves. The influence of reduced VEC for chemical bonding including the formation of interslab Ge{sub 2} dimers is also discussed. The magnetic property measurements prove that the non-magnetic Li substitution leads to the ferromagnetic (FM)-like ground state for Ce{sub 4}LiGe{sub 4} and the co-existence of antiferromagntic (AFM) and FM ground states for Sm{sub 4}LiGe{sub 4}. - Graphical abstract: Reported is a combined effect of the chemical pressure and the reduced VEC caused by the smaller monovalent non-magnetic Li substitution for the larger trivalent magnetic rare-earth metals in the RE{sub 4}LiGe{sub 4} (RE=La, Ce, Pr, and Sm) system. This results in the structure transformation from the Sm{sub 5}Ge{sub 4}-type to the Gd{sub 5}Si{sub 4}-type structure and the changes in magnetic properties. Display Omitted - Highlights: • Four Li-containing intermetallic compounds RE{sub 4}LiGe{sub 4} (RE=La, Ce, Pr and Sm) were synthesized. • The combined effect of the chemical pressure and the reduced VEC caused by Li substitution for a rare-earth metal results in the structure transformation. • Electronic structures and magnetic properties of title compounds were thoroughly investigated.

  11. Energy efficient microwave synthesis of mesoporous Ce0.5M0.5O2 (Ti, Zr, Hf) nanoparticles for low temperature CO oxidation in an ionic liquid – a comparative study

    SciTech Connect (OSTI)

    Alammar, Tarek; Chow, Ying -Kit; Mudring, Anja -Verena

    2014-11-19

    Ce0.5M0.5O2 (M = Ti, Zr, Hf) nanoparticles have been successfully synthesized by microwave irradiation in the ionic liquid [C4mim][Tf2N] (1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide). The morphology, crystallinity, and chemical composition of the obtained materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy, and N2–adsorption measurements. XRD and Raman spectroscopy analyses confirmed the formation of solid solutions with cubic fluorite structure. The catalytic activities of the Ce0.5M0.5O2 (M = Ti, Zr, Hf) nanoparticles were investigated in the low-temperature oxidation of CO. Ce0.5Zr0.5O2 nanospheres exhibit the best performance (100% conversion at 350 °C), followed by Ce0.5Hf0.5O2 (55% conversion at 360 °C) and Ce0.5Ti0.5O2 (11% conversion at 350 °C). Heating the as-prepared Ce0.5Zr0.5O2 to 600 °C for extended time leads to a decrease in surface area and, as expected decreased catalytic activity. Depending on the ionic liquid the obtained Ce0.5Zr0.5O2 exhibits different morphologies, varying from nano-spheres in [C4mim][Tf2N] and [P66614][Tf2N] (P66614 = trishexyltetradecylphosphonium) to sheet-like assemblies in [C3mimOH][Tf2N] (C3mimOH = 1-(3-hydroxypropyl)-3-methylimidazolium). As a result, the microwave synthesis superiority to other heating methods like sonochemical synthesis and conventional heating was proven by comparative experiments where the catalytic activity of Ce0.5Zr0.5O2 obtained by alternate methods such as conventional heating was found to be poorer than that of the microwave-synthesised material.

  12. A comparative study of SrO and BaO doping to CeO{sub 2}-ZrO{sub 2}: Characteristic and its catalytic performance for three-way catalysts

    SciTech Connect (OSTI)

    Guo, Jiaxiu; National Engineering Research Center for Flue Gas Desulfurization, Chengdu 610065 ; Shi, Zhonghua; Wu, Dongdong; Yin, Huaqiang; National Engineering Research Center for Flue Gas Desulfurization, Chengdu 610065 ; Gong, Maochu; Chen, Yaoqiang; National Engineering Research Center for Flue Gas Desulfurization, Chengdu 610065

