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1

OTS NOTE  

Office of Legacy Management (LM)

* pp4 r G- .2- * pp4 r G- .2- OTS NOTE DATE: April 24, 1991 TO: Alexander Williams FROM: Dan Stou tF L SUBJECT: American Potash and Chemical Company Elimination Recommendation The attached memorandum and supporting documents are the basis for our recommendation to eliminate the former American Potash and Chemical Company site from further consideration under FUSRAP. The site is located in West Hanover, Massachusetts. Documents discovered to date indicating use or handling of radioactive material by American Potash consist of a National Lead Company of Ohio (NLO) internal memorandum which discusses tests American Potash performed for Union Carbide Nuclear Corporation (Oak Ridge), an Atomic Energy Commission (AEC) prime contractor. The site predecessor, National Fireworks Ordnance

2

James L. Liveman, Acting AssLBtaOt  

Office of Legacy Management (LM)

1 1 - * -w : L i P / ' 5- . . . c James L. Liveman, Acting AssLBtaOt Secretay for 2nv??Onnur_nt ( IQ UZT'ZXSI~ OF :ZZ&JA On Dctezher 6, 1977, and ridtcr E. smitil, Edward J . Jaacwsky , De?ar+nent of hrgarme SaCanal Laborawry (AS.), _- _. - - -zatzgy (DOE), visited tlhe University of iJeva&, Ekekay ScMal of %iaes. The purpose ___ was to dLscu!38 tke -8: opcraZ4Qns of tbcse fuCti'I?-'n= **-A-- A e fl' the v?L&gl: ~~ BHIC --c-r &atic . - . dtselopxzeat studies on vsrlous tppes of ursrAum orw. -- ,------- Dlscussians uer4 held ~5th Dr. kztkwr Bakr XII, Da, tisd ?Lr. trsly Franh, R&Fatiac Safety Offl~er. . . D*Qcu~siO=: sd:k Dr. Baker establfshad that work witi UZZL&IZI .ore Ls - 0 still b-2 petfazzzd 21 the azws where the PSC wurk was pcrforned.

3

E-Print Network 3.0 - arvo ots tnu Sample Search Results  

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

) + 2EK(w, ) + O(t3 ) , as t 0, where wn and wnn denote the rst and second Source: Frey, Pascal - Laboratoire Jacques-Louis Lions, Universit Pierre-et-Marie-Curie, Paris 6...

4

Error Recovery for a Boiler System with OTS PID Controller Tom Anderson, Mei Feng, Steve Riddle, Alexander Romanovsky  

E-Print Network [OSTI]

1 Error Recovery for a Boiler System with OTS PID Controller Tom Anderson, Mei Feng, Steve Riddle employing an OTS (Off-The-Shelf) item. The case study used a Simulink model of a steam boiler system, employing software models of the PID controller and the steam boiler system rather than conducting

Newcastle upon Tyne, University of

5

Error Recovery for a Boiler System with OTS PID Controller Tom Anderson, Mei Feng, Steve Riddle, Alexander Romanovsky  

E-Print Network [OSTI]

Error Recovery for a Boiler System with OTS PID Controller Tom Anderson, Mei Feng, Steve Riddle-The-Shelf) item. The case study used a Simulink model of a steam boiler system together with an OTS PID in practice, employing software models of the PID controller and the steam boiler system rather than

Newcastle upon Tyne, University of

6

O/O'/07D/-I0072J'OtJo?  

Office of Legacy Management (LM)

O/O'/07D/-I0072J'OtJo? O/O'/07D/-I0072J'OtJo? u.s Depai'tntenf,of Energy Ohio Field Office Parcel 6, 7, and 8 A.emedy (Monitored Natura'i Attenuation) Groundwater Monitoring Plan . , CH2MHILL * This page intentionally left blank Parcel 6, 7, a.nd 8 Remedy (Monit'ored Natural Attetluation) Groundwater M.onitoring Plan DQcenibe.r· 200$ F'Ii1ai Prepared for the U.S. Department of Energy Ohio Field Office This page intentionally left blank ABSTRACT Parcels 6, 7, and 8 are three tracts of land that comprise the majority of the remaining Mound Closure Project in ~iamisburg, Ohio. The final remedy for Parcels 6, 7, and 8 combines institutional controls in the form of deed. restrictions on future land and groundwater use and monitored natural attenuation (MNA). MNA is being utilized as a

7

University/Classified Non-Exempt OT Compensation The College of William and Mary/VIMS Banner ID # : Date  

E-Print Network [OSTI]

