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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Platinum Nanoclusters Out-Perform Single Crystals  

NLE Websites -- All DOE Office Websites (Extended Search)

Platinum Nanoclusters Out-Perform Single Crystals Print Platinum Nanoclusters Out-Perform Single Crystals Print When it comes to metal catalysts, platinum is the standard. However, at about $2,000 an ounce, the high cost of the raw material presents major challenges for the future wide-scale use of platinum in fuel cells. Berkeley Lab research suggests that one possible way to meet these challenges is to think small. Researchers from Berkeley Lab's Materials Sciences Division have found that under high pressure-comparable to the pressures at which many industrial technologies operate-platinum surfaces can change their structure dramatically in response to the presence of high-coverage reactants. High-pressure scanning tunneling microscopes (STM) and ambient-pressure x-ray photoelectron spectroscopy (AP-XPS) at ALS Beamlines 9.3.2 and 11.0.2 allowed researchers to study catalysts' structure and composition under realistic conditions.

2

Platinum Nanoclusters Out-Perform Single Crystals  

NLE Websites -- All DOE Office Websites (Extended Search)

Platinum Nanoclusters Out-Perform Single Crystals Print Platinum Nanoclusters Out-Perform Single Crystals Print When it comes to metal catalysts, platinum is the standard. However, at about $2,000 an ounce, the high cost of the raw material presents major challenges for the future wide-scale use of platinum in fuel cells. Berkeley Lab research suggests that one possible way to meet these challenges is to think small. Researchers from Berkeley Lab's Materials Sciences Division have found that under high pressure-comparable to the pressures at which many industrial technologies operate-platinum surfaces can change their structure dramatically in response to the presence of high-coverage reactants. High-pressure scanning tunneling microscopes (STM) and ambient-pressure x-ray photoelectron spectroscopy (AP-XPS) at ALS Beamlines 9.3.2 and 11.0.2 allowed researchers to study catalysts' structure and composition under realistic conditions.

3

Platinum Nanoclusters Out-Perform Single Crystals  

NLE Websites -- All DOE Office Websites (Extended Search)

Platinum Nanoclusters Out-Perform Single Crystals Print Platinum Nanoclusters Out-Perform Single Crystals Print When it comes to metal catalysts, platinum is the standard. However, at about $2,000 an ounce, the high cost of the raw material presents major challenges for the future wide-scale use of platinum in fuel cells. Berkeley Lab research suggests that one possible way to meet these challenges is to think small. Researchers from Berkeley Lab's Materials Sciences Division have found that under high pressure-comparable to the pressures at which many industrial technologies operate-platinum surfaces can change their structure dramatically in response to the presence of high-coverage reactants. High-pressure scanning tunneling microscopes (STM) and ambient-pressure x-ray photoelectron spectroscopy (AP-XPS) at ALS Beamlines 9.3.2 and 11.0.2 allowed researchers to study catalysts' structure and composition under realistic conditions.

4

Platinum Nanoclusters Out-Perform Single Crystals  

NLE Websites -- All DOE Office Websites (Extended Search)

Platinum Nanoclusters Out-Perform Single Crystals Print Platinum Nanoclusters Out-Perform Single Crystals Print When it comes to metal catalysts, platinum is the standard. However, at about $2,000 an ounce, the high cost of the raw material presents major challenges for the future wide-scale use of platinum in fuel cells. Berkeley Lab research suggests that one possible way to meet these challenges is to think small. Researchers from Berkeley Lab's Materials Sciences Division have found that under high pressure-comparable to the pressures at which many industrial technologies operate-platinum surfaces can change their structure dramatically in response to the presence of high-coverage reactants. High-pressure scanning tunneling microscopes (STM) and ambient-pressure x-ray photoelectron spectroscopy (AP-XPS) at ALS Beamlines 9.3.2 and 11.0.2 allowed researchers to study catalysts' structure and composition under realistic conditions.

5

Platinum Nanoclusters Out-Perform Single Crystals  

NLE Websites -- All DOE Office Websites (Extended Search)

Platinum Nanoclusters Out-Perform Single Crystals Print Platinum Nanoclusters Out-Perform Single Crystals Print When it comes to metal catalysts, platinum is the standard. However, at about $2,000 an ounce, the high cost of the raw material presents major challenges for the future wide-scale use of platinum in fuel cells. Berkeley Lab research suggests that one possible way to meet these challenges is to think small. Researchers from Berkeley Lab's Materials Sciences Division have found that under high pressure-comparable to the pressures at which many industrial technologies operate-platinum surfaces can change their structure dramatically in response to the presence of high-coverage reactants. High-pressure scanning tunneling microscopes (STM) and ambient-pressure x-ray photoelectron spectroscopy (AP-XPS) at ALS Beamlines 9.3.2 and 11.0.2 allowed researchers to study catalysts' structure and composition under realistic conditions.

6

Platinum Nanoclusters Out-Perform Single Crystals  

NLE Websites -- All DOE Office Websites (Extended Search)

Platinum Nanoclusters Out-Perform Single Crystals Print Platinum Nanoclusters Out-Perform Single Crystals Print When it comes to metal catalysts, platinum is the standard. However, at about $2,000 an ounce, the high cost of the raw material presents major challenges for the future wide-scale use of platinum in fuel cells. Berkeley Lab research suggests that one possible way to meet these challenges is to think small. Researchers from Berkeley Lab's Materials Sciences Division have found that under high pressure-comparable to the pressures at which many industrial technologies operate-platinum surfaces can change their structure dramatically in response to the presence of high-coverage reactants. High-pressure scanning tunneling microscopes (STM) and ambient-pressure x-ray photoelectron spectroscopy (AP-XPS) at ALS Beamlines 9.3.2 and 11.0.2 allowed researchers to study catalysts' structure and composition under realistic conditions.

7

Platinum Nanoclusters Out-Perform Single Crystals  

NLE Websites -- All DOE Office Websites (Extended Search)

Platinum Nanoclusters Out-Perform Single Platinum Nanoclusters Out-Perform Single Crystals Platinum Nanoclusters Out-Perform Single Crystals Print Wednesday, 27 October 2010 00:00 When it comes to metal catalysts, platinum is the standard. However, at about $2,000 an ounce, the high cost of the raw material presents major challenges for the future wide-scale use of platinum in fuel cells. Berkeley Lab research suggests that one possible way to meet these challenges is to think small. Researchers from Berkeley Lab's Materials Sciences Division have found that under high pressure-comparable to the pressures at which many industrial technologies operate-platinum surfaces can change their structure dramatically in response to the presence of high-coverage reactants. High-pressure scanning tunneling microscopes (STM) and ambient-pressure x-ray photoelectron spectroscopy (AP-XPS) at ALS Beamlines 9.3.2 and 11.0.2 allowed researchers to study catalysts' structure and composition under realistic conditions.

8

Platinum Nanoclusters Out-Perform Single Crystals  

NLE Websites -- All DOE Office Websites (Extended Search)

gas, a reactant involved in many important industrial catalytic processes, including the Fischer-Tropsch process for making liquid hydrocarbons, the oxidation process in...

9

SINGLE CRYSTAL NEUTRON DIFFRACTION.  

SciTech Connect

Single-crystal neutron diffraction measures the elastic Bragg reflection intensities from crystals of a material, the structure of which is the subject of investigation. A single crystal is placed in a beam of neutrons produced at a nuclear reactor or at a proton accelerator-based spallation source. Single-crystal diffraction measurements are commonly made at thermal neutron beam energies, which correspond to neutron wavelengths in the neighborhood of 1 Angstrom. For high-resolution studies requiring shorter wavelengths (ca. 0.3-0.8 Angstroms), a pulsed spallation source or a high-temperature moderator (a ''hot source'') at a reactor may be used. When complex structures with large unit-cell repeats are under investigation, as is the case in structural biology, a cryogenic-temperature moderator (a ''cold source'') may be employed to obtain longer neutron wavelengths (ca. 4-10 Angstroms). A single-crystal neutron diffraction analysis will determine the crystal structure of the material, typically including its unit cell and space group, the positions of the atomic nuclei and their mean-square displacements, and relevant site occupancies. Because the neutron possesses a magnetic moment, the magnetic structure of the material can be determined as well, from the magnetic contribution to the Bragg intensities. This latter aspect falls beyond the scope of the present unit; for information on magnetic scattering of neutrons see Unit 14.3. Instruments for single-crystal diffraction (single-crystal diffractometers or SCDs) are generally available at the major neutron scattering center facilities. Beam time on many of these instruments is available through a proposal mechanism. A listing of neutron SCD instruments and their corresponding facility contacts is included in an appendix accompanying this unit.

KOETZLE,T.F.

2001-03-13T23:59:59.000Z

10

Predicting Deformation of Single Crystal Niobium Using Crystal ...  

Science Conference Proceedings (OSTI)

... Nb. Crystal plasticity models capable of predicting shape changes in single crystal Nb dog bone samples having different orientations have been developed,  ...

11

Light Scattering by Single Natural Ice Crystals  

Science Conference Proceedings (OSTI)

During the South Pole Ice Crystal Experiment, angular scattering intensities (ASIs) of single ice crystals formed in natural conditions were measured for the first time with the polar nephelometer instrument. The microphysical properties of the ...

Valery Shcherbakov; Jean-François Gayet; Brad Baker; Paul Lawson

2006-05-01T23:59:59.000Z

12

Czochralski Grown Ce,Gd:YAG Single Crystals  

Science Conference Proceedings (OSTI)

In this work we propose a new concept of white LED, based on the single crystal phosphor plates (SCPPs) of Czochralski grown Ce,Gd:YAG single crystal.

13

Anisotropic Shock Propagation in Single Crystals  

Science Conference Proceedings (OSTI)

Most single-crystal shock experiments have been performed in high-symmetry directions while the nature of shock propagation in low-symmetry directions remains relatively unstudied. It is well known that small-amplitude, linear acoustic waves propagating in low-symmetry directions can focus and/or form caustics (Wolfe, 1995). In this report we provide evidence for similar focusing behavior in nonlinear (shock) waves propagating in single crystals of silicon and diamond. Using intense lasers, we have driven non-planar (divergent geometry) shock waves through single-crystals of silicon or diamond and into an isotropic backing plate. On recovery of the backing plates we observe a depression showing evidence of anisotropic plastic strain with well-defined crystallographic registration. We observe 4-, 2-, and 3-fold symmetric impressions for [100], [110], and [111] oriented crystals respectively.

Eggert, J; Hicks, D; Celliers, P; Bradley, D; Cox, J; Unites, W; Collins, G; McWilliams, R; Jeanloz, R; Bruygoo, S; Loubeyre, P

2005-05-26T23:59:59.000Z

14

Single-Crystal-to-Single-Crystal Transformations in One Dimensional Ag-Eu Helical System  

SciTech Connect

Single-crystal-to-single-crystal transformation of 1-D 4d-4f coordination polymers have been investigated for the first time. It displays high selectivity for Mg2+ and can be used as magnesium ion-selective luminescent probe. More importantly, we observed the transformation of meso-helical chain to rac-helical chain as a function of temperature.

Cai, Yue-Peng; Zhout, Xiu-Xia; Zhout, Zheng-Yuan; Zhu, Shi-Zheng; Thallapally, Praveen K.; Liu, Jun

2009-07-06T23:59:59.000Z

15

High Cycle Fatigue in a Single Crystal Superalloy: Time ...  

Science Conference Proceedings (OSTI)

Keywords: Single crystal superalloys, High cycle fatigue, Environmental coatings, Rupture ... modes were modeled separately and then combined into a damage.

16

Variation in Machinability of Single Crystal Materials in Micromechanical Machining  

E-Print Network (OSTI)

Single Crystal Cutting of Brass”, Annals of the CIRP, Vol.in microcutting of brass as a function of crystallographic

Lee, Dae-Eun; Min, Sangkee; Deichmueller, Manuel; Dornfeld, David

2006-01-01T23:59:59.000Z

17

Solar cell structure incorporating a novel single crystal silicon material  

DOE Patents (OSTI)

A novel hydrogen rich single crystal silicon material having a band gap energy greater than 1.1 eV can be fabricated by forming an amorphous region of graded crystallinity in a body of single crystalline silicon and thereafter contacting the region with atomic hydrogen followed by pulsed laser annealing at a sufficient power and for a sufficient duration to recrystallize the region into single crystal silicon without out-gassing the hydrogen. The new material can be used to fabricate semiconductor devices such as single crystal silicon solar cells with surface window regions having a greater band gap energy than that of single crystal silicon without hydrogen.

Pankove, Jacques I. (Princeton, NJ); Wu, Chung P. (Trenton, NJ)

1983-01-01T23:59:59.000Z

18

Undercooling Related Casting Defects in Single Crystal Turbine ...  

Science Conference Proceedings (OSTI)

ger problem during the single crystal solidification of turbine blades for stationary gas turbines. Hence the intention of tem- perature measurements during the ...

19

Femtosecond Laser Micromachining of Single-Crystal Superalloys  

Science Conference Proceedings (OSTI)

scale features in multi-layer material systems for aerospace and power generation components. Introduction. Multiple generations of single crystal superalloys ...

20

The Formation of SRZ on a Fourth Generation Single Crystal ...  

Science Conference Proceedings (OSTI)

4th generation nickel-base single crystal (SC) superalloy with aluminide coating ... Granular precipitates distributed in the upper part of SRZ, and needle-like ...

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Porosity Clusters and Recrystallization in Single Crystal Components  

Science Conference Proceedings (OSTI)

The influence of cross-section transients on dendritic single-crystal growth in the .... Ceramic accumulations in the transient region also influence heat transfer.

22

Single Crystal PWA 1472 in High Pressure Hydrogen  

Science Conference Proceedings (OSTI)

SINGLE CRYSTAL PWA 1472. IN HIGH PRESSURE HYDROGEN. D. P. DeLUCA, R. W. HATALA. UNITED TECHNOLOGIES. PRATT & WHITNEY. P. 0.

23

Determination of Atomistic Structure of Ni-Base Single Crystal ...  

Science Conference Proceedings (OSTI)

l-2-1, Sengen, Tsukuba Science City, 305, Japan. *Department of ... The atomic locations of alloying elements in some Ni-base single crystal superalloys have ...

24

Light output simulation of LYSO single crystal  

E-Print Network (OSTI)

We used the Geant4 simulation toolkit to estimate the light collection in a LYSO crystal by using cosmic muons and E=105 MeV electrons. The light output as a function of the crystal length is studied. Significant influence of the crystal wrapping in the reflective paper and optical grease coupling to the photodetectors on the light output is demonstrated.

Usubov, Zafar

2013-01-01T23:59:59.000Z

25

Multiscale Modelling of Single Crystal Superalloys for Gas Turbine Blades  

E-Print Network (OSTI)

Multiscale Modelling of Single Crystal Superalloys for Gas Turbine Blades PROEFSCHRIFT ter Multiscale Modelling of Single Crystal Superalloys for Gas Turbine Blades / by Tiedo Tinga. ­ Eindhoven accumulation 120 5.5 Application 121 5.6 Summary and conclusions 128 6. Application to gas turbine parts 131 6

26

Mechanical Deformation of Single Crystal and Nanocrystalline ...  

Science Conference Proceedings (OSTI)

... hexagonal crystal structure and is commonly used as a solid lubricant and liquid lubricant additive. The objective of this work is to use atomistic simulations to ...

27

A Single Crystal Niobium RF Cavity of the TESLA Shape  

DOE Green Energy (OSTI)

A fabrication method for single crystal niobium cavities of the TESLA shape was proposed on the basis of metallographic investigations and electron beam welding tests on niobium single crystals. These tests showed that a cavity can be produced without grain boundaries even in the welding area. An appropriate annealing allows the outgassing of hydrogen and stress relaxation of the material without destruction of the single crystal. A prototype single crystal single cell cavity was built. An accelerating gradient of 37.5 MV/m was reached after approximately 110 mu-m of Buffered Chanical Polishing (BCP) and in situ baking at 120°C for 6 hrs with a quality factor exceeding 2x1010 at 1.8 K. The developed fabrication method can be extended to fabrication of multi cell cavities.

W. Singer; X. Singer; P. Kneisel

2007-09-01T23:59:59.000Z

28

Single Scattering Properties of Atmospheric Ice Crystals  

Science Conference Proceedings (OSTI)

Simulations of scattering and polarization properties for randomly oriented polyhedral ice crystals are presented based on the geometric optics and the far-field diffraction approximation. Particle shapes range from various hexagonal symmetric ...

Andreas Macke; Johannes Mueller; Ehrhard Raschke

1996-10-01T23:59:59.000Z

29

TOPAZ - Single Crystal Diffractometer | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

TOPAZ-Media Gallery View a Quick Time movie showing Compact Crystal Positioning System. (27 MB) View a 1.55 minute movie (AVI format) showing the sample orienter moving. (405 MB)...

30

Single crystal Processing and magnetic properties of gadolinium nickel  

SciTech Connect

GdNi is a rare earth intermetallic material that exhibits very interesting magnetic properties. Spontaneous magnetostriction occurs in GdNi at T{sub C}, on the order of 8000ppm strain along the c-axis and only until very recently the mechanism causing this giant magnetostriction was not understood. In order to learn more about the electronic and magnetic structure of GdNi, single crystals are required for anisotropic magnetic property measurements. Single crystal processing is quite challenging for GdNi though since the rare-earth transition-metal composition yields a very reactive intermetallic compound. Many crystal growth methods are pursued in this study including crucible free methods, precipitation growths, and specially developed Bridgman crucibles. A plasma-sprayed Gd{sub 2}O{sub 3} W-backed Bridgman crucible was found to be the best means of GdNi single crystal processing. With a source of high-quality single crystals, many magnetization measurements were collected to reveal the magnetic structure of GdNi. Heat capacity and the magnetocaloric effect are also measured on a single crystal sample. The result is a thorough report on high quality single crystal processing and the magnetic properties of GdNi.

Shreve, Andrew John [Ames Laboratory

2012-11-02T23:59:59.000Z

31

NETL: Gasification Systems - Single-Crystal Sapphire Optical...  

NLE Websites -- All DOE Office Websites (Extended Search)

Single-Crystal Sapphire Optical Fiber Sensor Instrumentation Virginia Polytechnic Institute Project No.: DE-FC26-99FT40685 Phase I - The Photonics Laboratory at Virginia Tech has...

32

Photorefractive Properties of Stoichiometric Lithium Niobate Single Crystals  

SciTech Connect

The specific features of photorefractive light scattering in nominally pure stoichiometric (Li/Nb = 1) sin- gle crystals grown from a melt with 58.6 mol % Li{sub 2}O (LiNbO{sub 3}st) and in the stoichiometric single crystals grown from a melt of congruent composition in the presence of K{sub 2}O flux (LiNbO{sub 3}stK{sub 2}O) have been investi- gated. At an excitation power of 30 mW, LiNbO{sub 3}stK{sub 2}O single crystals are found to exhibit a stronger photo- refractive effect than LiNbO{sub 3}st single crystals.

Sidorov, N. V. [Russian Academy of Sciences, Institute of Chemistry and Technology of Rare Earth Elements and Mineral Raw Materials, Kola Scientific Center (Russian Federation); Antonycheva, E. A.; Syui, A. V. [Far Eastern State Transport University (Russian Federation); Palatnikov, M. N., E-mail: palat_mn@chemy.kolasc.net.ru [Russian Academy of Sciences, Institute of Chemistry and Technology of Rare Earth Elements and Mineral Raw Materials, Kola Scientific Center (Russian Federation)

2010-11-15T23:59:59.000Z

33

Shock Driven Twinning in Tantalum Single Crystals  

Science Conference Proceedings (OSTI)

Recovery based observations of high pressure material behavior generated under high explosively driven flyer based loading conditions are reported. Two shock pressures, 25, and 55 GPa and four orientations {l_brace}(100), (110), (111), (123){r_brace} were considered. Recovered material was characterized using electron backscatter diffraction along with a limited amount of transmission electron microscopy to assess the occurrence of twinning under each test condition. Material recovered from 25 GPa had a very small fraction of twinning for the (100), (110), and (111) oriented crystals while a more noticeable fraction of the (123) oriented crystal was twinned. Material recovered from 55 GPa showed little twinning for (100) orientation slightly more for the (111) orientation and a large area fraction for the (123) orientation. The EBSD and TEM observations of the underlying deformation substructure are rationalized by comparing with previous static and dynamic results.

McNaney, J M; HSUING, L M; Barton, N R; Kumar, M

2009-07-20T23:59:59.000Z

34

TOPAZ: the Single Crystal Diffractometer at SNS | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

TOPAZ-Single-Crystal Diffractometer TOPAZ-Single-Crystal Diffractometer TOPAZ instrument scientist Christina Hoffmann and scientific associate Matt Frost at TOPAZ. TOPAZ instrument scientist Christina Hoffmann and scientific associate Matt Frost at TOPAZ. TOPAZ is an elastic scattering instrument that allows for probing of material structures and responses under controlled environmental conditions. It enables neutron measurement of the same single-crystal samples that is possible with x-ray diffraction. Data are collected on samples of 0.1 mm3 or less. Resolution is such that an average unit cell size of [50 × 50 × 50] Å3 for compounds of moderate complexity can be easily accommodated. This includes inorganic large and porous framework and guest-host materials, metal (in-)organic cluster and

35

Growth of large single crystals of MgO  

SciTech Connect

The progressive identification of new high-technology applications and requirements for MgO single crystals in the commercial realm, as well as in DOE and other government-agency project areas, has resulted in an increased demand and international market for this material. Specifically, the demand for MgO crystals in large sizes and quantities is presently increasing due to existing and developing applications that include: (a) MgO substrates for the formation of electro-optic thin films and devices, (b) epitaxial substrates for high-temperature thin-film superconducting devices MgO optical components - including high-temperature windows, lenses, and prisms, and (d) specialty MgO crucibles and evaporation sources for thin-film production. In the course of CRADA ORNL92-0091, carried out with Commercial Crystal Laboratories of Naples, Florida as the commercial participant, we have made major progress in increasing the size of single crystals of MgO produced by means of the submerged-arc-fusion technique-thereby increasing the commercial utility of this material. Prior to the accomplishments realized in the course of this CRADA, the only commercially available single crystals of MgO were produced in Japan, Israel, and Russia. The results achieved in the course of CRADA ORNL92-0091 have now led to the establishment of a domestic commercial source of MgO single-crystal substrates and components, and the U.S. is no longer totally dependent on foreign sources of this increasingly important material.

Boatner, L.A. [Oak Ridge National Lab., TN (United States); Urbanik, M. [Commercial Crystal Laboratories, Inc., Naples, FL (United States)

1997-06-12T23:59:59.000Z

36

Single crystal to single crystal transition in (10, 3)-d framework with pyrazine-2-carboxylate ligand: Synthesis, structures and magnetism  

Science Conference Proceedings (OSTI)

Assembling of pyrazine-2-carboxylate (Pzc) acid with nickel chlorine under solvothermal condition with MeOH as solvent gave a porous complex 1 {l_brace}[Ni(Pzc)ClH{sub 2}O]{center_dot}MeOH{r_brace}{sub n} with 1D channels. In 1 the ligands and metal ions are connected by three of each other and a rare (10,3)-d topology net is gained. The MeOH molecules filled in the 1D channels as guests. It is interesting that 1 undergoes a single-crystal-to-single-crystal transformation to another complex 2 when the guest MeOH molecules in the channels are exchanged by water molecules. Magnetic study indicates anti-ferromagnetic couplings exist in the two complexes and the guest exchange in the complex has little influence on the magnetism. - Graphical abstract: A porous complex 1 with rare (10,3)-d net was gained, and 1 underwent a single-crystal-to-single-crystal transformation to another phase 2. Highlights: Black-Right-Pointing-Pointer New (10,3)-d net was obtained with pyrazine-2-carboxylate ligands as a triangular node. Black-Right-Pointing-Pointer The complex 1 has a 1D channel filled with methanol molecules as guests. Black-Right-Pointing-Pointer 1 could undergo SCSC structural transition to 2 after guests exchanged. Black-Right-Pointing-Pointer Antiferromagnetic interactions were found in 1 and 2.

Yang, Qian [School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin 300384 (China) [School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin 300384 (China); Department of Chemistry, Tianjin Key Lab on Metal and Molecule-based Material Chemistry, Nankai University, Tianjin 300071 (China); Zhao, Jiong-Peng, E-mail: horryzhao@yahoo.com [School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin 300384 (China)] [School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin 300384 (China); Liu, Zhong-Yi [College of Chemistry, Tianjin Key Laboratory of Structure and Performance for Functional Molecules, Tianjin Normal University, Tianjin 300387 (China)] [College of Chemistry, Tianjin Key Laboratory of Structure and Performance for Functional Molecules, Tianjin Normal University, Tianjin 300387 (China)

2012-12-15T23:59:59.000Z

37

ATMOSPHERIC EFFECTS ON THE PERFORMANCE OF CDZNTE SINGLE CRYSTAL DETECTORS  

Science Conference Proceedings (OSTI)

The production of high-quality ternary single-crystal materials for radiation detectors has progressed over the past 15 years. One of the more common materials being studied is CdZnTe (CZT), which can be grown using several methods to produce detector-grade materials. The work presented herein examines the effects of environmental conditions including temperature and humidity on detector performance [full-width at half-maximum (FWHM)] using the single pixel with guard detector configuration. The effects of electrical probe placement, reproducibility, and aging are also presented.

Washington, A.; Duff, M.; Teague, L.

2010-05-12T23:59:59.000Z

38

Acquisition of Single Crystal Growth and Characterization Equipment  

Science Conference Proceedings (OSTI)

Final Report for DOE Grant No. DE-FG02-04ER46178 'Acquisition of Single Crystal Growth and Characterization Equipment'. There is growing concern in the condensed matter community that the need for quality crystal growth and materials preparation laboratories is not being met in the United States. It has been suggested that there are too many researchers performing measurements on too few materials. As a result, many user facilities are not being used optimally. The number of proficient crystal growers is too small. In addition, insufficient attention is being paid to the enterprise of finding new and interesting materials, which is the driving force behind much of condensed matter research and, ultimately, technology. While a detailed assessment of this situation is clearly needed, enough evidence of a problem already exists to compel a general consensus that the situation must be addressed promptly. This final report describes the work carried out during the last four years in our group, in which a state-of-the-art single crystal growth and characterization facility was established for the study of novel oxides and intermetallic compounds of rare earth, actinide and transition metal elements. Research emphasis is on the physics of superconducting (SC), magnetic, heavy fermion (HF), non-Fermi liquid (NFL) and other types of strongly correlated electron phenomena in bulk single crystals. Properties of these materials are being studied as a function of concentration of chemical constituents, temperature, pressure, and magnetic field, which provide information about the electronic, lattice, and magnetic excitations at the root of various strongly correlated electron phenomena. Most importantly, the facility makes possible the investigation of material properties that can only be achieved in high quality bulk single crystals, including magnetic and transport phenomena, studies of the effects of disorder, properties in the clean limit, and spectroscopic and scattering studies through efforts with numerous collaborators. These endeavors will assist the effort to explain various outstanding theoretical problems, such as order parameter symmetries and electron-pairing mechanisms in unconventional superconductors, the relationship between superconductivity and magnetic order in certain correlated electron systems, the role of disorder in non-Fermi liquid behavior and unconventional superconductivity, and the nature of interactions between localized and itinerant electrons in these materials. Understanding the mechanisms behind strongly correlated electron behavior has important technological implications.

Maple, M. Brian; Zocco, Diego A.

2008-12-09T23:59:59.000Z

39

Large pyramid shaped single crystals of BiFeO{sub 3} by solvothermal synthesis method  

SciTech Connect

Synthesis parameters are optimized in order to grow single crystals of multiferroic BiFeO{sub 3}. 2 to 3 mm size pyramid (tetrahedron) shaped single crystals were successfully obtained by solvothermal method. Scanning electron microscopy with EDAX confirmed the phase formation. Raman scattering spectra of bulk BiFeO3 single crystals have been measured which match well with reported spectra.

Sornadurai, D.; Ravindran, T. R.; Paul, V. Thomas; Sastry, V. Sankara [Condensed Matter Physics Division, Materials Science Group, Physical Metallurgy Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu (India); Condensed Matter Physics Division, Materials Science Group (India)

2012-06-05T23:59:59.000Z

40

Strength anomaly in B2 FeAl single crystals  

Science Conference Proceedings (OSTI)

Strength and deformation microstructure of B2 Fe-39 and 48%Al single crystals (composition given in atomic percent), which were fully annealed to remove frozen-in vacancies, have been investigated at temperatures between room temperature and 1073K. The hardness of as-homogenized Fe-48Al is higher than that of as-homogenized Fe-39Al while after additional annealing at 698K the hardness of Fe-48Al becomes lower than that of Fe-39Al. Fe-39Al single crystals slowly cooled after homogenizing at a high temperature were deformed in compression as a function of temperature and crystal orientation. A peak of yield strength appears around 0.5T{sub m} (T{sub m} = melting temperature). The orientation dependence of the critical resolved shear stress does not obey Schmid`s law even at room temperature and is quite different from that of b.c.c. metals and B2 intermetallics at low temperatures. At the peak temperature slip transition from -type to -type is found to occur macroscopically and microscopically, while it is observed in TEM that some of the [111] dislocations decompose into [101] and [010] on the (1096I) plane below the peak temperature. The physical sources for the positive temperature dependence of yield stress of B2 FeAl are discussed based on the obtained results.

Yoshimi, K.; Hanada, S.; Yoo, M.H. [Oak Ridge National Lab., TN (United States); Matsumoto, N. [Tohoku Univ. (Japan). Graduate School

1994-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

NETL: Gasification - Single-Crystal Sapphire Optical Fiber Sensor  

NLE Websites -- All DOE Office Websites (Extended Search)

Gasifier Optimization and Plant Supporting Systems Gasifier Optimization and Plant Supporting Systems Single-Crystal Sapphire Optical Fiber Sensor Instrumentation Virginia Polytechnic Institute and State University Center for Photonics Technology Project Number: DE-FC26-99FT40685 Project Description Phase I - The Photonics Laboratory at Virginia Tech has successfully developed a novel temperature sensor capable of operating at temperatures up to 1600 °C and in harsh conditions. The sensor uses single-crystal sapphire to make an optically-based measurement and will fulfill the need for the real-time monitoring of high temperatures created in gasification processes. Phase II - Based on a successful Phase I laboratory demonstration of a Broadband Polarimetric Differential Interferometric (BPDI) temperature sensor, Virginia Tech's Phase II development objective is to further the development of the sensor for industrial use in slagging coal gasifiers. This will include ruggedizing the design of the sensor and creation of a suitable protective housing such that it can be placed into existing ports of coal gasifiers. The potential industrial use of the sensor will be determined through full-scale testing and development. The sensor design and fabrication has been completed and is undergoing testing. Overall performance and survivability of the sensor will be determined.

42

HYDROGEN CHEMISORPTION ON Pt SINGLE CRYSTAL SURFACES IN ACIDIC SOLUTIONS  

DOE Green Energy (OSTI)

Hydrogen chemisorption from dilute acidic solution onto Pt single crystal surfaces was examined using an electrochemical cell directly coupled to LEED/Auger analytical system. No pre-anodization was used prior to observing hydrogen adsorption by cyclic voltammetry so that clean surfaces having the ordered structures indicated by LEED were studied. The problem of contributions from non-ordered parts of the electrode like support wires and edges was solved by using a gold evaporation masking technique. The specific contribution of atomic imperfections to the voltammetry curve was deduced from the ordered and countable imperfections occurring on high Miller index single crystal surfaces that have a stepped structure. The H-Pt bond energy Has found to be structure sensitive, and sensitive both to local site geometry and long range order in the surface. The bond strength was found to vary systematically: n(111)x(100) > (100) > n(111)x(111) > (110) > (111). Distinct states for hydrogen at steps versus hydrogen on terraces could be distinguished. The (110) surface is shown to be a (111) vicinal, probably the [3(111) x 2(111)] microfacetted surface. The zero coverage heat of adsorption on the well-ordered (111) surface (48 kJ/mol) in solutions is the same as the value reported by Ertl and co-workers for adsorption on a (111) surface in vacuum. Adsorption Isotherms for hydrogen on the (111) and (100) surfaces is adequately fit by the classical model for immobile adsorption at single sites with nearest neighbor repulsive interaction.

Ross, Jr., Philip N.

1980-04-01T23:59:59.000Z

43

Bruker Workshop on Single Crystal X-Ray Diffraction  

NLE Websites -- All DOE Office Websites (Extended Search)

Diagnosis and Treatment of Problem Structures: Diagnosis and Treatment of Problem Structures: A Bruker Workshop on Single Crystal X-Ray Diffraction May 30, 2008 Chemistry Department University of Tennessee Knoxville, TN This meeting focuses on the scientific resources of four ORNL user facilities funded by the DOE Office of Basic Energy Sciences. Who Should Attend Synopsis Goals Scheduled Agenda Workshop Materials Confirmed Speakers Important Dates Registration - now open Location - Directions and Map Sponsors Organizing and Local Committee Contacts Relevant Literature, References, Websites Local Information Bruker - UT Workshop Who Should Attend? The Workshop is directed to the newcomer as well as the experienced user of a Bruker Apex / Apex-II system and SHELX software. It will concentrate on hard to solve and/or refine problem structures. We envision it to be

44

Dislocation nucleation in bcc Ta single crystals studied by nanoindentation  

SciTech Connect

The study of dislocation nucleation in closed-packed metals by nanoindentation has recently attracted much interest. Here, we address the peculiarities of the incipient plasticity in body centered cubic (bcc) metals using low index Ta single-crystals as a model system. The combination of nanoindentation with high-resolution atomic force microscopy provides us with experimental atomic-scale information on the process of dislocation nucleation and multiplication. Our results reveal a unique deformation behavior of bcc Ta at the onset of plasticity which is distinctly different from that of closed-packed metals. Most noticeable, we observe only one rather than a sequence of discontinuities in the load-displacement curves. This and other differences are discussed in context of the characteristic plastic deformation behavior of bcc metals.

Biener, M M; Biener, J; Hodge, A M; Hamza, A V

2007-08-08T23:59:59.000Z

45

Single crystal metal wedges for surface acoustic wave propagation  

DOE Patents (OSTI)

An ultrasonic testing device has been developed to evaluate flaws and inhomogeneities in the near-surface region of a test material. A metal single crystal wedge is used to generate high frequency Rayleigh surface waves in the test material surface by conversion of a slow velocity, bulk acoustic mode in the wedge into a Rayleigh wave at the metal-wedge test material interface. Particular classes of metals have been found to provide the bulk acoustic modes necessary for production of a surface wave with extremely high frequency and angular collimation. The high frequency allows flaws and inhomogeneities to be examined with greater resolution. The high degree of angular collimation for the outgoing ultrasonic beam permits precision angular location of flaws and inhomogeneities in the test material surface.

Fisher, E.S.

1980-05-09T23:59:59.000Z

46

Single crystal metal wedges for surface acoustic wave propagation  

DOE Patents (OSTI)

An ultrasonic testing device has been developed to evaluate flaws and inhomogeneities in the near-surface region of a test material. A metal single crystal wedge is used to generate high frequency Rayleigh surface waves in the test material surface by conversion of a slow velocity, bulk acoustic mode in the wedge into a Rayleigh wave at the metal-wedge test material interface. Particular classes of metals have been found to provide the bulk acoustic modes necessary for production of a surface wave with extremely high frequency and angular collimation. The high frequency allows flaws and inhomogeneities to be examined with greater resolution. The high degree of angular collimation for the outgoing ultrasonic beam permits precision angular location of flaws and inhomogeneities in the test material surface.

Fisher, Edward S. (Wheaton, IL)

1982-01-01T23:59:59.000Z

47

Rene' N4: A First Generation Single Crystal Turbine Airfoil Alloy with ...  

Science Conference Proceedings (OSTI)

GE Aircraft Engine's first generation single crystal (SX) turbine airfoil alloy, Rene N ..... Aircraft Engines, and Warren King who is now with GE Power. Generation ...

48

Surface and Edge Quality Variation in Precision Machining of Single Crystal and Polycrystalline Materials  

E-Print Network (OSTI)

single crystal cutting of b brass. Ann. CIRP, 1980, 8 Sato,micromilling of microgrooves on brass and stainless steelin microcutting of brass as a function of crystallographic

Min, Sangkee; Lee, D.E.; de Grave, A.; Valente, Carlos M. O.; Lin, J.; Dornfeld, David

2006-01-01T23:59:59.000Z

49

Surface and Edge Quality Variation in Precision Machining of Single Crystal and Polycrystalline Materials  

E-Print Network (OSTI)

Single Crystal Cutting of b Brass,” Annals of the CIRP, vol.in microcutting of brass as a function of crystallographicmicromilling of microgrooves on brass and stainless steel

Min, Sangkee; Lee, Dae-Eun; de Grave, Arnaud; De Oliveira Valente, Carlos M; Lin, Judy; Dornfeld, David A

2004-01-01T23:59:59.000Z

50

Polymorphic single crystal {r_reversible} single crystal transition in K{sub 0.975}Rb{sub 0.025}NO{sub 3}  

Science Conference Proceedings (OSTI)

Polymorphic transformations in K{sub 0.975}Rb{sub 0.025}NO{sub 3} single crystals have been investigated by optical microscopy and X-ray diffraction. The equilibrium temperature between modifications II and III has been determined. It is established that the crystal growth at II {r_reversible} III polymorphic transitions is accompanied by the formation and growth of daughter-modification nuclei in the matrix crystal.

Asadov, Yu. G., E-mail: yusifasadov@rambler.ru; Nasirov, E. V. [Azerbaijan National Academy of Sciences, Institute of Physics (Azerbaijan)

2010-09-15T23:59:59.000Z

51

Superconducting Proximity Effect in Single-Crystal Nanowires  

E-Print Network (OSTI)

This dissertation describes experimental studies of the superconducting proximity effect in single-crystal Pb, Sn, and Zn nanowires of lengths up to 60 um, with both ends of the nanowires in contact with macroscopic electrodes that are either superconducting (Sn or Pb) or non-superconducting (Au). The Pb, Sn, and Zn nanowires are fabricated using a template-based electrochemical deposition method. Electric contacts to the nanowires are formed in situ during electrochemical growth. This method produces high transparency contacts between a pair of macroscopic electrodes and a single nanowire, circumventing the formation of oxide or other poorly conducting interface layers. Extensive analyses of the structure and the composition of the nanowire samples are presented to demonstrate that (1) the nanowires are single crystalline and (2) the nanowires are clean without any observable mixing of the materials from the electrodes. The nanowires being investigated are significantly longer than the nanowires with which electrode-induced superconductivity was previously investigated by other groups. We have observed that in relatively short (~6 um) Sn and Zn nanowires, robust superconductivity is induced at the superconducting transition temperatures of the electrodes. When Sn and Pb nanowires are in contact with a pair of Au electrodes, superconductivity is suppressed completely. For nanowires of 60 um in length, although the suppression of superconductivity by Au electrodes is only partial, the induced superconductivity at the higher transition temperatures of the electrodes remains full and robust. Therefore, an anomalous superconducting proximity effect has been observed on a length scale which far exceeds the expected length based on the existing theories of the proximity effect. The measured current-voltage characteristic of the nanowires reveals more details such as hysteresis, multiple Andreev reflection, and phase-slip centers. An interesting relation between the proximity effect and the residual-resistance-ratio of the nanowires has also been observed. Possible mechanisms for this proximity effect are discussed based on these experimental observations.

Liu, Haidong

2009-05-01T23:59:59.000Z

52

Arc-melting preparation of single crystal LaB.sub.6 cathodes  

DOE Patents (OSTI)

A method for preparing single crystals of lanthanum hexaboride (LaB.sub.6) by arc melting a rod of compacted LaB.sub.6 powder. The method is especially suitable for preparing single crystal LaB.sub.6 cathodes for use in scanning electron microscopes (SEM) and scanning transmission electron microscopes (STEM).

Gibson, Edwin D. (Ames, IA); Verhoeven, John D. (Ames, IA)

1977-06-21T23:59:59.000Z

53

Discontinuous surface cracks during stress corrosion cracking of stainless steel single crystal  

E-Print Network (OSTI)

Discontinuous surface cracks during stress corrosion cracking of stainless steel single crystal L Keywords: A. Stainless steel B. SEM C. Stress corrosion a b s t r a c t Single crystal 321 stainless steel, and the river-markings exhibited microshear facets along the {1 1 1} plane. Interaction between the main crack

Volinsky, Alex A.

54

Dye-doped cholesteric-liquid-crystal room-temperature single-photon source*  

E-Print Network (OSTI)

Dye-doped cholesteric-liquid-crystal room-temperature single-photon source* SVETLANA G. LUKISHOVAy, 250 East River Road, Rochester, New York 14623-1299, USA (Received 30 June 2003) Abstract. Fluorescence antibunching from single terrylene molecules embedded in a cholesteric-liquid-crystal host is used

Stroud, Carlos R.

55

DEVELOPMENT OF PROTECTIVE COATINGS FOR SINGLE CRYSTAL TURBINE BLADES  

DOE Green Energy (OSTI)

Turbine blades in coal derived syngas systems are subject to oxidation and corrosion due to high steam temperature and pressure. Thermal barrier coatings (TBCs) are developed to address these problems. The emphasis is on prime-reliant design and a better coating architecture, having high temperature and corrosion resistance properties for turbine blades. In Phase I, UES Inc. proposed to develop, characterize and optimize a prime reliant TBC system, having smooth and defect-free NiCoCrAlY bond layer and a defect free oxide sublayer, using a filtered arc technology. Phase I work demonstrated the deposition of highly dense, smooth and defect free NiCoCrAlY bond coat on a single crystal CMSX-4 substrate and the deposition of alpha-alumina and yttrium aluminum garnet (YAG) sublayer on top of the bond coat. Isothermal and cyclic oxidation test and pre- and post-characterization of these layers, in Phase I work, (with and without top TBC layer of commercial EB PVD YSZ) revealed significant performance enhancement.

Amarendra K. Rai

2006-12-04T23:59:59.000Z

56

Crack tip plasticity in single crystal UO2: Atomistic simulations  

SciTech Connect

The fracture behavior of single crystal uranium dioxide is studied using molecular dynamics simulations at room temperature. Initially, an elliptical notch is created on either {111} or {110} planes, and tensile loading is applied normal to the crack planes. For cracks on both planes, shielding of crack tips by plastic deformation is observed, and crack extension occurs for crack on {111} planes only. Two plastic processes, dislocation emission and phase transformation are identified at crack tips. The dislocations have a Burgers vector of ?110?/2, and glide on {100} planes. Two metastable phases, the so-called Rutile and Scrutinyite phases, are identified during the phase transformation, and their relative stability is confirmed by separate density- functional-theory calculations. Examination of stress concentration near crack tips reveals that dislocation emission is not an effective shielding mechanism. The formation of new phases may effectively shield the crack provided all phase interfaces formed near the crack tips are coherent, as in the case of cracks residing on {110} planes.

Yongfeng Zhang; Paul C. Millett; Michael Tonks; Bulent Biner; Xiang-Yang Liu; David A. Andersson

2012-11-01T23:59:59.000Z

57

The crystal structure of {pi}-ErBO{sub 3}: New single-crystal data for an old problem  

Science Conference Proceedings (OSTI)

Single crystals of the orthoborate {pi}-ErBO{sub 3} were synthesized from Er{sub 2}O{sub 3} and B{sub 2}O{sub 3} under high-pressure/high-temperature conditions of 2 GPa and 800 {sup o}C in a Walker-type multianvil apparatus. The crystal structure was determined on the basis of single-crystal X-ray diffraction data, collected at room temperature. The title compound crystallizes in the monoclinic pseudowollastonite-type structure, space group C2/c, with the lattice parameters a=1128.4(2) pm, b=652.6(2) pm, c=954.0(2) pm, and {beta}=112.8(1){sup o} (R{sub 1}=0.0124 and wR{sub 2}=0.0404 for all data). -- graphical abstract: The first satisfying single-crystal structure determination of {pi}-ErBO{sub 3} sheds light on the extensively discussed structure of {pi}-orthoborates. The application of light pressure during the solid state synthesis yielded in high-quality crystals, due to pressure-induced crystallization. Research highlights: {yields} High-quality single crystals of {pi}-ErBO{sub 3} were prepared via high-pressure-induced crystallization. {yields} At least five different space groups for the rare-earth {pi}-orthoborates are reported. {yields} {pi}-ErBO{sub 3} is isotypic to the pseudowollastonite-type CaSiO{sub 3}. {yields} Remaining ambiguities regarding the structure of the rare-earth {pi}-orthoborates are resolved.

Pitscheider, Almut [Institut fuer Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universitaet Innsbruck, Innrain 52a, A-6020 Innsbruck (Austria); Kaindl, Reinhard [Institut fuer Mineralogie und Petrographie, Leopold-Franzens-Universitaet Innsbruck, Innrain 52, A-6020 Innsbruck (Austria); Oeckler, Oliver [Department Chemie, Ludwig-Maximilians-Universitaet Muenchen, Butenandtstrasse 5-13, D-81377 Muenchen (Germany); Huppertz, Hubert, E-mail: Hubert.Huppertz@uibk.ac.a [Institut fuer Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universitaet Innsbruck, Innrain 52a, A-6020 Innsbruck (Austria)

2011-01-15T23:59:59.000Z

58

Single shot ultrafast dynamic ellipsometry (UDE) of laser-driven shocks in single crystal explosives  

SciTech Connect

We report on the first experiments to measure states in shocked energetic single crystals with dynamic ellipsometry. We demonstrate that these ellipsometric techniques can produce reasonable Hugoniot values using small amounts of crystalline RDX and PETN. Pressures, particle velocities and shock velocities obtained using shocked ellipsometry are comparable to those found using gas-gun flyer plates and molecular dynamics calculations. The adaptation of the technique from uniform thin films of polymers to thick non-perfect crystalline materials was a significant achievement. Correct sample preparation proved to be a crucial component. Through trial and error, we were able to resolve polishing issues, sample quality problems, birefringence effects and mounting difficulties that were not encountered using thin polymer films.

Whitley, Von H [Los Alamos National Laboratory; Mcgrane, Shawn D [Los Alamos National Laboratory; Moore, David S [Los Alamos National Laboratory; Eakins, Dan E [Los Alamos National Laboratory; Bolme, Cindy A [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

59

Single crystal silicon as a macro-world structural material : application to compact, lightweight high pressure vessels  

E-Print Network (OSTI)

Single crystal silicon has promising inherent structural properties which are attractive for weight sensitive applications. Single crystal silicon, however, is a brittle material which makes the usable strength that can ...

Garza, Tanya Cruz

2011-01-01T23:59:59.000Z

60

Impurity Gettering Effect of Te Inclusions in Cdznte Single Crystals  

Science Conference Proceedings (OSTI)

The local impurity distribution in Te inclusions of CdZnTe (CZT) crystal was investigated by the time-of-flight secondary ion mass spectrometry (Tof-SIMS) technique. Direct evidence of impurity gettering in Te inclusions has been observed for the first time. The impurity gettering in Te inclusions originated from the diffusion mechanism during crystal growth and segregation mechanism during crystal cooling. This phenomenon is meaningful, because it reveals how Te inclusions affect CZT properties and provides a possible approach to reduce the impurities in CZT by the way of removing Te inclusions.