    2013-02-15

    Graphical abstract: Display Omitted Highlights: ► The prepared materials have a face-centered cubic structure and nanosize particles. ►Comparing to CZB, aged CZS has 494 μmol/g of OSC and 30 m{sup 2}/g of surface area. ► CZS and CZB have similar NO sorption and reductive properties and different H{sub 2} uptake. ► T{sub 50} of Pt-Rh/CZS/LA is as low as 199 °C for CO, 228 °C for NO, and 252 °C for C{sub 3}H{sub 8}. ► Pt-Rh/CZS/LA has wider working-window at 320 °C under different λ value. -- Abstract: Ceria-zirconia-strontia (Ce{sub 0.35}Zr{sub 0.55}Sr{sub 0.10}O{sub 1.9}) and ceria-zirconia-baria (Ce{sub 0.35}Zr{sub 0.55}Ba{sub 0.10}O{sub 1.9}) were synthesized using an oxidation-co-precipitation method with hydrogen peroxide (H{sub 2}O{sub 2}) as oxidant. The physical and chemical properties of the prepared materials were investigated using Brunauer–Emmett–Teller surface area characterization, transmission electron microscopy, X-ray diffraction, Raman spectra, X-ray photoelectron spectroscopy, and oxygen pulse reaction. The prepared materials were used in preparing three-way catalysts with low Pt and Rh content. Moreover, catalytic activities were evaluated at a fixed bed under a simulated gaseous mixture. The results are as follows: (1) the prepared materials have a face-centered cubic structure and are nano-sized; (2) aged Ce{sub 0.35}Zr{sub 0.55}Sr{sub 0.10}O{sub 1.9} has higher oxygen storage capacity (494 μmol/g), better thermal stability (30 m{sup 2}/g), good low-temperature reducibility, and high hydrogen uptake after TPR-redox cycles; (3) the light-off temperature (T{sub 50}) of Pt-Rh/CZS/LA can be as low as 199 °C for CO, 228 °C for NO, and 252 °C for C{sub 3}H{sub 8}; and (4) Pt-Rh/CZS/LA has a fairly wide working-window.

  13. Microsoft Word - S08846_2012_Annual_IC report

    Office of Legacy Management (LM)

    ... Cleanups (EPA 2005). U.S. Department of Energy Annual Assessment of the Effectiveness of ... 2. Prohibit the extraction or consumption of, exposure to, or the use in any way ...

  14. Idaho IC 61-119, Electrical Corporation Definition | Open Energy...

    Open Energy Info (EERE)

    61-119 provided in the Application and Definitions of the Public Utilities Law, amended 1917. Published NA Year Signed or Took Effect 1917 Legal Citation Not provided DOI Not...

  15. Coast Intelligen 150-IC with ECS | Open Energy Information

    Open Energy Info (EERE)

    Jump to: navigation, search Manufacturer Coast Intelligen Technology Type Internal Combustion Engine Engine Type Synchronous Generator Power Output 150 kW0.15 MW 150,000 W...

  16. Two-Stroke Uniflow Turbo-Compound IC Engine

    Broader source: Energy.gov [DOE]

    An evaluation study of a turbo-compounded concept engine consisting of a two-stroke, uniflow, four cylinder air cooled flat-four engine has been completed The concept includes a high pressure ratio supercharger compressor that is powered by an exhaust driven turbine. Downstream of the high pressure turbine is a low pressure power turbine that is geared to the engine crankshaft. The engine cylinders have 360 degree circumferential intake ports with swirl vanes, located at the bottom of the piston stroke. A large single exhaust valve is at the top of the cylinder. The fuel is injected downstream directly into the swirling airflow near the top of the piston stroke. The fuel is ignited by a high energy sparkplug. This engine offers very low fuel consumption in a compact, light weight package, with fuel flexibility.

  17. Microsoft Word - S08846_2012_Annual_IC report

    Office of Legacy Management (LM)

    ... Yes (X ) No ( ) Received data from city on 4-17-12. Results did not include any permitting ... specifications required the contractor to adher to all City construction requirements. ...

  18. Photo-Spectrometer Realized In A Standard Cmos Ic Process

    DOE Patents [OSTI]

    Simpson, Michael L. (Knoxville, TN); Ericson, M. Nance (Knoxville, TN); Dress, William B. (Knoxville, TN); Jellison, Gerald E. (Oak Ridge, TN); Sitter, Jr., David N. (Tucson, AZ); Wintenberg, Alan L. (Knoxville, TN)

    1999-10-12

    A spectrometer, comprises: a semiconductor having a silicon substrate, the substrate having integrally formed thereon a plurality of layers forming photo diodes, each of the photo diodes having an independent spectral response to an input spectra within a spectral range of the semiconductor and each of the photo diodes formed only from at least one of the plurality of layers of the semiconductor above the substrate; and, a signal processing circuit for modifying signals from the photo diodes with respective weights, the weighted signals being representative of a specific spectral response. The photo diodes have different junction depths and different polycrystalline silicon and oxide coverings. The signal processing circuit applies the respective weights and sums the weighted signals. In a corresponding method, a spectrometer is manufactured by manipulating only the standard masks, materials and fabrication steps of standard semiconductor processing, and integrating the spectrometer with a signal processing circuit.

  19. Microsoft Word - S08846_2012_Annual_IC report

    Office of Legacy Management (LM)

    MDC Property This page intentionally left blank U.S. Department of Energy Annual Assessment of the Effectiveness of Site-Wide Institutional Controls June 2012 Doc. No. S08846 Page B-1 Annual Assessment of the Effectiveness of Site-Wide Institutional Controls U.S. Department of Energy Doc. No. S08846 June 2012 Page B-2 U.S. Department of Energy Annual Assessment of the Effectiveness of Site-Wide Institutional Controls June 2012 Doc. No. S08846 Page B-3 Annual Assessment of the Effectiveness of

  20. Microsoft Word - S08846_2012_Annual_IC report

    Office of Legacy Management (LM)

    Listings and Photos of Monitoring Wells and Seeps This page intentionally left blank U.S. Department of Energy Annual Assessment of the Effectiveness of Site-Wide Institutional Controls June 2012 Doc. No. S08846 Page D-1 D1. Parcel 6, 7, and 8 Remedy Wells and Seeps Table D-1and Figure D-1 show the Parcel 6, 7, and 8 groundwater monitoring wells and seep locations. Table D-2 shows photos of all wells and seeps. All of the Parcel 6, 7, and 8 wells were locked and in good condition. Because the

  1. Microsoft Word - S08846_2012_Annual_IC report

    Office of Legacy Management (LM)

    Photos of T Building Red Concrete Cracks This page intentionally left blank U.S. Department of Energy Annual Assessment of the Effectiveness of Site-Wide Institutional Controls June 2012 Doc. No. S08846 Page E-1 E1. 2012 Photos of Red Concrete Cracks The following photographs in Table E-1 were taken to document the baseline condition of the cracks in the red concrete in specified rooms in T Building. The room diagram in Figure E-1 indicates the location of the cracks labeled A through I. Annual

  2. Microsoft PowerPoint - CASL IC member Overviews.pptx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Industry Council Meeting ALOFT Hotel, Greenville, SC April 12-13, 2016 CASL-U-2016-1092-000 2 2 Meeting Objectives Exchange of information about CASL's research and activities to: 1. Provide an opportunity for engagement between industry stakeholders and CASL researchers. 2. Present and seek feedback on the progress on CASL's R&D activities and plans. 3. Discuss CASL and industry priorities to ensure that they are aligned. 4. Identify strategic collaborations between industry and CASL Focus

  3. Microsoft Word - S10173_2013_Annual_IC.docx

    Office of Legacy Management (LM)

    ... IB Total MDC owned & showing on county web 176.3708 Mound Site Parcel IDs from ... Part of 6A road front Total BOI Solutions Inc. owned & showing on county web 5.6210 DOE ...

  4. Microsoft Word - S07757_2011 Mound IC Report

    Office of Legacy Management (LM)

    ... Chuck Friedman, Ellen Stanifer, Jeff Smith, Ken Karp, Karen Reed, Jane Powell, Brian ... Ken Karp, Anthony Campbell, Jeff Smith, and Frank Bullock inspecting T Building ...

  5. I.C. engines still key player in rail traction

    SciTech Connect (OSTI)

    Mullins, P.; Johnson, P.

    1994-07-01

    Still an important player in locomotive applications, internal combustion engines (diesel locomotives) are an obvious choice for hauling most freight, for shunting applications, and for passenger lines that are not economic to electrify. Today, research and testing continue to take place on natural gas-fueled locomotives, with a net result expected to benefit the railroads through reducing operational costs, while meeting new emissions regulations. 8 figs.