Yang, G.; Bolotnikov, A; Cui, Y; Camarda, G; Hossain, A; James, R

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Towards a LED based on a photonic crystal nanocavity for single photon sources at telecom wavelength  

Science Conference Proceedings (OSTI)

A fundamental step towards achieving an ''on demand'' single photon source would be the possibility of electrical pumping for a single QD and thus the integration of such a device in an opto-electronic circuit. In this work we describe the fabrication ... Keywords: LED, Optical nanocavities, Photonic crystals, Single photon sources

M. Francardi; A. Gerardino; L. Balet; N. Chauvin; D. Bitauld; C. Zinoni; L. H. Li; B. Alloing; N. Le Thomas; R. Houdré; A. Fiore

2008-05-01T23:59:59.000Z

62

Method for preparing homogeneous single crystal ternary III-V alloys  

DOE Patents (OSTI)

A method for producing homogenous single crystal III--V ternary alloys of high crystal perfection using a floating crucible system in which the outer crucible holds a ternary alloy of the composition desired to be produced in the crystal and an inner floating crucible having a narrow, melt-passing channel in its bottom wall holds a small quantity of melt of a pseudo-binary liquidus composition which would freeze into the desired crystal composition. The alloy of the floating crucible is maintained at a predetermined lower temperature than the alloy of the outer crucible, and a single crystal of the desired homogeneous alloy is pulled out of the floating crucible melt, as melt from the outer crucible flows into a bottom channel of the floating crucible at a rate that corresponds to the rate of growth of the crystal.

Ciszek, T.F.

1990-08-14T23:59:59.000Z

63

Novel approaches to power scaling of single-frequency photonic crystal fiber amplifiers.  

E-Print Network (OSTI)

??This dissertation presents experimental and theoretical studies of high power, single-frequency, ytterbium-doped photonic crystal fiber amplifiers. The objective of this effort is to identify issues… (more)

Robin, Craig

2011-01-01T23:59:59.000Z

64

A variable capacitor made from single crystal silicon fracture surface pairs  

E-Print Network (OSTI)

Complementary and nano-smooth single-crystal-silicon surfaces have been fabricated by deliberately fracturing a weakened portion of a larger structure whose flexural mechanism refines and concentrates an externally applied ...

Sprunt, Alexander D. (Alexander Dalziel), 1977-

2005-01-01T23:59:59.000Z

65

Anisotropic dewetting in ultra-thin single-crystal silicon-on-insulator films  

E-Print Network (OSTI)

The single crystal silicon-on-insulator thin film materials system represents both an ideal model system for the study of anisotropic thin film dewetting as well as a technologically important system for the development ...

Danielson, David T. (David Thomas)

2008-01-01T23:59:59.000Z

66

Microwave Radiative Transfer through Clouds Composed of Realistically Shaped Ice Crystals. Part I. Single Scattering Properties  

Science Conference Proceedings (OSTI)

This paper presents the results of a detailed study of the microwave single scattering properties of ice crystals expected in cirrus clouds. The discrete dipole approximation is used to compute scattering quantities of particles ranging in size ...

K. Franklin Evans; Graeme L. Stephens

1995-06-01T23:59:59.000Z

67

Single-Crystal Sapphire Optical Fiber Sensor Instrumentation for Coal Gasifiers  

NLE Websites -- All DOE Office Websites (Extended Search)

Single-Crystal Sapphire Optical Fiber Single-Crystal Sapphire Optical Fiber Sensor Instrumentation for Coal Gasifiers Description Accurate temperature measurement inside a coal gasifier is essential for safe, efficient, and cost-effective operation. However, current sensors are prone to inaccurate readings and premature failure due to harsh operating conditions like high temperature (1,200-1,600 °C), high pressure (up to 500 pounds per square inch gauge [psig]),

68

Recrystallization In Single Crystals Of Nickel Base Superalloys - TMS  

Science Conference Proceedings (OSTI)

single-phase y areas if the degree of cold work is not too high. Grain boundary ... Figure 1: Recrystallization phenomena on a turbine airfoil after solution heat ...

69

Characterization of Contamination Free Single-Crystal Sapphire and ...  

Science Conference Proceedings (OSTI)

What Can we Learn from Atomic Scale Calculations of Grain Boundary Properties? What Can We Learn from Measurements of Li-ion Battery Single Particles?

70

Laboratory Measurements of Light Scattering by Single Levitated Ice Crystals  

Science Conference Proceedings (OSTI)

The authors have measured the differential light-scattering cross sections and phase functions of single vapor-grown hexagonal ice particles levitated in an electrodynamic balance. The ice particles, grown at temperatures ?5° > T > ?10°C, were ...

Neil J. Bacon; Brian D. Swanson

2000-07-01T23:59:59.000Z

71

Low cost, single crystal-like substrates for practical, high efficiency solar cells  

Science Conference Proceedings (OSTI)

It is well established that high efficiency (20%) solar cells can be routinely fabricated using single crystal photovoltaic (PV) materials with low defect densities. Polycrystalline materials with small grain sizes and no crystallographic texture typically result in reduced efficiences. This has been ascribed primarily to the presence of grain boundaries and their effect on recombination processes. Furthermore, lack of crystallographic texture can result in a large variation in dopant concentrations which critically control the electronic properties of the material. Hence in order to reproducibly fabricate high efficiency solar cells a method which results in near single crystal material is desirable. Bulk single crystal growth of PV materials is cumbersome, expensive and difficult to scale up. We present here a possible route to achieve this if epitaxial growth of photovoltaic materials on rolling-assisted-biaxially textured-substrates (RABiTS) can be achieved. The RABiTS process uses well-established, industrially scaleable, thermomechanical processing to produce a biaxially textured or single-crystal-like metal substrate with large grains (50-100 {mu}m). This is followed by epitaxial growth of suitable buffer layers to yield chemically and structurally compatible surfaces for epitaxial growth of device materials. Using the RABiTS process it should be possible to economically fabricate single-crystal-like substrates of desired sizes. Epitaxial growth of photovoltaic devices on such substrates presents a possible route to obtaining low-cost, high performance solar cells.

Goyal, A.; Specht, E.D.; List, F.A. [and others

1997-09-01T23:59:59.000Z

72

Structural Characterization of Doped GaSb Single Crystals by X-ray Topography  

Science Conference Proceedings (OSTI)

We characterized GaSb single crystals containing different dopants (Al, Cd and Te), grown by the Czochralski method, by x-ray topography and high angular resolution x-ray diffraction. Lang topography revealed dislocations parallel and perpendicular to the crystal's surface. Double-crystal GaSb 333 x-ray topography shows dislocations and vertical stripes than can be associated with circular growth bands. We compared our high-angular resolution x-ray diffraction measurements (rocking curves) with the findings predicted by the dynamical theory of x-ray diffraction. These measurements show that our GaSb single crystals have a relative variation in the lattice parameter ({Delta}d/d) on the order of 10{sup -5}. This means that they can be used as electronic devices (detectors, for example) and as x-ray monochromators.

Honnicke, M.G.; Mazzaro, I.; Manica, J.; Benine, E.; M da Costa, E.; Dedavid, B. A.; Cusatis, C.; Huang, X. R.

2009-09-13T23:59:59.000Z

73

Thermographic analyses of the growth of Cd1-xZnxTe single crystals  

SciTech Connect

Bulk Cd1-xZnxTe (0single crystals for gamma-ray detectors are grown mainly from near-stoichiometric melts. We discuss the influence of the thermal pre-history of the melts (superheating, thermo-cycling, and cooling rate) on various physical properties based on our thermographic analyses, electrical conductivity and viscosity measurements. Increasing the Zn content causes non-monotonic dependencies in the quality of the crystals structure.

Kopach, O.V.; Bolotnikov, A.; Shcherbak, Larysa P.; Fochuk, Petro M.; and James, Ralph B.

2010-08-01T23:59:59.000Z

74

Sound velocity and attenuation in single-crystal C sub 60  

SciTech Connect

We report the studies of the elasticity of O{sub 60} single crystals. For sublimed fcc crystals, Young's modulus has an 8% jump at the first-order transition at 260 K. At {similar to}160 K there is a frequency-dependent elastic anomaly resulting from time dependent stress relaxation. Comparison with rotation rates seen in NMR suggests that the dynamics below 260 K is more complex than jumps between equivalent molecular configurations. Solvent grown monoclinic crystals have a second-order transition at 242 K, while the 160-K glass transition remains unchanged.

Shi, X.D.; Kortan, A.R.; Williams, J.M.; Kini, A.M.; Savall, B.M.; Chaikin, P.M. (Department of Physics, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States) Department of Physics, Princeton University, Princeton, New Jersey 08544 (United States) Argonne National Laboratory, Argonne, Illinois 60439 (United States) / AT T Bell Laboratory, 600 Mountain Avenue, Murray Hill, New Jersey 07974 (United States))

1992-02-10T23:59:59.000Z

75

Fabrication of Ordered Array of Tips-pentacene Micro- and Nano-scale Single Crystals  

E-Print Network (OSTI)

As an important type of organic semiconductors, organic small molecule crystals have great potential for low-cost applications such as plastic solar cells (PSC), organic light emitting diodes (OLED) and organic field-effect transistors (OFET). Among numerous molecular crystals, 6, 13-Bis(triisopropylsilylethynyl)pentacene (Tips-pentacene) has aroused much attention because it combines good solubility in common solvents and strong ?-? stacking from self-assembly. However, the inability to achieve ordered array of Tips-pentacene prevents the fabrication of high-performance organic integrated circuits. In this work, two new fabrication methods to pattern Tips-pentacene micro- and nano-scale single crystals are proposed. Both methods are facilitated by nanofabrication techniques such as nanoimprint and photolithography. In the first method, the surface of a silicon substrate is treated by surfactant coating and Tips-pentacene single crystals are deposited in squared patterns. In the second method, we made an ordered array of Tips-pentacene single crystals confined in Teflon-AF patterns. In both techniques, the effects of solvent type, processing temperature and template pattern size on crystal morphology and size are systematically studied.

Xia, Ning

2013-05-01T23:59:59.000Z

76

Aero engine test experience with CMSX-4{reg_sign} alloy single-crystal turbine blades  

SciTech Connect

A team approach involving a turbine engine company (Rolls-Royce), its single-crystal casting facilities, and a superalloy developer and ingot manufacturer (Cannon-Muskegon), utilizing the concepts of simultaneous engineering, has been used to develop CMSX-4 alloy successfully for turbine blade applications. CMSX-4 alloy is a second-generation nickel-base single-crystal superalloy containing 3 percent (wt) rhenium (Re) and 70 percent volume fraction of the coherent {gamma}{prime} precipitate strengthening phase. The paper details the single-crystal casting process and heat treatment manufacturing development for turbine blades in CMSX-4 alloy. Competitive single-crystal casting yields are being achieved in production and extensive vacuum heat treatment experience confirms CMSX-4 alloy to have a practical production solution heat treat/homogenization ``window.`` The creep-rupture data-base on CMSX-4 alloy now includes 325 data points from 17 heats including 3,630 kg (8,000 lb) production size heats. An appreciable portion of this data was machined-from-blade (MFB) properties, which indicate turbine blade component capabilities based on single-crystal casting process, component configuration, and heat treatment. The use of hot isostatic pressing (HIP) has been shown to eliminate single-crystal casting micropores, which along with the essential absence of {gamma}/{gamma}{prime} eutectic phase, carbides, stable oxide, nitride and sulfide inclusions, results in remarkably high mechanical fatigue properties, with smooth and particularly notched specimens. The Re addition has been shown not only to benefit creep and mechanical fatigue strength, but also bare oxidation, hot corrosion, and coating performance. The high level of balanced properties determined by extensive laboratory evaluation has been confirmed during engine testing of the Rolls-Royce Pegasus turbofan.

Fullagar, K.P.L.; Broomfield, R.W.; Hulands, M. [Rolls-Royce PLC, Derby (United Kingdom). Aerospace Group; Harris, K.; Erickson, G.L.; Sikkenga, S.L. [Cannon-Muskegon Corp., Muskegon, MI (United States). SPS Technologies

1996-04-01T23:59:59.000Z

77

Bulk single crystal ternary substrates for a thermophotovoltaic energy conversion system  

DOE Patents (OSTI)

A thermophotovoltaic energy conversion device and a method for making the device are disclosed. The device includes a substrate formed from a bulk single crystal material having a bandgap (E{sub g}) of 0.4 eV < E{sub g} < 0.7 eV and an emitter fabricated on the substrate formed from one of a p-type and an n-type material. Another thermophotovoltaic energy conversion device includes a host substrate formed from a bulk single crystal material and lattice-matched ternary or quaternary III-V semiconductor active layers.

Charache, G.W.; Baldasaro, P.F.; Nichols, G.J.

1996-12-31T23:59:59.000Z

78

Bulk single crystal ternary substrates for a thermophotovoltaic energy conversion system  

DOE Patents (OSTI)

A thermophotovoltaic energy conversion device and a method for making the device are disclosed. The device includes a substrate formed from a bulk single crystal material having a bandgap (E{sub g}) of 0.4 eV < E{sub g} < 0.7 eV and an emitter fabricated on the substrate formed from one of a p-type or an n-type material. Another thermophotovoltaic energy conversion device includes a host substrate formed from a bulk single crystal material and lattice-matched ternary or quaternary III-V semiconductor active layers. 12 figs.

Charache, G.W.; Baldasaro, P.F.; Nichols, G.J.

1998-06-23T23:59:59.000Z

79

Bulk single crystal ternary substrates for a thermophotovoltaic energy conversion system  

DOE Patents (OSTI)

A thermophotovoltaic energy conversion device and a method for making the device. The device includes a substrate formed from a bulk single crystal material having a bandgap (E.sub.g) of 0.4 eVsingle crystal material and lattice-matched ternary or quaternary III-V semiconductor active layers.

Charache, Greg W. (Clifton Park, NY); Baldasaro, Paul F. (Clifton Park, NY); Nichols, Greg J. (Burnt Hills, NY)

1998-01-01T23:59:59.000Z

80

Magnetic and electrical properties of UCr{sub 2}Al{sub 20} single crystals  

Science Conference Proceedings (OSTI)

Single crystals of UCr{sub 2}Al{sub 20} have been grown by flux method and characterized by means of X-ray diffraction, magnetic, heat capacity and electrical transport measurements. The compound exhibits weakly temperature-dependent, moderately exchange-enhanced Pauli paramagnetism and shows regular metallic conductivity. - Graphical abstract: Pauli-like temperature dependence of the molar magnetic susceptibility of single-crystalline UCr{sub 2}Al{sub 20}. Inset: field variation of the magnetization in UCr{sub 2}Al{sub 20} taken at 1.8 K. Highlights: Black-Right-Pointing-Pointer High quality single crystals of UCr{sub 2}Al{sub 20} have been grown. Black-Right-Pointing-Pointer Crystal structure of UCr{sub 2}Al{sub 20} has been refined from the single crystal X-ray diffraction data. Black-Right-Pointing-Pointer Magnetic, heat capacity and electrical transport data have been collected for single crystalline UCr{sub 2}Al{sub 20}. Black-Right-Pointing-Pointer Previous literature report on UCr{sub 2}Al{sub 20} has been corrected and supplemented with new data.

Swatek, P., E-mail: P.Swatek@int.pan.wroc.pl [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P. O. Box 1410, 50-950 Wroclaw (Poland); Kaczorowski, D., E-mail: D.Kaczorowski@int.pan.wroc.pl [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P. O. Box 1410, 50-950 Wroclaw (Poland)

2012-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

CO HYDROGENATION OVER CLEAN AND OXIDIZED RHODIUM FOIL AND SINGLE CRYSTAL CATALYSTS. CORRELATIONS OF CATALYST ACTIVITY, SELECTIVITY AND SURFACE COMPOSITION  

E-Print Network (OSTI)

AND OXIDIZED RHODIUM FOIL AND SINGLE CRYSTAL CATALYSTS.CORRELATIONS OF CATALYST ACTIVITY, SELECTIVITY AND SURFACEobserved over the clean Rh catalysts during the catalyzed

Castner, D.G.

2012-01-01T23:59:59.000Z

82

Structures with three dimensional nanofences comprising single crystal segments  

Science Conference Proceedings (OSTI)

An article includes a substrate having a surface and a nanofence supported by the surface. The nanofence includes a multiplicity of primary nanorods and branch nanorods, each of the primary nanorods being attached to said substrate, and each of the branch nanorods being attached to a primary nanorods and/or another branch nanorod. The primary and branch nanorods are arranged in a three-dimensional, interconnected, interpenetrating, grid-like network defining interstices within the nanofence. The article further includes an enveloping layer supported by the nanofence, disposed in the interstices, and forming a coating on the primary and branch nanorods. The enveloping layer has a different composition from that of the nanofence and includes a radial p-n single junction solar cell photovoltaic material and/or a radial p-n multiple junction solar cell photovoltaic material.

Goyal, Amit; Wee, Sung-Hun

2013-08-27T23:59:59.000Z

83

Method of forming single crystals of beta silicon carbide using liquid lithium as a solvent  

SciTech Connect

A method of growing single crystals of beta SiC from solution using molten lithium as a solvent for polycrystalline SiC feed material. Reasonable growth rates are accomplished at temperatures in the range of about 1330.degree. C. to about 1500.degree. C.

Lundberg, Lynn B. (Los Alamos, NM)

1982-01-01T23:59:59.000Z

84

Polarized Neutron Studies on Antiferromagnetic Single Crystals: Technical Report No. 4  

DOE R&D Accomplishments (OSTI)

The theory of neutron scattering by magnetic crystals as given by Halpern and Johnson predicts changes in the polarization state of the neutron beam upon scattering which depend upon the relative orientation of the neutron polarization vector and the crystal magnetic axis. This was investigated experimentally with a polarized beam spectrometer using single crystals of Cr{sub 2}O{sub 3} and alpha - Fe{sub 2}O{sub 3} in which reside unique antiferromagnetic axes. Studies were made on several different reflections in both crystals for a number of different temperatures both below and above the Neel point. Results support the theoretical predictions and indicate directions for the moments in these crystals consistent with previous work. A more detailed study of the polarization changes in the (111) reflection in alpha - Fe{sub 2}O{sub 3} at room temperature on application of a magnetic field was carried out, The results indicate that the principal source of the parasitic ferromagnetism in hematite is essentially independent of the orientation of the antiferromagnetic domains within the crystal.

Nathans, R.; Riste, T.; Shirane, G.; Shull, C.G.

1958-11-26T23:59:59.000Z

85

TOTAL DIFFRACTION AND THERMAL DIFFUSE SCATTERING FROM A MULTI-BOUNCE CHANNEL-CUT SINGLE CRYSTAL  

SciTech Connect

We studied Bragg diffraction and Thermal Diffuse Scattering (TDS) from a Si(111) channel-cut triple-bounce crystal using the time-of-flight technique at a pulsed neutron source. Cadmium shielding restricted the detector s direct view of the first bounce surface. The channel-cut crystal dramatically suppresses TDS in the vicinity of the (111), (333) and (444) Bragg reflections; however, TDS appears and increases with the decrease of wavelength in the range of the (555), (777) and (888) orders where cadmium becomes transparent and the single-bounce reflections and TDS contaminate the triple-bounce (555), (777) and (888) reflections.

Carpenter, John M [ORNL; Agamalian, Michael [ORNL

2010-01-01T23:59:59.000Z

86

ULTRASONIC MEASUREMENT OF POLARIZATION SWITCHING PROCESSES IN BARIUM- TITANATE SINGLE CRYSTAL  

SciTech Connect

A prevlously developed nondestructive piezoelectric method for studying the state of polarization of ferroelectric crystals is applied to study polarization switching in barium titanate single crystals. Three polarization processes are proposed. The first and second processes were designated nucleation and growth by Merz. The third process cannot be measured by conventional pulse methods, and hss a very slow polarizing velocity. Thls indicates the existence of layers which lie between the surface layer and inner layer. Switching time results ars considered in the light of the above experiments. (auth)

Husimi, K.; Kataoka, K.

1958-08-01T23:59:59.000Z

87

Study of photomodulated reflectance in 6H-SiC single crystals  

SciTech Connect

The effect of ultraviolet irradiation of the surface of silicon-carbide (6H-SiC) single crystals on their optical reflectivity in the visible and violet spectral regions is studied. It is shown that the photoreflection-signal intensity is maximal, if the light beam is incident at the Brewster angle and polarized parallel to the plane of incidence. The relative change induced in the refractive index of the surface layers of a crystal (10{sup -3}) upon exposure to nitrogen laser radiation, caused by the generation of nonequilibrium free charge carriers in the conduction band of the material, is established.

Gruzintsev, A. N., E-mail: gran@iptm.ru [Russian Academy of Sciences, Institute of Microelectronics Technology and Ultra-High-Purity Materials (Russian Federation)

2013-04-15T23:59:59.000Z

88

Metal oxide superconducting powder comprised of flake-like single crystal particles  

DOE Patents (OSTI)

Powder of a ceramic superconducting material is synthesized such that each particle of the powder is a single crystal having a flake-like, nonsymmetric morphology such that the c-axis is aligned parallel to the short dimension of the flake. Nonflake powder is synthesized by the normal methods and is pressed into pellets or other shapes and fired for excessive times to produce a coarse grained structure. The fired products are then crushed and ground producing the flake-like powder particles which exhibit superconducting characteristics when aligned with the crystal lattice. 3 figs.

Capone, D.W.; Dusek, J.

1994-10-18T23:59:59.000Z

89

Metal oxide superconducting powder comprised of flake-like single crystal particles  

DOE Patents (OSTI)

Powder of a ceramic superconducting material is synthesized such that each particle of the powder is a single crystal having a flake-like, nonsymmetric morphology such that the c-axis is aligned parallel to the short dimension of the flake. Nonflake powder is synthesized by the normal methods and is pressed into pellets or other shapes and fired for excessive times to produce a coarse grained structure. The fired products are then crushed and ground producing the flake-like powder particles which exhibit superconducting characteristics when aligned with the crystal lattice.

Capone, Donald W. (Bolingbrook, IL); Dusek, Joseph (Downers Grove, IL)

1994-01-01T23:59:59.000Z

90

Recent progress in large grain/single crystal high RRR niobium  

DOE Green Energy (OSTI)

High RRR bulk niobium Superconducting Radio Frequency (SRF) cavity technology is chosen for the International Linear Collider (ILC). The SRF community was convinced until now that fine grain polycrystalline RRR niobium sheets obtained via forging and cross rolling are essential for forming the SRF Cavities. However, it was recently discovered under a joint Reference Metals Company, Inc., - JLAB CRADA that large grain/single crystal RRR niobium sliced directly from ingots is highly ductile reaching 100 percent elongation. This discovery led to the successful fabrication of several SRF single and/or multi cell structures, formed with sliced RRR discs from the ingots, operating at 2.3, 1.5 and 1.3 GHz. This new exciting development is expected to offer high performance accelerator structures not only at reduced costs but also with simpler fabrication and processing conditions. As a result there is a renewed interest in the evaluation and understanding of the large grain and single crystal niobium with respect to their mechanical & physical properties as well as the oxidation behavior and the influence of impurities such as hydrogen and Ta. In this paper the results of many collaborative studies on large grain and single crystal high RRR niobium between JLAB, Universities and Industry are presented.

Ganapati Rao Myneni; Peter Kneisel; Tadeu Carneiro; S.R. Agnew; F. Stevie

2005-11-07T23:59:59.000Z

91

Thermal Degradation of Single Crystal Zinc Oxide and the Growth of Nanostructures  

SciTech Connect

Heat treatment of (0001) single crystal zinc oxide (ZnO) seems to degrade the surface morphology at high temperature. The degradation, however, does not suppress the growth of ZnO nanostructures on selective regions of the single crystal ZnO that have been sputtered with metallic zinc (Zn) and annealed at 800 degree sign C. On the uncoated regions, no growth occurs but the presence of pits suggests material loss from the surface. The formation of ZnO nanostructures on the selective regions could be aided by the preferential loss of oxygen as well as zinc suboxides from the uncoated regions. Indirect evidence of the role of oxygen and zinc suboxides can be inferred from the formation of nickel zinc oxide Ni{sub 0.9}Zn{sub 0.1}O and nickel oxide NiO{sub 2} when Zn is replaced by Ni and annealed under similar conditions.

Saw, K. G.; Tan, G. L. [Physics Section, School of Distance Education, Universiti Sains Malaysia, 11800 Penang (Malaysia); Hassan, Z.; Yam, F. K.; Ng, S. S. [Schools of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia)

2010-07-07T23:59:59.000Z

92

Oxygen and hydrogen evolution reaction on oriented single crystals of ruthenium dioxide  

DOE Green Energy (OSTI)

A novel design for water electrolysis using a solid polymer electrolyte is being developed by General Electric. Ruthenium is one of the best electrocatalysts for the oxygen evolution reaction. There are problems connected with the significant loss in electrocatalytic activity with time. This performance degradation is presumably due to the gradual formation of an RuO/sub 2/ film. We have performed electrochemical measurements on (100), (110) and (111) oriented single crystals of RuO/sub 2/ in order to elucidate the mechanism of the electrocatalytic process. Large single crystals were grown by the vapor transport method. Our investigation has revealed several interesting differences for the various orientations. This study indicates that RuO/sub 3/ may be an important intermediate species prior to oxygen evolution and that the formation of the RuO/sub 3/ is the rate limiting process. Similar results were previously obtained for IrO/sub 2/.

Berger, L I; Pollak, F H; Canivez, Y; O'Grady, W

1979-01-01T23:59:59.000Z

93

Single crystal growth and superconductivity of Ca(Fe1-xCox)2As2  

SciTech Connect

We report the single crystal growth of Ca(Fe1-xCox)2As2 (0 <= x <= 0.082) from Sn flux. The temperature-composition phase diagram is mapped out based on the magnetic susceptibility and electrical transport measurements. Phase diagram of Ca(Fe1-xCox)2As2 is qualitatively different from those of Sr and Ba, it could be due to both the charge doping and structural tuning effects associated with Co substitution.

Hu, Rongwei; Ran, Sheng; Budko, Serguei; Straszheim, Warren E.; Canfield, Paul C.

2012-05-18T23:59:59.000Z

94

A Comparison of Cocrystal Structure Solutions from Powder and Single Crystal Techniques  

DOE Green Energy (OSTI)

We demonstrate the effectiveness and accuracy of high resolution powder diffraction for determination of cocrystal structures through a double-blind study. Structures of 10 cocrystals of varying complexity were determined independently using single crystal and powder techniques. The two methodologies give identical molecular packing and hydrogen bond topology, and an rms difference in covalent bond lengths of 0.035 {angstrom}. Powder techniques are clearly sufficient to establish a complete characterization of cocrystal geometry.

S Lapidus; P Stephens; K Arora; T Shattock; M Zaworotko

2011-12-31T23:59:59.000Z

95

The effect of interelement dipole coupling in patterned ultrathin single crystal Fe square arrays  

SciTech Connect

The correlation between the magnetic properties and the interelement separation in patterned arrays of ultrathin single crystal Fe films of 12 monolayers (ML) grown on GaAs(100) has been studied. The critical condition to form single domain remanent states in the square elements was found to be 10 {mu}m in size and 20 {mu}m for the interelement separation. The coercivity was also found to increase with the increasing interelement separation in the patterned arrays. These results are attributed to the competition between the large in-plane uniaxial anisotropy, the demagnetizing field, and interelement dipole coupling as determined semiqualitatively by the ferromagnetic resonance measurements.

Sun Li; Zhai Ya [Department of Physics, Southeast University, Nanjing 211189 (China); Department of Electronics, Spintronics and Nanodevice Laboratory, University of York, York YO10 5DD (United Kingdom); Wong Pingkwanj; Zhang Wen; Xu Yongbing [Department of Electronics, Spintronics and Nanodevice Laboratory, University of York, York YO10 5DD (United Kingdom); Zou Xiao; Wu Jing [Department of Physics, University of York, York YO10 5DD (United Kingdom); Luo Linqiang; Zhai Hongru [National Laboratory of Solid Microstructures, Nanjing University, Nanjing 210093 (China)

2011-02-01T23:59:59.000Z

96

Effect of annealing on the electrical properties of thallium-doped PbTe single crystals  

Science Conference Proceedings (OSTI)

It is found that electrical parameters of PbTe single crystals, the character of the dependences of these parameters on temperature and Tl impurity concentration, and the conductivity type (signs of {alpha} and R) are governed to a great extent by the temperature of preliminary annealing. The cause of this effect is that the concentration of doubly charged vacancies in the tellurium sublattice increases with an increase in the annealing temperature, as a result of which the formation of electrically neutral or singly charged complexes of impurity-vacancy type becomes more likely.

Ahmedova, G. A., E-mail: gulgunahmed@yahoo.com; Abdinova, G. J.; Abdinov, J. Sh. [National Academy of Sciences of Azerbaijan, Abdullaev Institute of Physics (Azerbaijan)

2011-02-15T23:59:59.000Z

97

High-Cycle Fatigue of Single-Crystal Silicon Thin Films  

E-Print Network (OSTI)

When subjected to alternating stresses, most materials degrade, e.g., suffer premature failure, due to a phenomenon known as fatigue. It is generally accepted that in brittle materials, such as ceramics, fatigue can only take place in toughened solids, i.e., premature fatigue failure would not be expected in materials such as single crystal silicon. The results of this study, however, appear to be at odds with the current understanding of brittle material fatigue. Twelve thin-film ( 20 m thick) single crystal silicon specimens were tested to failure in a controlled air environment (30 0.1 C, 50 2% relative humidity). Damage accumulation and failure of the notched cantilever beams were monitored electrically during the "fatigue life" test. Specimen lives ranged from about 10 s to 48 days, or 1 10 6 to 1 10 11 cycles before failure over stress amplitudes ranging from approximately 4 to 10 GPa. A variety of mechanisms are discussed in light of the fatigue life data and fracture surface evaluation. [642] Index Terms---Fatigue failure, MEMS devices, single-crystal silicon, thin films.

Christopher L. Muhlstein; Stuart B. Brown; Robert O. Ritchie

2001-01-01T23:59:59.000Z

98

Thin Single Crystal Silicon Solar Cells on Ceramic Substrates: November 2009 - November 2010  

DOE Green Energy (OSTI)

In this program we have been developing a technology for fabricating thin (< 50 micrometres) single crystal silicon wafers on foreign substrates. We reverse the conventional approach of depositing or forming silicon on foreign substrates by depositing or forming thick (200 to 400 micrometres) ceramic materials on high quality single crystal silicon films ~ 50 micrometres thick. Our key innovation is the fabrication of thin, refractory, and self-adhering 'handling layers or substrates' on thin epitaxial silicon films in-situ, from powder precursors obtained from low cost raw materials. This 'handling layer' has sufficient strength for device and module processing and fabrication. Successful production of full sized (125 mm X 125 mm) silicon on ceramic wafers with 50 micrometre thick single crystal silicon has been achieved and device process flow developed for solar cell fabrication. Impurity transfer from the ceramic to the silicon during the elevated temperature consolidation process has resulted in very low minority carrier lifetimes and resulting low cell efficiencies. Detailed analysis of minority carrier lifetime, metals analysis and device characterization have been done. A full sized solar cell efficiency of 8% has been demonstrated.

Kumar, A.; Ravi, K. V.

2011-06-01T23:59:59.000Z

99

Millimeter size single crystals of superconducting YBa[sub 2]Cu[sub 3]O[sub x  

DOE Patents (OSTI)

A method of growing large, up to 1 mm size single crystals of superconducting YBa[sub 2]Cu[sub 3]O[sub x], wherein x equals from 6.5 to 7.2 is disclosed.

Damento, M.A.; Gschneidner, K.A. Jr.

1989-04-25T23:59:59.000Z

100

Structural / magnetic phase transitions and superconductivity in Ba(Fe1-xTMx)2As2 single crystals.  

E-Print Network (OSTI)

??BaFe2As2 single crystal undergoes strongly coupled tetragonal to orthorhombic / paramagnetic to antiferromagnetic phase transitions at 134 K and can become superconducting under doping. To… (more)

Ni, Ni

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Thermo-mechanical fatigue of polycrystalline, directionally solidified and single crystal nickel base superalloys repaired by laser beam welding.  

E-Print Network (OSTI)

??The low cycle thermo-mechanical fatigue of laser beam welded conventionally cast Inconel 738, directionally solidified René 80 and single crystal René N5 has been evaluated.… (more)

Durocher, Jonathan

2013-01-01T23:59:59.000Z

102

Millimeter size single crystals of superconducting YBa.sub.2 Cu.sub.3 O.sub .  

DOE Patents (OSTI)

A method of growing large, up to 1 mm size single crystals of superconducting YBa.sub.2 Cu.sub.3 O.sub.x, wherein x equals from 6.5 to 7.2.

Damento, Michael A. (Ames, IA); Gschneidner, Jr., Karl A. (Ames, IA)

1989-04-25T23:59:59.000Z

103

Time-dependent Protein-directed Growth of Gold Nanoparticles within a Single Crystal of Lysozyme  

SciTech Connect

Gold nanoparticles are useful in biomedical applications due to their distinct optical properties and high chemical stability. Reports of the biogenic formation of gold colloids from gold complexes has also led to an increased level of interest in the biomineralization of gold. However, the mechanism responsible for biomolecule-directed gold nanoparticle formation remains unclear due to the lack of structural information about biological systems and the fast kinetics of biomimetic chemical systems in solution. Here we show that intact single crystals of lysozyme can be used to study the time-dependent, protein-directed growth of gold nanoparticles. The protein crystals slow down the growth of the gold nanoparticles, allowing detailed kinetic studies to be carried out, and permit a three-dimensional structural characterization that would be difficult to achieve in solution. Furthermore, we show that additional chemical species can be used to fine-tune the growth rate of the gold nanoparticles.

H Wei; Z Wang; J Zhang; S House; Y Gao; L Yang; H Robinson; L Tan; H Xing; C Hou

2011-12-31T23:59:59.000Z

104

Time-dependent, protein-directed growth of gold nanoparticles within a single crystal of lysozyme  

SciTech Connect

Gold nanoparticles are useful in biomedical applications due to their distinct optical properties and high chemical stability. Reports of the biogenic formation of gold colloids from gold complexes has also led to an increased level of interest in the biomineralization of gold. However, the mechanism responsible for biomolecule-directed gold nanoparticle formation remains unclear due to the lack of structural information about biological systems and the fast kinetics of biomimetic chemical systems in solution. Here we show that intact single crystals of lysozyme can be used to study the time-dependent, protein-directed growth of gold nanoparticles. The protein crystals slow down the growth of the gold nanoparticles, allowing detailed kinetic studies to be carried out, and permit a three-dimensional structural characterization that would be difficult to achieve in solution. Furthermore, we show that additional chemical species can be used to fine-tune the growth rate of the gold nanoparticles.

Wei, H.; Robinson, H.; Wang, Z.; Zhang, J.; House, S.; Gao, Y.-G.; Yang, L.; Tan, L. H.; Xing, H.; Hou, C.; Robertson, I. M.; Zuo, J.-M.; Lu, Y.

2011-01-30T23:59:59.000Z

105

A Computational Approach to Homogenizing Nickel-Based Single Crystal Alloys  

NLE Websites -- All DOE Office Websites (Extended Search)

Computational Approach to Homogenizing Nickel-Based Computational Approach to Homogenizing Nickel-Based Single Crystal Alloys Contact NETL Technology Transfer Group techtransfer@netl.doe.gov May 2013 Significance * Provides significantly diminished processing costs, including reduced energy consumption and throughput times, and increased availability of capital equipment such as furnaces, due to shorter heat treatments * Generates superior Ni-based superalloys with improved performance in downstream applications * Provides extreme flexibility, allowing for modification to meet the differing constraints of individual production facilities and the level of homogenization desired

106

Electrical properties of PbTe single crystals with excess tellurium  

Science Conference Proceedings (OSTI)

The effects of excess (up to 0.1 at %) Te atoms and heat treatment at 473 and 573 K for 120 h on the conductivity {sigma}, thermopower {alpha}, and Hall coefficient R of PbTe single crystals are studied. It is shown that excess Te atoms and annealing strongly affect the values and character of the temperature dependences of these parameters and the signs of {alpha} and R at low temperatures, which is caused by the acceptor effect of these atoms and the formation of antisite defects due to localization of Te in vacancies of the lead sublattice upon annealing.

Bagiyeva, G. Z., E-mail: bagieva-gjulandam@rambler.ru; Mustafayev, N. B.; Abdinova, G. Dj.; Abdinov, D. Sh. [National Academy of Sciences of Azerbaijan, Abdullaev Institute of Physics (Azerbaijan)

2011-11-15T23:59:59.000Z

107

Modelling off Hugoniot Loading Using Ramp Compression in Single Crystal Copper  

SciTech Connect

The application of a ramp load to a sample is a method by which the thermodynamic variables of the high pressure state can be controlled. The faster the loading rate, the higher the entropy and higher the temperature. This paper describes moleculer dynamics (MD) simulations with 25 million atoms which investigate ramp loading of single crystal copper. The simulations followed the propagation of a 300ps ramp load to 3Mbar along the [100] direction copper. The simulations were long enough to allow the wave front to steepen into a shock, at which point the simulated copper sample shock melted.

Hawreliak, J; Remington, B A; Lorenzana, H; Bringa, E; Wark, J

2010-11-29T23:59:59.000Z

108

Thin Single Crystal Silicon Solar Cells on Ceramic Substrates: November 2009 - November 2010  

Science Conference Proceedings (OSTI)

In this program we have been developing a technology for fabricating thin (cost raw materials. This 'handling layer' has sufficient strength for device and module processing and fabrication. Successful production of full sized (125 mm X 125 mm) silicon on ceramic wafers with 50 micrometre thick single crystal silicon has been achieved and device process flow developed for solar cell fabrication. Impurity transfer from the ceramic to the silicon during the elevated temperature consolidation process has resulted in very low minority carrier lifetimes and resulting low cell efficiencies. Detailed analysis of minority carrier lifetime, metals analysis and device characterization have been done. A full sized solar cell efficiency of 8% has been demonstrated.

Kumar, A.; Ravi, K. V.

2011-06-01T23:59:59.000Z

109

Monolithic single GaN nanowire laser with photonic crystal microcavity on silicon  

SciTech Connect

Optically pumped lasing at room temperature in a silicon based monolithic single GaN nanowire with a two-dimensional photonic crystal microcavity is demonstrated. Catalyst-free nanowires with low density ({approx}10{sup 8} cm{sup -2}) are grown on Si by plasma-assisted molecular beam epitaxy. High resolution transmission electron microscopy images reveal that the nanowires are of wurtzite structure and they have no observable defects. A single nanowire laser fabricated on Si is characterized by a lasing transition at {lambda}=371.3 nm with a linewidth of 0.55 nm. The threshold is observed at a pump power density of {approx}120 kW/cm{sup 2} and the spontaneous emission factor {beta} is estimated to be 0.08.

Heo, Junseok; Guo Wei; Bhattacharya, Pallab [Center for Nanoscale Photonics and Spintronics, University of Michigan, Ann Arbor, Michigan 48109-2122 (United States)

2011-01-10T23:59:59.000Z

110

High Efficiency Single Crystal CdTe Solar Cells: November 19, 2009 - January 31, 2011  

DOE Green Energy (OSTI)

The goal of the program was to develop single crystal CdTe-based top cells grown on Si solar cells as a platform for the subsequent manufacture of high efficiency tandem cells for CPV applications. The keys to both the single junction and the tandem junction cell architectures are the ability to grow high quality single-crystal CdTe and CdZnTe layers on p-type Si substrates, to dope the CdTe and CdZnTe controllably, both n and p-type, and to make low resistance ohmic front and back contacts. EPIR demonstrated the consistent MBE growth of CdTe/Si and CdZnTe/Si having high crystalline quality despite very large lattice mismatches; epitaxial CdTe/Si and CdZnTe/Si consistently showed state-of-the-art electron mobilities and good hole mobilities; bulk minority carrier recombination lifetimes of unintentionally p-doped CdTe and CdZnTe grown by MBE on Si were demonstrated to be consistently of order 100 ns or longer; desired n- and p-doping levels were achieved; solar cell series specific resistances <10 ?-cm2 were achieved; A single-junction solar cell having a state-of-the-art value of Voc and a unverified 16.4% efficiency was fabricated from CdZnTe having a 1.80 eV bandgap, ideal for the top junction in a tandem cell with a Si bottom junction.

Carmody, M.; Gilmore, A.

2011-05-01T23:59:59.000Z

111

Nd:YAG single-crystal fiber laser: Room-temperature cw operation using a single LED as an end pump  

SciTech Connect

cw laser action has been obtained using as-grown single-crystal Nd:YAG fibers end-pumped by a single high-radiance LED. The fibers were 0.5 cm long and 80 ..mu..m in dia; the diameter of the LED luminous area was 85 ..mu..m. The lowest cw laser threshold was observed at a diode drive current of 45 mA. (AIP)

Stone, J.; Burrus, C.A.; Dentai, A.G.; Miller, B.I.

1976-07-01T23:59:59.000Z

112

Fundamental Studies of Tl-Ba-Ca-Cu-O Single Crystals and New High-Temperature Superconducting Compounds  

Science Conference Proceedings (OSTI)

Experimental studies in creating new compounds may lead to a better understanding of high-temperature superconductors. Flux creep activation energies (minimum energies that cause magnetic flux motion) were designed in one new compound, single crystals of laboratory-grown Tl2Ba2CaCu2Ox, using an ac-susceptibility technique. Investigations also measured crystal resistivity and used a new processing technique to form high-quality Tl-based thin films.

1992-07-01T23:59:59.000Z

113

Time-Resolved Femtosecond Laser Desorption from Wide-BandGap Single Crystals  

Science Conference Proceedings (OSTI)

We have used femtosecond laser pulse pairs to measure the positive ion yield, from wide band-gap single crystals, as a function of time-delay between pulses. Two-pulse correlation allows direct observation of solid state and surface dynamics on an ultrafast timescale. The ion yield, from 265 nm irradiated MgO and KBr, depends critically on the time delay between two sub-threshold pulses. For example, the Mg+ desorption yield displays three distinct features; a coherence peak, followed by rise, and decay features. In contract, the yield of K+ from KBr displays only the coherence peak and picosecond decay features. The data suggest, that although the nanosecond ion desorption mechanism is dominated by defect photoabsorption, significant electron-hole pair production may contribute to the desorption mechanism following femtosecond excitation. Nanosecond photoexcitation of KBr near 6.4 eV leads to desorption of hyperthermal neutral bromine atoms without a significant thermal velocity component. Two-photon femtosecond excitation at 3.2 eV produces very similar results. Multiphoton femtosecond excitation provides an efficient excitation mechanism of the wide-gap material. These results are likely general for ionic crystals and are consistent with a recently described theoretical model.

Hess, Wayne P. (BATTELLE (PACIFIC NW LAB)); Joly, Alan G. (BATTELLE (PACIFIC NW LAB)); Beck, Kenneth M. (University of Central Florida ); Dickinson, J T. (8392); Claude R. Phipps

2002-09-01T23:59:59.000Z

114

TEM and SIMS Analysis of (100), (110), and (111) Single Crystal Niobium  

DOE Green Energy (OSTI)

Single crystal niobium specimens of (100), (110) and (111) crystal orientations have been analyzed using TEM and SIMS. The TEM specimens were prepared using Focused Ion Beam (FIB) and show niobium oxide thicknesses ranging from 4.9 to 8.3 nm for the three specimens after buffer chemical polishing. The oxide layers appear uniform and no significant sub-oxide region was noted. SIMS analysis was made for all three orientations on hydrogen, carbon, and oxygen before and after heat treatments at 90, 600, and 1250ºC. Hydrogen is at a high level between the oxide layer and niobium, but at a relatively low level in the oxide. No high oxygen concentration region was noted in the niobium below the oxide. C contamination on the surface is detected mainly at the surface. Analysis after heat treatments showed some decrease in hydrogen after the 600ºC heat treatment, and significant oxidation of the niobium after the 1250ºC heat treatment.

A. D. Batchelor; D. N. Leonard; P. E. Russell; F. A. Stevie; D. P. Griffis; G. R. Myneni

2006-10-30T23:59:59.000Z

115

Development of Single Crystal Chemical Vapor Deposition Diamonds for Detector Applications  

Science Conference Proceedings (OSTI)

Diamond was studied as a possible radiation hard technology for use in future high radiation environments. With the commissioning of the LHC expected in 2010, and the LHC upgrades expected in 2015, all LHC experiments are planning for detector upgrades which require radiation hard technologies. Chemical Vapor Deposition (CVD) diamond has now been used extensively in beam conditions monitors as the innermost detectors in the highest radiation areas of BaBar, Belle and CDF and is installed and operational in all LHC experiments. As a result, this material is now being discussed as an alternative sensor material for tracking very close to the interaction region of the super-LHC where the most extreme radiation conditions will exist. Our work addressed the further development of the new material, single-crystal Chemical Vapor Deposition diamond, towards reliable industrial production of large pieces and new geometries needed for detector applications.

Rainer Wallny

2012-10-15T23:59:59.000Z

116

Aniline hydrogenolysis on the Pt(111) single crystal surface: Mechanisms for C-N bond activation  

SciTech Connect

Hydrogenolysis of C-N bond on transition metals is a crucial step in hydrodenitrogenation (HDN) reactions. Despite the overall complexity of HDN processes, the details of important surface reactions can be characterized using model reactions of organonitrogen compounds on single crystal model catalysts. The structure and reactivity of well characterized aniline monolayers on the Pt(111) surface both in vacuum and in the presence of hydrogen is discussed here. Adsorption and reactions of aniline were studied by Gland and Somorjai on the Pt(111) and Pt(100) surfaces, and more recently by Benziger`s group on the Ni(111) and Ni(100) surfaces. On both Pt and Ni surfaces, aniline {pi} bonds through the aromatic ring with its ring parallel to the substrate surface.

Huang, S.X.; Gland, J.L. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Chemistry; Fischer, D.A. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Chemistry]|[National Inst. of Standards and Technology, Gaithersburg, MD (United States). Materials Dept.

1993-12-31T23:59:59.000Z

117

Laser interactions with embedded Ca metal nanoparticles in single crystal CaF{sub 2}  

SciTech Connect

Single crystal calcium fluoride (CaF{sub 2}) is an important material for vacuum-ultraviolet optics. Nevertheless, prolonged exposure to energetic radiation can color the material by producing calcium metal nanoparticles. We compare the effectiveness of laser conditioning treatments at wavelengths ranging from the near infrared to the deep ultraviolet in removing this coloration. Treatments at 157, 532, and 1064 nm can significantly reduce the visible coloration due to nanoparticles. In contrast, irradiation at 248 nm has little effect at fluences below the damage threshold for the material employed in this work. We present evidence that the effect of laser irradiation on coloration is principally thermal and is largely confined to the first 50 ns after each laser pulse. We attribute the wavelength dependence of the bleaching process to the wavelength dependence associated with Mie absorption by metal nanoparticles. The consequences of these observations with regard to laser conditioning processes in bulk optical materials are discussed.

Cramer, L.P.; Schubert, B.E.; Petite, P.S.; Langford, S.C.; Dickinson, J.T. [Materials Science Program and Physics Department, Washington State University, Pullman, Washington 99164-2814 (United States)

2005-04-01T23:59:59.000Z

118

Mo-6%Nb single crystal alloy creep strength demonstration for long life thermionic power systems  

DOE Green Energy (OSTI)

Experimental results of one- and two-dimensional creep testing for single crystal Mo-6%Nb alloy are presented. Three 1-D specimens were creep-tested for up to 3000 hours at 1873 to 1973 K and 5 to 15 MPa. One 2-D specimen tube was creep-tested for 2000 hours at 1873 K/15MPa. Results confirm the high creep strength of Mo-6%Nb for long life (10 to 15 year) TFE emitter application in thermionic space nuclear power systems. After the initial transition stage (about 1000 hours), quasi-steady state 1-D and 2-D creep rates were within 20% of each other suggesting little significant effect of anisotropy. More data points will be needed to define the Sherby-Dom parameters with statistical accuracy. {copyright} 1995 {ital American} {ital Institute} {ital of} {ital Physics}

Rhee, H.S.; Zheng, C.; Kent Koester, J. [Space Power, Inc., 621 River Oaks Parkway, San Jose, California 95134 (United States); Yastrebkov, A.; Nikolaev, Y.; Gontar, A. [Scientific Industrial Association Lutch, Podolsk, Moscow Region (Russian Federation)

1995-01-20T23:59:59.000Z

119

Nanoporous films for epitaxial growth of single crystal semiconductor materials : final LDRD report.  