  6. UNIDO ICS Portal for Technology Transfer | Open Energy Information

    Open Energy Info (EERE)

    ex.php?titleUNIDOICSPortalforTechnologyTransfer&oldid329335" Feedback Contact needs updating Image needs updating Reference needed Missing content Broken link Other...

  7. Microsoft Word - S07757_2011 Mound IC Report

    Office of Legacy Management (LM)

    1 Doc. No. S07757 Page B-1 Annual Assessment of the Effectiveness of Site-Wide Institutional Controls U.S. Department of Energy Doc. No. S07757 June 2011 Page B-2 U.S. Department of Energy Annual Assessment of the Effectiveness of Site-Wide Institutional Controls June 2011 Doc. No. S07757 Page B-3 Annual Assessment of the Effectiveness of Site-Wide Institutional Controls U.S. Department of Energy Doc. No. S07757 June 2011

  8. Microsoft Word - S07757_2011 Mound IC Report

    Office of Legacy Management (LM)

    Listings and Photos of Monitoring Wells and Seeps This page intentionally left blank U.S. Department of Energy Annual Assessment of the Effectiveness of Site-Wide Institutional Controls June 2011 Doc. No. S07757 Page D-i Contents 1.0 Parcel 6, 7, and 8 Remedy Wells and Seeps ..................................................................... D-1 2.0 OU-1 (Parcel 9) Wells ....................................................................................................... D-6 3.0 Phase I

  9. Specific Heat of Ce{sub 0.8}La{sub 0.2}Al{sub 3} in Magnetic Fields: A Test of the Anisotropic Kondo Picture

    SciTech Connect (OSTI)

    Pietri, R.; Ingersent, K.; Andraka, B.

    2001-02-05

    The specific heat C of Ce{sub 0.8}La {sub 0.2}Al{sub 3} has been measured as a function of temperature T in magnetic fields up to 14T. A large peak in C at 2.3K has recently been ascribed to an anisotropic Kondo effect in this compound. A 14-T field depresses the temperature of the peak by only 0.2K, but strongly reduces its height. The corresponding peak in C/T shifts from 2.1K at zero field to 1.7K at 14T. The extrapolated specific heat coefficient {gamma}=lim/T{yields}0 C/T increases with field over the range studied. We show that these trends are inconsistent with the anisotropic Kondo model.

  10. Charge-coupled substituted garnets (Y 3x Ca 0.5x M 0.5x )Fe?O?? (M = Ce, Th): Structure and stability as crystalline nuclear waste forms

    SciTech Connect (OSTI)

    Guo, Xiaofeng; Kukkadapu, Ravi K.; Lanzirotti, Antonio; Newville, Matthew; Engelhard, Mark H.; Sutton, Stephen R.; Navrotsky, Alexandra

    2015-04-20

    The garnet structure has been proposed as a potential crystalline nuclear waste form for accommodation of actinide elements, especially uranium (U). In this study, yttrium iron garnet (YIG) as a model garnet host was studied for the incorporation of U analogs, cerium (Ce) and thorium (Th), incorporated by a charge-coupled substitution with calcium (Ca) for yttrium (Y) in YIG, namely, 2Y? = Ca? + M??, where M?? = Ce?? or Th??. Single-phase garnets Y3xCa0.5xM0.5xFe?O?? (x = 0.10.7) were synthesized by the citratenitrate combustion method. Ce was confirmed to be tetravalent by X-ray absorption spectroscopy and X-ray photoelectron spectroscopy. X-ray diffraction and ??FeMssbauer spectroscopy indicated that M?? and Ca? cations are restricted to the c site, and the local environments of both the tetrahedral and the octahedral Fe? are systematically affected by the extent of substitution. The charge-coupled substitution has advantages in incorporating Ce/Th and in stabilizing the substituted phases compared to a single substitution strategy. Enthalpies of formation of garnets were obtained by high-temperature oxide melt solution calorimetry, and the enthalpies of substitution of Ce and Th were determined. The thermodynamic analysis demonstrates that the substituted garnets are entropically rather than energetically stabilized. This suggests that such garnets may form and persist in repositories at high temperature but might decompose near room temperature.

  11. Charge-Coupled Substituted Garnets (Y3-xCa0.5xM0.5x)Fe5O12 (M = Ce, Th): Structure and Stability as Crystalline Nuclear Waste Forms

    SciTech Connect (OSTI)

    Guo, Xiaofeng; Kukkadapu, Ravi K.; Lanzirotti, Antonio; Newville, Matthew; Engelhard, Mark H.; Sutton, Stephen R.; Navrotsky, Alexandra

    2015-06-08

    The garnet structure has been proposed as a potential crystalline nuclear waste form for accommodation of actinide elements, especially uranium (U). In this study, yttrium iron garnet (YIG) as a model garnet host was studied for the incorporation of U analogs, cerium (Ce) and thorium (Th), incorporated by a charge-coupled substitution with calcium (Ca) for yttrium (Y) in YIG, namely, 2Y3+ = Ca2+ + M4+, where M4+ = Ce4+ or Th4+. Single-phase garnets Y3–xCa0.5xM0.5xFe5O12 (x = 0.1–0.7) were synthesized by the citrate–nitrate combustion method. Ce was confirmed to be tetravalent by X-ray absorption spectroscopy and X-ray photoelectron spectroscopy. X-ray diffraction and 57Fe–Mössbauer spectroscopy indicated that M4+ and Ca2+ cations are restricted to the c site, and the local environments of both the tetrahedral and the octahedral Fe3+ are systematically affected by the extent of substitution. The charge-coupled substitution has advantages in incorporating Ce/Th and in stabilizing the substituted phases compared to a single substitution strategy. Enthalpies of formation of garnets were obtained by high temperature oxide melt solution calorimetry, and the enthalpies of substitution of Ce and Th were determined. The thermodynamic analysis demonstrates that the substituted garnets are entropically rather than energetically stabilized. This suggests that such garnets may form and persist in repositories at high temperature but might decompose near room temperature.

  12. Quantum critical fluctuations in the heavy fermion compound Ce(Ni0.935 Pd0.065)2Ge2

    SciTech Connect (OSTI)

    Wang, C. H.; Poudel, L.; Taylor, A. E.; Lawrence, J. M.; Christianson, A. D.; Chang, S.; Rodriguez-Rivera, J. A.; Lynn, J. W.; Podlesnyak, A. A.; Ehlers, G.; Baumbach, R. E.; Bauer, E. D.; Gofryk, K.; Ronning, F.; McClellan, K. J.; Thompson, J. D.

    2015-01-14

    Electric resistivity, specific heat, magnetic susceptibility, and inelastic neutron scattering experi- ments were performed on a single crystal of the heavy fermion compound Ce(Ni0.935 Pd0.065)2Ge2 in order to study the spin fluctuations near an antiferromagnetic (AF) quantum critical point (QCP). The resistivity and the specific heat coefficient for T ≤ 1 K exhibit the power law behavior expected for a 3D itinerant AF QCP (ρ(T) ~ T3/2 and γ(T) ~ γ0 - bT1/2). However, for 2 ≤ T ≤ 10 K, the susceptibility and specific heat vary as log T and the resistivity varies linearly with temperature. Furthermore, despite the fact that the resistivity and specific heat exhibit the non-Fermi liquid behavior expected at a QCP, the correlation length, correlation time, and staggered susceptibility of the spin fluctuations remain finite at low temperature. We suggest that these deviations from the divergent behavior expected for a QCP may result from alloy disorder.

  13. Percolation theory and quantum critical systems: A new description of the critical behavior in Ce(Ru{sub 0.24}Fe{sub 0.76}){sub 2}Ge{sub 2}

    SciTech Connect (OSTI)

    Gaddy, John; Heitmann, Tom; Montfrooij, Wouter

    2014-05-07

    The onset of ordering in quantum critical systems is characterized by a competition between the Kondo shielding of magnetic moments and the ordering of these moments. We show how a distribution of Kondo shielding temperaturesresulting from chemical dopingleads to critical behavior whose main characteristics are given by percolation physics. With the aid of Monte Carlo computer simulations, we are able to infer the low temperature part of the distribution of shielding temperatures in heavily doped quantum critical Ce(Ru{sub 0.24}Fe{sub 0.76}){sub 2}Ge{sub 2}. Based on this distribution, we show that the ordering dynamicssuch as the growth of the correlation length upon coolingcan be understood by the spawning of magnetic clusters. Our findings explain why the search for universal exponents in quantum critical systems has been unsuccessful: the underlying percolation network associated with the chemical doping of quantum critical systems has to be incorporated in the modeling of these quantum critical systems.