Science Conference Proceedings (OSTI)

This senior council Tier 1 LDRD was focused on exploring the use of porous growth masks as a method for defect reduction during heteroepitaxial crystal growth. Initially our goal was to investigate porous silica as a growth mask, however, we expanded the scope of the research to include several other porous growth masks on various size scales, including mesoporous carbon, photolithographically patterned SU-8 and carbonized SU-8 structures. Use of photolithographically defined growth templates represents a new direction, unique in the extensive literature of patterned epitaxial growth, and presents the possibility of providing a single step growth mask. Additional research included investigation of pore viability via electrochemical deposition into high aspect ratio photoresist. This project was a small footprint research effort which, nonetheless, produced significant progress towards both the stated goal as well as unanticipated research directions.

Rowen, Adam M.; Koleske, Daniel David; Fan, Hongyou; Brinker, C. Jeffrey; Burckel, David Bruce; Williams, John Dalton; Arrington, Christian L.; Steen, William Arthur

2007-10-01T23:59:59.000Z

120

Type-I superconductivity in YbSb2 single crystals  

SciTech Connect

We present evidence of type-I superconductivity in YbSb2 single crystals from dc and ac magnetization, heat capacity, and resistivity measurements. The critical temperature and critical field are determined to be Tc? 1.3 K and Hc? 55 Oe. A small Ginzburg-Landau parameter ?= 0.05, together with typical magnetization isotherms of type-I superconductors, small critical field values, a strong differential paramagnetic effect signal, and a field-induced change from second- to first-order phase transition, confirms the type-I nature of the superconductivity in YbSb2. A possible second superconducting state is observed in the radio-frequency susceptibility measurements, with Tc(2)? 0.41 K and Hc(2)? 430 Oe.

Zhao, Liang L.; Lausberg, Stefan; Kim, Hyunsoo; Tanatar, Makariy A.; Brando, Manuel; Prozorov, Ruslan; Morosan, E.

2012-06-25T23:59:59.000Z

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
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121

Crack resistance and atomic structure of Li{sub 2}B{sub 4}O{sub 7} single crystals  

SciTech Connect

The nature of destruction of single crystals of lithium tetraborate Li{sub 2}B{sub 4}O{sub 7} under the action of a concentrated load is investigated. It is established that planes of easy crack propagation in Li{sub 2}B{sub 4}O{sub 7} single crystals are the (100), (010), (001), and {l_brace}111{r_brace} planes. It is found that crack propagation occurs in each case along the atomic layers that are linked by bridge oxygen atoms between main structural units (B{sub 4}O{sub 9}) and, therefore, are most weakly bound.

Dolzhenkova, E. F., E-mail: dol@isc.kharkov.ua; Baumer, V. N.; Tolmachev, A. V. [National Academy of Sciences of Ukraine, Institute for Single Crystals (Ukraine)

2006-03-15T23:59:59.000Z

122

Influence of ITO-silver wire electrode structure on the performance of single-crystal silicon solar cells  

Science Conference Proceedings (OSTI)

This study aimed to explore the effect of various electrode forms on single-crystal silicon solar cells by changing their front and back electrode structures. The high light penetration depth of the Indium Tin Oxide (ITO) and the high conductivity of ...

Wern-Dare Jheng

2012-01-01T23:59:59.000Z

123

Faraday Discuss. Chem. SOC.,1989, 87, 337-344 Butane Hydrogenolysis over Single-crystal Rhodium Catalysts  

E-Print Network (OSTI)

Faraday Discuss. Chem. SOC.,1989, 87, 337-344 Butane Hydrogenolysis over Single-crystal Rhodium&M University, College Station, Texas 77843, U.S.A. Hydrogenolysis of n-butane has been studied over the (110 of surface composition and geometry.' For example, in our laboratories, the activity for ethane' and butane

Goodman, Wayne

124

Effects of hydrogen anneals on oxygen deficient SrTio3-x single crystals  

E-Print Network (OSTI)

3?x with a low electrical resistivity. These crystals showedout in the same atmo- sphere. Electrical resistivities were

Jalan, Bharat; Engel-Herbert, Roman; Mates, Thomas E.; Stemmer, Susanne

2008-01-01T23:59:59.000Z

125

Application of ITO/Al reflectors for increasing the efficiency of single-crystal silicon solar cells  

Science Conference Proceedings (OSTI)

It is shown that an increase in the efficiency and manufacturability of single-junction single-crystal silicon photoelectric converters of solar energy requires the use of a back-surface reflector based on conductive transparent indium-tin oxide (ITO) 0.25-2 {mu}m thick. To increase the efficiency and reduce the sensitivity to the angle of light incidence on the photoreceiving surface of multijunction photoelectric converters with vertical diode cells based on single-crystal silicon, ITO/Al reflectors with an ITO layer >1 {mu}m thick along vertical boundaries of diode cells should be fabricated. The experimental study of multijunction photoelectric converters with ITO/Al reflectors at diode cell boundaries shows the necessity of modernizing the used technology of ITO layers to achieve their theoretically calculated thickness.

Kopach, V. R.; Kirichenko, M. V., E-mail: kirichenko_mv@mail.ru; Khrypunov, G. S.; Zaitsev, R. V. [National Technical University, 'Kharkiv Poly technical Institute' (Ukraine)

2010-06-15T23:59:59.000Z

126

Zinc ion and neutral emission from single crystal zinc oxide during 193-nm excimer laser exposure  

SciTech Connect

Mass resolved time-of-flight measurements on neutral zinc atoms and zinc ions show energetic ions and neutrals during 193-nm irradiation of single crystals of semiconducting zinc oxide. Typical Zn+ kinetic energies are 3-5 eV. At fluences (energy per unit area per pulse) below 200 mJ/cm2, the ion intensities (per laser pulse) decrease monotonically to low values with laser pulse number. The depletion kinetics change from exponential to second order near 50 mJ/cm2. We attribute this change to the annihilation of defects yielding Zn+ emission when Zn+ or other surface defects become mobile. At fluences between 200 and 300 mJ/cm2, Zn+ emission becomes more sustained due to defects created by the laser. In this same fluence range, we observe the onset of detectable neutral atomic zinc emission. These neutral atoms display Maxwell-Boltzmann kinetic energy distributions w th effective surface temperatures that approach 5000 K as the fluence is raised to 350 mJ/cm2. These high surface temperatures are remarkable given the low etch rates observed at these fluences, suggesting that heated layer is extremely thin. We propose emission mechanisms and experiments to resolve outstanding questions.

Kahn, E. H. [Washington State University; Langford, S. C. [Washington State University; Boatner, Lynn A [ORNL; Dickinson, J. T. [Washington State University

2011-01-01T23:59:59.000Z

127

Conductivity anisotropy in the doped Bi{sub 2}Te{sub 3} single crystals  

Science Conference Proceedings (OSTI)

Temperature dependences (temperature range T = 0.5-300 K) of resistivity in the plane of layers and in the direction perpendicular to the layers, and the galvanomagnetic effects in undoped and doped Bi{sub 2}Te{sub 3} single crystals are studied (magnetic field H < 80 kOe, T = 0.5-4.2 K). It is shown that upon doping of Bi{sub 2}Te{sub 3} with the Group III atoms (In and B), conductivity anisotropy increases mainly due to an increase in resistivity in the direction perpendicular to the layers. This fact makes it possible to assume that the atoms of these impurities are incorporated mainly into the van der Waal gaps between the layers upon doping. It is also revealed that, upon doping of Bi{sub 2}Te{sub 3} with In and B, the temperature dependence of conductivity becomes weaker, which indicates an increase in the role of scattering by defects in scattering mechanisms. The concentrations and mobilities of charge carriers, values of the Hall factor conditioned by the anisotropy of effective masses and orientation of ellipsoids with respect to crystallographic axes, areas of the extreme section of the Fermi surface by the plane perpendicular to the direction of the magnetic field, and the Fermi energy are evaluated.

Abdullaev, N. A., E-mail: anadir@azintex.com; Kakhramanov, S. Sh.; Kerimova, T. G.; Mustafayeva, K. M. [Azerbaijan National Academy of Sciences, Institute of Physics (Azerbaijan); Nemov, S. A. [St. Petersburg State Polytechnical University (Russian Federation)

2009-02-15T23:59:59.000Z

128

Luminescence from self-trapped holes in manganese-doped calcium fluoride single crystals  

SciTech Connect

Thermally stimulated luminescence (TSL) and electron spin resonance (ESR) measurements on x-irradiated CaF/sub 2/:Mn (0.1 wt %) single crystals have been conducted in the interval 70 to 300 K. Prominent TSL peaks occur near 150 K (345- and 495-nm emission) and 200 K (predominantly 495-nm emission) with thermal decay of ESR centers at these same temperatures. Taken collectively the data suggest that 150 K TSL emission is due to mobile holes from V/sub K/ centers recombining with both trapped electrons and Mn/sup +/ ions, i.e., V/sub K/ + e/sup -/ ..-->.. 345-nm emission, and V/sub K/ + Mn/sup +/ ..-->.. (Mn/sup 2 +/)* + hv (495-nm emission). Additionally, H centers are formed by transformation of V/sub K/ centers. At 200 K, holes from H centers recombine with Mn/sup +/ to produce excited-state (Mn/sup 2 +/)* which decays by emitting 495-nm radiation.

Jahan, M.S.; Cooke, D.W.; Alexander, C. Jr.

1987-01-01T23:59:59.000Z

129

Welding and weldability of directionally solidified single crystal nickel-base super-alloys  

DOE Green Energy (OSTI)

The objective of this CRADA project was to investigate the weldability of polycrystalline, directionally-solidified, and single-crystal, nickel-base super-alloys. These materials are used extensively in turbine engine components. The ability to weld these materials is highly desirable in that it would greatly facilitate component fabrication. Welding of these materials would also have the potential benefit of allowing for the repair of cracked or worn components. Specifically, the program had four objectives: (1) to evaluate the weldability of nickel-base super-alloys; (2) to characterize the solidification microstructure of the welds; (3) to evaluate the phase stability of the weldments during exposure to service conditions; and (4) to determine the mechanical properties of the welds. Westinghouse Electric Corporation was to supply material for the program, in both as-case and heat-treated form. This was to include commercially available as well as experimental alloys developed at Westinghouse. ORNL was to perform weldability tests on the materials using a variety of welding procedures.

vitek, j.m.

1996-09-01T23:59:59.000Z

130

Influence of composition on microstructural parameters of single crystal nickel-base superalloys  

Science Conference Proceedings (OSTI)

Fourteen nickel-base superalloy single crystals containing a range of chromium (Cr), cobalt (Co), molybdenum (Mo), and rhenium (Re) levels, and fixed amounts of aluminum (Al) and tantalum (Ta), were examined to determine the effect of bulk composition on basic microstructural parameters, including {gamma} Prime solvus, {gamma} Prime volume fraction, topologically close-packed (TCP) phases, {gamma} and {gamma} Prime phase chemistries, and {gamma}-{gamma} Prime lattice mismatch. Regression models describing the influence of bulk alloy composition on each of the microstructural parameters were developed and compared to predictions by a commercially-available software tool that used computational thermodynamics. Co produced the largest change in {gamma} Prime solvus over the wide compositional range explored and Mo produced the biggest effect on the {gamma} lattice parameter over its range, although Re had a very potent influence on all microstructural parameters investigated. Changing the Cr, Co, Mo, and Re contents in the bulk alloy had an impact on their concentrations in the {gamma} matrix and to a smaller extent in the {gamma} Prime phase. The software tool under-predicted {gamma} Prime solvus temperatures and {gamma} Prime volume fractions, and over-predicted TCP phase volume fractions at 982 Degree-Sign C. However, the statistical regression models provided excellent estimations of the microstructural parameters and demonstrated the usefulness of such formulas. - Highlights: Black-Right-Pointing-Pointer Effects of Cr, Co, Mo, and Re on microstructure in new low density superalloys Black-Right-Pointing-Pointer Co produced a large change in {gamma} Prime solvus; Mo had a large effect on lattice mismatch. Black-Right-Pointing-Pointer Re exhibited very potent influence on all microstructural parameters was investigated. Black-Right-Pointing-Pointer {gamma} and {gamma} Prime phase chemistries both varied with temperature and alloy composition. Black-Right-Pointing-Pointer Computational thermodynamic modeling tool did not accurately predict microstructure.

MacKay, R.A., E-mail: Rebecca.A.MacKay@nasa.gov [NASA Glenn Research Center, 21000 Brookpark Rd., Cleveland, Ohio 44135 (United States); Gabb, T.P. [NASA Glenn Research Center, 21000 Brookpark Rd., Cleveland, Ohio 44135 (United States); Garg, A. [NASA Glenn Research Center, 21000 Brookpark Rd., Cleveland, Ohio 44135 (United States); University of Toledo, 2801 W. Bancroft, Toledo, Ohio 43606 (United States); Rogers, R.B.; Nathal, M.V. [NASA Glenn Research Center, 21000 Brookpark Rd., Cleveland, Ohio 44135 (United States)

2012-08-15T23:59:59.000Z

131

Growth of Bi doped cadmium zinc telluride single crystals by Bridgman oscillation method and its structural, optical, and electrical analyses  

Science Conference Proceedings (OSTI)

The II-VI compound semiconductor cadmium zinc telluride (CZT) is very useful for room temperature radiation detection applications. In the present research, we have successfully grown Bi doped CZT single crystals with two different zinc concentrations (8 and 14 at. %) by the Bridgman oscillation method, in which one experiment has been carried out with a platinum (Pt) tube as the ampoule support. Pt also acts as a cold finger and reduces the growth velocity and enhances crystalline perfection. The grown single crystals have been studied with different analysis methods. The stoichiometry was confirmed by energy dispersive by x-ray and inductively coupled plasma mass spectroscopy analyses and it was found there is no incorporation of impurities in the grown crystal. The presence of Cd and Te vacancies was determined by cathodoluminescence studies. Electrical properties were assessed by I-V analysis and indicated higher resistive value (8.53x10{sup 8} {Omega} cm) for the crystal grown with higher zinc concentration (with Cd excess) compare to the other (3.71x10{sup 5} {Omega} cm).

Carcelen, V.; Rodriguez-Fernandez, J.; Dieguez, E. [Dpto. Fisica de Materiales, Laboratorio de Crecimiento de Cristales, Facultad de Ciencias, Univ. Autonoma de Madrid, 28049 Cantoblanco (Spain); Hidalgo, P. [Dpto. Fisica de Materiales, Facultad de Ciencias Fisicas, Univ. Complutense de Madrid, 28040 Madrid (Spain)

2010-05-15T23:59:59.000Z

132

Large single crystal quaternary alloys of IB-IIIA-Se/sub 2/ and methods of synthesizing the same  

DOE Patents (OSTI)

New alloys of Cu/sub x/Ag/sub (1-x)/InSe/sub 2/ (where x ranges between 0 and 1 and preferably has a value of about 0.75) and CuIn/sub y/Ga/sub (1-y)/Se/sub 2/ (where y ranges between 0 and 1 and preferably has a value of about 0.90) in the form of single crystals with enhanced structure perfection, which crystals are substantially free of fissures, are disclosed. Processes are disclosed for preparing the new alloys of Cu/sub x/Ag/sub (1-x)/InSe/sub 2/. The process includes placing stoichiometric quantities of a Cu, Ag, In, and Se reaction mixture or stoichiometric quantities of a Cu, In, Ga, and Se reaction mixture in a refractory crucible in such a manner that the reaction mixture is surrounded by B/sub 2/O/sub 3/, placing the thus loaded crucible in a chamber under a high pressure atmosphere of inert gas to confine the volatile Se to the crucible, and heating the reaction mixture to its melting point. The melt can then be cooled slowly to form, by direct solidification, a single crystal with enhanced structure perfection, which crystal is substantially free of fissures.

Ciszek, T.F.

1986-07-15T23:59:59.000Z

133

Large single crystal quaternary alloys of IB-IIIA-SE.sub.2 and methods of synthesizing the same  

DOE Patents (OSTI)

New alloys of Cu.sub.x Ag.sub.(1-x) InSe.sub.2 (where x ranges between 0 and 1 and preferably has a value of about 0.75) and CuIn.sub.y Ga.sub.(1-y) Se.sub.2 (where y ranges between 0 and 1 and preferably has a value of about 0.90) in the form of single crystals with enhanced structure perfection, which crystals are substantially free of fissures are disclosed. Processes are disclosed for preparing the new alloys of Cu.sub.x Ag.sub.(1-x) InSe.sub.2. The process includes placing stoichiometric quantities of a Cu, Ag, In, and Se reaction mixture or stoichiometric quantities of a Cu, In, Ga, and Se reaction mixture in a refractory crucible in such a manner that the reaction mixture is surrounded by B.sub.2 O.sub.3, placing the thus loaded crucible in a chamber under a high pressure atmosphere of inert gas to confine the volatile Se to the crucible, and heating the reaction mixture to its melting point. The melt can then be cooled slowly to form, by direct solidification, a single crystal with enhanced structure perfection, which crystal is substantially free of fissures.

Ciszek, Theodore F. (Evergreen, CO)

1988-01-01T23:59:59.000Z

134

Growth of single-crystal {alpha}-MnO{sub 2} nanorods on multi-walled carbon nanotubes  

Science Conference Proceedings (OSTI)

Single-crystal {alpha}-MnO{sub 2} nanorods were grown on multi-walled carbon nanotubes (MWNTs) in H{sub 2}SO{sub 4} aqueous solution. The morphology and microstructure of the composites were examined by transmission electron microscopy, high-resolution transmission electron microscopy (HRTEM), X-ray diffractometry and energy dispersive spectroscopy (EDS). The results show that {alpha}-MnO{sub 2} single-crystal nanorods with a mean diameter of 15 nm were densely grown on the surface of MWNTs. Those MWNTs/MnO{sub 2} composites were used as an electrode material for supercapacitors, and it was found that the supercapacitor performance using MWNTs/MnO{sub 2} composites was improved largely compared to that using pure MWNTs and {alpha}-MnO{sub 2} nanorod mechanically mixed with MWNTs.

Chen Yong [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Key Laboratory of Tropic Biological Resources, MOE, Hainan University, 58 Renmin Road, Haikou 570228 (China); Liu Chenguang; Liu Chang [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Lu Gaoqing [ARC Centre for Functional Nanomaterials, Australian Institute of Bioengineering and Nanotechnology, University of Queensland, QLD 4072 (Australia); Cheng Huiming [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China)], E-mail: cheng@imr.ac.cn

2007-11-06T23:59:59.000Z

135

Efficient light coupling from integrated single-mode waveguides to supercollimating photonic crystals on silicon-on-insulator platforms  

E-Print Network (OSTI)

We propose rib waveguides as an efficient and practical solution to the coupling of light from integrated single-mode waveguides to supercollimating planar photonic crystals. By three-dimensional simulations, we demonstrate transmission efficiencies higher than 90 % at wavelengths close to 1.55 microns in a device that can be fabricated on conventional silicon-on-insulator platforms. This approach constitutes a significant step toward the integration of supercollimating structures on photonic chips.

Vynck, K; d'Yerville, M Le Vassor; Cassagne, D

2007-01-01T23:59:59.000Z

136

Generation of polarization entangled photon pairs by a single crystal interferometric source pumped by femtosecond laser pulses  

E-Print Network (OSTI)

Photon pairs, highly entangled in polarization have been generated under femtosecond laser pulse excitation by a type I crystal source, operating in a single arm interferometric scheme. The relevant effects of temporal walk-off existing in these conditions between the ordinary and extraordinary photons were experimentally investigated. By introducing a suitable temporal compensation between the two orthogonal polarization components highly entangled pulsed states were obtained.

M. Barbieri; C. Cinelli; F. De Martini; P. Mataloni

2006-06-01T23:59:59.000Z

137

A Nano-Quantum Photonic Model for Justification of Dispersion in Single Crystal Film of NPP  

E-Print Network (OSTI)

In this paper, we present a nano-quantum photonic model for justification of normal dispersion in a thin crystal film of NPP. In this method, we assume a laser beam consists of a flow of energetic particles. By precise analyzing of photon interaction with pi-electron system of benzene ring in NPP crystal, we will attain refractive index (RI) in any wavelength and compare the results with experimental data.

Hassan Kaatuzian; AliAkbar Wahedy Zarch

2006-11-24T23:59:59.000Z

138

Model catalytic studies of single crystal, polycrystalline metal, and supported catalysts  

E-Print Network (OSTI)

This dissertation is focused on understanding the structure-activity relationship in heterogeneous catalysis by studying model catalytic systems. The catalytic oxidation of CO was chosen as a model reaction for studies on a variety of catalysts. A series of Au/TiO2 catalysts were prepared from various metalorganic gold complexes. The catalytic activity and the particle size of the gold catalysts were strongly dependent on the gold complexes. The Au/TiO2 catalyst prepared from a tetranuclear gold complex showed the best performance for CO oxidation, and the average gold particle size of this catalyst was 3.1 nm. CO oxidation was also studied over Au/MgO catalysts, where the MgO supports were annealed to various temperatures between 900 and 1300 K prior to deposition of Au. A correlation was found between the activity of Au clusters for the catalytic oxidation of CO and the F-center concentration in the MgO support. In addition, the catalytic oxidation of CO was studied in a batch reactor over supported Pd/Al2O3 catalysts, a Pd(100) single crystal, as well as polycrystalline metals of rhodium, palladium, and platinum. A hyperactive state, corresponding to an oxygen covered surface, was observed at high O2/CO ratios at elevated pressures. The reaction rate at this state was significantly higher than that on CO-covered surfaces at stoichiometric conditions. The oxygen chemical potential required to achieve the hyperactive state depends on the intrinsic properties of the metal, the particle size, and the reaction temperature. A well-ordered ultra-thin titanium oxide film was synthesized on the Mo(112) surface as a model catalyst support. Two methods were used to prepare this Mo(112)- (8x2)-TiOx film, including direct growth on Mo(112) and indirect growth by deposition of Ti onto monolayer SiO2/Mo(112). The latter method was more reproducible with respect to film quality as determined by low-energy electron diffraction and scanning tunneling microscopy. The thickness of this TiOx film was one monolayer and the oxidation state of Ti was +3 as determined by Auger spectroscopy, high-resolution electron energy loss spectroscopy, and X-ray photoelectron spectroscopy.

Yan, Zhen

2007-12-01T23:59:59.000Z

139

Regular pattern formation through the retraction and pinch-off of edges during solid-state dewetting of patterned single crystal films  

E-Print Network (OSTI)

We report the formation of regular patterns of metal lines via solid-state dewetting of lithographically patterned single-crystal Ni(110) films with square and cross shapes. During the solid-state dewetting, valleys develop ...

Ye, Jongpil

140

Monte Carlo Modeling of Diffuse Scattering from Single Crystals: The Program ZMC  

SciTech Connect

Diffuse scattering probes the local ordering in a crystal, whereas Bragg peaks are descriptive of the average long-range ordering. The population of local configurations can be explored by modeling the three-dimensional distribution of diffuse scattering. Local configurations are not constrained by the average crystallographic symmetry, so one way of modeling diffuse scattering is by modeling a disordered (short-range-ordered) structure and then calculating its diffuse scattering. The structure must contain enough unit cells to give a statistically valid model of the populations of local configurations, and so requirements for a program to model this ordering are very different from programs that model average crystal structures (used to fit the Bragg diffraction). ZMC is a program that has been developed to model diffuse scattering, particularly from molecular crystals. The strategies used to tackle the problem and the way in which they are implemented will be discussed.

Goossens, D.J.; Heerdegen, A.P.; Chan, E.J.; Welberry, T.R. (ANU)

2012-04-30T23:59:59.000Z

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Photoconductivity and luminescence of CuInSe{sub 2} single crystals at a high level of optical excitation  

Science Conference Proceedings (OSTI)

The luminance-current and spectral characteristics of photoluminescence of the CuInSe{sub 2} single crystals are studied. The superlinear portion of the excitation-intensity dependence of photoconductivity at low excitation intensities in compensated p-CuInSe{sub 2} crystals is explained on the basis of a recombination model. The emission band that peaked at 0.98 eV in the n-CuInSe{sub 2} photoluminescence spectrum corresponds to radiative recombination of electrons at the donor level with a depth of 0.04 eV. The maximum in the band intensity corresponds to the energy gap between the trap level and the valence band.

Guseinov, A. G.; Salmanov, V. M.; Mamedov, R. M. [Baku State University (Azerbaijan)], E-mail: rovshan63@rambler.ru

2006-04-15T23:59:59.000Z

142

Electroluminescence and phototrigger effect in single crystals of GaS{sub x}Se{sub 1-x} alloys  

Science Conference Proceedings (OSTI)

The effects of switching and electroluminescence as well as the interrelation between these effects in single crystals of GaS{sub x}Se{sub 1-x} alloys are detected and studied. It is established that the threshold voltage for switching depends on temperature, resistivity, and composition of alloys, and also on the intensity and spectrum of photoactive light. As a result, a phototrigger effect is observed; this effect arises under irradiation with light from the fundamental-absorption region. Electroluminescence is observed in the subthreshold region of the current-voltage characteristic; the electroluminescence intensity decreases drastically to zero as the sample is switched from a high-resistivity state to a low-resistivity state. Experimental data indicating that the electroluminescence and the switching effect are based on the injection mechanism (as it takes place in other layered crystals of the III-V type) are reported.

Kyazym-Zade, A. G., E-mail: bsu_aydin@yahoo.com; Salmanov, V. M.; Mokhtari, A. G.; Dadashova, V. V.; Agaeva, A. A. [Baku State University (Azerbaijan)

2008-05-15T23:59:59.000Z

143

Annealing as grown large volume CZT single crystals increased spectral resolution  

Science Conference Proceedings (OSTI)

The spectroscopic performance of current large-volume Cadmium 10% Zinc Telluride, Cd{sub 0.9}Zn{sub 0.1}Te, (CZT) detectors is impaired by cumulative effect of tellurium precipitates (secondary phases) presented in CZT single-crystal grown by low-pressure Bridgman techniques(1). This statistical effect may limit the energy resolution of large-volume CZT detectors (typically 2-5% at 662 keV for 12-mm thick devices). The stochastic nature of the interaction prevents the use of any electronic or digital charge correction techniques without a significant reduction in the detector efficiency. This volume constraint hampers the utility of CZT since the detectors are inefficient at detecting photons >1MeV and/or in low fluency situations. During the project, seven runs CZT ingots have been grown, in these ingots the indium dopant concentrations have been changed in the range between 0.5ppm to 6ppm. The I-R mapping imaging method has been employed to study the Te-precipitates. The Teprecipitates in as-grown CZT wafers, and after annealing wafers have been systematically studied by using I-R mapping system (home installed, resolution of 1.5 {micro}m). We employed our I-R standard annealing CZT (Zn=4%) procedure or two-steps annealing into radiation CZT (Zn=10%), we achieved the 'non'-Te precipitates (size CZT n+-type with resistivity > 10{sup 9-10} {Omega}-cm. We believe that the Te-precipitates are the p-type defects, its reducing number causes the CZT became n+-type, therefore we varied or reduced the indium dapant concentration during the growth and changed the Te-precipitates size and density by using different Cd-temperature and different annealing procedures. We have made the comparisons among Te-precipitates size, density and Indium dopant concentrations, and we found that the CZT with smaller size of Te-precipitates is suitable for radiation uses but non-Te precipitates is impossible to be used in the radiation detectors, because the CZT would became un-dopant or 'intrinsic' with non radiation affection (we have studied before). We used 3 weeks annealing time for 3-5 mm thickness CZT wafres, if the thickness increased to 10-15mm, the annealing time would be increased to many months, which is very unpractical and very difficult to control the CZT property. We have obtained as-grown CZT by using adding the extra Cd before growth, which showed the smaller size of Te-precipitates and excellent radiation performance. These CZT has very high {micro}{tau}(e) >1 x 10{sup -2}cm{sup 2}/V, {rho} > 2 x 10{sup 10} {Omega}-cm, and the thickness could be up to 80-100mm. The energy resolution of the detector (thickness>10mm) at 662 keV is about 1.2% without any correction (2) and according to Aquila, the 0.5-0.8% resolution at 662 keV would be expected by using appropriated electronic correction.

Dr. Longxia Li

2008-03-19T23:59:59.000Z

144

Development of metal etch mask by single layer lift-off for silicon nitride photonic crystals  

Science Conference Proceedings (OSTI)

We present a method for fabrication of nanoscale patterns in silicon nitride (SiN) using a hard chrome mask formed by metal liftoff with a negative ebeam resists (maN-2401). This approach enables fabrication of a robust etch mask without the need for ... Keywords: Metal liftoff, Nanofabrication, Nanophotonics, Photonic crystals (PC), Silicon nitride (SiN)

Kang-mook Lim; Shilpi Gupta; Chad Ropp; Edo Waks

2011-06-01T23:59:59.000Z

145

Effect of surface treatments on self-trapped exciton luminescence in single-crystal CaF{sub 2}  

SciTech Connect

We show that near-surface defects produced by mechanical treatments and electron irradiation can significantly enhance the intensity of luminescence due to the decay of self-trapped excitons (STEs) in single-crystal calcium fluoride during 157- and 193-nm irradiation. For example, polishing can double the intensity of the STE luminescence. Defects produced by mechanical indentation can either increase or decrease the luminescence intensity, depending on the indentation force. Electron irradiation also enhances subsequent STE luminescence. When electron-irradiated samples are annealed, additional increases in luminescence intensity are observed. Plausible mechanisms for the observed effects on STE luminescence intensity are discussed.

Cramer, L.P.; Cumby, T.D.; Leraas, J.A.; Langford, S.C.; Dickinson, J.T. [Department of Physics and Materials Science Program, Washington State University, Pullman, Washington 99164-2814 (United States)

2005-05-15T23:59:59.000Z

146

Single-crystal sup 40 Ar/ sup 39 Ar dating of the Olorgesailie Formation, southern Kenya rift  

SciTech Connect

Single-crystal laser fusion {sup 40}Ar/{sup 39}Ar analyses and several conventional bulk fusion {sup 40}K- {sup 40}Ar dates have been used to determine the age of volcaniclastic strata within the Olorgesailie Formation and of associated volcanic and sedimentary units of the southern Kenya rift. In the principal exposures along the southern edge of the Legemunge Plain, the formation spans the interval from approximately 500 to 1,000 ka. Deposition continued to the east along the Ol Keju Nyiro river where a tuff near the top of the formation has been dated at 215 ka. In these exposures, the formation is unconformably overlain by sediments dated at 49 ka. A possible source for the Olorgesailie tephra, the Ol Doinyo Nyokie volcanic complex, contains as ash flow dated at {approximately} 1 Ma, extending the known age range of this complex to encompass that of virtually the entire Olorgesailie Formation in the Legemunge Plain. These geologic examples illustrate the importance of the single-crystal {sup 40}Ar/{sup 39}Ar dating technique whereby contaminant, altered, or otherwise aberrant grains can be identified and eliminated from the determination of eruptive ages for reworked or altered pyroclastic deposits. The authors have presented a computer-modeling procedure based on an inverse-isochron analysis that promotes a more objective approach to trimming {sup 40}Ar/{sup 39}Ar isotope data sets of this type.

Deino, A. (Geochronology Center of the Inst. of Human Origins, Berkeley, CA (United States)); Potts, R. (Smithsonian Institution, Washington, DC (United States))

1990-06-10T23:59:59.000Z

147

Mid- and Far-Infrared Reflection/Absorption Spectroscopy (IRAS) Studies of NO on Rh Single Crystal Surfaces  

DOE Green Energy (OSTI)

The NO/CO reaction over Rh metal in automobile catalytic converters is critical to the control of emissions of these pollutant molecules. As part of a program to determine the elementary mechanism(s) of this reaction, we have been performing mid- and far-infrared reflection/absorption spectroscopic (IRAS) measurements of the adsorption and co-adsorption and co-adsorption of NO and CO on Rh single crystal surfaces. Of particular interest is the low-frequency range of the IRAS spectra where we hoped to observe features due to metal-N stretching and/or bending vibrational motions. In particular, we hoped to obtain information regarding the site-requirements for the dissociation of the NO molecule on various Rh single crystal surfaces. An important result from our earlier work is that the selectivity of the reaction for the two nitrogen-containing products, N2 and N2O, is a strong function of the Rh surface structure. On the basis of ancillary data, we suggested that the location of adsorbed NO and N-atoms (formed from dissociation of adsorbed NO) on various Rh surfaces could, perhaps account for the selectivity differences.

Peden, Charles HF; He, Ting; Pilling, M.; Hirschmugl, Carol J.; Gardner, P.

2001-02-01T23:59:59.000Z

148

In Situ Tensile Testing of Single Crystal Molybdenum Alloy Fibers with Various Dislocation Densities in a Scanning Electron Microscope  

SciTech Connect

In-situ tensile tests have been performed in a dual beam focused ion beam and scanning electron microscope on as-grown and prestrained single-crystal molybdenum-alloy (Mo-alloy) fibers. The fibers had approximately square cross sections with submicron edge lengths and gauge lengths in the range of 9-41 {mu}m. In contrast to previously observed yield strengths near the theoretical strength of 10 GPa in compression tests of {approx}1-3-{mu}m long pillars made from similar Mo-alloy single crystals, a wide scatter of yield strengths between 1 and 10 GPa was observed in the as-grown fibers tested in tension. Deformation was dominated by inhomogeneous plastic events, sometimes including the formation of Lueders bands. In contrast, highly prestrained fibers exhibited stable plastic flow, significantly lower yield strengths of {approx}1 GPa, and stress-strain behavior very similar to that in compression. A simple, statistical model incorporating the measured dislocation densities is developed to explain why the tension and compression results for the as-grown fibers are different.

George, Easo P [ORNL; Johanns, K. [University of Tennessee, Knoxville (UTK); Sedlmayr, A. [Karlsruhe Institute of Technology, Karlsruhe, Germany; Phani, P. Sudharshan [University of Tennessee, Knoxville (UTK); Monig, R. [Karlsruhe Institute of Technology, Karlsruhe, Germany; Kraft, O. [Karlsruhe Institute of Technology, Karlsruhe, Germany; Pharr, George M [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL)

2012-01-01T23:59:59.000Z

149

In situ transmission electron microscopy study of electric-field-induced microcracking in single crystal Pb,,Mg13Nb23...O3 PbTiO3  

E-Print Network (OSTI)

In situ transmission electron microscopy study of electric-field-induced microcracking in single March 2000; accepted for publication 2 May 2000 In this letter, we report in situ transmission electron microscopy TEM study of effect of a cyclic electric field on microcracking in a single crystal piezoelectric

Chen, Haydn H.

150

Fabrication of large-area ultra-thin single crystal silicon membranes  

SciTech Connect

Perfectly, crystalline, 55 nm thick silicon membranes have been fabricated over several square millimeters and used to observe transmission ion channeling patterns showing the early evolution of the axially channeled beam angular distribution for small tilts away from the [011] axis. The reduced multiple scattering through such thin layers allows fine angular structure produced by the highly non-equilibrium transverse momentum distribution of the channeled beam during its initial propagation in the crystal to be resolved. The membrane crystallinity and flatness were measured by using proton channeling measurements and the surface roughness of 0.4 nm using atomic force microscopy.

Dang, Z. Y.; Motapothula, M.; Ow, Y. S. [Center for Ion Beam Applications, Physics Department, National University of Singapore, Lower Kent Ridge Road, Singapore 117542 (Singapore); Venkatesan, T. [NanoCore, National University of Singapore, Singapore 117576 (Singapore); Breese, M. B. H. [Center for Ion Beam Applications, Physics Department, National University of Singapore, Lower Kent Ridge Road, Singapore 117542 (Singapore); Singapore Synchrotron Light Source (SSLS), National University of Singapore, 5 Research Link, Singapore 117603 (Singapore); Rana, M. A. [Physics Division, Directorate of Science, PINSTECH, P.O. Nilore, Islamabad (Pakistan); Osman, A. [National Centre for Physics (NCP), Shahdara Valley Road, Islamabad (Pakistan)

2011-11-28T23:59:59.000Z

151

Schottky barrier height behavior of Pt-Ru alloy contacts on single-crystal n-ZnO  

SciTech Connect

We investigated the Schottky barrier height (SBH) behavior of binary alloy Schottky contacts on n-type zinc oxide (n-ZnO) single crystals. Pt-Ru alloy electrodes were deposited on the Zn-polar and O-polar faces of ZnO substrates by combinatorial ion-beam deposition under identical conditions. The crystal structures of the Pt-Ru alloy film changed from the Pt phase (cubic structure) to the Ru phase (hexagonal structure) in the Pt-Ru alloy phase diagram with decreasing Pt content. The SBH, determined from current-voltage measurements, decreased with decreasing Pt content, indicating that the SBH behavior also followed the Pt-Ru alloy phase diagram. The alloy electrodes on the Zn-polar face showed better Schottky properties than those on the O-polar face. Hard x-ray photoelectron spectroscopy revealed a difference in the interface oxidization of the Pt-Ru alloy: the interface of the O-polar face and Pt-Ru mixed phase with poor crystallinity had a more oxidized layer than that of the Zn-polar face. As a result of this oxidization, the O-polar face, Pt-Ru mixed, and Ru phases showed poor Schottky properties.

Nagata, T.; Haemori, M.; Hayakawa, R.; Yoshitake, M.; Chikyow, T. [Advanced Electronic Materials Center, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Volk, J. [Research Institute for Technical Physics and Materials Science, H-1121 Budapest, Konkoly Thege Miklos ut 29-33 (Hungary); Yamashita, Y. [Advanced Electronic Materials Center, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); NIMS Beamline Station at SPring-8, National Institute for Materials Science, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Yoshikawa, H.; Ueda, S.; Kobayashi, K. [NIMS Beamline Station at SPring-8, National Institute for Materials Science, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

2010-05-15T23:59:59.000Z

152

Microsoft Word - 41344_Texas A&M_Mech of Single Crystal Blades_Factsheet_Rev01_10-03.doc  

NLE Websites -- All DOE Office Websites (Extended Search)

Investigation into the Mechanics of Single Crystal Turbine Blades Investigation into the Mechanics of Single Crystal Turbine Blades with a View Toward Enhancing Turbine Efficiency October 8, 2003 DE-FC26-01NT41344 1 FACT SHEET I. PROJECT PARTICIPANTS PI: K.R.Rajagopal, Texas A & M University Co-PI: I.J.Rao, New Jersey Institute of Technology II. PROJECT DESCRIPTION A. Objective(s) To model the behavior of single crystal turbine blades within a full thermodynamic framework, accounting for the evolving anisotropy of the material as it deforms and the creep behavior at different temperatures. B. Background/Relevancy The preferred solution to the generation of electric power is by means of gas turbines as they are cheaper and produce considerably less carbon monoxide than conventional methods of power

153

Synthesis of Room-Temperature Ferromagnetic Cr-doped TiO?(110) Rutile Single Crystals using Ion Implantation  

SciTech Connect

Ferromagnetic Cr-doped rutile TiO? single crystals were synthesized by high-temperature ion implantation. The associated structural, compositional and magnetic properties were studied by x-ray photoelectron spectroscopy, Rutherford backscattering spectrometry, proton induced x-ray emission, x-ray diffraction, Cr K- and L-shell near-edge x-ray absorption spectroscopy, and vibrating sample magnetometry. Cr was distributed uniformly to the depth of about 300 nm with an average concentration of ~1 at. %. The samples are semiconducting and ferromagnetic as implanted, with a saturation magnetization of 0.29???B/Cr atom at room temperature. Cr is in a formal oxidation state of +3 throughout the implanted region, and no CrO? is detected.

Shutthanandan, V.; Thevuthasan, Suntharampillai; Droubay, Timothy; Heald, Steve M.; Engelhard, Mark H.; McCready, David E.; Chambers, Scott A.; Nachimuthu, Ponnusamy; Mun, B. S.

2006-01-01T23:59:59.000Z

154

The formation of metallic nanoparticles in single crystal CaF{sub 2} under 157 nm excimer laser irradiation  

SciTech Connect

Single crystal calcium fluoride (CaF{sub 2}) is an important material for vacuum-ultraviolet optical components. Unfortunately, all metal halides tend to form defects when exposed to energetic particles and laser radiation, and these defects can degrade optical performance. Here we examine the consequences of exposing CaF{sub 2} to 157 nm excimer laser radiation and show that several tens of thousands of pulses at fluences near 1 J/cm{sup 2} can color the material. Absorption spectra of the exposed material confirm the formation of metallic calcium nanoparticles similar to those produced by other forms of energetic radiation. The rate of nanoparticle formation depends on the bulk temperature and displays a local maximum near 50 deg. C. Absorption measurements at 157 nm display a transient absorption component that grows during prolonged irradiation and disappears on time scales of several minutes after irradiation ceases. The implications of these effects in optical components are discussed.

Cramer, L.P.; Langford, S.C.; Dickinson, J.T. [Physics Department, Washington State University, Pullman, Washington 99164-2814 (United States)

2006-03-01T23:59:59.000Z

155

Detection of charge transfer processes in Cr-doped SrTiO{sub 3} single crystals  

SciTech Connect

An insulator-to-metal transition is observed in Cr-doped SrTiO{sub 3} single crystals upon extended exposure to a high electric field, namely, electroconditioning (EC). Electron paramagnetic resonance (EPR) and transport measurements under laser irradiation show anticorrelation between the Cr{sup 3+} EPR signal and the electrical current. This proves that the Cr{sup 3+} ions are responsible for the photocurrent that initiates the EC process. We observe the presence of Cr{sup 3+}/Cr{sup 4+} mixed valencies in the bulk in the conducting state. The EPR characterization of the spectra in the conducting state excludes the possibility of a Cr{sup 3+}-oxygen vacancy complex in the bulk as a result of the EC.

La Mattina, F. [Physik-Institut der Universitaet Zuerich, Winterthurerstr. 190, CH-8057 Zuerich (Switzerland); IBM Research, Zurich Research Laboratory, Saeumerstr. 4, CH-8803 Rueschlikon (Switzerland); Bednorz, J. G.; Alvarado, S. F. [IBM Research, Zurich Research Laboratory, Saeumerstr. 4, CH-8803 Rueschlikon (Switzerland); Shengelaya, A. [Physics Institute of Tbilisi State University, Chavchavadze 3, GE-0128, Tbilisi (Georgia); Keller, H. [Physik-Institut der Universitaet Zuerich, Winterthurerstr. 190, CH-8057 Zuerich (Switzerland)

2008-07-14T23:59:59.000Z

156

In-Plane Electronic Anisotropy of Underdoped ___122___ Fe-Arsenide Superconductors Revealed by Measurements of Detwinned Single Crystals  

SciTech Connect

The parent phases of the Fe-arsenide superconductors harbor an antiferromagnetic ground state. Significantly, the Neel transition is either preceded or accompanied by a structural transition that breaks the four fold symmetry of the high-temperature lattice. Borrowing language from the field of soft condensed matter physics, this broken discrete rotational symmetry is widely referred to as an Ising nematic phase transition. Understanding the origin of this effect is a key component of a complete theoretical description of the occurrence of superconductivity in this family of compounds, motivating both theoretical and experimental investigation of the nematic transition and the associated in-plane anisotropy. Here we review recent experimental progress in determining the intrinsic in-plane electronic anisotropy as revealed by resistivity, reflectivity and ARPES measurements of detwinned single crystals of underdoped Fe arsenide superconductors in the '122' family of compounds.

Fisher, Ian Randal

2012-05-08T23:59:59.000Z

157

Epitaxial europium oxide on Ni(100) with single-crystal quality  

SciTech Connect

High quality epitaxy of EuO on Ni(100) is developed in an in situ scanning tunneling microscopy (STM) and low-energy electron diffraction (LEED) study. A careful selection of the initial growth parameters is decisive to obtain a surface oxide suitable for the subsequent epitaxy of single phase EuO(100). After the creation of a three layer thick coalesced oxide film for the subsequent growth a distillation technique is applied. Appropriate annealing of films with up to 100 nm thickness generates sufficient conductivity for STM and electron spectroscopies. Oxygen vacancies are directly imaged by STM. They are of decisive importance for the metal-to-insulator transition around the temperature of the ferromagnetic-to-paramagnetic transition. A fast relaxation of the initial biaxial strain observed by LEED leaves little hope for an increase of the Curie temperature through epitaxial compression. Ex situ x-ray adsorption spectroscopy and magneto-optical Kerr effect microscopy measurements of thicker films are consistent with the stoichiometric single phase EuO with bulk properties.

Foerster, Daniel F.; Klinkhammer, Juergen; Busse, Carsten; Altendorf, Simone G.; Michely, Thomas; Hu Zhiwei; Chin Yiying; Tjeng, L. H.; Coraux, Johann; Bourgault, Daniel [II. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Strasse 77, D-50937 Koeln (Germany); II. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Strasse 77, D-50937 Koeln, Germany and Max Planck Institute for Chemical Physics of Solids, Noethnitzerstr. 40, D-01187 Dresden (Germany); Institut Neel, CNRS-UJF, 25 rue des Martyrs, F-38042 Grenoble Cedex 9 (France)

2011-01-15T23:59:59.000Z

158

The Role of -Al2O3 Single Crystal Support to Pt Nanoparticles Construction Zhongfan Zhang*, Long Li*, Lin-lin Wang**, Sergio I. Sanchez***, Qi Wang****,  

E-Print Network (OSTI)

The Role of -Al2O3 Single Crystal Support to Pt Nanoparticles Construction Zhongfan Zhang*, Long Li the preparation of a model Pt/-Al2O3 catalyst and its characterization by a cross-sectional high-resolution electron microscopy (XHREM) method. Pt/-Al2O3 is the most important technologically-relevant heterogeneous

Frenkel, Anatoly

159

Rapid Charge Transport in Dye-Sensitized Solar Cells Made from Vertically Aligned Single-Crystal Rutile TiO2 Nanowires  

Science Conference Proceedings (OSTI)

A rapid solvothermal approach was used to synthesize aligned 1D single-crystal rutile TiO2 nanowire (NW) arrays on transparent conducting substrates as electrodes for dye-sensitized solar cells. The NW arrays showed a more than 200 times faster charge transport (see picture) and a factor four lower defect state density than conventional rutile nanoparticle films.

Feng, X.; Zhu, K.; Frank, A. J.; Grimes, C. A.; Mallouk, T. E.