  14. Syntheses, structure and rare earth metal photoluminescence of new and known isostructural A{sub 2}Mo{sub 4}Sb{sub 2}O{sub 18} (A=Ce, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) compounds

    SciTech Connect (OSTI)

    Mohitkar, Shrikant A.; Kalpana, G.; Vidyasagar, K.

    2011-04-15

    Nine new A{sub 2}Mo{sub 4}Sb{sub 2}O{sub 18} (A=Ce, Pr, Eu, Tb, Ho, Er, Tm, Yb, Lu) compounds have been synthesized by solid-state reactions. They are isostructural with six reported analogues of yttrium and other lanthanides and the monoclinic unit cell parameters of all fifteen of them vary linearly with the size of A{sup 3+} ion. Single crystal X-ray structures of eight A{sub 2}Mo{sub 4}Sb{sub 2}O{sub 18} (A=Ce, Pr, Eu, Gd, Tb, Ho, Er, Tm) compounds have been determined. Neat A{sub 2}Mo{sub 4}Sb{sub 2}O{sub 18} (A=Pr, Sm, Eu, Tb, Dy, Ho, Er, Tm) compounds exhibit characteristic rare earth metal photoluminescence. -- Graphical abstract: Among the fifteen isostructural A{sub 2}Mo{sub 4}Sb{sub 2}O{sub 18} (A=rare earth metal) molybdoantimonites, eight (A=Pr, Sm, Eu, Tb, Dy, Ho, Er, Tm) compounds exhibit neat characteristic lanthanide photoluminescence in the 200-800 nm range at room temperature. Display Omitted Research highlights: {yields} Syntheses of nine new A{sub 2}Mo{sub 4}Sb{sub 2}O{sub 18} (A=Ce, Pr, Eu, Tb, Ho, Er, Tm, Yb, Lu) compounds. {yields} X-ray structures of eight A{sub 2}Mo{sub 4}Sb{sub 2}O{sub 18} (A=Ce, Pr, Eu, Gd, Tb, Ho, Er, Tm) compounds. {yields} Photoluminescence of neat A{sub 2}Mo{sub 4}Sb{sub 2}O{sub 18} (A=Pr, Sm, Eu, Tb, Dy, Ho, Er, Tm) compounds.

  15. D{sub 3h} [A-CE{sub 3}-A]{sup −} (E = Al and Ga, A = Si, Ge, Sn, and Pb): A new class of hexatomic mono-anionic species with trigonal bipyramidal carbon

    SciTech Connect (OSTI)

    Wu, Yan-Bo E-mail: zxwang@ucas.ac.cn; Li, Yan-Qin; Bai, Hui; Lu, Hai-Gang; Li, Si-Dian; Zhai, Hua-Jin; Wang, Zhi-Xiang E-mail: zxwang@ucas.ac.cn

    2014-03-14

    The non-classical trigonal bipyramidal carbon (TBPC) arrangement generally exists as transition states (TSs) in nucleophilic bimolecular substitution (S{sub N}2) reactions. Nevertheless, chemists have been curious about whether such a carbon bonding could be stable in equilibrium structures for decades. As the TBPC arrangement was normally realized as cationic species theoretically and experimentally, only one anionic example ([At-C(CN){sub 3}-At]{sup −}) was computationally devised. Herein, we report the design of a new class of anionic TBPC species by using the strategy similar to that for stabilizing the non-classical planar hypercoordinate carbon. When electron deficient Al and Ga were used as the equatorial ligands, eight D{sub 3h} [A-CE{sub 3}-A]{sup −} (E = Al and Ga, A = Si, Ge, Sn, and Pb) TBPC structures were found to be the energy minima rather than TSs at both the B3LYP and MP2 levels. Remarkably, the energetic results at the CCSD(T) optimization level further identify [Ge-CAl{sub 3}-Ge]{sup −} and [Sn-CGa{sub 3}-Sn]{sup −} even to be the global minima and [Si-CAl{sub 3}-Si]{sup −} and [Ge-CGa{sub 3}-Ge]{sup −} to be the local minima, only slightly higher than their global minima. The electronic structure analyses reveal that the substantial ionic C–E bonding, the peripheral E–A covalent bonding, and the axial mc-2e (multi center-two electrons) bonding play roles in stabilizing these TBPC structures. The structural simplicity and the high thermodynamic stability suggest that some of these species may be generated and captured in the gas phase. Furthermore, as mono-anionic species, their first vertical detachment energies are differentiable from those of their nearest isomers, which would facilitate their characterization via experiments such as the negative ion photoelectron spectroscopy.