2012-03-12T23:59:59.000Z

160

Thermal transport of the single-crystal rare-earth nickel borocarbides RNi2B2C  

E-Print Network (OSTI)

The quaternary intermetallic rare-earth nickel borocarbides RNi2B2C are a family of compounds that show magnetic behavior, superconducting behavior, and/or both. Thermal transport measurements reveal both electron and phonon scattering mechanisms, and can provide information on the interplay of these two long-range phenomena. In general the thermal conductivity kappa is dominated by electrons, and the high temperature thermal conductivity is approximately linear in temperature and anomalous. For R=Tm, Ho, and Dy the low-temperature thermal conductivity exhibits a marked loss of scattering at the antiferromagnetic ordering temperature T-N. Magnon heat conduction is suggested for R=Tm. The kappa data for R=Ho lends evidence for gapless superconductivity in this material above T-N. Unlike the case for the non-magnetic superconductors in the family, R=Y and Lu, a phonon peak in the thermal conductivity below T-c is not observed down to T=1.4 K for the magnetic superconductors. Single-crystal quality seems to have a strong effect on kappa. The electron-phonon interaction appears to weaken as one progresses from R=Lu to R=Gd. The resistivity data shows the loss of scattering at T-N for R=Dy, Tb, and Gd; and the thermoelectric power for all three of these materials exhibits an enhancement below T-N.

Hennings, BD; Naugle, Donald G.; Canfield, PC.

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Thermal chemistry of copper(I)-N,N '-di-sec-butylacetamidinate on Cu(110) single-crystal surfaces  

Science Conference Proceedings (OSTI)

The surface chemistry of copper(I)-N,N'-di-sec-butylacetamidinate on Cu(110) single-crystal surfaces has been characterized under ultrahigh vacuum by temperature programmed desorption (TPD) and X-ray photoelectron spectroscopy. A series of thermal stepwise conversions were identified, starting with the partial dissociative adsorption of the copper acetamidinate dimers into a mixture of monomers and dimers on the surface. An early dissociation of a C-N bond leads to the production of N-sec-butylacetamidine, which is detected in TPD experiments in three temperature regimes, the last one centered around 480 K. Butene, and a small amount of butane, is also detected above approximately 500 K, and hydrogen production, an indication of dehydrogenation of surface fragments, is observed at 460, 550 and 670 K. In total, only about 10% of the initial copper(I)-N,N'-di-sec-butylacetamidinate adsorbed monolayer decomposes, and only about {approx}3% of carbon is left behind on the surface after heating to high temperatures. The implications of this surface chemistry to the design of chemical film growth processes using copper acetamidinates as precursors are discussed.

Ma Qiang; Zaera, Francisco; Gordon, Roy G. [Department of Chemistry, University of California, Riverside, California 92521 (United States); Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States)

2012-01-15T23:59:59.000Z

162

New oxyfluoride glass with high fluorine content and laser patterning of nonlinear optical BaAlBO{sub 3}F{sub 2} single crystal line  

Science Conference Proceedings (OSTI)

A new oxyfluoride glass of 50BaF{sub 2}-25Al{sub 2}O{sub 3}-25B{sub 2}O{sub 3} (mol. %) with a large fraction of fluorine, i.e., F/(F + O) = 0.4, was prepared using a conventional melt-quenching method in order to synthesize new glass-ceramics containing nonlinear optical oxyfluoride crystals. The refractive index at 632.8 nm and ultra-violet cutoff wavelength of the glass were 1.564 and {approx}200 nm, respectively. Eu{sup 3+} ions in the glass showed a high quantum yield of 88% in the photoluminescence spectrum in the visible region. BaAlBO{sub 3}F{sub 2} crystals (size: 50-100 nm) showing second harmonic generations were formed through the crystallization of the glass. Lines consisting of BaAlBO{sub 3}F{sub 2} crystals were patterned successfully on the glass surface by laser irradiations (Yb:YVO{sub 4} laser with a wavelength of 1080 nm, laser power of 1.1 W, scanning speed of 8 {mu}m/s). High resolution transmission electron microscope observations combined with a focused ion beam technique indicate that BaAlBO{sub 3}F{sub 2} crystals are highly oriented just like a single crystal. The present study proposes that the new oxyfluoride glass and glass-ceramics prepared have a high potential for optical device applications.

Shionozaki, K.; Honma, T.; Komatsu, T. [Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka-cho, Nagaoka 940-2188 (Japan)

2012-11-01T23:59:59.000Z

163

Use of evaporative fractional crystallization in the pretreatment process of multi-salt single shell tank Hanford nuclear wastes.  

E-Print Network (OSTI)

??The purpose of the work described in this thesis was to explore the use of fractional crystallization as a technology that can be used to… (more)

Nassif, Laurent

2007-01-01T23:59:59.000Z

164

Cost Effective Single Crystals  

Science Conference Proceedings (OSTI)

three relevant technologies, namely casting, alloy development and orientation measurement, developed by Rolls-Royce to enable the cost effective production.

165

Bridgman Growth of Large SrI2:Eu2+ Single Crystals: A High-performance Scintillator for Radiation Detection Applications  

SciTech Connect

Single-crystal strontium iodide (SrI2) doped with relatively high levels (e.g., 3 - 6 %) of Eu2+ exhibits characteristics that make this material superior, in a number of respects, to other scintillators that are currently used for radiation detection. Specifically, SrI2:Eu2+ has a light yield that is significantly higher than LaBr3:Ce3+ -a currently employed commercial high-performance scintillator. Additionally, SrI2:Eu2+ is characterized by an energy resolution as high as 2.6% at the 137Cs gamma-ray energy of 662 keV, and there is no radioactive component in SrI2:Eu2+ - unlike LaBr3:Ce3+ that contains 138La. The Ce3+-doped LaBr3 decay time is, however, faster (30 nsec) than the 1.2 sec decay time of SrI2:Eu2+. Due to the relatively low melting point of strontium iodide (~515 oC), crystal growth can be carried out in quartz crucibles by the vertical Bridgman technique. Materials-processing and crystal-growth techniques that are specific to the Bridgman growth of europium-doped strontium iodide scintillators are described here. These techniques include the use of a porous quartz frit to physically filter the molten salt from a quartz antechamber into the Bridgman growth crucible and the use of a bent or bulb grain selector design to suppress multiple grain growth. Single crystals of SrI2:Eu2+ scintillators with good optical quality and scintillation characteristics have been grown in sizes up to 5.0 cm in diameter by applying these techniques. Other aspects of the SrI2:Eu2+ crystal-growth methods and of the still unresolved crystal-growth issues are described here.

Boatner, Lynn A [ORNL; Ramey, Joanne Oxendine [ORNL; Kolopus, James A [ORNL; Hawrami, Rastgo [Radiation Monitoring Devices, Watertown, MA; Higgins, William [Radiation Monitoring Devices, Watertown, MA; Van Loef, Edgar [Radiation Monitoring Devices, Watertown, MA; Glodo, J. [Radiation Monitoring Devices, Watertown, MA; Shah, Kanai [Radiation Monitoring Devices, Watertown, MA; Bhattacharya, P. [Fisk University, Nashville, TN; Tupitsyn, E [Fisk University, Nashville, TN; Groza, Michael [Fisk University, Nashville, TN; Burger, Arnold [Fisk University, Nashville, TN

2013-01-01T23:59:59.000Z

166

Single-crystal micro/nanostructures and thin films of lamellar molybdenum oxide by solid-state pyrolysis of organometallic derivatives of a cyclotriphosphazene  

Science Conference Proceedings (OSTI)

The solid-state pyrolysis of organometallic derivatives of a cyclotriphosphazene is demonstrated to be a new, simple and versatile solid-state templating method for obtaining single-crystal micro- and nanocrystals of transition and valve metal oxides. The technique, when applied to Mo-containing organometallics N{sub 3}P{sub 3}[OC{sub 6}H{sub 4}CH{sub 2}CN.Mo(CO){sub 5}]{sub 6} and N{sub 3}P{sub 3}[OC{sub 6}H{sub 4}CH{sub 2}CN.Mo(CO){sub 4} py]{sub 6}, results in stand-alone and surface-deposited lamellar MoO{sub 3} single crystals, as determined by electron and atomic force microscopies and X-ray diffraction. The size and morphology of the resulting crystals can be tuned by the composition of the precursor. X-ray photoelectron and infrared spectroscopies indicate that the deposition of highly lamellar MoO{sub 3} directly on an oxidized (400 nm SiO{sub 2}) surface or (100) single-crystal silicon surfaces yields a layered uniphasic single-crystal film formed by cluster diffusion on the surface during pyrolysis of the metal-carbonyl derivatives. For MoO{sub 3} in its layered form, this provides a new route to an important intercalation material for high energy density battery materials. - Graphical abstract: Lamellar MoO{sub 3} micro- and nanocrystals are prepared by pyrolysis of the organometallics N{sub 3}P{sub 3}[OC{sub 6}H{sub 4}CH{sub 2}CN.Mo(CO){sub 5}]{sub 6} (I) and N{sub 3}P{sub 3}[OC{sub 6}H{sub 4}CH{sub 2}CN.Mo(CO){sub 4} py]{sub 6} (II), in air at 800 {sup o}C. The single-crystal products exhibit a high degree of turbostratic layering (see image). Deposition and subsequent pyrolysis of uniphasic MoO{sub 3} from the precursors is also possible on suitable substrates and supports.

Diaz, Carlos, E-mail: cdiaz@uchile.c [Departamento de Quimica, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); Lavayen, Vladimir [Departamento de Fisica, Universidad Tecnica Federico Santa Maria, Valparaiso 2390123 (Chile); O'Dwyer, Colm, E-mail: colm.odwyer@ul.i [Department of Physics and Materials and Surface Science Institute, University of Limerick, Limerick (Ireland)

2010-07-15T23:59:59.000Z

167

A New Parameterization of Single Scattering Solar Radiative Properties for Tropical Anvils Using Observed Ice Crystal Size and Shape Distributions  

Science Conference Proceedings (OSTI)

Parameterizations of single scattering properties currently used in cloud resolving and general circulation models are somewhat limited in that they typically assume the presence of single particle habits, do not adequately account for the ...

Greg M. McFarquhar; Ping Yang; Andreas Macke; Anthony J. Baran

2002-08-01T23:59:59.000Z

168

In situ dehydration behavior of zeolite-like pentagonite: A single-crystal X-ray study  

SciTech Connect

The structural modifications upon heating of pentagonite, Ca(VO)(Si{sub 4}O{sub 10}){center_dot}4H{sub 2}O (space group Ccm2{sub 1}, a=10.3708(2), b=14.0643(2), c=8.97810(10) A, V=1309.53(3) A{sup 3}) were investigated by in situ temperature dependent single-crystal X-ray structure refinements. Diffraction data of a sample from Poona district (India) have been measured in steps of 25 up to 250 Degree-Sign C and in steps of 50 Degree-Sign C between 250 and 400 Degree-Sign C. Pentagonite has a porous framework structure made up by layers of silicate tetrahedra connected by V{sup 4+}O{sub 5} square pyramids. Ca and H{sub 2}O molecules are extraframework occupants. Room temperature diffraction data allowed refinement of H positions. The hydrogen-bond system links the extraframework occupants to the silicate layers and also interconnects the H{sub 2}O molecules located inside the channels. Ca is seven-fold coordinated forming four bonds to O of the tetrahedral framework and three bonds to extraframework H{sub 2}O. The H{sub 2}O molecule at O9 showing a high displacement parameter is not bonded to Ca. The dehydration in pentagonite proceeds in three steps. At 100 Degree-Sign C the H{sub 2}O molecule at O8 was released while O9 moved towards Ca. As a consequence the displacement parameter of H{sub 2}O at O9 halved compared to that at room temperature. The unit-cell volume decreased to 1287.33(3) A{sup 3} leading to a formula with 3H{sub 2}O per formula unit (pfu). Ca remained seven-fold coordinated. At 175 Degree-Sign C Ca(VO)(Si{sub 4}O{sub 10}){center_dot}3H{sub 2}O transformed into a new phase with 1H{sub 2}O molecule pfu characterized by doubling of the c axis and the monoclinic space group Pn. Severe bending of specific T--O--T angles led to contraction of the porous three-dimensional framework. In addition, H{sub 2}O at O9 was expelled while H{sub 2}O at O7 approached a position in the center of the channel. The normalized volume decreased to 1069.44(9) A{sup 3}. The Ca coordination reduced from seven- to six-fold. At 225 Degree-Sign C a new anhydrous phase with space group Pna2{sub 1} but without doubling of c had formed. Release of H{sub 2}O at O7 caused additional contraction of T--O--T angles and volume reduction (V=1036.31(9) A{sup 3}). Ca adopted five-fold coordination. During heating excursion up to 400 Degree-Sign C this anhydrous phase remained preserved. Between room temperature and 225 Degree-Sign C the unit-cell volume decreased by 21% due to dehydration. The dehydration steps compare well with the thermo-gravimetric data reported in the literature. - Graphical abstract: Pentagonite structure at room temperature and at 225 Degree-Sign C. Highlights: Black-Right-Pointing-Pointer We investigate the relationship between the removal of H{sub 2}O molecules and structural modifications of the framework of pentagonite. Black-Right-Pointing-Pointer Pentagonite undergoes phase transitions upon heating. Black-Right-Pointing-Pointer We analyze similarities and differences between pentagonite and related structures.

Danisi, Rosa Micaela, E-mail: rosa.danisi@krist.unibe.ch [Mineralogical Crystallography, Institute of Geological Sciences, University of Bern, Freiestrasse 3, Bern CH-3012 (Switzerland); Armbruster, Thomas; Lazic, Biljana [Mineralogical Crystallography, Institute of Geological Sciences, University of Bern, Freiestrasse 3, Bern CH-3012 (Switzerland)

2013-01-15T23:59:59.000Z

169

Preparation and properties of evaporated CdTe films compared with single-crystal CdTe. Progress report No. 5, November 1, 1981-January 31, 1982  

DOE Green Energy (OSTI)

The hot-wall vacuum evaporator system has been put into use with successful deposition of seven thin films of n-type CdTe on glass. Microprobe analysis indicated that the films were stoichiometric CdTe. Optical transmission showed a well-defined absorption edge. Film resistivities on glass were reduced from 1.7 x 10/sup 8/ ohm-cm, to 6 x 10/sup 4/ ohm-cm by In doping; film resistivities under AM1.5 illumination are 2.0 x 10/sup 4/ and 5 x 10/sup 2/ ohm-cm, respectively compared to the dark values given above. Temperature dependence of the dark conductivity of the undoped CdTe film indicates an activation energy of 0.79 eV; in the light the activation energy was reduced to 0.1 eV. The high dark resistivity and activation energy indicate high intergrain potential barriers, which could produce the high resistivities observed even with fairly high free electron densities in the grains. Comparison will be sought between these results and those found for films deposited epitaxially on single crystal substrates. A detailed summary of absorption constant vs wavelength data for CdTe has been assembled for both single crystal and thin film materials. The absorption constant for thin film material appears to vary from 2 x 10/sup 4/ cm/sup -1/ at 8000A to 10/sup 5/ cm/sup -1/ at 5000A; single crystal values may be slightly higher. EBIC and light scanning techniques are being developed for characterizing grain boundary effects in bicrystals, and to evaluate the effects of passivation techniques. Defect densities at a grain boundary in a p-type bicrystal were found to range from 2 x 10/sup 12/ to 8 x 10/sup 12/ cm/sup -2/eV/sup -1/, using data derived from the J-V dependence of the grain boundary.

Bube, R H

1982-01-01T23:59:59.000Z

170

In-Situ Observation of the Stress-Induced Stochastic Twin Boundary Motion in off Stoichiometric NiMnGa Single Crystal  

Science Conference Proceedings (OSTI)

Stochastic motion of the type II twin boundary in off stoichiometric NiMnGa single crystal is confirmed by in-situ X-ray microdiffraction during external stress field loading. Assymmetry between tensile and compressive parts of the loading and large hysteresis loop is found. Formation of local strained regions is predecessing each boundary movement. The location of strained regions adjusts to the position of the twin boundary. Abrupt motion of the boundary correlates with the corresponding spikes at the load/displacement curve.

Barabash, Rozaliya [ORNL; Kirchlechner, Christoph [Max-Planck-Institut fur Eisenforschung, Germany; Robach, Odile [European Synchrotron Radiation Facility (ESRF); Sozinov, Alexei [AdaptaMat, Finland

2013-01-01T23:59:59.000Z

171

Sublimation of Ice Crystals  

Science Conference Proceedings (OSTI)

Recent experiments on the sublimation of single crystals of ice in an atmosphere of air indicate that the sublimation rate is diffusion limited and initially solid prismatic crystals evolve into time-independent shapes similar to confocal ...

Jon Nelson

1998-03-01T23:59:59.000Z

172

Single-crystal Raman spectroscopy and X-ray crystallography at beamline X26-C of the NSLS  

E-Print Network (OSTI)

Three-dimensional structures derived from X-ray diffraction of protein crystals provide a wealth of information. Features and interactions important for the function of macromolecules can be deduced and catalytic mechanisms postulated. Still, many questions can remain, for example regarding metal oxidation states and the interpretation of ‘mystery density’, i.e. ambiguous or unknown features within the electron density maps, especially at 2A ? resolutions typical of most macromolecular structures. Beamline X26-C at the

Deborah Stoner-ma; John M. Skinner; Dieter K. Schneider; Matt Cowan; Robert M. Sweet; Allen M. Orville

2010-01-01T23:59:59.000Z

173

Features of the charge-transport mechanism in layered Bi{sub 2}Te{sub 3} single crystals doped with chlorine and terbium  

Science Conference Proceedings (OSTI)

The temperature dependences (T = 5-300 K) of the resistivity in the plane of layers and in the direction perpendicular to the layers, as well as the Hall effect and the magnetoresistance (H < 80 kOe, T = 0.5-4.2 K) in Bi{sub 2}Te{sub 3} single crystals doped with chlorine and terbium, are investigated. It is shown that the doping of Bi{sub 2}Te{sub 3} with terbium atoms results in p-type conductivity and in increasing hole concentration. The doping of Bi{sub 2}Te{sub 3} with chlorine atoms modifies also the character of its conductivity instead of changing only the type from p to n. In the temperature dependence of the resistivity in the direction perpendicular to layers, a portion arises with the activation conductivity caused by the hopping between localized states. The charge-transport mechanism in Bi{sub 2}Te{sub 3} single crystals doped with chlorine is proposed.

Abdullaev, N. A., E-mail: anadir@azintex.com; Abdullaev, N. M.; Aliguliyeva, H. V.; Kerimova, T. G.; Mehdiyev, G. S. [National Academy of Sciences of Azerbaijan, Abdullaev Institute of Physics (Azerbaijan); Nemov, S. A. [St. Petersburg State Polytechnic University (Russian Federation)

2011-01-15T23:59:59.000Z

174

Magnetic Field Induced Phase Transitions in Gd5(Si1.95Ge2.05)Single Crystal and the Anisotropic Magnetocaloric Effect  

Science Conference Proceedings (OSTI)

The magnetization measurements using a Gd{sub 5}(Si{sub 1.95}Ge{sub 2.05}) single crystal with the magnetic field applied along three crystallographic directions, [001], [010] and [100], were carried out as function of applied field (0-56 kOe) at various temperatures ({approx}5-320 K). The magnetic-field induced phase transformations at temperature above the zero-field critical temperature, i.e. the paramagnetic (PM) {leftrightarrow} ferromagnetic (FM) transitions with application or removal of magnetic field, are found to be temperature dependent and hysteretic. The corresponding critical fields increase with increasing temperature. The magnetic field (H)-temperature (T) phase diagrams have been constructed for the Gd{sub 5}(Si{sub 1.95}Ge{sub 2.05}) single crystal with field along the three directions. A small anisotropy has been observed. The magnetocaloric effect (MCE) has been calculated from the isothermal magnetization data, and the observed anisotropy correlates with H-T phase diagrams. The results are discussed in connection with the magnetic-field induced martensitic-like structural transition observed in the Gd{sub 5}(Si{sub 2}Ge{sub 2})-type compounds.

H. Tang; V.K. Pecharsky; A.O. Pecharsky; D.L. Schlagel; T.A. Lograsso; K.A. Gschneidner,jr.

2004-09-30T23:59:59.000Z

175

Preparation and properties of evaporated CdTe films compared with single-crystal CdTe. Progress report no. 6, February 1, 1982-April 30, 1982  

DOE Green Energy (OSTI)

Films of n-type CdTe:In have been deposited by hot-wall vacuum evaporation (HWVE) on 7059 glass substrates, BaF/sub 2/ single crystal substrates, metal (Pt, Cr, Mo, Al) coated glass substrates, and single crystal p-type CdTe substrates. Films deposited on 7059 glass show typically a dark resistivity of 2 x 10/sup 5/ ohm-cm and a light resistivity of 3 x 10/sup 2/ ohm-cm. With increasing In source temperature, the resistivity decreases, but actually increases slightly again if the T/sub In/ is raised above 600/sup 0/C. Photoexcitation increases the electron density but does not affect the electron mobility. It appears that the grains are depleted in the dark. Films deposited on BaF/sup 2/ show dark resistivity of about 5 ohm-cm and light resistivity of about 2 ohm-cm, corresponding to electron densities of about 3 x 10/sup 16/ cm/sup -3/ and electron mobilities of about 30 cm/sup 2//V-sec. For doping levels abpove 10/sup 16/ cm/sup -3/ photoexcitation increases the mobility, but not the electron density; it appears that the grains are not depleted in the dark in this case. Cr coated 7059 glass makes an ohmic contact to n-type CdTe films. A Schottky diode formed with a 100A thick Au layer showed V/sub oc/ = 0.46 V, J/sub sc/ = 9 mA/cm/sup 2/ and a solar efficiency of about 2%. An n/p homojunction device was made by HWVE deposition of a 1.5 ..mu..m thick n-type CdTe layer on a p-type CdTe single crystal substrate. Values of V/sub oc/ = 0.73 V and J/sub sc/ = 0.24 mA/cm/sup 2/ were obtained. Grain boundary investigations showed the additive quality of two independent grain boundaries when measured in series, and tested the effects of passivation by Au, Cu, Li and H/sub 2/ in p-type CdTe grain boundaries, and In in n-type CdTe grain boundaries. Marked decreases in grain boundary resistance were observed after Li diffusion and H/sub 2/ diffusion in p-type CdTe.

Bube, R H

1982-01-01T23:59:59.000Z

176

Structurally-driven metal-insulator transition in Ca{sub 2}Ru{sub 1-x}Cr{sub x}O{sub 4} (0{<=}x<0.14): A single crystal X-ray diffraction study  

Science Conference Proceedings (OSTI)

Correlation between structure and transport properties are investigated in high-quality single-crystals of Ca{sub 2}Ru{sub 1-x}Cr{sub x}O{sub 4} with 013.5% and the system behaves as an insulator. Such a large, sharp metal-insulator transition and tuneable transition temperature may have potential applications in electronic devices. -- Graphical abstract: The metal-insulator transition temperature (T{sub MI}) was drastically reduced by Cr doping, and is closely related to the distortion of structure. Display Omitted Research highlights: {yields} The metal-insulator transition temperature (T{sub MI}) was drastically reduced by doping Cr into Ca{sub 2}RuO{sub 4} single crystal. {yields} Detailed single crystal structural analysis provided important insight into this structurally-driven metal-insulator transition. {yields} Negative Volume Thermal Expansion (NVTE) was observed with increasing temperature.

Qi, T.F., E-mail: tqi2@uky.ed [Center for Advanced Materials, University of Kentucky, Lexington, KY 40506 (United States); Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States); Ge, M. [Center for Advanced Materials, University of Kentucky, Lexington, KY 40506 (United States); High Magnetic Field Laboratory, University of Science and Technology of China, Hefei, Anhui 230026 (China); Korneta, O.B. [Center for Advanced Materials, University of Kentucky, Lexington, KY 40506 (United States); Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States); Parkin, S. [Center for Advanced Materials, University of Kentucky, Lexington, KY 40506 (United States); Department of Chemistry, University of Kentucky, Lexington, KY 40506 (United States); De Long, L.E.; Cao, G. [Center for Advanced Materials, University of Kentucky, Lexington, KY 40506 (United States); Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States)

2011-04-15T23:59:59.000Z

177

An energy-conserving two-temperature model of radiation damage in single-component and binary Lennard-Jones crystals  

SciTech Connect

Two-temperature models are used to represent the interaction between atoms and free electrons during thermal transients such as radiation damage, laser heating, and cascade simulations. In this paper, we introduce an energy-conserving version of an inhomogeneous finite reservoir two-temperature model using a Langevin thermostat to communicate energy between the electronic and atomic subsystems. This energy-conserving modification allows the inhomogeneous two-temperature model to be used for longer and larger simulations and simulations of small energy phenomena, without introducing nonphysical energy fluctuations that may affect simulation results. We test this model on the annealing of Frenkel defects. We find that Frenkel defect annealing is largely indifferent to the electronic subsystem, unless the electronic subsystem is very tightly coupled to the atomic subsystem. We also consider radiation damage due to local deposition of heat in two idealized systems. We first consider radiation damage in a large face-centered-cubic Lennard-Jones (LJ) single-component crystal that readily recrystallizes. Second, we consider radiation damage in a large binary glass-forming LJ crystal that retains permanent damage. We find that the electronic subsystem parameters can influence the way heat is transported through the system and have a significant impact on the number of defects after the heat deposition event. We also find that the two idealized systems have different responses to the electronic subsystem. The single-component LJ system anneals most rapidly with an intermediate electron-ion coupling and a high electronic thermal conductivity. If sufficiently damaged, the binary glass-forming LJ system retains the least permanent damage with both a high electron-ion coupling and a high electronic thermal conductivity. In general, we find that the presence of an electronic gas can affect short and long term material annealing.

Phillips, Carolyn L. [Applied Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States); Crozier, Paul S. [Department of Multiscale Dynamic Materials Modeling, Sandia National Laboratories, P.O. Box 5800, MS 1322, Albuquerque, New Mexico 87185-1322 (United States)

2009-08-21T23:59:59.000Z

178

Thermally Processed High-Mobility MOS Thin-Film Transistors on Transferable Single-Crystal Elastically Strain-Sharing Si/SiGe/Si Nanomembranes  

DOE Green Energy (OSTI)

Demonstration of high-performance MOS thin-film transistors (TFTs) on elastically strain-sharing single-crystal Si/SiGe/Si nanomembranes (SiNMs) that are transferred to foreign substrates is reported. The transferable SiNMs are realized by first growing pseudomorphic SiGe and Si layers on silicon-on-insulator (SOI) substrates, and then, selectively removing the buried oxide (BOX) layer from the SOI. Before the release, only the SiGe layer is compressively strained. Upon release, part of the compressive strain in the SiGe layer is transferred to the thin Si layers, and the Si layers, thus, become tensile strained. Both the initial compressive strain state in the SiGe layer and the final strain sharing state between the SiGe and the Si layers are verified with X-ray diffraction measurements. The TFTs are fabricated employing the conventional high-temperature MOS process on the strain-shared SiNMs that are transferred to an oxidized Si substrate. The transferred strained-sharing SiNMs show outstanding thermal stability and can withstand the high-temperature TFT process on the new host substrate. The strained-channel TFTs fabricated on the new host substrate show high current drive capability and an average electron effective mobility of 270 cm{sup 2}/V ldr s. The results suggest that transferable and thermally stable single-crystal elastically strain- sharing SiNMs can serve as excellent active material for high-speed device application with a simple and scalable transfer method. The demonstration of MOS TFTs on the transferable nanomembranes may create the opportunity for future high-speed Si CMOS heterogeneous integration on any substrate.

Yuan, H.-C.; Kelly, M. M.; Savage, D. E.; Lagally, M. G.; Celler, G. K.; Zhenqiang, M.

2008-03-01T23:59:59.000Z

179

Preparation and properties of evaporated CdTe films compared with single crystal CdTe. Progress report No. 4, August 1-October 31, 1981  

DOE Green Energy (OSTI)

The hot-wall vacuum evaporation system is nearly complete and the first films are expected in early December. CdTe homojunction cells were theoretically modelled and to some extent tested experimentally using the n-type CdTe film on p-type CdTe crystal homojunction cells previously deposited at Linz. Modelling emphasizes the known importance of surface recombination velocity for such homojunction cells. The n-type layer on the experimental cell was thinned by etching from 5 micrometers to 1.5 micrometers, with a corresponding increase in short-circuit current from 0.1 to 1 mA/cm/sup 2/. This behavior is as theoretically expected; to obtain a short-circuit current of 11 mA/cm/sup 2/, as required for a 10% cell, requires a thickness of about 0.2 micrometers for a surface recombination velocity of 10/sup 6/ cm/sec and other realistic cell parameters. By doping experiments on single crystal CdTe, it has been shown that the hole density does decrease when the P dopant density is decreased below a critical value in CdTe:P crystals, thus eliminating the possibility that the major acceptors in the P-doped crystals were not P impurity. Attempts to heavily dope CdTe with As were less successful, but this may be due to the use of elemental As as the dopant in this case rather than a compound of the dopant. Cs was shown to be an effective dopant of CdTe and resistivities as low as 0.3 ohm-cm corresponding to hole densities in the low 10/sup 17/ cm/sup -3/ range were obtained. An apparent correlation between the low-temperature barrier height associated with a grain boundary in CdTe and the angle of mismatch between the two grains has been observed. Improved capacitance of grain boundary measurements should yield defect densities.

Bube, R H

180

Vortex creep and critical current densities in superconducting (Ba,K)Fe2As2 single crystals  

Science Conference Proceedings (OSTI)

The surprisingly rapid relaxation of the sustainable current density in the critical state of single-crystalline Ba1?xKxFe2As2 is investigated for magnetic fields oriented parallel to the c axis and to the ab plane, respectively. Due to the inadequacy of standard analysis procedures developed for flux creep in the high-temperature superconducting cuprates, we develop a simple, straightforward data treatment technique that reveals the creep mechanism and the creep exponent ?. At low magnetic fields, below the second magnetization peak, ? varies only slightly as a function of temperature and magnetic flux density B. From the data, we determine the temperature and field dependencies of the effective activation barrier for creep. At low temperatures, the measured current density approaches the zero-temperature critical current density (in the absence of creep) to within a factor 2, thus lending credence to earlier conclusions drawn with respect to the pinning mechanism. The comparable values of the experimental screening current density and the zero-temperature critical current density reveal the limited usefulness of the widely used “interpolation formula.”

Konczykowski, M.; van Der Beek, C.J.; Tanatar, Makariy A.; Luo, Huiqian; Wang, Zhaosheng; Shen, Bing; Wen, Hai Hu; Prozorov, Ruslan

2012-07-13T23:59:59.000Z

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181

Cation distribution in a Fe-bearing K-feldspar from Itrongay,Madagascar. A combined neutron- and X-ray single crystal diffractionstudy  

Science Conference Proceedings (OSTI)

We determined the cation distribution and ordering of Si, Al and Fe on the tetrahedral sites of a monoclinic low-sanidine from Itrongay, Madagascar, by combined neutron- and X-ray single-crystal diffraction. The cation distribution was determined by means of a simultaneous refinement using neutron- and X-ray data, as well as by combining scattering densities obtained from separate refinements with chemical data from a microprobe experiment. The two methods give the same results and show that Fe is fully ordered on T1, whereas Al shows a high degree of disorder. Based on this and previously published temperature-dependent X-ray data, we conclude that it is preferential ordering of Fe on T1 even at high temperature, rather than a high diffusion kinetics of Fe, which causes this asymmetry in ordering behavior between Al and Fe. The preferential ordering of Fe3+ relative to Al3+ in T1 is consistent with its 25 percent larger ionic radius.

Ackermann, Sonia; Kunz, Martin; Armbruster, Thomas; Schefer,Jurg; Hanni, Henry

2005-05-02T23:59:59.000Z

182

The role of hydrogen in the hydrogenation and hydrogenolysis of aniline on the nickel single crystal surfaces: Its implication on the mechanisms of HDN reactions  

SciTech Connect

The selectivity of hydrogenation and hydrogenolysis reactions for organonitrogen compounds on transition metal surfaces depends heavily on the availability of surface hydrogen surface under reaction conditions. The surface hydrogen produced during dehydrogenation of adsorbed aniline upon thermal activation does not significantly modify hydrogenolysis reactions because it desorbs below the reaction temperatures. A series of experiments which use external hydrogen to control the concentration of surface hydrogen at reaction temperatures are reported here. In situ kinetic measurements in the presence of reactive hydrogen environments have been used to probe the details of the adsorbed species and reaction mechanisms. Nickel single crystals have been used as well defined model catalysts for hydrodenitrogenation (HDN) reactions. Previously, the effect of external hydrogen on aniline hydrogenolysis on the Pt(111) surface has been reported. On Pt(111), C-N bond activation is substantially enhanced in the presence of hydrogen. The increased C-N bond cleavage is facilitated by hydrogen which maintains a parallel adsorption of the aromatic derivative of aniline. In the absence of surface hydrogen, the adsorbed intermediate tilts away from surface because of partial dehydrogenation with increasing temperature at about 400 K. This paper will discuss a recent study of aniline reactions on the Ni(100) and Ni(111) surfaces both in the presence and absence of hydrogen. Reactivity comparisons will also be made for these two nickel surfaces towards adsorbed aniline.

Huang, S.X.; Gland, J.L. [Univ. of Michigan, Ann Arbor, MI (United States); Fischer, D.A. [National Institute of Standards and Technology, Gaithersburg, MD (United States)

1995-02-01T23:59:59.000Z

183

The interaction of 193-nm excimer laser radiation with single-crystal zinc oxide: The generation of atomic Zn line emission at laser fluences below breakdown  

SciTech Connect

The production of gas phase atomic and ionic line spectra accompanying the high laser fluence irradiation of solid surfaces is well known and is most often due to the production and interaction of high densities of atoms, ions, and electrons generated from laser-induced breakdown. The resulting plasma expands and moves rapidly away from the irradiated spot and is accompanied by intense emission of light. This type of plume is well studied and is frequently exploited in the technique of chemical analysis known as laser induced breakdown spectroscopy. Here, we describe a similar but weaker emission of light generated in vacuum by the laser irradiation of single crystal ZnO at fluences well below breakdown; this emission consists entirely of optical line emission from excited atomic Zn. We compare the properties of the resulting laser-generated gas-phase light emission (above and below breakdown) and describe a mechanism for the production of the low-fluence optical emission resulting from a fortuitous choice of material and laser wavelength.

Kahn, E. H. [Washington State University, Pullman; Langford, S. C. [Washington State University, Pullman; Dickinson, J. T. [Washington State University, Pullman; Boatner, Lynn A [ORNL

2013-01-01T23:59:59.000Z

184

I. Interaction of ammonia with single crystal rhodium catalysts. II. Hydrogen and nitrogen adsorption on a W(111) surface: a theoretical molecular orbital approach  

DOE Green Energy (OSTI)

Rates of ammonia decomposition on (110), (100), and (111) single crystal faces of rhodium were measured at 580 to 725/sup 0/K and 10/sup -3/ to 500 x 10/sup -3/ torr. The decomposition rates were proportional to P/sub NH/sub 3//sup/1/2/ and P/sub NH/sub 3// at low and high hydrogen pressures, respectively. The H/sub 2/ kinetic order varied from 0 (low P/sub H/sub 2//) to -1.0 (high P/sub H/). The rate was independent of N/sub 2/ pressure. NH/sub 3/ decomposes about 1.5 times faster than ND/sub 3/ on the (110) and (111) faces. Rates on the (110) surface are over 10 times as rapid as on the (111). LEED, Auger, and flash desorption experiments indicated that boron was a significant surface poison and that the Rh(110) surface was essentially nitrogen-free. A rate expression is derived from a model involving surface species Rh/sub 2/NH, RhH, and RhN on a nearly bare RH surface. The rate limiting process involves the concurrent dehydrogenation of Rh/sub 2/NH and desorption of N/sub 2/. A decreasing NH/sub 3/ order (< 1/2) at high P/sub NH/sub 3// and low T is due to buildup of surface intermediates. The relative bonding energies of hydrogen and nitrogen chemisorbed at three sites on a W(111) surface were obtained via the extended Hueckel molecular orbital theory. The preferred site for both H and N chemisorption was determined as the TOP position, i.e., a single coordination site on top of a protruding W atom. The W(111) surface was simulated by truncated arrays of seven tungsten atoms. The basis set for the calculations included the tungsten valence orbitals plus the filled 5p orbitals needed for repulsion at small internuclear distances. N adsorption in the three-fold holes available on the W(111) lattices used disrupted the W--W bonds sufficiently to cause the overall bond energy to be less than for the single coordination site. The dissymmetry between the three-fold lattices and the four-fold W d orbitals may also be a contributing factor.

Vavere, A.

1979-01-01T23:59:59.000Z

185

Description and procedures for synchrotron radiation, small molecule, single crystal crystallography of plutonium complexes at ALS beamline 11.3.1  

E-Print Network (OSTI)

Crystallography of Plutonium Complexes at ALS Beamlineof the Structural Parameters of Plutonium Complexes by Smallpreparation and growth of the plutonium complexes (crystals)

Gorden, A.E.V.; Raymond, K.N.; Shuh, D.K.

2008-01-01T23:59:59.000Z

186

Direct evidence of a zigzag spin-chain structure in the honeycomb lattice: A neutron and x-ray diffraction investigation of single-crystal Na2IrO3  

Science Conference Proceedings (OSTI)

We have combined single crystal neutron and x-ray diffractions to investigate the magnetic and crystal structures of the honeycomb lattice $\\rm Na_2IrO_3$. The system orders magnetically below $18.1(2)$~K with Ir$^{4+}$ ions forming zigzag spin chains within the layered honeycomb network with ordered moment of $\\rm 0.22(1)~\\mu_B$/Ir site. Such a configuration sharply contrasts the N{\\'{e}}el or stripe states proposed in the Kitaev-Heisenberg model. The structure refinement reveals that the Ir atoms form nearly ideal 2D honeycomb lattice while the $\\rm IrO_6$ octahedra experience a trigonal distortion that is critical to the ground state. The results of this study provide much-needed experimental insights into the magnetic and crystal structure crucial to the understanding of the exotic magnetic order and possible topological characteristics in the 5$d$-electron based honeycomb lattice.

Ye, Feng [ORNL; Chi, Songxue [ORNL; Cao, Huibo [ORNL; Chakoumakos, Bryan C [ORNL; Fernandez-Baca, Jaime A [ORNL; Custelcean, Radu [ORNL; Qi, Tongfei [University of Kentucky; Korneta, O. B. [University of Kentucky, Lexington; Cao, Gang [University of Kentucky

2012-01-01T23:59:59.000Z

187

A von Hamos x-ray spectrometer based on a segmented-type diffraction crystal for single-shot x-ray emission spectroscopy and time-resolved resonant inelastic x-ray scattering studies  

SciTech Connect

We report on the design and performance of a wavelength-dispersive type spectrometer based on the von Hamos geometry. The spectrometer is equipped with a segmented-type crystal for x-ray diffraction and provides an energy resolution in the order of 0.25 eV and 1 eV over an energy range of 8000 eV-9600 eV. The use of a segmented crystal results in a simple and straightforward crystal preparation that allows to preserve the spectrometer resolution and spectrometer efficiency. Application of the spectrometer for time-resolved resonant inelastic x-ray scattering and single-shot x-ray emission spectroscopy is demonstrated.

Szlachetko, J. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Nachtegaal, M.; Boni, E. de; Willimann, M.; Safonova, O.; Sa, J.; Smolentsev, G.; Szlachetko, M.; Bergamaschi, A.; Schmitt, B.; David, C.; Luecke, A. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Bokhoven, J. A. van [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Institute for Chemical and Bioengineering, ETH Zurich, 8093 Zuerich (Switzerland); Dousse, J.-Cl.; Hoszowska, J.; Kayser, Y. [Department of Physics, University of Fribourg, 1700 Fribourg (Switzerland); Jagodzinski, P. [University of Technology, Kielce (Poland)

2012-10-15T23:59:59.000Z

188

Upper critical fields and thermally-activated transport of Nd(0.7Fe0.3) FeAs single crystal  

SciTech Connect

We present measurements of the resistivity and the upper critical field H{sub c2} of Nd(O{sub 0.7}F{sub 0.3})FeAs single crystals in strong DC and pulsed magnetic fields up to 45 T and 60 T, respectively. We found that the field scale of H{sub c2} is comparable to {approx}100 T of high T{sub c} cuprates. H{sub c2}(T) parallel to the c-axis exhibits a pronounced upward curvature similar to what was extracted from earlier measurements on polycrystalline samples. Thus this behavior is indeed an intrinsic feature of oxypnictides, rather than manifestation of vortex lattice melting or granularity. The orientational dependence of H{sub c2} shows deviations from the one-band Ginzburg-Landau scaling. The mass anisotropy decreases as T decreases, from 9.2 at 44K to 5 at 34K. Spin dependent magnetoresistance and nonlinearities in the Hall coefficient suggest contribution to the conductivity from electron-electron interactions modified by disorder reminiscent that of diluted magnetic semiconductors. The Ohmic resistivity measured below T{sub c} but above the irreversibility field exhibits a clear Arrhenius thermally activated behavior over 4--5 decades. The activation energy has very different field dependencies for H{parallel}ab and H{perpendicular}ab. We discuss to what extent different pairing scenarios can manifest themselves in the observed behavior of H{sub c2}, using the two-band model of superconductivity. The results indicate the importance of paramagnetic effects on H{sub c2}(T), which may significantly reduce H{sub c2}(0) as compared to H{sub c2}(0) {approx}200--300 T based on extrapolations of H{sub c2}(T) near T{sub c} down to low temperatures.

Balakirev, Fedor F [Los Alamos National Laboratory; Jaroszynski, J [NHMFL, FSU; Hunte, F [NHMFL, FSU; Balicas, L [NHMFL, FSU; Jo, Youn - Jung [NHMFL, FSU; Raicevic, I [NHMFL, FSU; Gurevich, A [NHMFL, FSU; Larbalestier, D C [NHMFL, FSU; Fang, L [CHINA; Cheng, P [CHINA; Jia, Y [CHINA; Wen, H H [CHINA

2008-01-01T23:59:59.000Z

189

Out-of-plane negative magnetoresistance of Bi{sub 2}Sr{sub 1.6}La{sub 0.4}CuO{sub 6+{delta}} single crystals in the underdoped region  

Science Conference Proceedings (OSTI)

In order to investigate a relationship between the carrier concentration and negative magnetoresistance in the underdoped region, they have performed out-of-plane electrical resistivity measurements for underdoped Bi{sub 2}Sr{sub 1.6}La{sub 0.4}CuO{sub 6+{delta}} single crystals. Giant negative magnetoresistance has been observed in the most abundant carrier sample with {delta} = 0.12 in the experiment. The negative magnetoresistance reduces with decreasing carrier concentration.

Akazawa, Teruhiko; Ikeda, Hiroshi; Ozawa, Norihiko; Kouno, Hideki; Yoshizaki, Ryozo

1999-12-01T23:59:59.000Z

190

Mechanochemical Synthesis of Nonstoichiometric Fluorite Ca{sub 1-x} La{sub x} F{sub 2+x} Nanocrystals from CaF{sub 2} and LaF{sub 3} Single Crystals  

Science Conference Proceedings (OSTI)

The nonstoichiometric Ca{sub 1-x} La{sub x}F{sub 2+x} phase (x {>=} 0.1) is obtained by mechanochemical synthesis from CaF{sub 2} and LaF{sub 3} single crystals. This phase is the first representative of fluorite fluorides obtained by mechanochemical synthesis in the MF{sub m}-RF{sub n} systems (m fluoride ions in the crystal bulk. Mechanochemical synthesis of a multicomponent fluoride material with nanometer grains opens a new chapter in the chemistry of inorganic fluorides. A decrease of the sintering temperature of the powders with nanometer grains is very important for preparing dense fluoride ceramics of complicated compositions and other polycrystalline forms of fluoride materials.

Sobolev, B.P.; Sul'yanov, S.N.; Sorokin, N.I.; Zhmurova, Z.I. [Shubnikov Institute of Crystallography, Russian Academy of Sciences, Leninskii pr. 59, Moscow, 119333 (Russian Federation); Sviridov, I.A.; Fadeeva, V.I. [Moscow State University, Moscow, 119992 (Russian Federation); Herrero, P.; Landa-Canovas, A.; Rojas, R.M. [Instituto de Ciencia de Materiales de Madrid, Madrid (Spain)

2005-05-15T23:59:59.000Z

191

Study of the Stability of 3C-SiC Single Crystals Using High-Resolution Diffuse X-Ray Scattering  

SciTech Connect

The stability of (001)-oriented 3C silicon carbide crystals is studied by a method coupling high resolution x-ray diffraction and numerical simulations. The analysis of the diffuse scattering intensity distribution along selected directions in reciprocal space allows us to obtain qualitative and quantitative informations regarding the 3C-6H transition. Our latest results concerning the influence of the initial crystal quality (presence of defects) and of annealing time on the 3C-6H transition are presented in this article.

Dompoint, D.; Boulle, A. [Science des Procedes Ceramiques et de Traitements de Surface (SPCTS) CNRS UMR 6638, ENSCI, 47 avenue Albert Thomas 87065 Limoges Cedex (France); Galben-Sandulache, I. G.; Chaussende, D. [Laboratoire des Materiaux et du Genie Physique (LMGP) CNRS UMR 5628, Grenoble INP, Minatec, 3 parvis Louis Neel, BP 257, 38016 Grenoble Cedex 01 (France)

2010-11-01T23:59:59.000Z

192

Technology Development for High-Efficiency Solar Cells and Modules Using Thin (<80 um) Single-Crystal Silicon Wafers Produced by Epitaxy: June 11, 2011 - April 30, 2013  

DOE Green Energy (OSTI)

Final technical progress report of Crystal Solar subcontract NEU-31-40054-01. The objective of this 18-month program was to demonstrate the viability of high-efficiency thin (less than 80 um) monocrystalline silicon (Si) solar cells and modules with a low-cost epitaxial growth process.

Ravi, T. S.

2013-05-01T23:59:59.000Z

193

Effect of a high electric field on the conductivity of MnGa{sub 2}S{sub 4}, MnIn{sub 2}S{sub 4}, and MnGaInS{sub 4} single crystals  

Science Conference Proceedings (OSTI)

The results of studying the effect of a high electric field on the conductivity of MnGa{sub 2}S{sub 4}, MnIn{sub 2}S{sub 4}, and MnGaInS{sub 4} single crystals are reported. The activation energy is determined in high and low electric fields. It is established that the decrease in the activation energy with increasing the external voltage is associated with decreasing the depth of the potential well, in which the electron is located.

Niftiev, N. N. [Azerbaijan State Pedagogical University (Azerbaijan); Tagiev, O. B. [National Academy of Sciences of Azerbaijan, Institute of Physics (Azerbaijan)

2009-09-15T23:59:59.000Z

194

Quartz crystal growth  

DOE Patents (OSTI)

A process for growing single crystals from an amorphous substance that can undergo phase transformation to the crystalline state in an appropriate solvent. The process is carried out in an autoclave having a lower dissolution zone and an upper crystallization zone between which a temperature differential (.DELTA.T) is maintained at all times. The apparatus loaded with the substance, solvent, and seed crystals is heated slowly maintaining a very low .DELTA.T between the warmer lower zone and cooler upper zone until the amorphous substance is transformed to the crystalline state in the lower zone. The heating rate is then increased to maintain a large .DELTA.T sufficient to increase material transport between the zones and rapid crystallization. .alpha.-Quartz single crystal can thus be made from fused quartz in caustic solvent by heating to 350.degree. C. stepwise with a .DELTA.T of 0.25.degree.-3.degree. C., increasing the .DELTA.T to about 50.degree. C. after the fused quartz has crystallized, and maintaining these conditions until crystal growth in the upper zone is completed.