  16. R-Cold: Order (2013-CE-5354)

    Broader source: Energy.gov [DOE]

    DOE ordered R-Cold, Inc. to pay a $8,000 civil penalty after finding R-Cold had failed to certify that any basic models of walk-in cooler or freezer components comply with the applicable energy conservation standards.

  17. Linac Coherent Light SourCe

    Energy Savers [EERE]

    Lights in the Darkness and Hope from the Labs Lights in the Darkness and Hope from the Labs December 31, 2012 - 11:39am Addthis A map of intensities merged using the CrystFEL software suite from almost two hundred thousand diffraction patterns obtained from in vivo grown crystals of Trypanosoma brucei cathepsin B. This map is used to synthesize the three-dimensional molecular structure of the enzyme. | Photo courtesy of Karol Nass/CFEL A map of intensities merged using the CrystFEL software

  18. Danby Products: Proposed Penalty (2012-CE-1415)

    Broader source: Energy.gov [DOE]

    DOE alleged in a Notice of Proposed Civil Penalty that Danby Products, Inc. failed to certify refrigerators and freezers as compliant with the energy conservation standards.

  19. Danby Products: Order (2012-CE-1415)

    Broader source: Energy.gov [DOE]

    DOE ordered Danby Products to pay a $9,900 civil penalty after finding Danby had failed to certify that certain models of refrigerators and freezers comply with the applicable energy conservation standard.

  20. Quorum: Proposed Penalty (2014-CE-32013)

    Broader source: Energy.gov [DOE]

    DOE alleged in a Notice of Proposed Civil Penalty that Davoil, Inc. d/b/a Quorum International, Inc. failed to certify a variety of ceiling fans as compliant with the applicable energy conservation standards.

  1. Microsoft Word - hCE1.doc

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the treatment of cocaine and heroin abuse, and victims of chemical warfare or terrorism. ... Offices of Basic Energy Sciences and Biological and Environmental Research, with ...

  2. Trastar: Proposed Penalty (2013-CE-49003)

    Broader source: Energy.gov [DOE]

    DOE alleged in a Notice of Proposed Civil Penalty that Trastar Inc. failed to certify a variety of basic models of traffic signal modules and pedestrian models as compliant with the applicable energy conservation standards.

  3. Commercial Display Systems: Order (2013-CE-5350)

    Broader source: Energy.gov [DOE]

    DOE ordered Commercial Display Systems, LLC to pay a $8,000 civil penalty after finding Commercial Display Systems had failed to certify that any basic models of walk-in cooler and freezer components comply with the applicable energy conservation standards.

  4. Kold Pack: Order (2013-CE-5323)

    Broader source: Energy.gov [DOE]

    DOE ordered Kold Pack, Inc. to pay a $8,000 civil penalty after finding Kold Pack had failed to certify that certain models of walk-in cooler and freezer components comply with the applicable energy conservation standards.

  5. Fagor America: Order (2014-CE-23018)

    Broader source: Energy.gov [DOE]

    DOE ordered Fagor America, Inc. to pay a $6,500 civil penalty after finding Fagor America had failed to certify that certain models of cooking products comply with the applicable energy conservation standards.

  6. Fagor America: Proposed Penalty (2014-CE-23018)

    Broader source: Energy.gov [DOE]

    DOE alleged in a Notice of Proposed Civil Penalty that Fagor America, Inc. failed to certify various basic models of cooking products as compliant with the applicable energy conservation standards.