Baughman, Richard J. (Albuquerque, NM)

1992-01-01T23:59:59.000Z

195

Growth conditions, structure, Raman characterization and optical properties of Sm-doped (Lu{sub x}Gd{sub 1-x}){sub 2}SiO{sub 5} single crystals grown by the Czochralski method  

Science Conference Proceedings (OSTI)

The (Lu{sub x}Gd{sub 0.995-x}Sm{sub 0.005}){sub 2}SiO{sub 5} single crystals with x=0.095, 0.11, 0.15, 0.17, 0.19 0.35 and 0.5 were grown by the Czochralski method. Structural properties were investigated by X-ray diffraction measurements. Unit cell parameters and cell volume were determined by the Rietveld refinement of the collected X-ray powder spectra. The segregation features between Gd and Lu were estimated and analyzed. Vibrational properties of the solid solutions were analyzed on the basis of polarized Raman spectra acquired at 300-875 K temperature range. Absorption and emission spectra of Sm{sup 3+} ion in the crystals with different composition were analyzed in the terms of dopant energy levels, oscillator strengths of transitions and spectral features of luminescence bands in the visible range. Both structural and optical investigations revealed that change of Lu{sup 3+} content in (Lu{sub x}Gd{sub 0.995-x}Sm{sub 0.005}){sub 2}SiO{sub 5} solid solution crystals induces the phase transition from C2/c (Lu{sub 2}SiO{sub 5}) to P2{sub 1}/c (Gd{sub 2}SiO{sub 5}) structure. It was found that the break of LSO to GSO-type structure occurs at 0.15Single crystals of Sm{sup 3+}-doped (Lu{sub x}Gd{sub 1-x}){sub 2}SiO{sub 5} solid solutions have been grown by Czochralski method and characterized by various techniques. Crystal structure changes from C2/c to P2{sub 1}/c for composition with 0.15crystal structure causes changes in emission spectra. Highlights: Black-Right-Pointing-Pointer The (Lu{sub x}Gd{sub 1-x}){sub 2}SiO{sub 5} crystals are an alternative to LSO and GSO hosts for applications. Black-Right-Pointing-Pointer The break of the P2{sub 1}/c to C2/c structure in (Lu{sub x}Gd{sub 1-x}){sub 2}SiO{sub 5}:Sm occurs for 0.15

GLowacki, MichaL, E-mail: glowacki@ifpan.edu.pl [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Dominiak-Dzik, Grazyna; Ryba-Romanowski, Witold; Lisiecki, RadosLaw; Strzep, Adam [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, ul. Okolna 2, 50-950 WrocLaw (Poland); Runka, Tomasz; Drozdowski, MirosLaw [Faculty of Technical Physics, Poznan University of Technology, ul. Nieszawska 13A, 60-965 Poznan (Poland); Domukhovski, Viktor [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Diduszko, Ryszard [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Institute of Electronic Materials Technology, ul. Wolczynska 133, 01-919 Warsaw (Poland); Berkowski, Marek [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland)

2012-02-15T23:59:59.000Z

196

Effect of {gamma}-ray radiation on electrical properties of heat-treated Tb{sub x}Sn{sub 1-x}Se single crystals  

Science Conference Proceedings (OSTI)

The effect of {gamma}-ray radiation on the electrical properties of heat-treated Tb{sub 0.01}Sn{sub 0.99}Se (sample 1) and Tb{sub 0.05}Sn{sub 0.95}Se (sample 2) samples is studied. It is found that, as a result of irradiation with {gamma}-ray 1.25-MeV photons, the charge-carrier concentration decreases in the temperature range T = 77-200 K by 17 and 6.3% for samples 1 and 2, respectively. It is assumed that, in the course of irradiation with {gamma}-ray photons, terbium impurity atoms are located between sites of the crystal lattice; in addition, Frenkel defects are formed.

Huseynov, J. I., E-mail: cih_58@mail.ru; Jafarov, T. A. [Azerbaijan State Pedagogical University (Azerbaijan)

2012-04-15T23:59:59.000Z

197

Single crystals of the fluorite nonstoichiometric phase Eu{sub 0.916}{sup 2+}Eu{sub 0.084}{sup 3+}F{sub 2.084} (conductivity, transmission, and hardness)  

Science Conference Proceedings (OSTI)

The nonstoichiometric phase EuF{sub 2+x} has been obtained via the partial reduction of EuF{sub 3} by elementary Si at 900-1100 deg. C. Eu{sub 0.916}{sup 2+}Eu{sub 0.084}{sup 3+}F{sub 2.084} (EuF{sub 2.084}) single crystals have been grown from melt by the Bridgman method in a fluorinating atmosphere. These crystals belong to the CaF{sub 2} structure type (sp. gr. Fm3-barm) with the cubic lattice parameter a = 5.8287(2) A, are transparent in the spectral range of 0.5-11.3 {mu}m, and have microhardness H{sub {mu}} = 3.12 {+-} 0.13 GPa and ionic conductivity {sigma} = 1.4 x 10{sup -5} S/cm at 400 deg. C with the ion transport activation energy E{sub a} = 1.10 {+-} 0.05 eV. The physicochemical characteristics of the fluorite phases in the EuF{sub 2} - EuF{sub 3} systems are similar to those of the phases in the SrF{sub 2} - EuF{sub 3} and SrF{sub 2} - GdF{sub 3} systems due to the similar lattice parameters of the EuF{sub 2} and SrF{sub 2} components. Europium difluoride supplements the list of fluorite components MF{sub 2} (M = Ca, Sr, Ba, Cd, Pb), which are crystal matrices for nonstoichiometric (nanostructured) fluoride materials M{sub 1-x}R{sub x}F{sub 2+x} (R are rare earth elements).

Sobolev, B. P., E-mail: fluorides@ns.crys.ras.ru; Turkina, T. M.; Sorokin, N. I.; Karimov, D. N.; Komar'kova, O. N.; Sulyanova, E. A. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

2010-07-15T23:59:59.000Z

198

Hydrogen in polar intermetallics: Syntheses and structures of the ternary Ca5Bi3D0.93, Yb5Bi3Hx, and Sm5Bi3H~1 by powder neutron or single crystal X-ray diffraction  

DOE Green Energy (OSTI)

The syntheses of the title compounds are described in detail. Structural characterizations from refinements of single crystal X-ray diffraction data for Yb{sub 5}Bi{sub 3}H{sub x} and Sm{sub 5}Bi{sub 3}H{sub 1} and of powder neutron diffraction data for Ca{sub 5}Bi{sub 3}D{sub 0.93(3)} are reported. These confirm that all three crystallize with the heavy atom structure type of {beta}-Yb{sub 5}Sb{sub 3}, and the third gives the first proof that the deuterium lies in the center of nominal calcium tetrahedra, isostructural with the Ca{sub 5}Sb{sub 3}F-type structure. These Ca and Yb phases are particularly stable with respect to dissociation to Mn{sub 5}Si{sub 3}-type product plus H{sub 2}. Some contradictions in the literature regarding Yb{sub 5}Sb{sub 3} and Yb{sub 5}Sb{sub 3}H{sub x} phases are considered in terms of adventitious hydrogen impurities that are generated during reactions in fused silica containers at elevated temperatures.

Leon-Escamilla, E. Alejandro; Dervenagas, Panagiotis; Stasis, Constantine; Corbett, John D.

2010-01-01T23:59:59.000Z

199

Manifestation of light and heavy electrons in the galvanomagnetic characteristics of Te-doped n-Bi{sub 0.88}Sb{sub 0.12} single crystals  

Science Conference Proceedings (OSTI)

The components of resistivity ({rho}{sub ij}), Hall coefficient (R{sub ijk}), and magnetoresistance ({rho}{sub ij,kl}) of n-Bi{sub 0.88}Sb{sub 0.12} single crystals doped with tellurium to 0.01, 0.1, and 0.2 at % have been measured in the temperature range of 77-300 K. It is concluded that light and heavy electrons are involved in transport processes. The energy spacing between the bands of light and heavy electrons is found to be 40 meV, and the ratios of the effective masses and electron mobilities are estimated as m{sub 2}*/m{sub l}* = 3 and b Almost-Equal-To 0.16, respectively.

Tairov, B. A., E-mail: btairov@physics.ab.az; Ibragimova, O. I., E-mail: ofeliya_i@physics.ab.az; Rahimov, A. H. [National Academy of Sciences of Azerbaijan, Institute of Physics (Azerbaijan); Brazis, R., E-mail: brazis@pfi.lt [Semiconductor Physics Institute (Lithuania)

2011-02-15T23:59:59.000Z

200

Single-Crystal Intermetallic M-Sn (M ) Fe, Cu, Co, Ni) Nanospheres as Negative Electrodes for Lithium-Ion Batteries  

DOE Green Energy (OSTI)

FeSn{sub 2}, Cu{sub 6}Sn{sub 5}, CoSn{sub 3}, and Ni{sub 3}Sn{sub 4} single-crystalline nanospheres with a characteristic uniform particle size of 40 nm have been synthesized via a modified polyol process, aiming at determining and understanding their intrinsic cycling performance as negative electrode materials for lithium-ion batteries. We find that, in this morphologically controlled condition, the reversible capacities follow FeSn{sub 2} > Cu{sub 6}Sn{sub 5} {approx} CoSn{sub 3} > Ni{sub 3}Sn{sub 4}, which is not directly decided by their theoretical capacities or lithium-driven volume changes. FeSn{sub 2} exhibits the best electrochemical activity among these intermetallic nanospheres and an effective solid electrolyte interface, which explains its superior cycling performance. The small particle dimension also improves cycling stability and Li{sup +} diffusion.

Wang, X.; Han, W; Chen, J; Graetz, J

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


201

Hot Corrosion Resistant and High Strength Nickel-Based Single ...  

Science Conference Proceedings (OSTI)

Flow chart for the design of hot-corrosion resistant and high strength nickel- based single crystal superalloys. Fig.& Typical SEM image of designed single-.

202

Crystal Plasticity Modeling on Single Crystal and Polycrystal of a ...  

Science Conference Proceedings (OSTI)

Multiscale Modeling of Fracture Resistance in TRIP-Assisted Multiphase Steels ... Statistical Failure Analysis of Crystallographically Isotropic Porous Materials.

203

High Speed Single Crystal Casting Technique  

Science Conference Proceedings (OSTI)

and regulation of convection ... produced by an ordinary casting method because the solidification time is so long as to .... Water Cooled Chillplate. 1 t'Elevator.

204

Creep Deformation Anisotropy in Single Crystal Superalloys  

Science Conference Proceedings (OSTI)

45% acetic acid and 10% perchloric acid at O°C and 25 V. These foils were examined both at IHI and ONERA. @cperiment.al ., results. Creep.. propert.ie_s.. at.

205

Multiaxial Creep Deformation of Single Crystal Superalloys ...  

Science Conference Proceedings (OSTI)

For example, in power law creep the creep rate is described by the relation i .... The map was generated using a grid of 150~150 with a step size of 2Opm, and a.

206

Stripes of increased diamagnetic susceptibility in underdoped superconducting Ba(Fe[subscript 1?x]Co[subscript x])[subscript 2]As[subscript 2] single crystals: Evidence for an enhanced superfluid density at twin boundaries  

SciTech Connect

Superconducting quantum interference device microscopy shows stripes of increased diamagnetic susceptibility in the superconducting state of twinned, orthorhombic, underdoped crystals of Ba(Fe{sub 1-x}Co{sub x}){sub 2}As{sub 2}, but not in tetragonal overdoped crystals. These stripes are consistent with enhanced superfluid density on twin boundaries.

Kalisky, B.; Kirtley, J.R.; Analytis, J.G.; Chu, Jiun-Haw; Vailionis, A.; Fisher, I.R.; Moler, K.A. (Stanford)

2010-10-22T23:59:59.000Z

207

NIST CNR SANS Bonze-Hart Perfect Crystal Diffractometer ...  

Science Conference Proceedings (OSTI)

... 8, Neutron transmission of single-crystal magnesium fluoride, JG Barker, DF Mildner, JA Rodriguez, P. Thiyagarajan, J Appl. Cryst. 41, 6, 1003, 2008 ...

208

Method of making coherent multilayer crystals  

DOE Patents (OSTI)

A new material consisting of a coherent multilayer crystal of two or more elements where each layer is composed of a single element. Each layer may vary in thickness from about 2 .ANG. to 2500 .ANG.. The multilayer crystals are prepared by sputter deposition under conditions which slow the sputtered atoms to near substrate temperatures before they contact the substrate.

Schuller, Ivan K. (Woodridge, IL); Falco, Charles M. (Woodridge, IL)

1984-01-01T23:59:59.000Z

209

Coherent multilayer crystals and method of making  

DOE Patents (OSTI)

A new material is described consisting of a coherent multilayer crystal of two or more elements where each layer is composed of a single element. Each layer may vary in thickness from about 2 A to 2500 A. The multilayer crystals are prepared by sputter deposition under conditions which slow the sputtered atoms to near substrate temperatures before they contact the substrate.

Schuller, I.K.; Falco, C.M.

1980-10-30T23:59:59.000Z

210

Magnetic-resonance and thermophysical studies of the magnetic phase diagram for a GdFe{sub 2.1}Ga{sub 0.9}(BO{sub 3}){sub 4} single crystal  

Science Conference Proceedings (OSTI)

The antiferromagnetic resonance, heat capacity, magnetic properties, and magnetic phase diagram of a GdFe{sub 3}(BO{sub 3}){sub 4} crystal in which some of the iron ions were substituted by diamagnetic gallium ions have been investigated. It has been found that the Neel temperature upon diamagnetic substitution decreased to 17 K compared to 38 K in the unsubstituted crystal. The effective exchange and anisotropy fields for GdFe{sub 2.1}Ga{sub 0.9}(BO{sub 3}){sub 4} have been estimated from the field dependences of magnetization and resonance measurements. The magnetic phase diagram of the crystal has been constructed from magnetic and resonance measurements. In GdFe{sub 2.1}Ga{sub 0.9}(BO{sub 3}){sub 4}, there is no spontaneous reorientation and, in the absence of a magnetic field, the crystal remains an easy-axis one in the entire domain of magnetic ordering. The critical field of the reorientation transition to an induced easy-plane state in a magnetic field along the trigonal axis has been found to increase compared to that in the unsubstituted crystal.

Pankrats, A. I.; Petrakovskii, G. A.; Tugarinov, V. I., E-mail: vit@iph.krasn.ru; Kartashev, A. V.; Temerov, V. L. [Russian Academy of Science, Siberian Branch, Kirensky Institute of Physics (Russian Federation)

2011-09-15T23:59:59.000Z

211

Development of Economically Doped Heat-Resistant Nickel Single ...  

Science Conference Proceedings (OSTI)

Presentation Title, Development of Economically Doped Heat-Resistant Nickel Single-Crystal Superalloys for Blades of Perspective Gas Turbine Engines.

212

Development of A Low Angle Grain Boundary Resistant Single ...  

Science Conference Proceedings (OSTI)

single crystal buckets or vanes of industrial gas turbines. First, the effects of ... In the field of industrial gas turbines (IGT), application of SC components is ...

213

The Effect of Temperature on the Deformation Structure of Single ...  

Science Conference Proceedings (OSTI)

THE EFFECT OF TEMPERATURE ON THE DEFORMATION STRUCTURE OF. SINGLE CRYSTAL NICKEL BASE SUPERALLOYS. M.Dollar' and I.M.Bernstein$.

214

Crystallization process  

DOE Patents (OSTI)

An improved crystallization process is disclosed for separating a crystallizable material and an excluded material which is at least partially excluded from the solid phase of the crystallizable material obtained upon freezing a liquid phase of the materials. The solid phase is more dense than the liquid phase, and it is separated therefrom by relative movement with the formation of a packed bed of solid phase. The packed bed is continuously formed adjacent its lower end and passed from the liquid phase into a countercurrent flow of backwash liquid. The packed bed extends through the level of the backwash liquid to provide a drained bed of solid phase adjacent its upper end which is melted by a condensing vapor.

Adler, Robert J. (Shaker Heights, OH); Brown, William R. (Brecksville, OH); Auyang, Lun (Highland Heights, OH); Liu, Yin-Chang (Richmond Heights, OH); Cook, W. Jeffrey (Cleveland Heights, OH)

1986-01-01T23:59:59.000Z

215

High energy resolution, high angular acceptance crystal monochromator  

DOE Patents (OSTI)

A 4-bounce dispersive crystal monochromator reduces the bandpass of synchrotron radiation to a 10-50 meV range without sacrificing angular acceptance. The monochromator includes the combination of an asymmetrical channel-cut single crystal of lower order reflection and a symmetrical channel-cut single crystal of higher order reflection in a nested geometric configuration. In the disclosed embodiment, a highly asymmetrically cut (.alpha.=20) outer silicon crystal (4 2 2) with low order reflection is combined with a symmetrically cut inner silicon crystal (10 6 4) with high order reflection to condition a hard x-ray component (5-30 keV) of synchrotron radiation down to the .mu.eV-neV level. Each of the crystals is coupled to the combination of a positioning inchworm and angle encoder via a respective rotation stage for accurate relative positioning of the crystals and precise energy tuning of the monochromator.

Alp, Ercan E. (Bolingbrook, IL); Mooney, Timothy M. (Westmont, IL); Toellner, Thomas (Green Bay, WI)

1996-06-04T23:59:59.000Z

216

High energy resolution, high angular acceptance crystal monochromator  

DOE Patents (OSTI)

A 4-bounce dispersive crystal monochromator reduces the bandpass of synchrotron radiation to a 10-50 meV range without sacrificing angular acceptance. The monochromator includes the combination of an asymmetrical channel-cut single crystal of lower order reflection and a symmetrical channel-cut single crystal of higher order reflection in a nested geometric configuration. In the disclosed embodiment, a highly asymmetrically cut ({alpha}=20) outer silicon crystal (4 2 2) with low order reflection is combined with a symmetrically cut inner silicon crystal (10 6 4) with high order reflection to condition a hard x-ray component (5--30 keV) of synchrotron radiation down to the {micro}eV-neV level. Each of the crystals is coupled to the combination of a positioning inchworm and angle encoder via a respective rotation stage for accurate relative positioning of the crystals and precise energy tuning of the monochromator. 7 figs.

Alp, E.E.; Mooney, T.M.; Toellner, T.

1996-06-04T23:59:59.000Z

217

Single-crystal X-ray and neutron diffraction investigations of the temperature dependence of the structure of the Tc = 10 K organic superconductor. kappa. -(ET) sub 2 Cu(NCS) sub 2. [where ET or BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene, C sub 10 H sub 8 S sub 8  

Science Conference Proceedings (OSTI)

The crystal structure of {kappa}-(ET){sub 2}Cu(NCS){sub 2} (ET or BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene, C{sub 10}H{sub 8}S{sub 8}) has been examined by single-crystal neutron and X-ray diffraction at temperatures between 298 and 15 K. Comparison of the low temperature ordered structures determined by use of X-ray and neutron diffraction with the previously reported crystallographically disordered room temperature X-ray structure indicates the avoidance of close H{center dot}{center dot}{center dot}H contacts as the reason for the conformational disorder of the terminal ethylene groups of the ET molecules at high temperatures. The space group is monoclinic noncentrosymmetric P2{sub 1}, Z = 2. Unit cell parameters at 118 K are a = 16.359(4), b = 8.418(2), c = 12.855(3) {angstrom}, {beta} = 111.21(2){degree}, and V = 1650.3(7) {angstrom}{sup 3}; at 15 K, a = 16.373(5), b = 8.375(3), c = 12.775(6) {angstrom}, {beta} = 111.45(4){degree}, and V = 1630(1) {angstrom}{sup 3}. The interlayer spacing a {center dot} sin {beta} remains constant upon cooling from 298 to 15 K even though the a axis increases slightly in length.

Schultz, A.J.; Beno, M.A.; Geiser, U.; Wang, H.H.; Kini, A.; Williams, J.M. (Argonne National Lab., IL (United States)); Myunghwan Whangbo (North Carolina State Univ., Raleigh (United States))

1991-10-01T23:59:59.000Z

218

Apparatus for mounting crystal  

DOE Patents (OSTI)

A thickness monitor useful in deposition or etching reactor systems comprising a crystal-controlled oscillator in which the crystal is deposited or etched to change the frequency of the oscillator. The crystal rests within a thermally conductive metallic housing and arranged to be temperature controlled. Electrode contacts are made to the surface primarily by gravity force such that the crystal is substantially free of stress otherwise induced by high temperature.

Longeway, Paul A. (East Windsor, NJ)

1985-01-01T23:59:59.000Z

219

Crystal Lattice Structures - TMS  

Science Conference Proceedings (OSTI)

Feb 7, 2007 ... This resource contains 273 common crystal lattice structures indexed by Strukturbericht designation, Pearson symbol, space group, prototype, ...

220

Crystal oriented (Bi  

Science Conference Proceedings (OSTI)

The remnant polarization and piezoelectric constant of crystal oriented BNBT ... Energy Landscape in Frustrated Systems: Cation Hopping and Relaxation in ...

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Monochromator Crystal Glitch Library  

DOE Data Explorer (OSTI)

Users can view glitch spectra online, list specific crystal orientations, and download PDF files of the glitch spectra. (Specialized Interface)

222

Electrically driven photonic crystal nanocavity devices  

E-Print Network (OSTI)

Interest in photonic crystal nanocavities is fueled by advances in device performance, particularly in the development of low-threshold laser sources. Effective electrical control of high performance photonic crystal lasers has thus far remained elusive due to the complexities associated with current injection into cavities. A fabrication procedure for electrically pumping photonic crystal membrane devices using a lateral p-i-n junction has been developed and is described in this work. We have demonstrated electrically pumped lasing in our junctions with a threshold of 181 nA at 50K - the lowest threshold ever demonstrated in an electrically pumped laser. At room temperature we find that our devices behave as single-mode light-emitting diodes (LEDs), which when directly modulated, have an ultrafast electrical response up to 10 GHz corresponding to less than 1 fJ/bit energy operation - the lowest for any optical transmitter. In addition, we have demonstrated electrical pumping of photonic crystal nanobeam LEDs...

Shambat, Gary; Petykiewicz, Jan; Mayer, Marie A; Majumdar, Arka; Sarmiento, Tomas; Harris, James; Haller, Eugene E; Vuckovic, Jelena

2012-01-01T23:59:59.000Z

223

Polarized IR and Raman spectra of Ca{sub 2}MgSi{sub 2}O{sub 7}, Ca{sub 2}ZnSi{sub 2}O{sub 7} and Sr{sub 2}MgSi{sub 2}O{sub 7} single crystals: Temperature-dependent studies of commensurate to incommensurate and incommensurate to normal phase transitions  

Science Conference Proceedings (OSTI)

IR and Raman spectra of Ca{sub 2}MgSi{sub 2}O{sub 7}, Ca{sub 2}ZnSi{sub 2}O{sub 7} and Sr{sub 2}MgSi{sub 2}O{sub 7} oriented single crystals and powders have been measured. The temperature dependence of phonons has been established in the 4-650 K range. Discussion of the results has been performed on the basis of factor group approach for the tetragonal P4-bar 2{sub 1}m (D{sub 2d}{sup 3}) space group with Z=2. The assignment of the bands observed to the internal and external modes has been made on their polarization behaviour, phonon energy calculations and literature data. The evidences of the LO-TO splitting and commensurate (C) to incommensurate (IC) as well as incommensurate (IC) to normal (N) phase transitions have been found. As a representative example, the results obtained for the spontaneous Raman scattering have also been used in the discussion of the stimulated Raman spectra of Ca{sub 2}ZnSi{sub 2}O{sub 7}. - Graphical abstract: Raman and IR spectra of Ca{sub 2}MgSi{sub 2}O{sub 7}, Ca{sub 2}ZnSi{sub 2}O{sub 7}, Sr{sub 2}MgSi{sub 2}O{sub 7} have been measured. The temperature dependence of phonons has been established in the 4-650 K range. The evidences of the LO-TO splitting and commensurate (C) to incommensurate (IC) as well as incommensurate (IC) to normal (N) phase transitions have been found. Highlights: Black-Right-Pointing-Pointer Polarized IR and Raman spectra of pyrosilicates single crystals have been studied. Black-Right-Pointing-Pointer Temperature dependence of the phonon bands and LO-TO splitting have been analysed. Black-Right-Pointing-Pointer Commensurate to incommensurate and to normal phase have been evidenced in the spectra. Black-Right-Pointing-Pointer Phonon calculations have been used in assignment of the normal modes. Black-Right-Pointing-Pointer Stimulated Raman spectra of Ca{sub 2}ZnSi{sub 2}O{sub 7} crystal have been measured and analysed.

Hanuza, J. [Institute of Low Temperatures and Structure Research, Polish Academy of Sciences, ul. Okolna 2, Wroclaw (Poland); Department of Bioorganic Chemistry, Institute of Chemistry and Food Technology, Wroclaw University of Economics, 118/120 Komandorska str., Wroclaw (Poland); Ptak, M., E-mail: m.ptak@int.pan.wroc.pl [Institute of Low Temperatures and Structure Research, Polish Academy of Sciences, ul. Okolna 2, Wroclaw (Poland); Maczka, M.; Hermanowicz, K. [Institute of Low Temperatures and Structure Research, Polish Academy of Sciences, ul. Okolna 2, Wroclaw (Poland); Lorenc, J. [Department of Bioorganic Chemistry, Institute of Chemistry and Food Technology, Wroclaw University of Economics, 118/120 Komandorska str., Wroclaw (Poland); Kaminskii, A.A. [Institute of Crystallography, Russian Academy of Sciences, Moscow (Russian Federation)

2012-07-15T23:59:59.000Z

224

Photonic crystal light source  

DOE Patents (OSTI)

A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

Fleming, James G. (Albuquerque, NM); Lin, Shawn-Yu (Albuquerque, NM); Bur, James A. (Corrales, NM)

2004-07-27T23:59:59.000Z

225

HANFORD MEDIUM-LOW CURIE WASTE PRETREATMENT ALTERNATIVES PROJECT FRACTIONAL CRYSTALLIZATION PILOT SCALE TESTING FINAL REPORT  

Science Conference Proceedings (OSTI)

The Fractional Crystallization Pilot Plant was designed and constructed to demonstrate that fractional crystallization is a viable way to separate the high-level and low-activity radioactive waste streams from retrieved Hanford single-shell tank saltcake. The focus of this report is to review the design, construction, and testing details of the fractional crystallization pilot plant not previously disseminated.

HERTING DL

2008-09-16T23:59:59.000Z

226

Characterization of Ice Crystals in Clouds by Simple Mathematical Expressions Based on Successive Modification of Simple Shapes  

Science Conference Proceedings (OSTI)

The technique based on the concept of successive modification of simple shapes using elementary mathematical functions to represent the shape and size of ice crystals in clouds is discussed. Two hypothetical samples of ice crystals, a single-...

Pao K. Wang

1997-08-01T23:59:59.000Z

227

Method for the preparation of photochromic insulating crystals  

DOE Patents (OSTI)

A method for preparing reversible-photochromic magnesium oxide (MgO) crystals. Single crystals of MgO doped with both lithium (Li) and nickel (Ni) are grown by a conventional arc fusion method. The as-grown crystals are characterized by an amber coloration. The crystals lose the amber coloration and become photochromic when they are thermochemically reduced by heating at temperatures greater than 1000.degree. K. in a hydrogen atmosphere. Alternate irradiation with UV and visible light result in rejuvenation and bleaching of the amber coloration, respectively.

Abraham, Marvin M. (Oak Ridge, TN); Boldu, Jose L. (Mexico City, MX); Chen, Yok (Oak Ridge, TN); Orera, Victor M. (Zaragosa, ES)

1986-01-01T23:59:59.000Z

228

Resonance electronic Raman scattering in rare earth crystals  

Science Conference Proceedings (OSTI)

The intensities of Raman scattering transitions between electronic energy levels of trivalent rare earth ions doped into transparent crystals were measured and compared to theory. A particle emphasis was placed on the examination of the effect of intermediate state resonances on the Raman scattering intensities. Two specific systems were studied: Ce/sup 3 +/(4f/sup 1/) in single crystals of LuPO/sub 4/ and Er/sup 3 +/(4f/sup 11/) in single crystals of ErPO/sub 4/. 134 refs., 92 figs., 33 tabs.

Williams, G.M.

1988-11-10T23:59:59.000Z

229

Microsoft Word - FEAA064O_ORNL_Welding Single Cystal_Factsheet...  

NLE Websites -- All DOE Office Websites (Extended Search)

Welding and Weld Repair of Single Crystal Gas Turbine Alloys (Oak Ridge National Laboratory) FACT SHEET I. PROJECT PARTICIPANTS A. Prime Participant: Oak Ridge National Laboratory...

230

Phononic crystal devices  

DOE Patents (OSTI)

Phononic crystals that have the ability to modify and control the thermal black body phonon distribution and the phonon component of heat transport in a solid. In particular, the thermal conductivity and heat capacity can be modified by altering the phonon density of states in a phononic crystal. The present invention is directed to phononic crystal devices and materials such as radio frequency (RF) tags powered from ambient heat, dielectrics with extremely low thermal conductivity, thermoelectric materials with a higher ratio of electrical-to-thermal conductivity, materials with phononically engineered heat capacity, phononic crystal waveguides that enable accelerated cooling, and a variety of low temperature application devices.

El-Kady, Ihab F. (Albuquerque, NM); Olsson, Roy H. (Albuquerque, NM)

2012-01-10T23:59:59.000Z

231

Channeling through Bent Crystals  

Science Conference Proceedings (OSTI)

Bent crystals have demonstrated potential for use in beam collimation. A process called channeling is when accelerated particle beams are trapped by the nuclear potentials in the atomic planes within a crystal lattice. If the crystal is bent then the particles can follow the bending angle of the crystal. There are several different effects that are observed when particles travel through a bent crystal including dechanneling, volume capture, volume reflection and channeling. With a crystal placed at the edge of a particle beam, part of the fringe of the beam can be deflected away towards a detector or beam dump, thus helping collimate the beam. There is currently FORTRAN code by Igor Yazynin that has been used to model the passage of particles through a bent crystal. Using this code, the effects mentioned were explored for beam energy that would be seen at the Facility for Advanced Accelerator Experimental Tests (FACET) at a range of crystal orientations with respect to the incoming beam. After propagating 5 meters in vacuum space past the crystal the channeled particles were observed to separate from most of the beam with some noise due to dechanneled particles. Progressively smaller bending radii, with corresponding shorter crystal lengths, were compared and it was seen that multiple scattering decreases with the length of the crystal therefore allowing for cleaner detection of the channeled particles. The input beam was then modified and only a portion of the beam sent through the crystal. With the majority of the beam not affected by the crystal, most particles were not deflected and after propagation the channeled particles were seen to be deflected approximately 5mm. After a portion of the beam travels through the crystal, the entire beam was then sent through a quadrupole magnet, which increased the separation of the channeled particles from the remainder of the beam to a distance of around 20mm. A different code, which was developed at SLAC, was used to create an angular profile plot which was compared to what was produced by Yazynin's code for a beam with no multiple scattering. The results were comparable, with volume reflection and channeling effects observed and the range of crystal orientations at which volume reflection is seen was about 1 mrad in both simulations.

Mack, Stephanie; /Ottawa U. /SLAC

2012-09-07T23:59:59.000Z

232

Quantum extended crystal PDE's  

E-Print Network (OSTI)

Our recent results on {\\em extended crystal PDE's} are generalized to PDE's in the category $\\mathfrak{Q}_S$ of quantum supermanifolds. Then obstructions to the existence of global quantum smooth solutions for such equations are obtained, by using algebraic topologic techniques. Applications are considered in details to the quantum super Yang-Mills equations. Furthermore, our geometric theory of stability of PDE's and their solutions, is also generalized to quantum extended crystal PDE's. In this way we are able to identify quantum equations where their global solutions are stable at finite times. These results, are also extended to quantum singular (super)PDE's, introducing ({\\em quantum extended crystal singular (super) PDE's}).

Agostino Prástaro

2011-05-01T23:59:59.000Z

233

Cirrus Crystal Terminal Velocities  

Science Conference Proceedings (OSTI)

Cirrus crystal terminal velocities are of primary importance in determining the rate of transport of condensate from upper- to middle-tropospheric levels and profoundly influence the earth’s radiation balance through their effect on the rate of ...

Andrew J. Heymsfield; Jean Iaquinta

2000-04-01T23:59:59.000Z

234

Crystals and Plants  

NLE Websites -- All DOE Office Websites (Extended Search)

Crystals and Plants Crystals and Plants Name: Diab Location: N/A Country: N/A Date: N/A Question: What will the likely effects of crystallized filaments in plant cells be? I had noticed that moth balls (para dichlorbenzene) tends within a very short temperature range to transform from a solid to gas and back to solid in the form of crystal filaments. I been wondering about the likely effects of an experiment in which a plant is placed in a chamber saturated with the fumes of a substance that had the same transformation properties of its state but none of the toxic effects be on the plants and will such filaments form inside the cell and rearrange its DNA strands or kill it outright? Replies: The following might be helpful: http://biowww.clemson.edu/biolab/mitosis.html http://koning.ecsu.ctstateu.edu/Plant_Physiology/osmosis.html

235

Welding of Single Crystal Superalloy CMSX-4: Experiments and ...  

Science Conference Proceedings (OSTI)

456. 115.0. 118.6. 0.395. 14.7. 381.0. 404.0. 500. 14.9. 8479. 466. 111.0. 114.3. 0.395. 15.6. 380.0. 402.0. 600. 16.8. 8433. 488. 106.0. 109.9. 0.396. 16.5. 383.0.

236

Back-Stress Induced Single Crystal Hillock Growth in Unpassivated ...  

Science Conference Proceedings (OSTI)

... and Nanotwinned Copper Lines under Electromigration at Device Operation Temperature ... of 100°C by using ultrahigh vacuum transmission electron microscopy. ... Internal Strain Evolution during Thermal Cycling in a Row of Lead- Free ...

237

Second-Generation Nickel-Base Single Crystal Superalloy  

Science Conference Proceedings (OSTI)

creased, the demands placed on turbine airfoils have escalated dramatically. ... The demand- ing goals established ..... (maximum tensile strain at minimum ...

238

Evaluation of Ruthenium-Bearing Single Crystal Superalloys - A ...  

Science Conference Proceedings (OSTI)

High fuel costs and increasing environmental pressures demand unprecedented and ambitious .... maximum of 200 cycles. The initial weight and dimensions of ...

239

V1, Alkanethiol Island Formation on Single Crystal Zinc Oxide ...  

Science Conference Proceedings (OSTI)

... through the Renewable Energy Materials Research Science and Engineering Center is ... A2, Observation and Elimination of Indium Surface Segregation ... B5, The Universal Optimal Seebeck Coefficient for Maximum Power Factor ..... X9, Solution-Processed Zirconium Oxide and Integration with Zinc-Tin Oxide Thin-

240

Development of Coated Single-Crystal Superalloy Systems for Gas ...  

Science Conference Proceedings (OSTI)

properties of the SC alloys (Figure 2) make SC alloys attractive for turbine airfoil applications in advanced fuel-efficient, high-performance aircraft gas turbine ...

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

New Phases in Ruthenium-Containing Single-Crystal Superalloys  

Science Conference Proceedings (OSTI)

in the performance and efficiency of aircraft and power generation turbines. To design alloys with long term microstructural stability at high temperatures requires ...

242

A New Technique to Characterize the Behavior of Single Crystal ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Thin walled turbine airfoils represent the most highly engineered components in a modern gas turbine engine. Typically, the behavior of these ...

243

Solvus New Generation Nickel-Based Superalloys for Single Crystal ...  

Science Conference Proceedings (OSTI)

The continuous demand of the gas turbine engine manufacturers for an increasing turbine inlet temperature have pushed the alloy designers to develop  ...

244

Magnetostrictive Behavior of Fe-W Alloy Single Crystals  

Science Conference Proceedings (OSTI)

Bonded Magnetocaloric Powders for the Refrigeration Application · Coercivity ... Industrial Requirements and Applications of Hard Magnetic Materials · Influence

245

Monitoring the Solidification of Single-Crystal Castings Using High ...  

Science Conference Proceedings (OSTI)

Work by Green11 extended XRD investigations to energies exceeding 150 keV. His flash XRD system also provided the facility for studying structural changes ...

246

Development of Ni-Based Single Crystal Superalloys for Power ...  

Science Conference Proceedings (OSTI)

maintenance cost should be kept lower to sustain electricity price at a reasonable level. Another reason is partially due to the location of the power plant since it ...

247

Closed Loop Control Techniques for the Growth of Single Crystal ...  

Science Conference Proceedings (OSTI)

through the use of the heat of fusion as an internal ..... furnace, the predominant heat transfer mode is emissive. .... The cubic structure is apparent in the cross-.

248

Fatigue Crack Propagation Rate Testing of Single Crystal ...  

Science Conference Proceedings (OSTI)

increased. Recrystallized surface grains were also produced on NASAIR 100 specimens; and although the FCP rate increased, observations of bench marks on ...

249

Behaviour of Single Crystal Superalloys under Cyclic Loading at ...  

Science Conference Proceedings (OSTI)

symmetry axis and the [OOl] direction, X, varied between 2” and 8” with ... placed symmetrically along the specimen gauge length was .... component, Figure 9a.

250

High Performance Single Crystal Superalloys Developed by the d ...  

Science Conference Proceedings (OSTI)

energy level (Md) of alloying elements was utili? .... The price might be changed by many factors, .... From the above trend, it was concluded that these properties.

251

Determination of Single Crystal Elastic Constants From DS- and DR ...  

Science Conference Proceedings (OSTI)

D.L. Anton, T. Khan, R.D. Kissinger, D.L. Klarstrom ... is determined by the two angles 8 and Q. The constants S,,, Su, and S,, characterize the elastic behaviour of ...

252

Anisotropy of High Temperature Deformation of Single Crystal ...  

Science Conference Proceedings (OSTI)

Edited by S.D. Antolovich, R.W. Stusrud, R.A. MacKay,. D.L. Anton, T. Khan, R.D. Kissinger, D.L. Klarstmm. The Minerals, Metals & Materials Society, 1992. 609 ...

253

Solidification Modeling of Complex Shaped Single Crystal Turbine ...  

Science Conference Proceedings (OSTI)

T. Khan, R.D. Kissinger, D.L. Klarstmm. The Minerals, Metals & Materials Society, ..... casting feeding ability during the last stage of s@Q$jcat~,l~~~ controlled.

254

Fatigue Crack Propagation in Single Crystal CMSX-2 at Elevated ...  

Science Conference Proceedings (OSTI)

D.L. Anton, T. Khan, R.D. Kissinger, D.L. Klarstrom. The Minerals, Metals & Materials Society, 1992 .... damaged q interface. The SEM stereo pair in Fin. 8 clearly ...

255

Some Effects of Carbon in the Production of Single Crystal ...  

Science Conference Proceedings (OSTI)

795. Superalloys 2004. Edited by K.A. Green, T.M. Pollock, H. Harada,. TMS (The Minerals, Metals & Materials Society), 2004. T.E. Howson, R.C. Reed, J.J. ...

256

Bio-inspired mechanical strengthening of single crystals of calcite  

Science Conference Proceedings (OSTI)

Microbial synthesis and fabrication of palladium nanoparticle catalysts by using the metal ion-reducing bacterium Shewanella algae · Micromechanical ...

257

Joint Development of a Fourth Generation Single Crystal Superalloy  

Science Conference Proceedings (OSTI)

dividing the concentration (in atomic percent) of each element in the phase by its ..... battery of uncoated and coated hot corrosion and oxidation tests.

258

Seeded Growth of Single Crystal Bilayer Graphene Arrays  

Science Conference Proceedings (OSTI)

Atomic -Scale Characterization of Nb-Doped SrTiO?3 Nanostructures for .... Metal Oxide Nanofibers Produced by a ForceSpinning Method for Battery Electrodes.

259

Development of Single Crystal Alloys for Specific Engine Applications  

Science Conference Proceedings (OSTI)

fatigue and environmental degradation. ... ed by the stacking fault energy, which therefore influences the ease of cross slip. ... antiphase boundary energies.

260

Development of a Hydrogen Resistant Superalloy For Single Crystal ...  

Science Conference Proceedings (OSTI)

Tenupol-3 polisher, using a solution of 45% acetic acid, 45% butyl cellosolve and 10% perchloric acid, cooled to 263 K and using a potential of 25 V.

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Deformation Behavior of Mg-Al-Zn Alloy Single Crystals  

Science Conference Proceedings (OSTI)

Synthesis and Characterization of Plasma Polymerized Thin Films Deposited from Benzene and Hexamethyldisiloxane Using (PECVD) Method · Synthesis and ...

262

Segregation of Elements in High Refactory Content Single Crystal ...  

Science Conference Proceedings (OSTI)

University of Florida, Dept. of Materials Science & Engineering. 116 Rhines Hall ... strength and ultimately to the development of gas turbine engines.

263

The Defect Energies and Deformation Mechanisms of Single Crystal Superalloys  

E-Print Network (OSTI)

vitally important in applications which require very high power out- puts from compact power sources, particularly in the aircraft and ship industries. Recently they have also been used industrially for pumping natural gas across continents and for small... continuous induction, compression, combustion and exhaust cycle. The continuous cycle and absence of reciprocating parts gives a smooth running engine which enables higher power outputs to be gained from gas turbines, when compared with piston engines...

Hillier, Graham Stewart

1985-01-29T23:59:59.000Z

264

Oxidation of Low Sulfur Single Crystal Nickel-Base Superalloys  

Science Conference Proceedings (OSTI)

oxidation in air at 1100°C approached a parabolic rate law, after a transient period, ... parabolic rate constants in good agreement with those for growth of a-

265

The Development of Single Crystal Superalloy Turbine Blades  

Science Conference Proceedings (OSTI)

Airbus Industries A310 aircraft. Engine certification and initial production shipments are planned for July of 1980. Alloy 454 turbine blades have also been  ...

266

Single Crystal Superalloys: The Transition from Primary to ...  

Science Conference Proceedings (OSTI)

clear to what extent this is due to an intrinsic link between the mechanisms of primary ..... Weak beam micrograph of A deformed to the start of secondary creep at ...

267

Poling-Induced Single-Crystal-like Piezoelectric Anisotropy in ...  

Science Conference Proceedings (OSTI)

Enhanced Piezoelectric Properties of Lead-Free Piezoelectric Materials by ... High-Energy Synchrotron X-Ray Diffraction for In-Situ Study of Structural Phase ...

268

Creep Deformation Mechanisms in Some Modern Single-Crystal ...  

Science Conference Proceedings (OSTI)

TMS-75 and TMS-138 are 3rd and 4th generation SC alloys, respectively ... under stresses of 735 MPa and 607 MPa for superalloys TMS-75,. TMS-138, and  ...

269

Morphology in Single Crystal Ni-Base Superalloys  

Science Conference Proceedings (OSTI)

These trends also can be seen in the specimen .... log. HH. VV. R. (1) here, H0 and V0 are the values of H and V in the initial ?/?' microstructure shown in Fig.1.

270

Rene' N6: Third Generation Single Crystal Superalloy  

Science Conference Proceedings (OSTI)

Bob Allen who sustained funding for the development of Ren6 N6 and led the scale-up and introduction of the alloy into production hardware. The authors also

271

Anisotropy of Nickel-Base Superalloy Single Crystals  

Science Conference Proceedings (OSTI)

lives near the [OOl], and Zoti Zives near the [Oil]. Crystak within about ... Reserve University, ..... [OOl] - [Oil] boundary do not have to rotate as far before reaching.

272

During Creep in Nickel-Base Superalloy Single Crystals  

Science Conference Proceedings (OSTI)

to develop well after the onset of second- ... machined bar form and then were quenched into oil. Thus, these latter specimens .... in the total amount of strain.

273

New Aspects of Freckle Formation during Single Crystal ...  

Science Conference Proceedings (OSTI)

tion of the rotated grid algorithm is given in [ 151. 2D-calculations of grain selection ... Materials for Advanced Power Engineering, eds. J. Le- comte- Beckers, F.

274

Process of making cryogenically cooled high thermal performance crystal optics  

DOE Patents (OSTI)

A method for constructing a cooled optic wherein one or more cavities are milled, drilled or formed using casting or ultrasound laser machining techniques in a single crystal base and filled with porous material having high thermal conductivity at cryogenic temperatures. A non-machined strain-free single crystal can be bonded to the base to produce superior optics. During operation of the cooled optic, N{sub 2} is pumped through the porous material at a sub-cooled cryogenic inlet temperature and with sufficient system pressure to prevent the fluid bulk temperature from reaching saturation.

Kuzay, T.M.

1990-06-29T23:59:59.000Z

275

Process of making cryogenically cooled high thermal performance crystal optics  

DOE Patents (OSTI)

A method is disclosed for constructing a cooled optic wherein one or more cavities are milled, drilled or formed using casting or ultrasound laser machining techniques in a single crystal base and filled with porous material having high thermal conductivity at cryogenic temperatures. A non-machined strain-free single crystal can be bonded to the base to produce superior optics. During operation of the cooled optic, N[sub 2] is pumped through the porous material at a sub-cooled cryogenic inlet temperature and with sufficient system pressure to prevent the fluid bulk temperature from reaching saturation. 7 figs.

Kuzay, T.M.

1992-06-23T23:59:59.000Z

276

Crystallization of Lipids, Nucleation to Application  

Science Conference Proceedings (OSTI)

Archive of Crystallization of Lipids, Nucleation to Application Crystallization of Lipids, Nucleation to Application Toronto, Canada Crystallization of Lipids, Nucleation to Application ...

277

Electro-optic crystal mosaics for the generation of terahertz radiation  

DOE Patents (OSTI)

Apparatus for the generation of high energy terahertz radiation is presented and comprises laser means effective to produce subpicosecond optical pulses and a mosaic comprising a plurality of planar electro-optic crystals fastened together edge to edge in the form of a grid. The electro-optic crystals are in optical communication with the subpicosecond optical pulses, and behave as a single large electro-optic crystal, producing high energy terahertz radiation by way of optical rectification. 5 figs.

Carrig, T.J.; Taylor, A.J.; Stewart, K.R.

1996-08-06T23:59:59.000Z

278

Light Scattering by Quasi-Spherical Ice Crystals  

Science Conference Proceedings (OSTI)

The shapes and single-scattering properties of small, irregular, quasi-spherical ice crystals, with equivalent radii between approximately 8 and 90 ?m and size parameters from about 90 to 1000, are studied using two-dimensional images measured by ...

Timo Nousiainen; Greg M. McFarquhar

2004-09-01T23:59:59.000Z

279

Silicon crystal growing by oscillating crucible technique  

DOE Patents (OSTI)

A process for growing silicon crystals from a molten melt comprising oscillating the container during crystal growth is disclosed.

Schwuttke, G.H.; Kim, K.M.; Smetana, P.

1983-08-03T23:59:59.000Z

280

Plenum type crystal growth chamber  

DOE Patents (OSTI)

Crystals are grown in a tank which is divided by a baffle into a crystal growth region above the baffle and a plenum region below the baffle. A turbine blade or stirring wheel is positioned in a turbine tube which extends through the baffle to generate a flow of solution from the crystal growing region to the plenum region. The solution is pressurized as it flows into the plenum region. The pressurized solution flows back to the crystal growing region through return flow tubes extending through the baffle. Growing crystals are positioned near the ends of the return flow tubes to receive a direct flow of solution.

Montgomery, K.E.

1990-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Cracks Cleave Crystals  

E-Print Network (OSTI)

The problem of finding what direction cracks should move is not completely solved. A commonly accepted way to predict crack directions is by computing the density of elastic potential energy stored well away from the crack tip, and finding a direction of crack motion to maximize the consumption of this energy. I provide here a specific case where this rule fails. The example is of a crack in a crystal. It fractures along a crystal plane, rather than in the direction normally predicted to release the most energy. Thus, a correct equation of motion for brittle cracks must take into account both energy flows that are described in conventional continuum theories and details of the environment near the tip that are not.