  7. Advance Energy Technologies: Order (2013-CE-5302)

    Broader source: Energy.gov [DOE]

    DOE ordered Advance Energy Technologies, Inc., to pay a $8,000 civil penalty after finding Advance Energy Technologies had failed to certify that certain models of walk-in cooler and freezer components comply with the applicable energy conservation standard.

  8. Kold Pack: Proposed Penalty (2013-CE-5323)

    Broader source: Energy.gov [DOE]

    DOE alleged in a Notice of Proposed Civil Penalty that Kold Pack, Inc. failed to certify walk-in cooler or freezer components as compliant with the energy conservation standards.

  9. Engineered Solutions: Order (2010-CE-2112)

    Broader source: Energy.gov [DOE]

    DOE issued an Order after entering into a Compromise Agreement with Engineered Solutions, Inc. to resolve a case involving the failure to certify dehumidifier basic model SD109.

  10. Basement Systems: Order (2010-CE-2110)

    Broader source: Energy.gov [DOE]

    DOE issued an Order after entering into a Compromise Agreement with Basement Systems, Inc. after finding Basement Systems had failed to certify that certain models of dehumdifiers comply with the applicable energy conservation standards.

  11. Volume International: Proposed Penalty (2014-CE-32014)

    Broader source: Energy.gov [DOE]

    DOE alleged in a Notice of Proposed Civil Penalty that Volume International Corporation failed to certify a variety of ceiling fans as compliant with the applicable energy conservation standards.

  12. Commercial Cooler: Order (2013-CE-5343)

    Broader source: Energy.gov [DOE]

    DOE ordered Commercial Cooler, Inc. to pay a $8,000 civil penalty after finding Commercial Cooler had failed to certify that certain models of walk-in cooler and freezer components comply with the applicable energy conservation standards.

  13. Kichler: Proposed Penalty (2014-CE-32007)

    Broader source: Energy.gov [DOE]

    DOE alleged in a Notice of Proposed Civil Penalty that The L.D. Kiebler Co. d/b/a Kichler Lighting failed to certify a variety of ceiling fans as compliant with the applicable energy conservation standards.

  14. Custom Coolers: Order (2013-CE-5315)

    Broader source: Energy.gov [DOE]

    DOE ordered Custom Coolers, LLC to pay a $8,000 civil penalty after finding Custom Coolers had failed to certify that certain models of walk-in cooler and freezer components comply with the applicable energy conservation standards.

  15. Paragon Sales: Proposed Penalty (2012-CE-1417)

    Broader source: Energy.gov [DOE]

    DOE alleged in a Notice of Proposed Civil Penalty that Paragon Sales Co., Inc., failed to certify certain Liebherr residential freezers as compliant with the energy conservation standards.

  16. MC Appliance: Proposed Penalty (2012-CE-1508)

    Broader source: Energy.gov [DOE]

    DOE alleged in a Notice of Proposed Civil Penalty that CNA International Inc. d/b/a MC Appliance Corporation failed to certify a variety of room air conditioners as compliant with the applicable energy conservation standards.

  17. American Range: Proposed Penalty (2014-CE-23006)

    Broader source: Energy.gov [DOE]

    DOE alleged in a Notice of Proposed Civil Penalty that American Range Corporation failed to certify cooking products as compliant with the applicable energy conservation standards.

  18. Viking Range: Order (2014-CE-23014)

    Broader source: Energy.gov [DOE]

    DOE ordered Viking Range, LLC to pay a $8,000 civil penalty after finding Viking Range had failed to certify that certain models of cooking products comply with the applicable energy conservation standards.

  19. American Range: Order (2014-CE-23006)

    Broader source: Energy.gov [DOE]

    DOE ordered American Range Corporation to pay a $8,000 civil penalty after finding American Range had failed to certify that certain models of cooking products comply with the applicable energy conservation standards.

  20. Electrolux: Proposed Penalty (2014-CE-23015)

    Broader source: Energy.gov [DOE]

    DOE alleged in a Notice of Proposed Civil Penalty that Electrolux North America, Inc. failed to certify cooking products as compliant with the applicable energy conservation standards.