Michael Marder

2004-03-05T23:59:59.000Z

282

Nano-manipulation of diamond-based single photon sources  

E-Print Network (OSTI)

The ability to manipulate nano-particles at the nano-scale is critical for the development of active quantum systems. This paper presents a new technique to manipulate diamond nano-crystals at the nano-scale using a scanning electron microscope, nano-manipulator and custom tapered optical fibre probes. The manipulation of a ~ 300 nm diamond crystal, containing a single nitrogen-vacancy centre, onto the endface of an optical fibre is demonstrated. The emission properties of the single photon source post manipulation are in excellent agreement with those observed on the original substrate.

E. Ampem-Lassen; D. A. Simpson; B. C. Gibson; S. Trpkovski; F. M. Hossain; S. T. Huntington; K. Ganesan; L. C. L. Hollenberg; S. Prawer

2009-05-18T23:59:59.000Z

283

Nano-manipulation of diamond-based single photon sources  

E-Print Network (OSTI)

The ability to manipulate nano-particles at the nano-scale is critical for the development of active quantum systems. This paper presents a new technique to manipulate diamond nano-crystals at the nano-scale using a scanning electron microscope, nano-manipulator and custom tapered optical fibre probes. The manipulation of a ~ 300 nm diamond crystal, containing a single nitrogen-vacancy centre, onto the endface of an optical fibre is demonstrated. The emission properties of the single photon source post manipulation are in excellent agreement with those observed on the original substrate.

Ampem-Lassen, E; Gibson, B C; Trpkovski, S; Hossain, F M; Huntington, S T; Ganesan, K; Hollenberg, L C L; Prawer, S

2009-01-01T23:59:59.000Z

284

Photo of the Week: How to Grow Superconducting Crystals | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

How to Grow Superconducting Crystals How to Grow Superconducting Crystals Photo of the Week: How to Grow Superconducting Crystals September 13, 2013 - 11:29am Addthis Many of the materials that scientists work with at Brookhaven National Laboratory are too small and too precise for traditional tools. In cases like these, the labs grow materials instead of building them. Brookhaven physicist Genda Gu pioneered techniques that grow some of the largest single-crystal high-temperature superconductors in the world. The glowing chamber in this photo grows superconducting crystals. To do so, the furnace focuses infrared light onto a rod, melting it around 4,000 degrees Fahrenheit. Under just the right conditions, the liquefied material recrystallizes as a single uniform structure, which is highly sensitive and takes about one month to form. | Photo courtesy of Brookhaven National Laboratory.

285

Parameterization of the scattering and absorption properties of individual ice crystals  

SciTech Connect

We present parameterizations of the single-scattering properties for individual ice crystals of various habits based on the results computed from the accurate light scattering calculations. The projected area, volume, and single-scattering properties of ice crystals with various shapes and sizes are computed for 56 narrow spectral bands covering 0.2-5 {mu}m. The ice crystal habits considered in this study are hexagonal plates, solid and hollow columns, planar and spatial bullet rosette, and aggregates that are commonly observed in cirrus clouds. Using the observational relationships between the aspect ratios and the sizes of ice crystals, we can define the three-dimensional structure of these ice crystal habits with respect to their maximum dimensions for light scattering calculations. The volume and projected area of ice crystals, expressed in terms of the diameters of the corresponding equivalent spheres, are first parameterized by employing the ice crystal maximum dimensions. Further, various analytical expressions as functions of the effective dimensions of ice crystals have been developed to parameterize the extinction and absorption efficiencies, asymmetry factor, and the truncation of the forward peak energy in the phase function. The present parameterization scheme provides an efficient approach to obtain the basic scattering and absorption properties of nonspherical ice crystals. (c) 2000 American Geophysical Union.

Yang, Ping [Department of Atmospheric Sciences, University of California, Los Angeles (United States)] [Department of Atmospheric Sciences, University of California, Los Angeles (United States); Liou, K. N. [Department of Atmospheric Sciences, University of California, Los Angeles (United States)] [Department of Atmospheric Sciences, University of California, Los Angeles (United States); Wyser, Klaus [Department of Meteorology, Stockholm University, Stockholm (Sweden)] [Department of Meteorology, Stockholm University, Stockholm (Sweden); Mitchell, David [Atmospheric Sciences Center, Desert Research Institute, Reno, Nevada (United States)] [Atmospheric Sciences Center, Desert Research Institute, Reno, Nevada (United States)

2000-02-27T23:59:59.000Z

286

Versatile collimating crystal stage for Bonse-Hart USAXS instrument.  

Science Conference Proceedings (OSTI)

An advanced ultra-small-angle X-ray scattering (USAXS) instrument, using the Bonse-Hart design and installed at APS, is a robust and reliable instrument, providing a scattering vector (q) range of nearly 4 decades (0.00015 to 1 {angstrom}{sup -1}), an intensity dynamic range of up to 9 decades, standard-less absolute intensity calibration, and USAXS imaging capabilities. This type of instrument typically uses channel-cut crystals in both the collimating (before sample) and analyzing (after sample) stages. The optical surfaces of these crystals are finished by etching processes, which leave an orange-peel surface texture, which would compromise the USAXS imaging quality. Therefore optics with highly polished surfaces using separated crystals in both collimating and analyzing stages were developed. A novel design of the optics and mechanical stage uses a fixed gap between the two separated collimating crystals in which a triangular section of the first crystal is removed, allowing for a variable number (1, 2, 4, 6, or 8) of crystal reflections for X-ray energies between 7 and 19 keV. The number of reflections is selected by lateral translation of the collimating crystal pair. Rotational alignment of the second crystal in the pair by an artificial channel-cut crystal mechanism, implemented with a novel high-stiffness weak link actuated by both a picomotor and a piezo-electric transducer, provides the capability to align or adjust an assembly of crystals to achieve the same performance as a single channel-cut crystal with integral weak link. The arrangement of both crystals is held on a removable base that can be remounted with precision within the Si(111) rocking curve on a three-point kinematic mount. Additional tilt adjustments are also provided for initial alignment. This monochromator has proven to be highly robust with respect to motions and vibrations, as well as flexible with respect to selection of number of reflections, and its performance directly resulted in the highly reliable performance of the whole USAXS instrument.

Ilavsky, J.; Shu, D.; Jemian, P. R.; Long, G. G.

2007-01-01T23:59:59.000Z

287

Characterizing time decay of bibenzyl scintillator using time correlated single photon counting  

Science Conference Proceedings (OSTI)

The time decay of several scintillation materials has been measured using the time correlated single photon counting method and a new organic crystal with a highly suppressed delayed light has been identified. Results comparing the light decay of the bibenzyl crystal with a xylene based detector, which is currently installed at National Ignition Facility will be presented.

Hatarik, R.; Bernstein, L. A.; Caggiano, J. A.; Carman, M. L.; Schneider, D. H. G.; Zaitseva, N. P. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Wiedeking, M. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); iThemba LABS, P.O. Box 722, 7129 Somerset West (South Africa)

2012-10-15T23:59:59.000Z

288

Florida Nuclear Profile - Crystal River  

U.S. Energy Information Administration (EIA) Indexed Site

Crystal River1" "Unit","Summer capacity (mw)","Net generation (thousand mwh)","Summer capacity factor (percent)","Type","Commercial operation date","License expiration date"...

289

VISUALS: Crystal Structure Animations - TMS  

Science Conference Proceedings (OSTI)

Jul 2, 2008 ... This site contains animated ball and stick models of anhydrite, aragonite, barite, beryl, biotite, calcite, ... "Crystal Structure Animations.

290

Nepheline Crystallization from Aluminosilicate Melts  

Al-limited and Al/Na-limited Hanford HLW. Figure 3. Crystallization during canister coolingis principal waste loading limiting factor . Current Nepheline Discriminator.

291

BY SILICON CRYSTALS  

NLE Websites -- All DOE Office Websites (Extended Search)

c October 29, 1942 a 1 1 _MIGH aECTgFXCATIOH - BY SILICON CRYSTALS . . c .. I n. The excellent pesformmce of Brftieh "red dot" c r y s t a l s f e explained R R due t o the kgife edge contact i n a t A polfehod ~ X ' f l i C B o H i g h frequency m c t l f f c n t f o n 8ependre c r i t i c a l l y on the ape%e;y of the rectifytnc boundary layer o f the crystal, C, For hl#$ comvere~on e f f i c i e n c y , the product c d t h i ~ capacity m a o f ' t h e @forward" (bulk) re-. sistance Rb o f the crystnl must b@ sm%P, depende primarily on the breadth of tha b f f e edge i t s lbngth. The contact am &harefore ~ E L V Q a rather large area wMQh prevents burn-out, thh3 t h e breadth of &h@ knife edge should be bdt8~1 than E~$O$B% % f I - ' amo For a knife edge, this produet very 14ttle upom For a wavsIL~n+3tih of PO emo the eowp,o%a%8sne 4

292

Frequency mixing crystal  

DOE Patents (OSTI)

In a laser system for converting infrared laser light waves to visible light comprising a source of infrared laser light waves and means of harmonic generation associated therewith for production of light waves at integral multiples of the frequency of the original wave, the improvement of said means of harmonic generation comprising a crystal having the chemical formula X{sub 2} Y(NO{sub 3}){sub 5} {center_dot} 2 nZ{sub 2}O wherein X is selected from the group consisting of Li, Na, K, Rb, Cs, and Tl; Y is selected from the group consisting of Sc, Y, La, Ce, Nd, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, and In; Z is selected from the group consisting of H and D; and n ranges from 0 to 4.

Ebbers, C.A.; Davis, L.E.; Webb, M.

1990-10-16T23:59:59.000Z

293

Frequency mixing crystal  

DOE Patents (OSTI)

In a laser system for converting infrared laser light waves to visible light comprising a source of infrared laser light waves and means of harmonic generation associated therewith for production of light waves at integral multiples of the frequency of the original wave, the improvement of said means of harmonic generation comprising a crystal having the chemical formula X{sub 2} Y(NO{sub 3}){sub 5} {center dot} 2 nZ{sub 2}O wherein X is selected from the group consisting of Li, Na, K, Rb, Cs, and Tl; Y is selected from the group consisting of Sc, Y, La, Ce, Nd, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, and In; Z is selected from the group consisting of H and D; and n ranges from 0 to 4.

Ebbers, C.A.; Davis, L.E.; Webb, M.

1990-10-16T23:59:59.000Z

294

Frequency mixing crystal  

DOE Patents (OSTI)

In a laser system for converting infrared laser light waves to visible light comprising a source of infrared laser light waves and means of harmoic generation associated therewith for production of light waves at integral multiples of the frequency of the original wave, the improvement of said means of harmonic generation comprising a crystal having the chemical formula X.sub.2 Y(NO.sub.3).sub.5 .multidot.2 nZ.sub.2 o wherein X is selected from the group consisting of Li, Na, K, Rb, Cs, and Tl; Y is selected from the group consisting of Sc, Y, La, Ce, Nd, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, and In; Z is selected from the group consisting of H and D; and n ranges from 0 to 4.

Ebbers, Christopher A. (Livermore, CA); Davis, Laura E. (Manteca, CA); Webb, Mark (Salida, CA)

1992-01-01T23:59:59.000Z

295

Lamella settler crystallizer  

DOE Patents (OSTI)

A crystallizer is described which incorporates a lamella settler and which is particularly applicable for use in batteries and power cells for electric vehicles or stationary applications. The lamella settler can be utilized for coarse particle separation or for agglomeration, and is particularly applicable to aluminum-air batteries or power cells for solving the hydrargillite (aluminum-hydroxide) removal problems from such batteries. This invention provides the advantages of very low energy consumption, turbulence, shear, cost and maintenance. Thus, due to the low shear and low turbulence of this invention, it is particularly effective in the control of aluminum hydroxide particle size distribution in the various sections of an aluminum-air system, as well as in other electrochemical systems requiring separation for phases of different densities. 3 figs.

Maimoni, A.

1990-12-18T23:59:59.000Z

296

Lamella settler crystallizer  

DOE Patents (OSTI)

A crystallizer which incorporates a lamella settler and which is particularly applicable for use in batteries and power cells for electric vehicles or stationary applications. The lamella settler can be utilized for coarse particle separation or for agglomeration, and is particularly applicable to aluminum-air batteries or power cells for solving the hydrargillite (aluminum-hydroxide) removal problems from such batteries. This invention provides the advantages of very low energy consumption, turbulence, shear, cost and maintenance. Thus, due to the low shear and low turbulence of this invention, it is particularly effective in the control of aluminum hydroxide particle size distribution in the various sections of an aluminum-air system, as well as in other electrochemical systems requiring separation for phases of different densities.

Maimoni, Arturo (Orinda, CA)

1990-01-01T23:59:59.000Z

297

Shallow Melt Apparatus for Semicontinuous Czochralski Crystal Growth  

DOE Patents (OSTI)

In a single crystal pulling apparatus for providing a Czochralski crystal growth process, the improvement of a shallow melt crucible (20) to eliminate the necessity supplying a large quantity of feed stock materials that had to be preloaded in a deep crucible to grow a large ingot, comprising a gas tight container a crucible with a deepened periphery (25) to prevent snapping of a shallow melt and reduce turbulent melt convection; source supply means for adding source material to the semiconductor melt; a double barrier (23) to minimize heat transfer between the deepened periphery (25) and the shallow melt in the growth compartment; offset holes (24) in the double barrier (23) to increase melt travel length between the deepened periphery (25) and the shallow growth compartment; and the interface heater/heat sink (22) to control the interface shape and crystal growth rate.

Wang, T.; Ciszek, T. F.

2006-01-10T23:59:59.000Z

298

Equilibrium Crystal Shape of Nickel  

SciTech Connect

The crystal shape of Ni particles, dewetted in the solid state on sapphire substrates, was examined as a function of the partial pressure of oxygen (P(O2)) and iron content using scanning and transmission electron microscopy. The chemical composition of the surface was characterized by atom-probe tomography. Unlike other FCC equilibrium crystal shapes, the Ni crystals containing little or no impurities exhibited a facetted shape, indicating large surface anisotropy. In addition to the {111}, {100} and {110} facets, which are usually present in the equilibrium crystal shape of FCC metals, high index facets were identified such as {135} and {138} at low P(O2), and {012} and {013} at higher P(O2). The presence of iron altered the crystal shape into a truncated sphere with only facets parallel to denser planes. The issue of particle equilibration is discussed specifically for the case of solid-state dewetting.

Meltzman, Hila [Technion, Israel Institute of Technology; Chatain, Dominique [Universite d'Aix-Marseille; Avizemer, Dan [Technion, Israel Institute of Technology; Besmann, Theodore M [ORNL; Kaplan, Prof. Wayne D. [Technion, Israel Institute of Technology

2011-01-01T23:59:59.000Z

299

Crystal Solar Inc | Open Energy Information  

Open Energy Info (EERE)

Crystal Solar Inc Jump to: navigation, search Name Crystal Solar Inc. Place Santa Clara, California Zip 94054 Sector Solar Product California-based developer of silicon solar...

300

Crystal-Tolerant Glass Approach For Mitigation Of Crystal Accumulation In Continuous Melters Processing Radioactive Waste  

SciTech Connect

High-level radioactive waste melters are projected to operate in an inefficient manner as they are subjected to artificial constraints, such as minimum liquidus temperature (T{sub L}) or maximum equilibrium fraction of crystallinity at a given temperature. These constraints substantially limit waste loading, but were imposed to prevent clogging of the melter with spinel crystals [(Fe, Ni, Mn, Zn)(Fe, Cr){sub 2}O{sub 4}]. In the melter, the glass discharge riser is the most likely location for crystal accumulation during idling because of low glass temperatures, stagnant melts, and small diameter. To address this problem, a series of lab-scale crucible tests were performed with specially formulated glasses to simulate accumulation of spinel in the riser. Thicknesses of accumulated layers were incorporated into empirical model of spinel settling. In addition, T{sub L} of glasses was measured and impact of particle agglomeration on accumulation rate was evaluated. Empirical model predicted well the accumulation of single crystals and/or smallscale agglomerates, but, excessive agglomeration observed in high-Ni-Fe glass resulted in an under-prediction of accumulated layers, which gradually worsen over time as an increased number of agglomerates formed. Accumulation rate of ~14.9 +- 1 nm/s determined for this glass will result in ~26 mm thick layer in 20 days of melter idling.

Kruger, Albert A. [Department of Energy, Office of River Protection, Richland, Washington (United States); Rodriguez, Carmen P. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Lang, Jesse B. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Huckleberry, Adam R. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Matyas, Josef [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Owen, Antoinette T. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

2012-08-28T23:59:59.000Z

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Towards improved CZT crystals.  

Science Conference Proceedings (OSTI)

Past experimental efforts to improve CZT crystals for gamma spectrometer applications have been focused on reducing micron-scale defects such as tellurium inclusions and precipitates. While these micron-scale defects are important, experiments have shown that the micron-scale variations in transport can be caused by the formation and aggregation of atomic-scale defects such as dislocations and point defect clusters. Moreover, dislocation cells have been found to act as nucleation sites that cause the formation of large precipitates. To better solve the uniformity problem of CZT, atomic-scale defects must be understood and controlled. To this end, we have begun to develop an atomistic model that can be used to reveal the effects of small-scale defects and to guide experiments for reducing both atomic- and micron-scale (tellurium inclusions and precipitates) defects. Our model will be based upon a bond order potential (BOP) to enable large-scale molecular dynamics simulations of material structures at a high-fidelity level that was not possible with alternative methods. To establish how BOP improves over existing approaches, we report here our recent work on the assessment of two representative literature CdTe interatomic potentials that are currently widely used: the Stillinger-Weber (SW) potential and the Tersoff-Rockett (TR) potential. Careful examinations of phases, defects, and surfaces of the CdTe system were performed. We began our study by using both potentials to evaluate the lattice constants and cohesive energies of various Cd, Te, and CdTe phases including dimer, trimer, chain, square, rhomboid, tetrahedron, diamond-cubic (dc), simple-cubic (sc), body-centered-cubic (bcc), face-centered cubic (fcc), hexagonal-close-packed (hcp), graphite-sheet, A8, zinc-blende (zb), wurtzite (wz), NaCl, CsCl, etc. We then compared the results with our calculations using the density functional theory (DFT) quantum mechanical method. We also evaluated the suitability of the two potentials to predict the surface reconstructions and surface energies, various defect configurations and defect energies (interstitials and voids), elastic constants, and melting temperatures of different phases. We found that both potentials predicted incorrect energy trends as compared with those predicted by the DFT method. Most seriously, both potentials predicted incorrect lowest energy phases. These studies clearly showed that the existing potentials are not sufficient for correctly predicting the charge transport properties of CdTe demonstrating the need for a new potential. We anticipate that our BOP method will overcome this problem and will accelerate the discovery of a synthesis approach to produce improved CZT crystals.

Zimmerman, Jonathan A.; Ward, Donald K.; Doty, F. Patrick; Wong, Bryan Matthew; Zhou, Xiao Wang

2010-03-01T23:59:59.000Z

302

Inclusion free cadmium zinc tellurium and cadmium tellurium crystals and associated growth method  

DOE Patents (OSTI)

The present disclosure provides systems and methods for crystal growth of cadmium zinc tellurium (CZT) and cadmium tellurium (CdTe) crystals with an inverted growth reactor chamber. The inverted growth reactor chamber enables growth of single, large, high purity CZT and CdTe crystals that can be used, for example, in X-ray and gamma detection, substrates for infrared detectors, or the like. The inverted growth reactor chamber enables reductions in the presence of Te inclusions, which are recognized as an important limiting factor in using CZT or CdTe as radiation detectors. The inverted growth reactor chamber can be utilized with existing crystal growth techniques such as the Bridgman crystal growth mechanism and the like. In an exemplary embodiment, the inverted growth reactor chamber is a U-shaped ampoule.

Bolotnikov, Aleskey E. (South Setauket, NY); James, Ralph B. (Ridge, NY)

2010-07-20T23:59:59.000Z

303

Three dimensional silicon photonic crystals fabricated by two photon phase mask lithography.  

SciTech Connect

We describe the fabrication of silicon three dimensional photonic crystals using polymer templates defined by a single step, two-photon exposure through a layer of photopolymer with relief molded on its surface. The resulting crystals exhibit high structural quality over large areas, displaying geometries consistent with calculation. Spectroscopic measurements of transmission and reflection through the silicon and polymer structures reveal excellent optical properties, approaching properties predicted by simulations that assume ideal layouts.

Wiltzius, P. (University of Illinois, Urbana-Champaign, Illinois); Braun, P. V. (University of Illinois, Urbana-Champaign, Illinois); Liao, H. (University of Illinois, Urbana-Champaign, Illinois); Brzezinski, A. (University of Illinois, Urbana-Champaign, Illinois); Chen, Y. C. (University of Illinois, Urbana-Champaign, Illinois); Nelson, E. (University of Illinois, Urbana-Champaign, Illinois); Shir, D. (University of Illinois, Urbana-Champaign, Illinois); Rogers, J. A. (University of Illinois, Urbana-Champaign, Illinois); Bogart, Katherine Huderle Andersen

2008-08-01T23:59:59.000Z

304

CARS polarized microscopy of three-dimensional director structures in liquid crystals  

E-Print Network (OSTI)

We demonstrate three-dimensional vibrational imaging of director structures in liquid crystals using coherent anti-Stokes Raman scattering (CARS) polarized microscopy. Spatial mapping of the structures is based on sensitivity of a polarized CARS signal to orientation of anisotropic molecules in liquid crystals. As an example, we study structures in a smectic material and demonstrate that single-scan CARS and two-photon fluorescence images of molecular orientation patterns are consistent with each other and with the structure model.

Kachynski, A V; Prasad, P N; Smalyukh, I I

2007-01-01T23:59:59.000Z

305

CARS polarized microscopy of three-dimensional director structures in liquid crystals  

E-Print Network (OSTI)

We demonstrate three-dimensional vibrational imaging of director structures in liquid crystals using coherent anti-Stokes Raman scattering (CARS) polarized microscopy. Spatial mapping of the structures is based on sensitivity of a polarized CARS signal to orientation of anisotropic molecules in liquid crystals. As an example, we study structures in a smectic material and demonstrate that single-scan CARS and two-photon fluorescence images of molecular orientation patterns are consistent with each other and with the structure model.

A. V. Kachynski; A. N. Kuzmin; P. N. Prasad; I. I. Smalyukh

2007-10-18T23:59:59.000Z

306

The trouble with crystal polymorphism  

Science Conference Proceedings (OSTI)

Crystal polymorphism is one of the most widely studied structural characteristics of fats used in spreads, shortening, and confectionery applications. Simply put, polymorphism refers to the fact that triacylglycerols (TAG), and other lipids, can crystalliz

307

PREPARATION OF REFRACTORY OXIDE CRYSTALS  

DOE Patents (OSTI)

A method is given for preparing uranium dioxide, thorium oxide, and beryllium oxide in the form of enlarged individual crystals. The surface of a fused alkali metal halide melt containing dissolved uranium, thorium, or beryllium values is contacted with a water-vapor-bearing inert gas stream at a rate of 5 to 10 cubic centimeters per minute per square centimeter of melt surface area. Growth of individual crystals is obtained by prolonged contact. Beryllium oxide-coated uranium dioxide crystals are prepared by disposing uranium dioxide crystals 5 to 20 microns in diameter in a beryllium-containing melt and contacting the melt with a water-vapor-bearing inert gas stream in the same manner. (AEC)

Grimes, W.R.; Shaffer, J.H.; Watson, G.M.

1962-11-13T23:59:59.000Z

308

Creation and recovery of a W(111) single atom gas field ion source  

Science Conference Proceedings (OSTI)

Tungsten single atom tips have been prepared from a single crystal W(111) oriented wire using the chemical assisted field evaporation and etching method. Etching to a single atom tip occurs through a symmetric structure and leads to a predictable last atom unlike etching with polycrystalline tips. The single atom tip formation procedure is shown in an atom by atom removal process. Rebuilds of single atom tips occur on the same crystalline axis as the original tip such that ion emission emanates along a fixed direction for all tip rebuilds. This preparation method could be utilized and developed to prepare single atom tips for ion source development.

Pitters, Jason L. [National Institute for Nanotechnology, National Research Council of Canada, Edmonton, Alberta T6G 2M9 (Canada); Urban, Radovan [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2G7 (Canada); Wolkow, Robert A. [National Institute for Nanotechnology, National Research Council of Canada, Edmonton, Alberta T6G 2M9 (Canada); Department of Physics, University of Alberta, Edmonton, Alberta T6G 2G7 (Canada)

2012-04-21T23:59:59.000Z

309

Single Electron Coherence  

Science Conference Proceedings (OSTI)

... Single electron tunneling (SET) devices have the amazing property that we can measure and control the motion of electrons one-by-one. ...

2012-07-25T23:59:59.000Z

310

Measuring Single Photons  

NLE Websites -- All DOE Office Websites (Extended Search)

by Phillip Warner. Dive right into the single photon pages here. Program Contact: Tom Jordan Web Maintainer: qnet-webmaster@fnal.gov Last Updated: 18 January 2000 http:...

311

Adaptive Liquid Crystal Windows  

SciTech Connect

Energy consumption by private and commercial sectors in the U.S. has steadily grown over the last decade. The uncertainty in future availability of imported oil, on which the energy consumption relies strongly, resulted in a dramatic increase in the cost of energy. About 20% of this consumption are used to heat and cool houses and commercial buildings. To reduce dependence on the foreign oil and cut down emission of greenhouse gases, it is necessary to eliminate losses and reduce total energy consumption by buildings. To achieve this goal it is necessary to redefine the role of the conventional windows. At a minimum, windows should stop being a source for energy loss. Ideally, windows should become a source of energy, providing net gain to reduce energy used to heat and cool homes. It is possible to have a net energy gain from a window if its light transmission can be dynamically altered, ideally electronically without the need of operator assistance, providing optimal control of the solar gain that varies with season and climate in the U.S. In addition, the window must not require power from the building for operation. Resolution of this problem is a societal challenge and of national interest and will have a broad global impact. For this purpose, the year-round, allclimate window solution to provide an electronically variable solar heat gain coefficient (SHGC) with a wide dynamic range is needed. AlphaMicron, Inc. (AMI) developed and manufactured 1ft × 1ft prototype panels for the world’s first auto-adjusting Adaptive Liquid Crystal Windows (ALCWs) that can operate from sunlight without the need for external power source and demonstrate an electronically adjustable SHGC. This novel windows are based on AlphaMicron’s patented e-Tint® technology, a guesthost liquid crystal system implemented on flexible, optically clear plastic films. This technology is suitable both for OEM and aftermarket (retro-fitting) lamination to new and existing windows. Low level of power consumption by ALCWs allows for on-board power electronics for automatic matching of transmission through windows to varying climate conditions without drawing the power from the power grid. ALCWs are capable of transmitting more sunlight in winters to assist in heating and less sunlight in summers to minimize overheating. As such, they can change the window from being a source of energy loss to a source of energy gain. In addition, the scalable AMI’s roll-to-roll process, proved by making 1ft × 1ftALCW prototype panels, allows for cost-effective production of large-scale window panels along with capability to change easily their color and shape. In addition to architectural glazing in houses and commercial buildings, ALCWs can be used in other applications where control of sunlight is needed, such as green houses, used by commercial produce growers and botanical gardens, cars, aircrafts, etc.

Taheri, Bahman; Bodnar, Volodymyr

2011-12-31T23:59:59.000Z

312

Growth of KH/sub 2/PO/sub 4/ crystals at constant temperature and supersaturation. Final report, October 20, 1980-October 20, 1981  

Science Conference Proceedings (OSTI)

A large three-zone crystallizer system was constructed and successfully operated for growing KH/sub 2/PO/sub 4/ single crystals. Under conditions of constant crystallization temperature and supersaturation, growth rates exceding 5 mm per day were demonstrated for KH/sub 2/PO/sub 4/ crystals of 5 x 5 cm cross section. The optical quality of these crystals was equivalent to that of crystals grown at rates presently considered as state-of-the-art (approx. 1 mm/day). Sample crystals were supplied for comparison testing. The three-zone system appears to be ideally suitable for growth of large-diameter KH/sub 2/PO/sub 4/ crystals for the Laser Fusion Program.

Loiacono, G.M.; Zola, J.; Kostecky, G.

1982-02-01T23:59:59.000Z

313

Molecular Dynamics Study of Phase Change of Water inside a Single-Walled Carbon Nanotube  

E-Print Network (OSTI)

The phase change of liquid water to ice crystal inside a single-walled carbon nanotube (SWNT) was studiedMolecular Dynamics Study of Phase Change of Water inside a Single-Walled Carbon Nanotube Shigeo phase change for various cooling rates in a SWNT with various chiralities were examined. With certain

Maruyama, Shigeo

314

Local Electromechanical Response at a Single Ferroelectric Domain Wall in Lithium Niobate  

E-Print Network (OSTI)

Local Electromechanical Response at a Single Ferroelectric Domain Wall in Lithium Niobate DAVID A electromechanical response across a single ferroelectric domain wall in congruent lithium niobate at room in the crystal, which interact with the domain wall. I. INTRODUCTION FERROELECTRIC lithium niobate and lithium

Gopalan, Venkatraman

315

Crystal Systems | Open Energy Information  

Open Energy Info (EERE)

Crystal Systems Crystal Systems Name Crystal Systems Address 27 Congress Street Place Salem, Massachusetts Zip 01970 Sector Solar Product Silicon producer Year founded 1971 Website http://www.crystalsystems.com/ Coordinates 42.5190384°, -70.8896271° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.5190384,"lon":-70.8896271,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

316

Crystallization and Solidification Properties of LipidsChapter 11 Ultrasonic Characterization of Lipid Crystallization  

Science Conference Proceedings (OSTI)

Crystallization and Solidification Properties of Lipids Chapter 11 Ultrasonic Characterization of Lipid Crystallization Health Nutrition Biochemistry eChapters Health - Nutrition - Biochemistry AOCS Press  

317

Crystallization and Solidification Properties of LipidsChapter 2 Molecular Modeling Applications in Lipid Crystallization  

Science Conference Proceedings (OSTI)

Crystallization and Solidification Properties of Lipids Chapter 2 Molecular Modeling Applications in Lipid Crystallization Health Nutrition Biochemistry eChapters Health - Nutrition - Biochemistry AOCS Press   ...

318

Manufacturing method of photonic crystal  

DOE Patents (OSTI)

A manufacturing method of a photonic crystal is provided. In the method, a high-refractive-index material is conformally deposited on an exposed portion of a periodic template composed of a low-refractive-index material by an atomic layer deposition process so that a difference in refractive indices or dielectric constants between the template and adjacent air becomes greater, which makes it possible to form a three-dimensional photonic crystal having a superior photonic bandgap. Herein, the three-dimensional structure may be prepared by a layer-by-layer method.

Park, In Sung; Lee, Tae Ho; Ahn, Jin Ho; Biswas, Rana; Constant, Kristen P.; Ho, Kai-Ming; Lee, Jae-Hwang

2013-01-29T23:59:59.000Z

319

Orientational relaxation in a discotic liquid crystal  

E-Print Network (OSTI)

We investigate orientational relaxation of a model discotic liquid crystal, consists of disc-like molecules, by molecular dynamics simulations along two isobars starting from the high temperature isotropic phase. The two isobars have been so chosen that (A) the phase sequence isotropic (I)-nematic (N)-columnar (C) appears upon cooling along one of them and (B) the sequence isotropic (I)-columnar (C) along the other. While the orientational relaxation in the isotropic phase near the I-N phase transition in system (A) shows a power law decay at short to intermediate times, such power law relaxation is not observed in the isotropic phase near the I-C phase boundary in system (B). In order to understand this difference (the existence or the absence of the power law decay), we calculated the the growth of the orientational pair distribution functions (OPDF) near the I-N phase boundary and also near the I-C phase boundary. We find that OPDF shows a marked growth in long range correlation as the I-N phase boundary is approached in the I-N-C system (A), but such a growth is absent in the I-C system, which appears to be consistent with the result that I-N phase transition in the former is weakly first order while the the I-C phase transition in the later is not weak. As the system settles into the nematic phase, the decay of the single-particle second-rank orientational OTCF follows a pattern that is similar to what is observed with calamitic liquid crystals and supercooled molecular liquids.

Dwaipayan Chakrabarti; Biman Jana; Biman Bagchi

2007-03-08T23:59:59.000Z

320

ARM - Field Campaign - CRYSTAL-FACE  

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsCRYSTAL-FACE govCampaignsCRYSTAL-FACE Campaign Links CRYSTAL-FACE Website Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : CRYSTAL-FACE 2002.06.26 - 2002.08.01 Lead Scientist : James Mather Data Availability Data is available to the general public at the ARM Archive. Questions regarding CRYSTAL-FACE or the PARSL data set may be directed to Jim Mather at the Pacific Northwest National Laboratory (Jim.Mather@pnl.gov) or visit the CRYSTAL-FACE web site at http://cloud1.arc.nasa.gov/crystalface/ For data sets, see below. Description From July 3-29, 2002 ARM took part in CRYSTAL-FACE (The Cirrus Regional Study of Tropical Anvils and Cirrus Layers -Florida Area Cirrus Experiment). CRYSTAL-FACE was organized by NASA but many agencies and

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Aggregation of Ice Crystals in Cirrus  

Science Conference Proceedings (OSTI)

Results are given from analysis of the aggregation of thick plate, columnar, and bullet rosette ice crystals in cirrus. Data were obtained from PMS 2D-C images, oil coated slides, and aircraft meteorological measurements. Crystal size ranged from ...

Masahiro Kajikawa; Andrew J. Heymsfield

1989-10-01T23:59:59.000Z

322

Ice Crystal Production by Mountain Surfaces  

Science Conference Proceedings (OSTI)

Evidence is presented for a process of ice crystal generation in supercooled orographic clouds in contact with snow-covered mountain surfaces. Comparisons of the crystal concentrations at the surface with aircraft sampling indicate that the “...

David C. Rogers; Gabor Vali

1987-09-01T23:59:59.000Z

323

SLAC National Accelerator Laboratory - Bendable Crystals Resolve...  

NLE Websites -- All DOE Office Websites (Extended Search)

Bendable Crystals Resolve Properties of X-ray Pulses By Glenn Roberts Jr. September 12, 2012 A frustrating flaw in a set of custom crystals for an instrument at SLAC National...

324

Crystallization and Solidification Properties of Lipids  

Science Conference Proceedings (OSTI)

A basic understanding of lipid crystallization and solidification is fundamental to understanding and optimizing products or systems containing lipids. Crystallization and Solidification Properties of Lipids Health acid analysis aocs april articles chlor

325

Ice Crystal Replication with Common Plastic Solutions  

Science Conference Proceedings (OSTI)

Use of common plastics, i.e., polystyrene, Plexiglas (polymethyl methacrylate) and Lexan (polycarbonate), was investigated for ice crystal replication. The results suggest that all common plastics tested are usable for ice crystal replication ...

Tsuneya Takahashi; Norihiko Fukuta

1988-02-01T23:59:59.000Z

326

Polymer Crystallization in 25 nm Spheres  

E-Print Network (OSTI)

Crystallization within the discrete spheres of a block copolymer mesophase was studied by time-resolved x-ray scattering. The cubic packing of microdomains, established by self-assembly in the melt, is preserved throughout crystallization by strong interblock segregation even though the amorphous matrix block is well above its glass transition temperature. Homogeneous nucleation within each sphere yields isothermal crystallizations which follow first-order kinetics, contrasting with the sigmoidal kinetics normally exhibited in the quiescent crystallization of bulk polymers.

Yueh-Lin Loo; Richard A. Register; Anthony J. Ryan

2000-03-30T23:59:59.000Z

327

Crystal of GTP Cyclohydrolase Type IB  

Science Conference Proceedings (OSTI)

This invention relates to a novel, bacterial GTP Cyclohydrolase Type IB enzyme, and the crystal structure thereof.

Swairjo, Manal A.; Iwata-Reuyl, Dirk; de Crecy-Lagard, Valerie

2012-12-11T23:59:59.000Z

328

Program on Technology Innovation: Crystal Habit Modifiers  

Science Conference Proceedings (OSTI)

This report presents the results of a review of the scientific and technical literature pertaining to the potential use of crystal habit modifiers to control the formation or consequent effects of deposits in nuclear plant systems. Crystal habit modifiers (CHMs) could potentially be added to the primary or secondary circuits of a pressurized water reactor (PWR) or to boiling water reactor (BWR) coolant as a means of controlling the crystal habit (shape) of the crystals that comprise primary and secondary...

2007-12-17T23:59:59.000Z

329

Estimating Flexoelectric Properties of Piezoelectric Crystals  

Science Conference Proceedings (OSTI)

Energy Harvesting Utilized Resonance Phenomena of Piezoelectric Unimorph · Estimating Flexoelectric Properties of Piezoelectric Crystals: Utilization of a ...

330

Quartz Crystal Microbalances Enable New Microscale Analytic ...  

Science Conference Proceedings (OSTI)

... The technique measures the reaction energy needed to decompose, oxidize ... quartz crystal microbalance, essentially a small piezoelectric disk of ...

2012-10-15T23:59:59.000Z

331

Dependence of carrier mobility on an electric field in gallium selenide crystals  

Science Conference Proceedings (OSTI)

The dependence of the mobility of charge carriers on voltage has been studied in undoped GaSe single crystals and crystals doped with gadolinium; the latter crystals have exhibited various values of dark resistivity ({rho}{sub d.r} Almost-Equal-To 10{sup 4}-10{sup 8} {Omega} cm at 77 K) and of the doping level (N = 10{sup -5}, 10{sup -4}, 10{sup -3}, 10{sup -2}, and 10{sup -1} at %). It is established that the dependence of the charge-carrier mobility on the electric field applied to the sample E {=} 10{sup 4} {Omega} cm) and in lightly doped GaSe crystals (N {<=} 10{sup -2} at %) in the region of T {<=} 150 K. It is found that this dependence is not related to heating of the charge carriers by an electric field; rather, it is caused by elimination of drift barriers as a result of injection.

Abdinov, A. Sh., E-mail: abdinov_axmed@yahoo.com; Babaeva, R. F., E-mail: Babaeva-Rena@yandex.ru; Rzayev, R. M. [Baku State University (Azerbaijan)

2012-06-15T23:59:59.000Z

332

Single event mass spectrometry  

DOE Patents (OSTI)

A means and method for single event time of flight mass spectrometry for analysis of specimen materials. The method of the invention includes pulsing an ion source imposing at least one pulsed ion onto the specimen to produce a corresponding emission of at least one electrically charged particle. The emitted particle is then dissociated into a charged ion component and an uncharged neutral component. The ion and neutral components are then detected. The time of flight of the components are recorded and can be used to analyze the predecessor of the components, and therefore the specimen material. When more than one ion particle is emitted from the specimen per single ion impact, the single event time of flight mass spectrometer described here furnis This invention was made with Government support under Contract No. W-7405-ENG82 awarded by the Department of Energy. The Government has certain rights in the invention.

Conzemius, Robert J. (Ames, IA)

1990-01-16T23:59:59.000Z

333

The Next Generation of Crystal Detectors  

E-Print Network (OSTI)

Heavy crystal scintillators are used widely in HEP experiments for precision measurements of photons and electrons. Future HEP experiments, however, require crystal scintillators of more bright, more fast, more radiation hard and less cost. This paper discusses several R&D directions for the next generation of crystal detectors for future HEP experiments.

Ren-Yuan Zhu

2013-08-22T23:59:59.000Z

334

Microsoft Word - FEAA064O_ORNL_Welding Single Cystal_Factsheet_Rev01.doc  

NLE Websites -- All DOE Office Websites (Extended Search)

Welding and Weld Repair of Single Crystal Gas Turbine Alloys Welding and Weld Repair of Single Crystal Gas Turbine Alloys (Oak Ridge National Laboratory) FACT SHEET I. PROJECT PARTICIPANTS A. Prime Participant: Oak Ridge National Laboratory (ORNL) B. Project Partners (no project funds to these partners): General Electric Corporation Siemens-Westinghouse Corporation Electric Power Research Institute (EPRI) PCC Airfoils Honeywell Aerospace Services Pratt and Whitney Corporation South Carolina Institute for Energy Studies II. PROJECT DESCRIPTION A. Objective It is the purpose of this project to investigate the potential for weld refurbishment and repair of single crystal gas turbine engine components and to determine processes, process conditions, and alloy compositions that will make such weld processing possible.

335

Cloud Ice Crystal Classification Using a 95-GHz Polarimetric Radar  

Science Conference Proceedings (OSTI)

Two algorithms are presented for ice crystal classification using 95-GHz polarimetric radar observables and air temperature (T). Both are based on a fuzzy logic scheme. Ice crystals are classified as columnar crystals (CC), planar crystals (PC), ...

K. Aydin; J. Singh

2004-11-01T23:59:59.000Z

336

Laser-cooled atoms inside a hollow-core photonic-crystal fiber  

E-Print Network (OSTI)

We describe the loading of laser-cooled rubidium atoms into a single-mode hollow-core photonic-crystal fiber. Inside the fiber, the atoms are confined by a far-detuned optical trap and probed by a weak resonant beam. We ...

Bajcsy, M.

337

Single Cell Mechanics BIOMATERIALS  

E-Print Network (OSTI)

Single Cell Mechanics BIOMATERIALS Our goal is to develop fundamental tools to measure the response of live cells to mechanical stimulation. The mechanisms by which cells convert mechanical forces evaluate the underlying mechanisms of cell mechanics. Objective Impact and Customers · Cancer, heart

338

Single-exciton nanocrystal laser  

SciTech Connect

A laser system employing amplification via a single exciton regime and to optical gain media having single exciton amplification is provided.

Klimov, Victor I. (Los Alamos, NM); Ivanov, Sergei A. (Albuquerque, NM)

2012-01-17T23:59:59.000Z

339

Superdense Crystal Packings of Ellipsoids  

E-Print Network (OSTI)

Particle packing problems have fascinated people since the dawn of civilization, and continue to intrigue mathematicians and scientists. Resurgent interest has been spurred by the recent proof of Kepler's conjecture: the face-centered cubic lattice provides the densest packing of equal spheres with a packing fraction $\\phi\\approx0.7405$ \\cite{Kepler_Hales}. Here we report on the densest known packings of congruent ellipsoids. The family of new packings are crystal (periodic) arrangements of nearly spherically-shaped ellipsoids, and always surpass the densest lattice packing. A remarkable maximum density of $\\phi\\approx0.7707$ is achieved for both prolate and oblate ellipsoids with aspect ratios of $\\sqrt{3}$ and $1/\\sqrt{3}$, respectively, and each ellipsoid has 14 touching neighbors. Present results do not exclude the possibility that even denser crystal packings of ellipsoids could be found, and that a corresponding Kepler-like conjecture could be formulated for ellipsoids.

Aleksandar Donev; Frank H. Stillinger; P. M. Chaikin; Salvatore Torquato

2004-03-10T23:59:59.000Z

340

Fast Crystals and Strong Glasses  

SciTech Connect

This talk describes new results on model colloid systems that provide insight into the behavior of fundamental problems in colloid physics, and more generally, for other materials as well. By visualizing the nucleation and growth of colloid crystals, we find that the incipient crystallites are much more disordered than expected, leading to a larger diversity of crystal morphologies. When the entropic contribution of these diverse morphologies is included in the free energy, we are able to describe the behavior very well, and can predict the nucleation rate surprisingly accurately. The talk also describes the glass transition in deformable colloidal particles, and will show that when the internal elasticity of the particles is included, the colloidal glass transition mimics that of molecular glass formers much more completely. These results also suggest that the elasticity at the scale of the fundamental unit, either colloid particle or molecule, determines the nature of the glass transition, as described by the "fragility."

Weitz, David [Harvard

2009-11-04T23:59:59.000Z

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Synthesis, crystal growth, structural and physicochemical studies of novel binary organic complex: 4-chloroaniline-3-hydroxy-4-methoxybenzaldehyde  

SciTech Connect

The solid-state reaction, which is solvent free and green synthesis, has been adopted to explore the novel compound. The phase diagram of 4-chloroaniline (CA) and 3-hydroxy-4-methoxybenzaldehyde (HMB) system shows the formation of a novel 1:1 molecular complex, and two eutectics on either sides of complex. Thermochemical studies of complex and eutectics have been carried out for various properties such as heat of fusion, entropy of fusion, Jackson's parameters, interfacial energy and excess thermodynamic functions. The formation of molecular complex was also studied by IR, NMR, elemental analysis and UV-Vis absorption spectra. The single crystal of molecular complex was grown and its XRD study confirms the formation of complex and identifies the crystal structure and atomic packing of crystal of complex. Transmission spectra of grown crystal of the complex show 70% transmittance efficiency with cut off wavelength 412 nm. The band gap and refractive index of the crystal of complex have also been studied. - Graphical abstarct: Exploiting phase diagram study and solvent free synthesis a novel compound was synthesized and its single crystal growth, atomic packing, energy band gap and refractive index were studied. Highlights: Black-Right-Pointing-Pointer Novel organic complex was synthesized using Green or solvent free synthesis. Black-Right-Pointing-Pointer Phase diagram study provided the information to identify the worthy composition of novel complex. Black-Right-Pointing-Pointer The single crystal of the sufficient size was grown from the ethanol solution. Black-Right-Pointing-Pointer Crystal analysis suggested that the covalent bond is formed between the two parent compounds. Black-Right-Pointing-Pointer The transmittance of the crystal was found to be 70% and it was transparent from 412 to 850 nm.

Sharma, K.P.; Reddi, R.S.B.; Bhattacharya, S. [Department of Chemistry, Centre of Advance Study, Banaras Hindu University, Varanasi-221005 (India); Rai, R.N., E-mail: rn_rai@yahoo.co.in [Department of Chemistry, Centre of Advance Study, Banaras Hindu University, Varanasi-221005 (India)

2012-06-15T23:59:59.000Z

342

Single spin asymmetries at CLAS  

DOE Green Energy (OSTI)

We present recent results from Jefferson Lab's CLAS detector on beam and target single-spin asymmetries in single pion electroproduction off unpolarized hydrogen and polarized NH 3 targets. Non-zero single-beam and single-target spin asymmetries are observed for the first time in semi-inclusive and exclusive pion production in hard-scattering kinematics.

Harut Avakian; Latifa Elouadrhiri

2003-05-19T23:59:59.000Z

343

Single rotor turbine engine  

SciTech Connect

There has been invented a turbine engine with a single rotor which cools the engine, functions as a radial compressor, pushes air through the engine to the ignition point, and acts as an axial turbine for powering the compressor. The invention engine is designed to use a simple scheme of conventional passage shapes to provide both a radial and axial flow pattern through the single rotor, thereby allowing the radial intake air flow to cool the turbine blades and turbine exhaust gases in an axial flow to be used for energy transfer. In an alternative embodiment, an electric generator is incorporated in the engine to specifically adapt the invention for power generation. Magnets are embedded in the exhaust face of the single rotor proximate to a ring of stationary magnetic cores with windings to provide for the generation of electricity. In this alternative embodiment, the turbine is a radial inflow turbine rather than an axial turbine as used in the first embodiment. Radial inflow passages of conventional design are interleaved with radial compressor passages to allow the intake air to cool the turbine blades.

Platts, David A. (Los Alamos, NM)

2002-01-01T23:59:59.000Z

344

High-energy x-ray production with pyroelectric crystals  

Science Conference Proceedings (OSTI)

The invention of pyroelectric x-ray generator technology has enabled researchers to develop ultraportable, low-power x-ray sources for use in imaging, materials analysis, and other applications. For many applications, the usefulness of an x-ray source is determined by its yield and endpoint energy. In x-ray fluorescence, for example, high-energy sources enable the excitation of the K-shell x-ray peaks for high-Z materials as well as the lower-energy L-shell peaks, allowing more positive sample identification. This report shows how a paired-crystal pyroelectric source can be used to approximately double the endpoint x-ray energy, in addition to doubling the x-ray yield, versus a single-crystal source. As an example of the advantage of a paired-crystal system, we present a spectrum showing the fluorescence of the K shell of thorium using a pyroelectric source, as well as a spectrum showing the fluorescence of the K shell of lead. Also shown is an x-ray spectrum with an endpoint energy of 215 keV.

Geuther, Jeffrey A.; Danon, Yaron [Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

2005-05-15T23:59:59.000Z

345

Phonon manipulation with phononic crystals.  

Science Conference Proceedings (OSTI)

In this work, we demonstrated engineered modification of propagation of thermal phonons, i.e. at THz frequencies, using phononic crystals. This work combined theoretical work at Sandia National Laboratories, the University of New Mexico, the University of Colorado Boulder, and Carnegie Mellon University; the MESA fabrication facilities at Sandia; and the microfabrication facilities at UNM to produce world-leading control of phonon propagation in silicon at frequencies up to 3 THz. These efforts culminated in a dramatic reduction in the thermal conductivity of silicon using phononic crystals by a factor of almost 30 as compared with the bulk value, and about 6 as compared with an unpatterned slab of the same thickness. This work represents a revolutionary advance in the engineering of thermoelectric materials for optimal, high-ZT performance. We have demonstrated the significant reduction of the thermal conductivity of silicon using phononic crystal structuring using MEMS-compatible fabrication techniques and in a planar platform that is amenable to integration with typical microelectronic systems. The measured reduction in thermal conductivity as compared to bulk silicon was about a factor of 20 in the cross-plane direction [26], and a factor of 6 in the in-plane direction. Since the electrical conductivity was only reduced by a corresponding factor of about 3 due to the removal of conductive material (i.e., porosity), and the Seebeck coefficient should remain constant as an intrinsic material property, this corresponds to an effective enhancement in ZT by a factor of 2. Given the number of papers in literature devoted to only a small, incremental change in ZT, the ability to boost the ZT of a material by a factor of 2 simply by reducing thermal conductivity is groundbreaking. The results in this work were obtained using silicon, a material that has benefitted from enormous interest in the microelectronics industry and that has a fairly large thermoelectric power factor. In addition, the techniques and scientific understanding developed in the research can be applied to a wide range of materials, with the caveat that the thermal conductivity of such a material be dominated by phonon, rather than electron, transport. In particular, this includes several thermoelectric materials with attractive properties at elevated temperatures (i.e., greater than room temperature), such as silicon germanium and silicon carbide. It is reasonable that phononic crystal patterning could be used for high-temperature thermoelectric devices using such materials, with applications in energy scavenging via waste-heat recovery and thermoelectric cooling for high-performance microelectronic circuits. The only part of the ZT picture missing in this work was the experimental measurement of the Seebeck coefficient of our phononic crystal devices. While a first-order approximation indicates that the Seebeck coefficient should not change significantly from that of bulk silicon, we were not able to actually verify this assumption within the timeframe of the project. Additionally, with regards to future high-temperature applications of this technology, we plan to measure the thermal conductivity reduction factor of our phononic crystals as elevated temperatures to confirm that it does not diminish, given that the nominal thermal conductivity of most semiconductors, including silicon, decreases with temperature above room temperature. We hope to have the opportunity to address these concerns and further advance the state-of-the-art of thermoelectric materials in future projects.

Kim Bongsang; Hopkins, Patrick Edward; Leseman, Zayd C.; Goettler, Drew F.; Su, Mehmet F. (University of New Mexico, Albuquerque, NM); El-Kady, Ihab Fathy; Reinke, Charles M.; Olsson, Roy H., III

2012-01-01T23:59:59.000Z

346

Component Overpressure Growth and Characterization of High Resistivity CdTe Crystals for Radiation Detectors  

Science Conference Proceedings (OSTI)

Spectrometer-grade CdTe single crystals with resistivities higher than 10{sup 9} {Omega} cm have been grown by the modified Bridgman method using zone-refined precursor materials (Cd and Te) under a Cd overpressure. The grown CdTe crystals had good charge-transport properties ({mu}{tau}{sub e} = 2 x 10{sup -3} cm{sup 2} V{sup -1}, {mu}{tau}{sub h} = 8 x 10{sup -5} cm{sup 2} V{sup -1}) and significantly reduced Te precipitates compared with crystals grown without Cd overpressure. The crystal growth conditions for the Bridgman system were optimized by computer modeling and simulation, using modified MASTRAPP program, and applied to crystal diameters of 14 mm (0.55'), 38 mm (1.5'), and 76 mm (3'). Details of the CdTe crystal growth operation, structural, electrical, and optical characterization measurements, detector fabrication, and testing using {sup 241}Am (60 keV) and {sup 137}Cs (662 keV) sources are presented.

Mandal, Krishna [EIC Laboratories, Inc.; Kang, Sung Hoon [EIC Laboratories, Inc.; Choi, Michael [EIC Laboratories, Inc.; Wei, Jiuan [State University of New York, Stony Brook; Zheng, Lili [State University of New York, Stony Brook; Zhang, Hui [State University of New York, Stony Brook; Jellison Jr, Gerald Earle [ORNL; Groza, Michael [Fisk University, Nashville, TN; Burger, Arnold [Fisk University, Nashville, TN

2007-01-01T23:59:59.000Z

347

How Spherical Plasma Crystals Form  

Science Conference Proceedings (OSTI)

The correlation buildup and the formation dynamics of the shell structure in a spherically confined one-component plasma are studied. Using Langevin dynamics simulations the relaxation processes and characteristic time scales and their dependence on the pair interaction and dissipation in the plasma are investigated. While in systems with Coulomb interaction (e.g., trapped ions) in a harmonic confinement shell formation starts at the plasma edge and proceeds inward, this trend is significantly weakened for dusty plasmas with Yukawa interaction. With a suitable change of the confinement conditions the crystallization scenario can be externally controlled.

Kaehlert, H.; Bonitz, M. [Institut fuer Theoretische Physik und Astrophysik, Christian-Albrechts Universitaet zu Kiel, 24098 Kiel (Germany)

2010-01-08T23:59:59.000Z

348

Versatile Collimating Crystal Stage for a Bonse-Hart USAXS Instrument  

SciTech Connect

An advanced ultra-small-angle X-ray scattering (USAXS) instrument, using the Bonse-Hart design and installed at APS, is a robust and reliable instrument, providing a scattering vector (q) range of nearly 4 decades (0.00015 to 1 Aa-1), an intensity dynamic range of up to 9 decades, standard-less absolute intensity calibration, and USAXS imaging capabilities. This type of instrument typically uses channel-cut crystals in both the collimating (before sample) and analyzing (after sample) stages. The optical surfaces of these crystals are finished by etching processes, which leave an orange-peel surface texture, which would compromise the USAXS imaging quality. Therefore optics with highly polished surfaces using separated crystals in both collimating and analyzing stages were developed. A novel design of the optics and mechanical stage uses a fixed gap between the two separated collimating crystals in which a triangular section of the first crystal is removed, allowing for a variable number (1, 2, 4, 6, or 8) of crystal reflections for X-ray energies between 7 and 19 keV. The number of reflections is selected by lateral translation of the collimating crystal pair. Rotational alignment of the second crystal in the pair by an artificial channel-cut crystal mechanism, implemented with a novel high-stiffness weak link actuated by both a picomotor and a piezo-electric transducer, provides the capability to align or adjust an assembly of crystals to achieve the same performance as a single channel-cut crystal with integral weak link. The arrangement of both crystals is held on a removable base that can be remounted with precision within the Si(111) rocking curve on a three-point kinematic mount. Additional tilt adjustments are also provided for initial alignment. This monochromator has proven to be highly robust with respect to motions and vibrations, as well as flexible with respect to selection of number of reflections, and its performance directly resulted in the highly reliable performance of the whole USAXS instrument.

Ilavsky, J.; Shu, D.; Jemian, P. R.; Long, G. G. [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States)

2007-01-19T23:59:59.000Z

349

Livermore scientists capture crystallization of materials in...  

NLE Websites -- All DOE Office Websites (Extended Search)

The team used multi-frame, nanosecond-scale imaging in the dynamic transmission electron microscope (DTEM) to create movies of the crystallization of phase change...

350

Silicon Nano-Crystal Waveguide (SNOW) Laser  

Silicon Nano-Crystal Waveguide (SNOW) Laser Note: The technology described above is an early stage opportunity. Licensing rights to this intellectual property may

351

PHASE-FIELD CRYSTAL MODELING OF NANOCRYSTAL ...  

Science Conference Proceedings (OSTI)

PHASE-FIELD CRYSTAL MODELING OF NANOCRYSTAL GROWTH. Edwin J. Schwalbach, James A. Warren, Kuo-An Wu, and Peter W. Voorhees. ...

352

Mul%crystal diffrac%on  

Science Conference Proceedings (OSTI)

Page 1. Mul%crystal diffrac%on DTU, Denmark: C. Gundlach, PC Hansen, D. Juul Jensen, EM Lauridsen, L. Margulies, J. Oddershede, ...

2013-06-07T23:59:59.000Z

353

Electromagnetic Wave Propagation in Two-Dimensional Photonic Crystals  

SciTech Connect

In this dissertation, they have undertaken the challenge to understand the unusual propagation properties of the photonic crystal (PC). The photonic crystal is a medium where the dielectric function is periodically modulated. These types of structures are characterized by bands and gaps. In other words, they are characterized by frequency regions where propagation is prohibited (gaps) and regions where propagation is allowed (bands). In this study they focus on two-dimensional photonic crystals, i.e., structures with periodic dielectric patterns on a plane and translational symmetry in the perpendicular direction. They start by studying a two-dimensional photonic crystal system for frequencies inside the band gap. The inclusion of a line defect introduces allowed states in the otherwise prohibited frequency spectrum. The dependence of the defect resonance state on different parameters such as size of the structure, profile of incoming source, etc., is investigated in detail. For this study, they used two popular computational methods in photonic crystal research, the Finite Difference Time Domain method (FDTD) and the Transfer Matrix Method (TMM). The results for the one-dimensional defect system are analyzed, and the two methods, FDTD and TMM, are compared. Then, they shift their attention only to periodic two-dimensional crystals, concentrate on their band properties, and study their unusual refractive behavior. Anomalous refractive phenomena in photonic crystals included cases where the beam refracts on the ''wrong'' side of the surface normal. The latter phenomenon, is known as negative refraction and was previously observed in materials where the wave vector, the electric field, and the magnetic field form a left-handed set of vectors. These materials are generally called left-handed materials (LHM) or negative index materials (NIM). They investigated the possibility that the photonic crystal behaves as a LHM, and how this behavior relates with the observed negatively refractive phenomena. They found that in the PC system, negative refraction is neither a prerequisite nor guarantees left-handed behavior. They examined carefully the condition to obtain left-handed behavior in the PC. They proposed a wedge type of experiment, in accordance with the experiment performed on the traditional LHM, to test these conditions. They found that for certain frequencies the PC shows left-handed behavior and acts in some respects like a homogeneous medium with a negative refractive index. they used the realistic PC system for this case to show how negative refraction occurs at the interface between a material with a positive and a material with a negative refractive index. Their findings indicate that the formation of the negatively refracted beam is not instantaneous and involves a transient time. With this time-dependent analysis, they were able to address previous controversial issues about negative refraction concerning causality and the speed of light limit. Finally, they attempt a systematic study of anomalous refractive phenomena that can occur at the air-PC interface. They observe cases where only a single refracted beam (in the positive or negative direction) is present, as well as cases with birefringence. they classify these different effects according to their origin and type of propagation (left-handed or not). For a complete study of the system, they also obtain expressions for the energy and group velocities, and show their equality. For cases with very low index contrast, band folding becomes an artificiality. They discuss the validity of their findings when they move to the limit of photonic crystals with a low index modulation.

Stavroula Foteinopoulou

2003-12-12T23:59:59.000Z

354

Single-Nucleon Densities  

NLE Websites -- All DOE Office Websites (Extended Search)

Densities Densities This web page presents single-nucleon densities calculated for a variety of nuclei in the range A=2-10 with some preliminary results for A=11,12. These are from variational Monte Carlo calculations (VMC) using the Argonne v18 two-nucleon and Urbana X three-nucleon potentials (AV18+UX). (Urbana X is intermediate between the Urbana IX and Illinois-7 models; it has the form of UIX supplemented with a two-pion S-wave piece, while the strengths of its terms are taken from the IL7 model. It does NOT have the three-pion-ring term of IL7.) These VMC wave functions are the starting trial functions for a number of recent Green's function Monte Carlo (GFMC) calculations: Brida, et al., Phys. Rev. C 84, 024319 (2011); McCutchan, et al., Phys. Rev. C 86, 024315 (2012);

355

Single-Column Modeling  

NLE Websites -- All DOE Office Websites (Extended Search)

C.J. Somerville and S. F. lacobellis C.J. Somerville and S. F. lacobellis Climate Research Division Scripps Institution of Oceanography University of California, San Diego La Jolla, CA 92093-0224 Our project is centered around a computationally efficient and economical one-dimensional (vertical) model, resembling a single column of a general circulation model (GCM) grid, applied to the experimental site of the Atmospheric Radiation Measurement (ARM) Program. The model contains a full set of modern GCM parameterizations of subgrid physical processes. To force the model, the advective terms in the budget equations are specified observationally from operational numerical weather prediction analyses. These analyses, based on four-dimensional data assimilation techniques, provide dynamically consistent wind fields and horizontal gradients

356

Growth Of Oriented Crystals At Polymerized Membranes  

DOE Patents (OSTI)

The present invention relates to methods and compositions for the growth and alignment of crystals at biopolymeric films. The methods and compositions of the present invention provide means to generate a variety of dense crystalline ceramic films, with totally aligned crystals, at low temperatures and pressures, suitable for use with polymer and plastic substrates.

Charych, Deborah H. (Albany, CA), Berman, Amir (Ben-Shiva, IL)

2000-01-25T23:59:59.000Z

357

RECIPIENT:Crystal Solar U.S. DEPARTMENT OF ENERGY EERE PROJECT MANAGEMENT CENTER  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Crystal Solar Crystal Solar U.S. DEPARTMENT OF ENERGY EERE PROJECT MANAGEMENT CENTER NEPA DETERMINATION Page I of3 STATE: CA PROJECT TITLE : Technology development for high efficiency solar cells and modules using thin « 80 IJrn) single crystal silicon wafers produced by epitaxy; NREL Tracking No. 11-018 (Reference 09-030) Funding Opportunity Announcement Number Procurement Instrument Number NEPA Control Number em Number NREl-l1-018 G010337 8aSM on my nview orlbe information concerning tbe proposed action, as NEPA Compliance Officer (authorized under DOE Onter 451.1A), I bave made the (ollowlng determination: ex, EA, [IS APPENDIX AND NUMBER: Description: 83.6 Siting, construction (or modification), operation, and decommissioning of facilities for indoor bench-scale research

358

Crystal plasticity analysis of constitutive behavior of 5754 ...  

Science Conference Proceedings (OSTI)

Crystal plasticity analysis of constitutive behavior of 5754 ... of crystal plasticity based analyses (Hu et al ... used includes an axisymmetric ram 200 mm ...

2013-03-09T23:59:59.000Z

359

Microfluidic systems for continuous crystallization of small organic molecules  

E-Print Network (OSTI)

This thesis presents one of the first demonstrations of continuous crystallization in microfluidic devices, and illustrates their use for various applications related to crystallization of small organic molecules. ...

Sultana, Mahmooda

2010-01-01T23:59:59.000Z

360

The luminescence characteristics of CsI(Na) crystal under {alpha} and X/{gamma} excitation  

SciTech Connect

In this paper, we study the effective decay time characteristic of CsI(Na) crystal under {sup 239}Pu alpha particle and {sup 137}Cs gamma-ray excitation using a single photon counting decay time measurement system. The measurement system employs a silicon optical fiber to couple and transit single photon. The slow decay time component of CsI(Na) crystal is 460-550 ns. We observe a 15 ns fast decay component under alpha particle excitation. In addition, we find that the primary stage of the falling edge in the decay time curve is non-exponential and drops rapidly when CsI(Na) crystal is excited by {sup 239}Pu alpha particles. Since the high density of self-trapped-excitons (STEs) is produced in alpha particle excitation process, we propose that the fast falling edge is corresponding to the quenching process of STEs which transit with non-radiation in the case of high excitation density. To prove this proposal, we excited the CsI(Na) crystal with sub-nanosecond intensive pulsed X-ray radiation. Our X-ray impinging results show that the fast falling edge also exists under low energy (average 100 keV) bremsstrahlung X-ray excitation.

Liu Jinliang [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Radiation Detection Research Center, Northwest Institute of Nuclear Technology, Xi'an, Shaanxi 710024 (China); Liu Fang [Radiation Detection Research Center, Northwest Institute of Nuclear Technology, Xi'an, Shaanxi 710024 (China); School of Nuclear Science and Engineering, North China Electric Power University, Beijing 102206 (China); Ouyang Xiaoping [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Radiation Detection Research Center, Northwest Institute of Nuclear Technology, Xi'an, Shaanxi 710024 (China); School of Nuclear Science and Engineering, North China Electric Power University, Beijing 102206 (China); Liu Bin [School of Nuclear Science and Engineering, North China Electric Power University, Beijing 102206 (China); Chen Liang; Ruan Jinlu; Zhang Zhongbing; Liu Jun [Radiation Detection Research Center, Northwest Institute of Nuclear Technology, Xi'an, Shaanxi 710024 (China)

2013-01-14T23:59:59.000Z

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Single-shot readout of an electron spin in silicon  

E-Print Network (OSTI)

The size of silicon transistors used in microelectronic devices is shrinking to the level where quantum effects become important. While this presents a significant challenge for the further scaling of microprocessors, it provides the potential for radical innovations in the form of spin-based quantum computers and spintronic devices. An electron spin in Si can represent a well-isolated quantum bit with long coherence times because of the weak spin-orbit coupling and the possibility to eliminate nuclear spins from the bulk crystal. However, the control of single electrons in Si has proved challenging, and has so far hindered the observation and manipulation of a single spin. Here we report the first demonstration of single-shot, time-resolved readout of an electron spin in Si. This has been performed in a device consisting of implanted phosphorus donors coupled to a metal-oxide-semiconductor single-electron transistor - compatible with current microelectronic technology. We observed a spin lifetime approaching 1 second at magnetic fields below 2 T, and achieved spin readout fidelity better than 90%. High-fidelity single-shot spin readout in Si opens the path to the development of a new generation of quantum computing and spintronic devices, built using the most important material in the semiconductor industry.

Andrea Morello; Jarryd J. Pla; Floris A. Zwanenburg; Kok W. Chan; Hans Huebl; Mikko Mottonen; Christopher D. Nugroho; Changyi Yang; Jessica A. van Donkelaar; Andrew D. C. Alves; David N. Jamieson; Christopher C. Escott; Lloyd C. L. Hollenberg; Robert G. Clark; Andrew S. Dzurak

2010-03-13T23:59:59.000Z

362

Optical spectra of U sup 2+ , U sup 3+ , and U sup 4+ ions in calcium fluoride crystals  

SciTech Connect

We report on optical spectra of single-valence U{sup 2+},U{sup 3+},U{sup 4+} ions in CaF{sub 2} crystals at 10 K. The report supplements two previous papers by the author.

Hargreaves, W.A. (1301 Poitras Drive, Vero Beach, Florida (USA))

1991-09-01T23:59:59.000Z

363

Fractionalization of Interstitials in Curved Colloidal Crystals  

E-Print Network (OSTI)

Understanding the out-of equilibrium behaviour of point defects in crystals, yields insights into the nature and fragility of the ordered state, as well as being of great practical importance. In some rare cases defects are spontaneously healed - a one-dimensional crystal formed by a line of identical charged particles, for example, can accommodate an interstitial (extra particle) by a re-adjusting all particle positions to even out the spacing. In sharp contrast, particles organized into a perfect hexagonal crystal in the plane cannot accommodate an interstitial by a simple re-adjustment of the particle spacing - the interstitial remains instead trapped between lattice sites and diffuses by hopping, leaving the crystal permanently defected. Here we report on the behavior of interstitials in colloidal crystals on curved surfaces. Using optical tweezers operated independently of three dimensional imaging, we insert a colloidal interstitial in a lattice of similar particles on flat and curved (positively and negatively) oil-glycerol interfaces and image the ensuing dynamics. We find that, unlike in flat space, the curved crystals self-heal through a collective rearrangement that re-distributes the increased density associated with the interstitial. The self-healing process can be interpreted in terms of an out of equilibrium interaction of topological defects with each other and with the underlying curvature. Our observations suggest the existence of "particle fractionalization" on curved surface crystals.

William T. M. Irvine; Mark J. Bowick; Paul M. Chaikin

2013-10-11T23:59:59.000Z

364

Threshold concentrations in zinc-doped lithium niobate crystals and their structural conditionality  

SciTech Connect

On the basis of precise X-ray diffraction study of lithium niobate single crystals of congruent composition and four zinc-doped (at 2.8, 5.2, 7.6, and 8.2 mol %) crystals, structural conditionality of the threshold concentrations of the dopant has been established. At these concentrations, the mechanism of zinc incorporation into crystal changes. As the zinc concentration increases, this element first substitutes excess niobium, localized in lithium positions, with a simultaneous decrease in the number of vacancies in these positions. Then zinc substitutes lithium with formation of new lithium vacancies. When a certain limit on the number of vacancies is reached, zinc begins to substitute niobium in its main positions. This process is naturally accompanied by a decrease in the number of vacancies to their complete disappearance and formation of a self-compensating crystal. The character of the dependence of the crystal physical properties on the dopant concentration changes specifically when the impurity concentration passes through the threshold values.

Chernaya, T. S.; Volk, T. R.; Verin, I. A.; Simonov, V. I., E-mail: simonov@ns.crys.ras.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

2008-07-15T23:59:59.000Z

365

Optical Properties and Wave Propagation in Semiconductor-Based Two-Dimensional Photonic Crystals  

Science Conference Proceedings (OSTI)

This work is a theoretical investigation on the physical properties of semiconductor-based two-dimensional photonic crystals, in particular for what concerns systems embedded in planar dielectric waveguides (GaAs/AlGaAs, GaInAsP/InP heterostructures, and self-standing membranes) or based on macro-porous silicon. The photonic-band structure of photonic crystals and photonic-crystal slabs is numerically computed and the associated light-line problem is discussed, which points to the issue of intrinsic out-of-lane diffraction losses for the photonic bands lying above the light line. The photonic states are then classified by the group theory formalism: each mode is related to an irreducible representation of the corresponding small point group. The optical properties are investigated by means of the scattering matrix method, which numerically implements a variable-angle-reflectance experiment; comparison with experiments is also provided. The analysis of surface reflectance proves the existence of selection rules for coupling an external wave to a certain photonic mode. Such rules can be directly derived from symmetry considerations. Lastly, the control of wave propagation in weak-index contrast photonic-crystal slabs is tackled in view of designing building blocks for photonic integrated circuits. The proposed designs are found to comply with the major requirements of low-loss propagation, high and single-mode transmission. These notions are then collected to model a photonic-crystal combiner for an integrated multi-wavelength-source laser.

Mario Agio

2002-12-31T23:59:59.000Z

366

Irradiated Single Crystals for High Temperature Measurements in Space Applications Alex A. Volinsky1  

E-Print Network (OSTI)

-to-access moving parts, such as rotating turbine disks, or jet nozzles, is even more challenging. These kinds heating. Sophisticated insulation systems are designed for thermal protection. One of the steps turbo pump temperature. INTRODUCTION New efficient engine and thermal protection systems design

Volinsky, Alex A.

367

Direct atomistic simulation of brittle-to-ductile transition in silicon single crystals  

E-Print Network (OSTI)

Silicon is an important material not only for semiconductor applications, but also for the development of novel bioinspired and biomimicking materials and structures or drug delivery systems in the context of nanomedicine. ...

Sen, Dipanjan

368

Atomistic Study of Crack-Tip Cleavage to Dislocation Emission Transition in Silicon Single Crystals  

E-Print Network (OSTI)

At low temperatures silicon is a brittle material that shatters catastrophically, whereas at elevated temperatures, the behavior of silicon changes drastically over a narrow temperature range and suddenly becomes ductile. ...

Sen, Dipanjan

369

Stress-Rupture Behavior of Single Crystal Superalloy M09A  

Science Conference Proceedings (OSTI)

... Corrosion Inhibition for Hydrochloric Acid Pickling · Using Resistance Heating to Create Full-Scale API RP2Z CTOD Samples ...

370

Effect of Ti and Ta on the Creep Properties of Single Crystal Co-Al-W ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, 2014 TMS Annual Meeting & Exhibition. Symposium , High-temperature Gamma (f.c.c.) /Gamma-Prime (L12 structure) Co-Al-W ...

371

Stretchable form of single crystal silicon for high performance electronics on rubber substrates  

DOE Patents (OSTI)

The present invention provides stretchable, and optionally printable, semiconductors and electronic circuits capable of providing good performance when stretched, compressed, flexed or otherwise deformed. Stretchable semiconductors and electronic circuits of the present invention preferred for some applications are flexible, in addition to being stretchable, and thus are capable of significant elongation, flexing, bending or other deformation along one or more axes. Further, stretchable semiconductors and electronic circuits of the present invention may be adapted to a wide range of device configurations to provide fully flexible electronic and optoelectronic devices.

University of Illinois (Urbana, IL)

2009-04-21T23:59:59.000Z

372

Stretchable form of single crystal silicon for high performance electronics on rubber substrates  

DOE Patents (OSTI)

The present invention provides stretchable, and optionally printable, semiconductors and electronic circuits capable of providing good performance when stretched, compressed, flexed or otherwise deformed. Stretchable semiconductors and electronic circuits of the present invention preferred for some applications are flexible, in addition to being stretchable, and thus are capable of significant elongation, flexing, bending or other deformation along one or more axes. Further, stretchable semiconductors and electronic circuits of the present invention may be adapted to a wide range of device configurations to provide fully flexible electronic and optoelectronic devices.

Rogers, John A. (Champaign, IL); Khang, Dahl-Young (Seoul, KR); Sun, Yugang (Naperville, IL); Menard, Etienne (Durham, NC)

2012-06-12T23:59:59.000Z

373

Phase on Creep Resistance of a Single Crystal Nickel-Based  

Science Conference Proceedings (OSTI)

creep condition, the cuboidal y' phase in the as-heat treated specimens ... deformation under the conditions of higher temperatures and relatively ... transformers.

374

H10: Pop-in and Creep Behavior of ZnO Single Crystal during ...  

Science Conference Proceedings (OSTI)

C19: Dissolution Behavior of Cu Under Bump Metallization in Ball Grid Array Structure ... E11: Evolution of the Grain Boundary Character Distribution During Grain ... for High Volume and Fast Turnaround Automated Inline TEM Sample Preparation .... H2: Triboluminescent Smart Sensors for Structural Health Monitoring.

375

Disorder effects in half-metallic Sr 2 FeMoO 6 single crystals  

Science Conference Proceedings (OSTI)

Double perovskites such as Sr 2 FeMoO 6 (SFMO) have been predicted to be half-metallic (100% spin polarized). However

Raghava P. Panguluri; Sheng Xu; Yutaka Moritomo; I. V. Solovyev; B. Nadgorny

2009-01-01T23:59:59.000Z

376

The Control of Sulfur Content in Nickel-Base, Single Crystal ...  

Science Conference Proceedings (OSTI)

... alumina to the substrate is improved by addition of reactive elements such as Hf, and Y. Mass Change/Area (mg/cm'). 1 ,. -2 t. -2.5 t. As Received. -. H2 AnP'ed.

377

Improved Single Crystal Superalloys, CMSX-4®(SLS)[La+Y] and ...  

Science Conference Proceedings (OSTI)

from 300-1370 ppm and CMSX-4 (SLS) [La+Y] components are currently operating in production turbine engines. Manufacturing flexibility, inventory cost control ...

378

Microsoft Word - 41344_Texas A&M_Mech of Single Crystal Blades...  

NLE Websites -- All DOE Office Websites (Extended Search)

and the development of cooling systems that can allow the temperature of the gas entering the turbine to be significantly higher than at the present moment....

379

E2, Fabrication of Flexible Single-Crystal Devices on Electrically ...  

Science Conference Proceedings (OSTI)

... rooftops, or the constantly-flexing realm of backpacks or tactical apparel that ... C2, Measurement of Nanoscale External Quantum Efficiency of Plastic Solar ...

380

Development of Next-Generation Ni-Base Single Crystal Superalloys  

Science Conference Proceedings (OSTI)

superalloys have been widely used as turbine aerofoil materials in jet engines and industrial gas turbines to increase the turbine inlet gas temperatures and ...

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

(Selective carbon oxygen bond scission during reactions of oxygenates on single crystal catalysts)  

SciTech Connect

We have discovered that the carbon-oxygen bond in methanol can be selectively broken if the surface structure of the platinum catalyst is appropriately tailored. The objective of this project is to determine if variations in surface structure allow one to selectively break C-O and C-H bonds. The decomposition of a wide range of oxygenates on several carefully chosen faces of group VIII metals will be examined to see when C-O bond scission occurs and what new chemistry we can find on stepped surfaces.

1992-01-01T23:59:59.000Z

382

[Selective carbon oxygen bond scission during reactions of oxygenates on single crystal catalysts]. Progress report  

SciTech Connect

We have discovered that the carbon-oxygen bond in methanol can be selectively broken if the surface structure of the platinum catalyst is appropriately tailored. The objective of this project is to determine if variations in surface structure allow one to selectively break C-O and C-H bonds. The decomposition of a wide range of oxygenates on several carefully chosen faces of group VIII metals will be examined to see when C-O bond scission occurs and what new chemistry we can find on stepped surfaces.

1992-08-01T23:59:59.000Z

383

107 Floating-Zone Growth and Characterization of Single Crystals of ...  

Science Conference Proceedings (OSTI)

005 Calcium Phosphates for Drug Carrier: Adsorption and Release Kinetics of Drugs ... 058 Properties Optimization of Refractory Mineral Resources in China.

384

MIGRATION OF GAS-LIQUID INCLUSIONS IN KC l AND NaC l SINGLE CRYSTALS  

E-Print Network (OSTI)

Engineering MIGRATION OF GAS-LIQUID INCLUSIONS IN KCi ANDLBL-11815 MIGRATION OF GAS- LIQUID INCJlJSION~; IN KC£ 1\\NDheat transport in the gas/liquid/solid ccrnposite medium;

Olander, Donald R.

2013-01-01T23:59:59.000Z

385

Development of Si-Bearing 4th Generation Ni-Base Single Crystal ...  

Science Conference Proceedings (OSTI)

analysis. FIM tips were prepared by electropolishing those square rods first in a solution of 10% perchloric acid with 90% ethanol at room temperature, and then ...

386

Waste Heat Energy Harvesting Using Olsen Cycle on PZN-5.5PT Single Crystals  

E-Print Network (OSTI)

thermal energy that would otherwise be wasted. In 2009, anthe energy consumed in the United States was wasted in the

McKinley, Ian Meeker; Kandilian, Razmig; Pilon, Laurent

2012-01-01T23:59:59.000Z

387

H5, Probing Stress Effects in Single Crystal Organic Transistors by ...  

Science Conference Proceedings (OSTI)

DD3, A New Approach to Make ZnO-Cu2O Heterojunctions for Solar Cells ... E2, AlGaAs/GaAs/GaN Wafer Fused HBTs with Ar Implanted Extrinsic Collectors.

388

AA4, Optical Properties of Gd Implanted ZnO Single Crystals  

Science Conference Proceedings (OSTI)

DD3, A New Approach to Make ZnO-Cu2O Heterojunctions for Solar Cells ... E2, AlGaAs/GaAs/GaN Wafer Fused HBTs with Ar Implanted Extrinsic Collectors.

389

Biopolymer Synthesis of Single Crystal La4Ga2O9 Nanowires  

Science Conference Proceedings (OSTI)

... next generation of nano-devices and may possibly reveal new chemical and physical ... Controlled Photolytic Release of Biocides for High Efficiency Decontamination ... Yeast-derived Glycolipids as Greener Structure Directing Agents for ...

390

Multi-paradigm modeling of mode I&II dynamic fracture mechanisms in single crystal silicon  

E-Print Network (OSTI)

In addition to its semi-conducting properties, silicon has the ability to be manipulated with high precision at very small length- scales. This property makes it very useful in the design of Nano/Micro-Electromechanical ...

Cohen, Alan, S. B. Massachusetts Institute of Technology

2008-01-01T23:59:59.000Z

391

Preparation, characterization and magnetic properties of an ordered FeCo single crystal  

E-Print Network (OSTI)

. Gautard, G. Couderchon, and L. Coutu, J. Magn. Magn. Mater. 160, 359 1996 . 5 J. H. Scott, Z. Turgut, K

McHenry, Michael E.

392

Alloy Design for High Strength Nickel-Base Single Crystal Alloys  

Science Conference Proceedings (OSTI)

Under a suitable lighting condition. (a kind of optical darkfield observation condition), it was found that the rafted .structure[lO] area looked bright, and deformed ...

393

Analysis of Stray Grain Formation in Single-Crystal Nickel-Based ...  

Science Conference Proceedings (OSTI)

Program, Office of Fossil Energy, U. S. Department of Energy, under contract DE- AC05-00OR22725 with UT-Battelle, LLC. The authors would like to thank ...

394

Indentation Size Effects in Single Crystal Copper as Revealed by Synchrotron X-ray Microdiffraction  

E-Print Network (OSTI)

50, 681-694 (2002). K. Durst, B. Backes, and M. Goken,Stanford University, 2005. K. Durst, B. Backes, O. Franke,function of indentation depth. Durst and Goken 16 as well as

Feng, G.

2009-01-01T23:59:59.000Z

395

Effects of Thermal Variables on the Growth of Single Crystals of Ni ...  

Science Conference Proceedings (OSTI)

by the Bridgman method, in which the control of heat transfer phenomena is most critical. ... If we grasp these heat transfer phenomena quantitatively, we can.

396

Tunable Visible and Near-IR Emission from Sub-10 nm Etched Single-Crystal Si  

E-Print Network (OSTI)

silicon devices in the form of light- emitting diode or laser structures. KEYWORDS Silicon nanowires

Heaton, Thomas H.

397

Cyclic Deformation Behavior of Aged FeNiCoAlTa Single Crystals  

Science Conference Proceedings (OSTI)

Dog-bone shaped specimens were tested up to 100 cycles after different aging heat treatments in order to characterize the cyclic stress-strain response and ...

398

New Boron and Silicon Free Single Crystal-Diffusion Brazing Alloys  

Science Conference Proceedings (OSTI)

Based on the activation energies for diffusion an increase in process temperature of ..... M. Nazmy et al., “Environmental effects on tensile and low cycle fatigue ...

399

Defect Grains in the Melt-Back Region of CMSX-4 Single Crystal ...  

Science Conference Proceedings (OSTI)

butanol, 45% acetic acid and 10% perchloric acid at 25 volts for approximately 15 seconds. Electron micrographs were taken using backscattered imaging in a ...

400

Hydrogen Hardening Effect in Heavily Deformed Single Crystal a-Iron  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2011. Symposium, Environmentally Assisted Cracking of Materials. Presentation Title, Hydrogen ...

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

TENSILE PROPERTIES AND DEFORMATION-INDUCED TRANSFORMATIONS IN METASTABLE AUSTENITIC SINGLE CRYSTALS  

E-Print Network (OSTI)

plane The magnitude of Ufo for any variant is a relativeall] 't/o (Tll) °n lo Ufo [Oln (IU) (Tll) (Ill) (Ill) a .

Goeser, G.A.

2010-01-01T23:59:59.000Z

402

Effects of hydrogen anneals on oxygen deficient SrTio3-x single crystals  

E-Print Network (OSTI)

have suggested that hydrogen may also be substituted on thethat the in?uence of hydrogen anneals on the conductivity ofmay be passivated by the hydrogen anneal. A complex Author

Jalan, Bharat; Engel-Herbert, Roman; Mates, Thomas E.; Stemmer, Susanne

2008-01-01T23:59:59.000Z

403

High Temperature Creep of Ru-Bearing Ni-Base Single Crystal ...  

Science Conference Proceedings (OSTI)

certain loading conditions, the rafted microstructure can be an effective .... As the load increased ... Philips PROFIT software was used to profile fit the {001} peak.

404

Distribution of Platinum Group Metals in Ni-Base Single Crystal ...  

Science Conference Proceedings (OSTI)

for lh followed by 1320°C for 5h and gas fan cooled. After then, TMS-91 was aged ... by gas fan cooled, and the other two alloys were aged at. 1100°C for 5h and ...

405

Waste Heat Energy Harvesting Using Olsen Cycle on PZN-5.5PT Single Crystals  

E-Print Network (OSTI)

energy converter for waste heat energy harvesting using co-L. “Pyroelectric waste heat energy harvesting using heatNo.3, pp.035015, 2012. WASTE HEAT ENERGY HARVESTING USING

McKinley, Ian Meeker; Kandilian, Razmig; Pilon, Laurent

2012-01-01T23:59:59.000Z

406

MAGNON SCATTERING OF SLOW NEUTRONS ON A PYRRHOTITE SINGLE CRYSTAL By ADAM WANIC,  

E-Print Network (OSTI)

of Nuclear Physics, Cracow, Poland. Institute of Nuclear Sciences " Boris Kidric ", Vinca, Yugoslavia (1 spectrometer installed at the TVRS reactor in Vinca. The energy analysis together with the diffraction method were applied and are described. The results are interpreted in the frame of spin wave theory. A spin

Paris-Sud XI, Université de

407

Ab-Initio Calculations of the Optical Properties of ?-NbN Single Crystal  

Science Conference Proceedings (OSTI)

Synthesis and Characterization of Pb Free Piezoelectric Ceramics - Barium ... Thermographic Characterization of Tensile Behavior in Railway Bogie Materials.

408

Creep Strength of Ni-Base Single-Crystal Superalloys on the ...  

Science Conference Proceedings (OSTI)

comparisons with TMS-75, TMS-82+ contains less Re, but the creep rupture life ... Figure 3 represents the microstructure in an alloy of the TMS-75 series, which ...

409

Group velocity dependence of propagation losses in single-line-defect photonic crystal  

E-Print Network (OSTI)

of 7, an additional loss is found to be only 5 dB=mm, thus proving a feasible usage of low vg by electron-beam lithography, and transferred into the core surface by reactive-ion-beam etching. The lower of the TE-like mode (electric field in slab plane). There is a singlemode below the light line, as indicated

410

Development of Exothermically Cast Single-Crystal MAR-M 247 and ...  

Science Conference Proceedings (OSTI)

AiResearch Manufacturing Co. of Arizona. A Division of The ... Elements such as Ni, Cr, Co, W, and .... mold preheat oven for exothermic ignition and firing.

411

High-pressure catalytic reactions over single-crystal metal surfaces  

E-Print Network (OSTI)

. Keywords: Energy, Biofuels, Shale gas, Alternative fuels, Diesel, Fisher ­ Tropsch 1 Corresponding author. The process is based on Fischer- Tropsch technology in which the shale gas is reformed with steam, while and industry; e.g. ExxonMobil announced a $600 million program [10-12]. However, the use of Fischer-Tropsch

Goodman, Wayne

412

Evolution of the Surface Science of Catalysis from Single Crystals to Metal Nanoparticles under Pressure  

E-Print Network (OSTI)

P. D. Yang, Angewandte Chemie-International Edition 2006,G. M. Schwab, Angewandte Chemie-International Edition 1967,

Somorjai, Gabor A.

2008-01-01T23:59:59.000Z

413

Microstructure and Defects of Co-Doped BaFe2As2 Single Crystal ...  

Science Conference Proceedings (OSTI)

Transmission electron microscopy revealed that the film on bare (STO) or ... Gdbco Coated Conductors on Clad-Type Textured Metal Substrates for HTS Cables.

414

An Investigation of the Compatibility of Nickel-Based Single Crystal ...  

Science Conference Proceedings (OSTI)

Roger C. Reed, Kenneth A. Green, Pierre Caron, Timothy P. Gabb, Michael G. Fahrmann, Eric S. ..... E.P. Busso, L. Wright, H.E. Evans, L.N. McCartney, S.R.J..

415

NMR and NQR parameters of ethanol crystal  

E-Print Network (OSTI)

Electric field gradients and chemical shielding tensors of the stable monoclinic crystal phase of ethanol are computed. The projector-augmented wave (PAW) and gauge-including projector-augmented wave (GIPAW) models in the periodic plane-wave density functional theory are used. The crystal data from X-ray measurements, as well as the structures where either all atomic, or only hydrogen atom positions are optimized in the density functional theory are analyzed. These structural models are also studied by including the semi-empirical Van der Waals correction to the density functional theory. Infrared spectra of these five crystal models are calculated.

Milinkovic, M

2012-01-01T23:59:59.000Z

416

CRYSTAL CHEMISTRY OF HYDROUS MINERALS  

DOE Green Energy (OSTI)

Hydrogen has long been appreciated for its role in geological processes of the Earth's crust. However, its role in Earth's deep interior has been neglected in most geophysical thinking. Yet it is now believed that most of our planet's hydrogen may be locked up in high pressure phases of hydrous silicate minerals within the Earth's mantle. This rocky interior (approximately 7/8 of Earth's volume) is conjectured to contain 1-2 orders of magnitude more water than the more obvious oceans (the ''hydrosphere'') and atmosphere. This project is aimed at using the capability of neutron scattering from hydrogen to study the crystal chemistry and stability of hydrogen-bearing minerals at high pressures and temperatures. At the most basic level this is a study of the atomic position and hydrogen bond itself. We have conducted experimental runs on hydrous minerals under high pressure and high temperature conditions. The crystallographic structure of hydrous minerals at extreme conditions and its structural stability, and hydrogen bond at high P-T conditions are the fundamental questions to be addressed. The behavior of the hydrous minerals in the deep interior of the Earth has been discussed.

Y. ZHAO; ET AL

2001-02-01T23:59:59.000Z

417

Seed crystals with improved properties for melt processing superconductors for practical applications  

DOE Patents (OSTI)

A method of fabricating bulk superconducting material is disclosed including RBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} comprising heating compressed powder oxides and/or carbonates of R and Ba and Cu present in mole ratios to form RBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} in physical contact with an oxide single crystal seed to a temperature sufficient to form a liquid phase in the RBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} while maintaining the single crystal seed solid to grow the superconducting material and thereafter cooling to provide a material including RBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}. R is a rare earth or Y or La and the single crystal seed has a lattice mismatch with RBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} of less than about 2% at the growth temperature. The starting material may be such that the final product contains a minor amount of R{sub 2}BaCuO{sub 5}.

Veal, B.W.; Paulikas, A.; Balachandran, U.; Zhong, W.

1997-03-18T23:59:59.000Z

418

Seed crystals with improved properties for melt processing superconductors for practical applications  

DOE Patents (OSTI)

A method of fabricating bulk superconducting material including RBa.sub.2 Cu.sub.3 O.sub.7-.delta. comprising heating compressed powder oxides and/or carbonates of R and Ba and Cu present in mole ratios to form RBa.sub.2 Cu.sub.3 O.sub.7-.delta. in physical contact with an oxide single crystal seed to a temperature sufficient to form a liquid phase in the RBa.sub.2 Cu.sub.3 O.sub.7-.delta. while maintaining the single crystal seed solid to grow the superconducting material and thereafter cooling to provide a material including RBa.sub.2 Cu.sub.3 O.sub.7-.delta.. R is a rare earth or Y or La and the single crystal seed has a lattice mismatch with RBa.sub.2 Cu.sub.3 O.sub.7-.delta. of less than about 2% at the growth temperature. The starting material may be such that the final product contains a minor amount of R.sub.2 BaCuO.sub.5.

Veal, Boyd W. (Downers Grove, IL); Paulikas, Arvydas (Downers Grove, IL); Balachandran, Uthamalingam (Hinsdale, IL); Zhong, Wei (Chicago, IL)

1997-01-01T23:59:59.000Z

419

Applications of Mechanical Vapor Recompression to Evaporation and Crystallization  

E-Print Network (OSTI)

Over the past 10-15 years, mechanical vapor recompression (MVR) has become the preferred system in many industrial evaporation and crystallization applications, because of its economy and simplicity of operation. In most instances, the need for steam to provide heat for the evaporation and cooling water for condensing the overhead vapors is virtually eliminated; and, at the same time, a wide range of turndown is available. An MVR is generally found to be the most economical choice when there is no boiler plant available or when electrical power is priced competitively in comparison to steam. Vapor recompression is accomplished using centrifugal, axial-flow, or positive displacement compressors and these compressors can be powered by electricity, steam turbine or a gas turbine. The use of an MVR Evaporator/Crystallizer provides a comparatively low cost means of expanding the production capability of an existing evaporation plant either by adding a "stand alone" unit or by reconfiguring a multiple-effect system into several single-effect MVR's.

Outland, J. S.

1995-04-01T23:59:59.000Z

420

Computational Study and Analysis of Structural Imperfections in 1D and 2D Photonic Crystals  

SciTech Connect

Dielectric reflectors that are periodic in one or two dimensions, also known as 1D and 2D photonic crystals, have been widely studied for many potential applications due to the presence of wavelength-tunable photonic bandgaps. However, the unique optical behavior of photonic crystals is based on theoretical models of perfect analogues. Little is known about the practical effects of dielectric imperfections on their technologically useful optical properties. In order to address this issue, a finite-difference time-domain (FDTD) code is employed to study the effect of three specific dielectric imperfections in 1D and 2D photonic crystals. The first imperfection investigated is dielectric interfacial roughness in quarter-wave tuned 1D photonic crystals at normal incidence. This study reveals that the reflectivity of some roughened photonic crystal configurations can change up to 50% at the center of the bandgap for RMS roughness values around 20% of the characteristic periodicity of the crystal. However, this reflectivity change can be mitigated by increasing the index contrast and/or the number of bilayers in the crystal. In order to explain these results, the homogenization approximation, which is usually applied to single rough surfaces, is applied to the quarter-wave stacks. The results of the homogenization approximation match the FDTD results extremely well, suggesting that the main role of the roughness features is to grade the refractive index profile of the interfaces in the photonic crystal rather than diffusely scatter the incoming light. This result also implies that the amount of incoherent reflection from the roughened quarterwave stacks is extremely small. This is confirmed through direct extraction of the amount of incoherent power from the FDTD calculations. Further FDTD studies are done on the entire normal incidence bandgap of roughened 1D photonic crystals. These results reveal a narrowing and red-shifting of the normal incidence bandgap with increasing RMS roughness. Again, the homogenization approximation is able to predict these results. The problem of surface scratches on 1D photonic crystals is also addressed. Although the reflectivity decreases are lower in this study, up to a 15% change in reflectivity is observed in certain scratched photonic crystal structures. However, this reflectivity change can be significantly decreased by adding a low index protective coating to the surface of the photonic crystal. Again, application of homogenization theory to these structures confirms its predictive power for this type of imperfection as well. Additionally, the problem of a circular pores in 2D photonic crystals is investigated, showing that almost a 50% change in reflectivity can occur for some structures. Furthermore, this study reveals trends that are consistent with the 1D simulations: parameter changes that increase the absolute reflectivity of the photonic crystal will also increase its tolerance to structural imperfections. Finally, experimental reflectance spectra from roughened 1D photonic crystals are compared to the results predicted computationally in this thesis. Both the computed and experimental spectra correlate favorably, validating the findings presented herein.

K.R. Maskaly

2005-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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421

Ammothermal Growth of Gan Substrates For Leds: High-Pressure Ammonothermal Process for Bulk Gallium Nitride Crystal Growth for Energy Efficient Commercially Competitive Lighting  

Science Conference Proceedings (OSTI)

Broad Funding Opportunity Announcement Project: The new GaN crystal growth method is adapted from that used to grow quartz crystals, which are very inexpensive and represent the second-largest market for single crystals for electronic applications (after silicon). More extreme conditions are required to grow GaN crystals and therefore a new type of chemical growth chamber was invented that is suitable for large-scale manufacturing. A new process was developed that grows GaN crystals at a rate that is more than double that of current processes. The new technology will enable GaN substrates with best-in-world quality at lowest-in-world prices, which in turn will enable new generations of white LEDs, lasers for full-color displays, and high-performance power electronics.

None

2011-01-01T23:59:59.000Z

422

Influence of the defect structure of {gamma}-La{sub 2(1-x)}Nd{sub 2x}S{sub 3} crystals on their spectroscopic properties  

Science Conference Proceedings (OSTI)

The photoluminescence and Raman scattering of undoped {gamma}-Ln{sub 2}S{sub 3} single crystals (Ln is a rare earth ion) and the decay kinetics of the {sup 4}F{sub 3/2} level of Nd ions in these crystals have been investigated. The distortion of the decay curve of the Nd {sup 4}F{sub 3/2} level upon excitation by light with {lambda} = 0.53 {mu}m is explained.

Mamedov, A. A., E-mail: tedd33@mail.ru [National Academy of Sciences of Azerbaijan, Institute of Physics (Azerbaijan)

2010-04-15T23:59:59.000Z

423

Synthesis and X-ray crystal structure determination of N-p-methylphenyl-4-benzoyl-3,4-diphenyl-2-azetidinone  

Science Conference Proceedings (OSTI)

The title compound, C{sub 29}H{sub 23}NO{sub 2}, has been characterized by single-crystal X-ray diffraction at two different temperatures (303 K and 120 K) and wavelengths (MoK{sub {alpha}} and CuK{sub {alpha}}). The non-centrosymmetric hexagonal crystal structure contains four-membered planar {beta}-lactam ring with an unusually long C-C bond. The {beta}-lactam ring is almost planar.

Kabak, Mehmet, E-mail: kabak@eng.ankara.edu.tr [University of Ankara, Department of Engineering Physics, Faculty of Engineering (Turkey); Senoez, Huelya [Hacettepe University, Faculty of Sciences, Department of Chemistry (Turkey); Elmali, Ayhan [University of Ankara, Department of Engineering Physics, Faculty of Engineering (Turkey); Adar, Vildan [Hacettepe University, Faculty of Sciences, Department of Chemistry (Turkey); Svoboda, Ingrid [Darmstadt University of Technology, Institute of Material Science (Germany); Dusek, Michal; Fejfarova, Karla [Institute of Physics (Czech Republic)

2010-12-15T23:59:59.000Z

424

JX Crystals Inc | Open Energy Information  

Open Energy Info (EERE)

JX Crystals Inc JX Crystals Inc Jump to: navigation, search Name JX Crystals Inc Place Issaquah, Washington State Zip 98027 Sector Solar Product JX Crystals designs and manufactures thermophotovoltaic gallium-antimonide cells for solar applications. Coordinates 47.530095°, -122.033799° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":47.530095,"lon":-122.033799,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

425

The diverse world of liquid crystals  

E-Print Network (OSTI)

slime, laundry detergent, textile fibers such as silk and Kevlar, crude oil, insect wings, mineral at Kent State University in Ohio. Liquid crystals are all around us: in high-strength plas- tics, snail

Palffy-Muhoray, Peter

426

Studying defects created by irradiating molybdenum crystals ...  

NLE Websites -- All DOE Office Websites (Extended Search)

by irradiating molybdenum crystals July 16, 2013 Tweet EmailPrint In order to study irradiation damage and inert gas bubble formation and growth behaviors, and to provide results...

427

Photo-responsive liquid crystal block copolymers/  

E-Print Network (OSTI)

Photo-responsive liquid crystal polymers (LCP) which contain azobenzene moieties have gained interest for their ability to change properties by merely irradiating them with the correct wavelength of light in the appropriate ...

Petr, Michael Thomas

2012-01-01T23:59:59.000Z

428

Photonic crystal: energy-related applications  

SciTech Connect

We review recent work on photonic-crystal fabrication using soft-lithography techniques. We consider applications of the resulting structures in energy-related areas such as lighting and solar-energy harvesting. In general, our aim is to introduce the reader to the concepts of photonic crystals, describe their history, development, and fabrication techniques and discuss a selection of energy-related applications.

Ye, Zhuo; Park, Joong-Mok; Constant, Kristen; Kim, Tae-Geun; Ho, Kai-Ming

2012-06-08T23:59:59.000Z

429

Single Cell Whole Genome Amplification  

NLE Websites -- All DOE Office Websites (Extended Search)

Single Cell Whole Genome Amplification Single Cell Whole Genome Amplification of Uncultivated Organisms Mircea Podar , Martin Keller , and Philip Hugenholtz (* ü ) Abstract Whole genome amplification of single cells is emerging as a powerful technique for accessing the genomes of individual members of microbial communi- ties without the complication of identifying the source of sequence data posed by shotgun sequencing of environmental samples (metagenomics). This method holds particular promise for the molecular unveiling of uncultivated organisms that com- prise the bulk of the microbial diversity and functionality on our planet. 1 Introduction Over the last two decades, it has become increasingly apparent that microbial diversity

430

Crystallization and Solidification Properties of LipidsChapter 9 Crystallization of Palm Oil Products  

Science Conference Proceedings (OSTI)

Crystallization and Solidification Properties of Lipids Chapter 9 Crystallization of Palm Oil Products Health Nutrition Biochemistry eChapters Health - Nutrition - Biochemistry 0B466411CD87C680D99B2D98B90D36F7 AOCS Press 

431

Plastic deformation of submicron-sized crystals studied by in-situ Kikuchi diffraction and dislocation imaging  

Science Conference Proceedings (OSTI)

The plastic deformation of submicron-size copper single crystals in the form of pillars has been characterized during in-situ compression in the transmission electron microscope up to strains of 28-33% using a state-of-the-art holder (PI-95 PicoIndenter). The dimensions of the crystals used were approx. 500 Multiplication-Sign 250 Multiplication-Sign 200 nm{sup 3} with the compression axis oriented 1.6 Degree-Sign from [110]. Local crystallographic orientations have been determined with high accuracy using a Kikuchi diffraction method and glide of dislocations over a pillar has also been observed directly by dark field imaging. The variation in the local orientation during deformation has been followed by in-situ convergent beam electron Kikuchi diffraction. The in-situ observations have been followed up by post-deformation measurements with the samples still mounted in the electron microscope. Crystal breakup following localized deformation was observed in two of three crystals examined, and for all crystals the direction of rotation during deformation is in agreement with slip taking place on a subset of the four slip systems, with the highest Schmid factors on the (111) and (- 1-11) slip planes. A diffraction-based Burgers vector analysis confirms that the active dislocations are from slip systems with the highest Schmid factors. These results from testing of micropillars are in good agreement with the deformation behaviour previously reported for both single- and poly-crystal samples with dimensions in the millimetre range. - Highlights: Black-Right-Pointing-Pointer We performed in-situ plastic deformation of submicron-sized copper single crystals. Black-Right-Pointing-Pointer We measured in-situ and ex-situ crystal rotation and imaged dislocation activities. Black-Right-Pointing-Pointer We measured crystallographic orientations and analyzed dislocation Burgers vectors. Black-Right-Pointing-Pointer Crystals' rotation in agreement with slip of dislocations with highest Schmid factor. Black-Right-Pointing-Pointer These results in good agreement with millimeter-scale samples' deformation behavior.

Zhang Xiaodan, E-mail: xzha@dtu.dk [Danish-Chinese Center for Nanometals, Materials Science and Advanced Characterization, Department for Wind Energy, Risoe Campus, Technical University of Denmark, DK-4000 Roskilde (Denmark); Godfrey, Andrew [Laboratory of Advanced Materials, Dept. Material Science and Engineering, Tsinghua University, Beijing 100084 (China); Winther, Grethe [Department of Mechanical Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark); Hansen, Niels; Huang Xiaoxu [Danish-Chinese Center for Nanometals, Materials Science and Advanced Characterization, Department for Wind Energy, Risoe Campus, Technical University of Denmark, DK-4000 Roskilde (Denmark)

2012-08-15T23:59:59.000Z

432

Manipulability of Single Transferable Vote  

E-Print Network (OSTI)

For many voting rules, it is NP-hard to compute a successful manipulation. However, NP-hardness only bounds the worst-case complexity. Recent theoretical results suggest that manipulation may often be easy in practice. We study empirically the cost of manipulating the single transferable vote (STV) rule. This was one of the first rules shown to be NP-hard to manipulate. It also appears to be one of the harder rules to manipulate since it involves multiple rounds and since, unlike many other rules, it is NP-hard for a single agent to manipulate without weights on the votes or uncertainty about how the other agents have voted. In almost every election in our experiments, it was easy to compute how a single agent could manipulate the election or to prove that manipulation by a single agent was impossible. It remains an interesting open question if manipulation by a coalition of agents is hard to compute in practice.

Walsh, Toby

2009-01-01T23:59:59.000Z

433

Charge transfer reactions in nematic liquid crystals  

DOE Green Energy (OSTI)

Ultrafast transient absorption studies of intramolecular photoinduced charge separation and thermal charge recombination were carried out on a molecule consisting of a 4-(N-pyrrolidino)naphthalene-1,8-imide donor (PNI) covalently attached to a pyromellitimide acceptor (PI) dissolved in the liquid crystal 4{prime}-(n-pentyl)-4-cyanobiphenyl (5CB). The temperature dependencies of the charge separation and recombination rates were obtained at temperatures above the nematic-isotropic phase transition of 5CB, where ordered microdomains exist and scattering of visible light by these domains is absent. The authors show that excited state charge separation is dominated by molecular reorientation of 5CB perpendicular to the director within the liquid crystal microdomains. They also show that charge recombination is adiabatic and is controlled by the comparatively slow collective reorientation of the liquid crystal microdomains relative to the orientation of PNI{sup +}-PI{sup {minus}}. They also report the results of time resolved electron paramagnetic resonance (TREPR) studies of photoinduced charge separation in a series of supramolecular compounds dissolved in oriented liquid crystal solvents. These studies permit the determination of the radical pair energy levels as the solvent reorganization energy increases from the low temperature crystalline phase, through the soft glass phase, to the nematic phase of the liquid crystal.

Wiederrecht, G.P. [Argonne National Lab., IL (United States). Chemistry Div.; Wasielewski, M.R. [Argonne National Lab., IL (United States). Chemistry Div.]|[Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry; Galili, T.; Levanon, H. [Hebrew Univ. of Jerusalem (Israel). Dept. of Physical Chemistry

1998-07-01T23:59:59.000Z

434

Freeze Crystallization Processes: Efficiency by Flexibility  

E-Print Network (OSTI)

Energy consumption in fractionating solutions by distillation and evaporation can be reduced by 70% to 90% by using freeze crystallization processes. The thermodynamic bases for the substantially lower energy requirements include: 1) The phase change is required only once in freeze processes, as opposed to the high reflux ratios needed in most distillation separations. 2) The latent heat of fusion is less than the heat of vaporization, and the process operates at a lower temperature, so the entropy of the separation is less. 3) A heat pump is used in the freeze crystallization process to transfer heat from the freezer to the melter, providing advantages similar to the vapor compression evaporator cycle. Freeze crystallization should be considered an alternative to all distillation and evaporation separation processes. The factors which affect the relative efficiency and economics of the process are discussed in this paper.

Heist, J. A.; Barron, T. S.

1983-01-01T23:59:59.000Z

435

The magnetic and crystal structures of Sr2IrO4: A neutron diffraction study  

SciTech Connect

We report a single-crystal neutron diffraction study of the layered Sr2IrO4. This work unambigu- ously determines the magnetic and crystal structures, and reveals that the spin orientation rigidly tracks the staggered rotation of the IrO6 octahedra in Sr2IrO4. The long-range antiferromagnetic order has a canted spin configuration with an ordered moment of 0.208(3) B/Ir site within the basal plane; a detailed examination of the spin canting yields 0.202(3) and 0.049(2) B/site for the a-axis and the b-axis, respectively. It is intriguing that forbidden nuclear reflections of space group I41/acd are also observed in a wide temperature range from 4 K to 600 K, which suggests a reduced crystal structure symmetry. This neutron scattering work provides a direct, well-refined experimen- tal characterization of the magnetic and crystal structures that are crucial to the understanding of the unconventional magnetism existent in this unusual magnetic insulator.

Ye, Feng [ORNL; Chi, Songxue [ORNL; Chakoumakos, Bryan C [ORNL; Fernandez-Baca, Jaime A [ORNL; Qi, Tongfei [University of Kentucky; Cao, Gang [University of Kentucky

2013-01-01T23:59:59.000Z

436

Deterministic nano-assembly of a coupled quantum emitter - photonic crystal cavity system  

E-Print Network (OSTI)

The interaction of a single quantum emitter with its environment is a central theme in quantum optics. When placed in highly confined optical fields, such as those created in optical cavities or plasmonic structures, the optical properties of the emitter can change drastically. In particular, photonic crystal (PC) cavities show high quality factors combined with an extremely small mode volume. Efficiently coupling a single quantum emitter to a PC cavity is challenging because of the required positioning accuracy. Here, we demonstrate deterministic coupling of single Nitrogen-Vacancy (NV) centers to high-quality gallium phosphide PC cavities, by deterministically positioning their 50 nm-sized host nanocrystals into the cavity mode maximum with few-nanometer accuracy. The coupling results in a 25-fold enhancement of NV center emission at the cavity wavelength. With this technique, the NV center photoluminescence spectrum can be reshaped allowing for efficient generation of coherent photons, providing new opportunities for quantum science.

T. van der Sar; J. Hagemeier; W. Pfaff; E. C. Heeres; S. M. Thon; H. Kim; P. M. Petroff; T. H. Oosterkamp; D. Bouwmeester; R. Hanson

2010-08-24T23:59:59.000Z

437

Entangled state generation with an intrinsically pure single-photon source and a weak coherent source  

E-Print Network (OSTI)

We report on the experimental generation of an entangled state with a spectrally pure heralded single-photon state and a weak coherent state. By choosing group-velocity matching in the nonlinear crystal, our system for producing entangled photons was 60 times brighter than that in the earlier experiment [Phys. Rev. Lett. 90, 240401 (2003)], with no need of bandpass filters. This entanglement system is useful for quantum information protocols that require indistinguishable photons from independent sources.

Rui-Bo Jin; Ryosuke Shimizu; Fumihiro Kaneda; Yasuyoshi Mitsumori; Hideo Kosaka; Keiichi Edamatsu

2013-03-12T23:59:59.000Z

438

Nano-crystal growth in cordierite glass ceramics studied with X-ray scattering  

E-Print Network (OSTI)

Nano-crystal growth in cordierite glass ceramics studiedmatrix in which crystalline nano-crystals are embedded. Bysample the Cr containing spinel nano crystals. In these SEM

Bras, Wim

2010-01-01T23:59:59.000Z

439

Cratering behavior in single- and poly-crystalline copper irradiated by an intense pulsed ion beam  

Science Conference Proceedings (OSTI)

When treated with intense pulsed ion beams (IPIB), many materials exhibit increased wear resistance, fatigue life, and hardness. However, this treatment often results in cratering and roughening of the surface. In this work, high purity single crystal and polycrystalline copper samples were irradiated with pulses from an IPIB to gain insight into the causes of this cratering behavior. Samples were treated with 1,2,5, and 10 shots at 2 J/cm{sup 2} and 5 J/cm{sup 2} average energy fluence per shot. Shots were about 400 ns in duration and consisted of a mixture of carbon, hydrogen, and oxygen ions at 300 keV. It was found that the single crystal copper cratered far less than the polycrystalline copper at the lower energy fluence. At the higher energy fluence, cratering was replaced by other forms of surface damage, and the single crystal copper sustained less damage at all but the largest number of shots. Molten debris from the Lucite anode (the ion source) was removed and redeposited on the samples with each shot.

Wood, B.P.; Bitteker, L.J.; Waganaar, W.J. [Los Alamos National Lab., NM (United States). Plasma Physics Group; Perry, A.J. [A.I.M.S. Marketing, San Diego, CA (United States)

1998-12-31T23:59:59.000Z

440

Single Particle Difraction at FLASH  

SciTech Connect

Single-pulse coherent diffraction patterns have been collected from randomly injected single particles with a soft X-ray free-electron laser (FEL). The intense focused FEL pulse gives a high-resolution low-noise coherent diffraction pattern of the object before that object turns into a plasma and explodes. A diffraction pattern of a single particle will only be recorded when the particle arrival into the FEL interaction region coincides with FEL pulse arrival and detector integration. The properties of the experimental apparatus coinciding with these three events set the data acquisition rate. For our single particle FLASH diffraction imaging experiments: (1) an aerodynamic lens stack prepared a particle beam that consisted of particles moving at 150-200 m/s positioned randomly in space and time, (2) the 10 fs long FEL pulses were delivered at a fixed rate, and (3) the detector was set to integrate and readout once every two seconds. The effect of these experimental parameters on the rate of data acquisition using randomly injected particles will be discussed. Overall, the ultrashort FEL pulses do not set the limit of the data acquisition, more important is the effective interaction time of the particle crossing the FEL focus, the pulse sequence structure and the detector readout rate. Example diffraction patterns of randomly injected ellipsoidal iron oxide nanoparticles in different orientations are presented. This is the first single particle diffraction data set of identical particles in different orientations collected on a shot-to-shot basis. This data set will be used to test algorithms for recovering 3D structure from single particle diffraction.

Bogan, M.; Boutet, S.; Starodub, Dmitri; Decorwin-Martin, Philippe; /SLAC; Chapman, H.; Bajt, S.; Schulz, J.; /DESY; Hajdu, Janos; Seibert, M.M.; Iwan, Bianca; Timneanu, Nicusor; /Uppsala U.; Marchesini, Stefano; /LBL, Berkeley; Barty, Anton; Benner, W.Henry; Frank, Matthias; Hau-Riege, Stefan P.; Woods, Bruce; /LLNL, Livermore; Rohner, Urs; /Tofwerk AG, Thun

2010-06-11T23:59:59.000Z

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

A High Resolution Monolithic Crystal, DOI, MR Compatible, PET Detector  

SciTech Connect

The principle objective of this proposal is to develop a positron emission tomography (PET) detector with depth-of-interaction (DOI) positioning capability that will achieve state of the art spatial resolution and sensitivity performance for small animal PET imaging. When arranged in a ring or box detector geometry, the proposed detector module will support <1 mm3 image resolution and >15% absolute detection efficiency. The detector will also be compatible with operation in a MR scanner to support simultaneous multi-modality imaging. The detector design will utilize a thick, monolithic crystal scintillator readout by a two-dimensional array of silicon photomultiplier (SiPM) devices using a novel sensor on the entrance surface (SES) design. Our hypothesis is that our single-ended readout SES design will provide an effective DOI positioning performance equivalent to more expensive dual-ended readout techniques and at a significantly lower cost. Our monolithic crystal design will also lead to a significantly lower cost system. It is our goal to design a detector with state of the art performance but at a price point that is affordable so the technology can be disseminated to many laboratories. A second hypothesis is that using SiPM arrays, the detector will be able to operate in a MR scanner without any degradation in performance to support simultaneous PET/MR imaging. Having a co-registered MR image will assist in radiotracer localization and may also be used for partial volume corrections to improve radiotracer uptake quantitation. The far reaching goal of this research is to develop technology for medical research that will lead to improvements in human health care.

Robert S Miyaoka

2012-03-06T23:59:59.000Z

442

Generation and use of high power 213 nm and 266 nm laser radiation and tunable 210-400 nm laser radiation with BBO crystal matrix array  

SciTech Connect

A 213 nm laser beam is capable of single photon ablative photodecomposition for the removal of a polymer or biological material substrate. Breaking the molecular bonds and displacing the molecules away from the substrate in a very short time period results in most of the laser photon energy being carried away by the displaced molecules, thus minimizing thermal damage to the substrate. The incident laser beam may be unfocussed and is preferably produced by quintupling the 1064 nm radiation from a Nd:YAG solid state laser, i.e., at 213 nm. In one application, the 213 nm laser beam is expanded in cross section and directed through a plurality of small beta barium borate (BBO) crystals for increasing the energy per photon of the laser radiation directed onto the substrate. The BBO crystals are arranged in a crystal matrix array to provide a large laser beam transmission area capable of accommodating high energy laser radiation without damaging the BBO crystals. The BBO crystal matrix array may also be used with 266 nm laser radiation for carrying out single or multi photon ablative photodecomposition. The BBO crystal matrix array may also be used in an optical parametric oscillator mode to generate high power tunable laser radiation in the range of 210-400 nm.

Gruen, Dieter M. (Downers Grove, IL)

2000-01-01T23:59:59.000Z

443

THE EFFECT OF VARIOUS DETECTOR GEOMETRIES ON THE PERFORMANCE OF CZT USING ONE CRYSTAL  

Science Conference Proceedings (OSTI)

CdZnTe (CZT) continues to be a major thrust interest mainly due to its potential application as a room temperature radiation detector. The performance of CZT detectors is directly related to the charge collection ability which can be affected by the configuration of the electrical contact. The charge collection efficiency is determined in part by the specific geometry of the anode contact which serves as the readout electrode. In this report, contact geometries including single pixel, planar, coplanar, and dual anode will be systematically explored by comparing the performance efficiencies of the detector using both low and high energy gamma rays. To help eliminate the effect of crystal quality variations, the contact geometries were fabricated on the same crystal detector with minimal polishing between contact placements.

Washington, A.; Duff, M.; Teague, L.

2011-06-21T23:59:59.000Z

444

UV LED lighting for automated crystal centring  

E-Print Network (OSTI)

A direct outcome of the exponential growth of macromolecular crystallography is the continuously increasing demand for synchrotron beam time, both from academic and industrial users. As more and more projects entail screening a profusion of sample crystals, fully automated procedures at every level of the experiments are being implemented at all synchrotron facilities. One of the major obstacles to achieving such automation lies in the sample recognition and centring in the X-ray beam. The capacity of UV light to specifically react with aromatic residues present in proteins or with DNA base pairs is at the basis of UV-assisted crystal centring. Although very efficient, a well known side effect of illuminating biological samples with strong UV sources is the damage induced on the irradiated samples. In the present study the effectiveness of a softer UV light for crystal centring by taking advantage of low-power light-emitting diode (LED) sources has been investigated. The use of UV LEDs represents a lowcost solution for crystal centring with high specificity.

Leonard M. G. Chavas; Yusuke Yamada; Masahiko Hiraki; Noriyuki Igarashi; Naohiro Matsugaki; Soichi Wakatsuki

2010-01-01T23:59:59.000Z

445

Synthetic thermoelectric materials comprising phononic crystals  

DOE Patents (OSTI)

Synthetic thermoelectric materials comprising phononic crystals can simultaneously have a large Seebeck coefficient, high electrical conductivity, and low thermal conductivity. Such synthetic thermoelectric materials can enable improved thermoelectric devices, such as thermoelectric generators and coolers, with improved performance. Such synthetic thermoelectric materials and devices can be fabricated using techniques that are compatible with standard microelectronics.

El-Kady, Ihab F; Olsson, Roy H; Hopkins, Patrick; Reinke, Charles; Kim, Bongsang

2013-08-13T23:59:59.000Z

446

The New Crystal Ball Experimental Program  

Science Conference Proceedings (OSTI)

The Crystal Ball Spectrometer is being used at the Brookhaven National Laboratory Alternating Gradient Synchrotron in a series of experiments that study final states of ??p and K ?p induced reactions that result in all neutral particles. Data have been obtained on the decays of N *

W. J. Briscoe; The Crystal Ball Collaboration; Abilene Christian University; Argonne National Laboratory; Arizona State University; Brookhaven National Laboratory; University of California at Los Angeles; University of Colorado; George Washington University; Universität Karlsruhe; Kent State University; University of Maryland; Petersburg Nuclear Physics Institute; University of Regina; Rudjer Boskovic Institute; Valparaiso University

2002-01-01T23:59:59.000Z

447

Admissible Pictures and Littlewood-Richardson Crystals  

E-Print Network (OSTI)

We present a one-to-one correspondence between the set of admissible pictures and the Littlewood-Richardson crystals. As a simple consequence, we shall show that the set of pictures does not depend on the choice of admissible orders.

Nakashima, Toshiki

2009-01-01T23:59:59.000Z

448

Radial-Radial Single Rotor Turbine  

NLE Websites -- All DOE Office Websites (Extended Search)

Radial-Radial Single Rotor Turbine Radial-Radial Single Rotor Turbine A rotor for use in turbine applications. June 26, 2013 Radial-Radial Single Rotor Turbine A rotor for use in...

449

Experimental studies of melting and crystallization processes in planetary interiors  

E-Print Network (OSTI)

Melting and crystallization processes on the Earth and Moon are explored in this thesis, and the topics of melt generation, transport, and crystallization are discussed in three distinct geologic environments: the Moon's ...

Krawczynski, Michael James

2011-01-01T23:59:59.000Z

450

Atmospheric Ice Crystals over the Antarctic Plateau in Winter  

Science Conference Proceedings (OSTI)

Falling ice crystals were collected daily on a gridded glass slide at South Pole Station, Antarctica, during the Antarctic winter of 1992 and were photographed through a microscope. Nine types of ice crystals are identified, which fall into three ...

Von P. Walden; Stephen G. Warren; Elizabeth Tuttle

2003-10-01T23:59:59.000Z

451

Isothermal Ice Crystallization Kinetics in the Gas-Diffusion...  

NLE Websites -- All DOE Office Websites (Extended Search)

Isothermal Ice Crystallization Kinetics in the Gas-Diffusion Layer of a Proton-Exchange-Membrane Fuel Cell Title Isothermal Ice Crystallization Kinetics in the Gas-Diffusion Layer...

452

Scattering Phase Function of Bullet Rosette Ice Crystals  

Science Conference Proceedings (OSTI)

Ice crystals in cirrus frequently exhibit the shape of a bullet rosette composed of multiple bullets that radiate from a junction center. The scattering phase function of these ice crystals, pertinent to the radiation budget of cirrus, may differ ...

Jean Iaquinta; Harumi Isaka; Pascal Personne

1995-05-01T23:59:59.000Z

453

Alignment of fee Crystals due to Transient Electric Fields  

Science Conference Proceedings (OSTI)

The alignment of columnar ice crystals due to the electric field surrounding a moving charged object, such as an aircraft, is modeled. The model allows the conditions of charge, velocity, ambient electric field, and size and shape of crystal to ...

D. A. Burrows; J. L. Stith

1986-06-01T23:59:59.000Z

454

Micro- and Nano-Crystal Orientations in Shells  

NLE Websites -- All DOE Office Websites (Extended Search)

Micro- and Nano-Crystal Orientations in Shells Micro- and Nano-Crystal Orientations in Shells Print Thursday, 12 April 2012 11:11 A research group from the University of Wisconsin...

455

Super-collimation in a rod-based photonic crystal  

E-Print Network (OSTI)

Super-collimation is the propagation of a light beam without spreading that occurs when the light beam is guided by the dispersion properties of a photonic crystal, rather than by defects in the photonic crystal. ...

Shih, Ta-Ming, Ph. D. Massachusetts Institute of Technology

2007-01-01T23:59:59.000Z

456

Computer-aided rational solvent selection for pharmaceutical crystallization  

E-Print Network (OSTI)

Solvents play an important role in crystallization, a commonly used separation and purification technique in the pharmaceutical, chemical and food industries. They affect crystal properties such as particle size distribution, ...

Chen, Jie, Ph. D. Massachusetts Institute of Technology

2010-01-01T23:59:59.000Z

457

James Fergason, a Pioneer in Advancing of Liquid Crystal Technology  

E-Print Network (OSTI)

James Lee Fergason (1934 - 2008) focused his research on the liquid crystals. His studies correspond to a relevant part of the history of soft matter science and technology of liquid crystals. Here a discussion of some of his researches.

Amelia Carolina Sparavigna

2013-10-28T23:59:59.000Z

458

Two-dimensional Photonic Crystals Fabricated by Nanoimprint Lithography  

E-Print Network (OSTI)

We report on the process parameters of nanoimprint lithography (NIL) for the fabrication of two-dimensional (2-D) photonic crystals. The nickel mould with 2-D photonic crystal patterns covering the area up to 20mm² is ...

Chen, A.

459

Engineering light using large area photonic crystal devices  

E-Print Network (OSTI)

Photonic crystals are fabricated structures composed of a periodic arrangement of materials with differing indices of refraction. This research has focused on the realization of two distinct photonic crystal structures in ...

Tandon, Sheila (Sheila N.), 1978-

2005-01-01T23:59:59.000Z

460

Single element laser beam shaper  

DOE Patents (OSTI)

A single lens laser beam shaper for converting laser beams from any spatial profile to a flat-top or uniform spatial profile. The laser beam shaper includes a lens having two aspheric surfaces. The beam shaper significantly simplifies the overall structure in comparison with conventional 2-element systems and therefore provides great ease in alignment and reduction of cost.

Zhang, Shukui (Yorktown, VA); Michelle D. Shinn (Newport News, VA)

2005-09-13T23:59:59.000Z

Note: This page contains sample records for the topic "out-perform single crystals" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Mathematical simulation and X-ray diffraction investigation of the crystal structure of 1-phenyl-1-tert-butyl-3-methyl-1,3-dihydroisobenzofuran  

SciTech Connect

An algorithm for using a priori generation of crystal structures by the discrete modeling method for the interpretation of data obtained from single-crystal X-ray diffraction experiments is considered. The crystal structure of 1-phenyl-1-tert-butyl-3-methyl-1,3-dihydroisobenzofuran is mathematically simulated using the discrete modeling of molecular packings and studied by X-ray diffraction. The simulation is performed for two isomers of the initial chemical compound that are possible from the viewpoint of the mechanism of the chemical reaction used in the synthesis of this compound. Appropriate models that can serve as starting models for solving and refining the crystal structure with the use of X-ray diffraction data are chosen from a complete set of calculated structural models in accordance with specific criteria. The structure is solved using a starting model calculated using the discrete modeling method and refined by the full-matrix least-squares procedure.

Maleev, A. V., E-mail: andr_mal@mail.ru; Zhitkov, I. K.; Potekhin, K. A. [Vladimir State Pedagogical University (Russian Federation)

2008-07-15T23:59:59.000Z

462

CdTe and Cd0.9Zn0.1Te Crystal Growth and Characterization for Nuclear Spectrometers  

Science Conference Proceedings (OSTI)

Large volume single crystals of CdTe and Cd0.9Zn0.1Te (CZT) have been grown by a controlled vertical Bridgman technique using in-house zone refined precursors and characterized through structural, electrical, optical, and spectroscopic methods. The grown crystals (diameter greater than or equal to 2.5 cm and length >10 cm) have shown promising characteristics for high-resolution room temperature solid-state radiation detectors due to their high resistivity (~1010 -cm for CdTe, and >1011 -cm for CZT) and good charge transport properties [ e ~ (2-5)x10-3 cm2/V]. The fabricated detectors in planar single element and Frisch collar configurations have shown very low leakage currents and high count rates for various sources, including Am-241, and Cs-137. The grown crystals have been further characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), and transmission two-modulator generalized ellipsometry (2-MGE). Details of the CdTe and CZT characterization results, detector fabrication steps, and testing with radiation sources are presented. The CdTe and CZT crystals have shown high prospects for low power rating solid-state nuclear spectrometers and medical imaging devices.

Mandal, Krishna [EIC Laboratories, Inc.; Kang, Sung Hoon [EIC Laboratories, Inc.; Choi, Michael [EIC Laboratories, Inc.; Wright, Gomez W [ORNL; Jellison Jr, Gerald Earle [ORNL

2006-01-01T23:59:59.000Z

463

Crystallization and Solidification Properties of LipidsChapter 17 Crystallization in Emulsion: Application to Thermal and Structural Behaviorof Milk Fat  

Science Conference Proceedings (OSTI)

Crystallization and Solidification Properties of Lipids Chapter 17 Crystallization in Emulsion: Application to Thermal and Structural Behaviorof Milk Fat Health Nutrition Biochemistry eChapters Health - Nutrition - Biochemistry AOCS Pre

464

Crystallization and Solidification Properties of LipidsChapter 10 Comparison of Experimental Techniques Used in Lipid Crystallization Studies  

Science Conference Proceedings (OSTI)

Crystallization and Solidification Properties of Lipids Chapter 10 Comparison of Experimental Techniques Used in Lipid Crystallization Studies Health Nutrition Biochemistry eChapters Health - Nutrition - Biochemistry 491A63F5EC71B64D1ED

465

Cherenkov high-order harmonic generation by multistep cascading in {chi}{sup (2)} nonlinear photonic crystal  

Science Conference Proceedings (OSTI)

We propose a scheme for efficient Cherenkov high-order harmonic generation. Second to fifth order harmonic wave are observed in a single periodically poled ferroelectric crystal in our experiment. The noncollinear high-order harmonic generation is produced via enhanced Cherenkov second harmonic cascaded with successive multistep sum-frequency generation with simultaneously longitudinal phase-matching. The emission angle and power dependencies are analyzed in detail experimentally, which coincide with theoretical predictions.

An Ning; Ren Huaijin [Department of Physics, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); State Key Laboratory on Fiber Optic Local Area Communication Networks and Advanced Optical Communication Systems, Shanghai 200240 (China); Zheng Yuanlin [Department of Physics, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Key Laboratory for Laser Plasmas (Ministry of Education), Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Deng Xuewei [Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Chen Xianfeng [Department of Physics, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); State Key Laboratory on Fiber Optic Local Area Communication Networks and Advanced Optical Communication Systems, Shanghai 200240 (China); Key Laboratory for Laser Plasmas (Ministry of Education), Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)

2012-05-28T23:59:59.000Z

466

Single-bunch synchrotron shutter  

DOE Patents (OSTI)

An apparatus for selecting a single synchrotron pulse from the millions of pulses provided per second from a synchrotron source includes a rotating spindle located in the path of the synchrotron pulses. The spindle has multiple faces of a highly reflective surface, and having a frequency of rotation f. A shutter is spaced from the spindle by a radius r, and has an open position and a closed position. The pulses from the synchrotron are reflected off the spindle to the shutter such that the speed s of the pulses at the shutter is governed by: s=4 {times} {pi} {times} r {times} such that a single pulse is selected for transmission through an open position of the shutter.

Norris, J.R.; Tang, Jau-Huei; Chen, Lin; Thurnauer, M.

1991-12-31T23:59:59.000Z

467

NIST Advances Single Photon Management for Quantum ...  

Science Conference Proceedings (OSTI)

NIST Advances Single Photon Management for Quantum Computers. For Immediate Release: January 19, 2011. ...

2011-01-20T23:59:59.000Z

468

Effective Light Dynamics in Perturbed Photonic Crystals  

E-Print Network (OSTI)

In this work, we rigorously derive effective dynamics for light from within a limited frequency range propagating in a photonic crystal that is modulated on the macroscopic level; the perturbation parameter $\\lambda \\ll 1$ quantifies the separation of spatial scales. We do that by rewriting the dynamical Maxwell equations as a Schr\\"odinger-type equation and adapting space-adiabatic perturbation theory. Just like in the case of the Bloch electron, we obtain a simpler, effective Maxwell operator for states from within a relevant almost invariant subspace. A correct physical interpretation for the effective dynamics requires to establish two additional facts about the almost invariant subspace: (1) The source-free condition has to be verified and (2) it has to support real states. The second point also forces one to consider a multiband problem even in the simplest possible setting; This turns out to be a major difficulty for the extension of semiclassical methods to the domain of photonic crystals.

Giuseppe De Nittis; Max Lein

2013-07-05T23:59:59.000Z

469

Quantum theory of photonic crystal polaritons  

E-Print Network (OSTI)

We formulate a full quantum mechanical theory of the interaction between electromagnetic modes in photonic crystal slabs and quantum well excitons embedded in the photonic structure. We apply the formalism to a high index dielectric layer with a periodic patterning suspended in air. The strong coupling between electromagnetic modes lying above the cladding light line and exciton center of mass eigenfunctions manifests itself with the typical anticrossing behavior. The resulting band dispersion corresponds to the quasi-particles coming from the mixing of electromagnetic and material excitations, which we call photonic crystal polaritons. We compare the results obtained by using the quantum theory to variable angle reflectance spectra coming from a scattering matrix approach, and we find very good quantitative agreement.

D. Gerace; M. Agio; L. C. Andreani

2004-02-09T23:59:59.000Z

470

Induced Positron Annihiliation Investigation of Cadmium Zinc Telluride Crystal Microstructures  

Science Conference Proceedings (OSTI)

Cadmium-Zinc-Telluride (CZT) crystals are used in semiconductor radiation detectors for the detection of x-ray and gamma radiation. However, production of detector grade crystals is difficult as small variations in compositional uniformity and primarily the zinc content can significantly affect the ability of the CZT crystal to function as a radiation detector. Currently there are no known nondestructive methods that can be used to identify detector grade crystals. The current test method is to fabricate and test the detector to determine if the crystal is sufficiently uniform and of the correct composition to be considered a detector grade crystal. Consequently, nondestructive detection methods are needed to identify detector grade crystals prior to the fabrication process. The purpose of this feasibility study was to perform a preliminary assessment of the ability of several new, nondestructive technologies based on Induced Positron Annihilation (IPA) to determine if detector grade CZT crystals can be identified. Results of measurements performed on specimens from Fisk University and EV Products, Inc. indicate that both the near surface Distributed Source Positron Annihilation (up to 3 mm penetration) and the volumetric Photon Induced Positron Annihilation methods may be suitable for determining CZT crystal quality. Further work on CZT crystals with a broader range of compositions and detector characteristics is needed to provide a well defined, calibrated, method for assessing CZT crystal quality.

D. W. Akers

2005-06-01T23:59:59.000Z

471

T-542: SAP Crystal Reports Server Multiple Vulnerabilities | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

2: SAP Crystal Reports Server Multiple Vulnerabilities 2: SAP Crystal Reports Server Multiple Vulnerabilities T-542: SAP Crystal Reports Server Multiple Vulnerabilities January 25, 2011 - 2:30pm Addthis PROBLEM: SAP Crystal Reports Server Multiple Vulnerabilities. PLATFORM: Crystal Reports Server 2008 ABSTRACT: Multiple vulnerabilities in SAP Crystal Reports Server 2008, which can be exploited by malicious users to disclose potentially sensitive information and by malicious people to conduct cross-site scripting attacks, manipulate certain data, and compromise a user's system. reference LINKS: Secunia Advisory SA43060 Vulnerability Report: Crystal Reports Server 2008 IMPACT ASSESSMENT: High Discussion: 1) Input passed to the "actId" parameter in InfoViewApp/jsp/common/actionNav.jsp, "backUrl" parameter in

472

T-542: SAP Crystal Reports Server Multiple Vulnerabilities | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

2: SAP Crystal Reports Server Multiple Vulnerabilities 2: SAP Crystal Reports Server Multiple Vulnerabilities T-542: SAP Crystal Reports Server Multiple Vulnerabilities January 25, 2011 - 2:30pm Addthis PROBLEM: SAP Crystal Reports Server Multiple Vulnerabilities. PLATFORM: Crystal Reports Server 2008 ABSTRACT: Multiple vulnerabilities in SAP Crystal Reports Server 2008, which can be exploited by malicious users to disclose potentially sensitive information and by malicious people to conduct cross-site scripting attacks, manipulate certain data, and compromise a user's system. reference LINKS: Secunia Advisory SA43060 Vulnerability Report: Crystal Reports Server 2008 IMPACT ASSESSMENT: High Discussion: 1) Input passed to the "actId" parameter in InfoViewApp/jsp/common/actionNav.jsp, "backUrl" parameter in

473

Photo of the Week: Butterflies, Crystal Nanostructures and Solar Cell  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Butterflies, Crystal Nanostructures and Solar Butterflies, Crystal Nanostructures and Solar Cell Research Photo of the Week: Butterflies, Crystal Nanostructures and Solar Cell Research October 26, 2012 - 11:44am Addthis What do butterflies and solar cell research have in common? Both have been developing tiny crystals that selectively reflect colors. Over millions of years of evolution, butterfly wings have developed the tiny crystal nanostructures that give butterflies their vivid colors. At Argonne National Laboratory, scientists are working to manufacture these crystals, which could one day be used to create "greener" and more efficient paints, fiber optics and solar cells. In this photo, the iridescent scales of an emerald-patched Cattleheart butterfly are magnified 20 times to highlight the crystals that selectively reflect green colors. | Photo courtesy of Argonne National Laboratory.

474

Program on Technology Innovation: Crystal Habit Modifiers  

Science Conference Proceedings (OSTI)

Effective water chemistry control in nuclear power plants is required for materials and fuel reliability, radiation source term control, and operations. This report documents the results of laboratory screening conducted in support of an EPRI initiative to assess the feasibility of using crystal habit modifiers (CHMs) in the primary or secondary coolant of pressurized water reactors (PWRs). Successful implementation of CHMs could have a significant impact on plant material condition, and operation and ma...

2010-10-21T23:59:59.000Z

475

Improving scintillation crystals using muon tomography  

SciTech Connect

The cosmic ray muon scanning array provides information on NaI(T1) crystals using some 65,536 trajectories, each measuring the NaI(T1) response to high energy muons. With this information, it is possible to use established computer-aided-tomography techniques to deconvolute these integrated responses and produce a detailed picture of the detector's interior.

Dowell, D.H.; Fineman, B.J.; Sandorfi, A.M.

1987-01-01T23:59:59.000Z

476

Photonic Crystals for Enhancing Thermophotovoltaic Energy Conversion  

DOE Green Energy (OSTI)

Thermophotovoltaics (TPV) converts the radiant energy of a thermal source into electrical energy using photovoltaic cells. TPV has a number of attractive features, including: fuel versatility (nuclear, fossil, solar, etc.), quiet operation, low maintenance, low emissions, light weight, high power density, modularity, and possibility for cogeneration of heat and electricity. Some of these features are highly attractive for military applications (Navy and Army). TPV could also be used for distributed power and automotive applications wherever fuel cells, microturbines, or cogeneration are presently being considered if the efficiencies could be raised to around 30%. This proposal primarily examine approaches to improving the radiative efficiency. The ideal irradiance for the PV cell is monochromatic illumination at the bandgap. The photonic crystal approach allows for the tailoring of thermal emission spectral bandwidth at specific wavelengths of interest. The experimental realization of metallic photonic crystal structures, the optical transmission, reflection and absorption characterization of it have all been carried out in detail and will be presented next. Additionally, comprehensive models of TPV conversion has been developed and applied to the metallic photonic crystal system.

LIN, SHAWN-YU; FLEMING, JAMES G.; MORENO, JOSEPH A.

2003-03-01T23:59:59.000Z

477

A multi-crystal wavelength dispersive x-ray spectrometer  

Science Conference Proceedings (OSTI)

A multi-crystal wavelength dispersive hard x-ray spectrometer with high-energy resolution and large solid angle collection is described. The instrument is specifically designed for time-resolved applications of x-ray emission spectroscopy (XES) and x-ray Raman scattering (XRS) at X-ray Free Electron Lasers (XFEL) and synchrotron radiation facilities. It also simplifies resonant inelastic x-ray scattering (RIXS) studies of the whole 2d RIXS plane. The spectrometer is based on the Von Hamos geometry. This dispersive setup enables an XES or XRS spectrum to be measured in a single-shot mode, overcoming the scanning needs of the Rowland circle spectrometers. In conjunction with the XFEL temporal profile and high-flux, it is a powerful tool for studying the dynamics of time-dependent systems. Photo-induced processes and fast catalytic reaction kinetics, ranging from femtoseconds to milliseconds, will be resolvable in a wide array of systems circumventing radiation damage.

Alonso-Mori, Roberto; Montanez, Paul; Delor, James; Bergmann, Uwe [LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Kern, Jan [LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720-8099 (United States); Sokaras, Dimosthenis; Weng, Tsu-Chien; Nordlund, Dennis [SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Tran, Rosalie; Yachandra, Vittal K.; Yano, Junko [Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720-8099 (United States)

2012-07-15T23:59:59.000Z

478

SINGLE HEATER TEST FINAL REPORT  

SciTech Connect

The Single Heater Test is the first of the in-situ thermal tests conducted by the U.S. Department of Energy as part of its program of characterizing Yucca Mountain in Nevada as the potential site for a proposed deep geologic repository for the disposal of spent nuclear fuel and high-level nuclear waste. The Site Characterization Plan (DOE 1988) contained an extensive plan of in-situ thermal tests aimed at understanding specific aspects of the response of the local rock-mass around the potential repository to the heat from the radioactive decay of the emplaced waste. With the refocusing of the Site Characterization Plan by the ''Civilian Radioactive Waste Management Program Plan'' (DOE 1994), a consolidated thermal testing program emerged by 1995 as documented in the reports ''In-Situ Thermal Testing Program Strategy'' (DOE 1995) and ''Updated In-Situ Thermal Testing Program Strategy'' (CRWMS M&O 1997a). The concept of the Single Heater Test took shape in the summer of 1995 and detailed planning and design of the test started with the beginning fiscal year 1996. The overall objective of the Single Heater Test was to gain an understanding of the coupled thermal, mechanical, hydrological, and chemical processes that are anticipated to occur in the local rock-mass in the potential repository as a result of heat from radioactive decay of the emplaced waste. This included making a priori predictions of the test results using existing models and subsequently refining or modifying the models, on the basis of comparative and interpretive analyses of the measurements and predictions. A second, no less important, objective was to try out, in a full-scale field setting, the various instruments and equipment to be employed in the future on a much larger, more complex, thermal test of longer duration, such as the Drift Scale Test. This ''shake down'' or trial aspect of the Single Heater Test applied not just to the hardware, but also to the teamwork and cooperation between multiple organizations performing their part in the test.

J.B. Cho

1999-05-01T23:59:59.000Z

479

Polarization-controlled single photons  

E-Print Network (OSTI)

Vacuum-stimulated Raman transitions are driven between two magnetic substates of a rubidium-87 atom strongly coupled to an optical cavity. A magnetic field lifts the degeneracy of these states, and the atom is alternately exposed to laser pulses of two different frequencies. This produces a stream of single photons with alternating circular polarization in a predetermined spatio-temporal mode. MHz repetition rates are possible as no recycling of the atom between photon generations is required. Photon indistinguishability is tested by time-resolved two-photon interference.

T. Wilk; S. C. Webster; H. P. Specht; G. Rempe; A. Kuhn

2006-10-26T23:59:59.000Z

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Polarization-controlled single photons  

E-Print Network (OSTI)

Vacuum-stimulated Raman transitions are driven between two magnetic substates of a rubidium-87 atom strongly coupled to an optical cavity. A magnetic field lifts the degeneracy of these states, and the atom is alternately exposed to laser pulses of two different frequencies. This produces a stream of single photons with alternating circular polarization in a predetermined spatio-temporal mode. MHz repetition rates are possible as no recycling of the atom between photon generations is required. Photon indistinguishability is tested by time-resolved two-photon interference.