University/Classified Non-Exempt OT Compensation The College of William and Mary/VIMS Employer: W&M VIMS Banner ID # : Date: Employee Name: Last First Middle University/Classified Non-Exempt Overtime

Swaddle, John

8

OTS NOTE  

Office of Legacy Management (LM)

@ 'Alexander Williams @ 'Alexander Williams FROM: Ed Mitchellqm SUBJECT: W.R. Grace Elimination Recommendation The purpose of this note is to provide you with certain information regarding the recommendation to eliminate W.R. Grace Company (the former Heavy Minerals Company), Chicago,Illinois, from consideration as a site under FUSRAP. Enclosed is a memo dated July 9, 1990: FUSRAP Considered Site Recommendation, for W.R. Grace Company. It recommends elimination in accordance with FUSRAP protocol. Also enclosed is some typed input material (dated July 9, 1990) about the site that you may want to use in the preparation of your Record of Elimination. If you concur, please provide a Record of Elimination to indicate DOE's decision to eliminate this site. In lieu of a separate memo, you may want

9

OTS NOTF  

Office of Legacy Management (LM)

NOTF NOTF DATE: December 18, 1990 TO: Alexander Williams, FROM:~ Dan Stou d- SUBJECT: Additional Considered Sites During historical searches I have identified several potential considered sites. .Two historical documents referencing three sites are attached and highlighted. The first attachment refers ,to'a four pound uranium rod shipped to the Catalytic Company (the Fernald construction contractor). It also notes that 100 pounds of uranium oxide was shipped to the,Milwaukee airport for Fred Stroke (an AEC/Argonne employee). I recommend these two sites be added to the eliminated database, as no additional information is available. The second attachment refers to potential thread rolling of 1500 Savannah River plant slugs at the Reed Rolled Thread and Die Co. in Worcester, MA.

10

OTS NOTE  

Office of Legacy Management (LM)

August 4, 1992 August 4, 1992 TO: Alexander Williams FROM: Ed Mitchell, Steve Fieser ' 565 SUBJECT: Revised Designation Package for Baker Brothers Site We have prepared the Designation Summary you requested for Baker Brothers Site, in Toledo, Ohio. This package supersedes the previous one provided on May 1, 1992, to reflect the documents that have since been finalized. The designationpackage consists of the following: o Designation Summary (8/4/92) o Authority Review (7/16/92) o Radiological Survey (3/92) A copy of each is enclosed. Also enclosed for your consideration is draft correspondence to FSRD, to designate this site for remedial action under FUSRAP. cc: C. Young, w/o enclosure J. Herman, w/o enclosure i DOE disk copy, EM-421 EM-421 Author (A. Williams, 3-8149)

11

OTS NOTE  

Office of Legacy Management (LM)

January 15, 1991 January 15, 1991 TO: Alexander Williams FROM: Dan Stout@ SUBJECT: Gruen Watch Company Consideration Recommendation Attached for your review is a consideration recommendation for the Gruen Watch Co. in Norwood, Ohio. The company was identified by an NLO radiological survey report. Gruen appears to have participated in brief test operations using their 60 ton mechanical press to shave and stamp washers. Small quantities of uranium appear to be involved, and the 1956 radiological surveys do not indicate significant dispersion of uranium during stamping operations. Because of the scarcity of records, limited period of operation for NLO, and absence of evidence of contamination, I recommend the site be eliminated from FUSRAP. Please call me if you have any questions.

12

OTS NOTE  

Office of Legacy Management (LM)

5, 1991 5, 1991 TO: Alexander Williams FROM: .B Dan Stout SUBJECT: Processes Research Elimination Recommendation The attached memorandum and supporting documents are the basis for our recommendation to eliminate the Processes Research, Incorporated site from further consideration under FUSRAP. The site is located in Cincinnati, Ohio. No documents have been discovered to date which specifically indicate use or handling of radioactive material by Processes Research. The principal record discovered is a letter subcontract from National Lead of Ohio (NLO) to Processes Research, dated 10/21/1952, for development of machining methods. A 1953 list of active NLO subcontracts does not list Processes Research. No additional records pertaining to Processes Research have been

13

OTS NOTE  

Office of Legacy Management (LM)

March 22, 1991 March 22, 1991 TO: A. Williams FROM: 0. Sto> Attached is a revised site summary for the Exxon Company in Linden, New Jersey. The summary incorporates new information from a file search and from a conversation with.an NRC inspector. The specific locations of AEC/MED operations have not been identified. .I." -:;1 5':' :?iv,::.;& & had been decontami "ated. The NRC inspector did note that the kC.Mackenzie E. Mitchell C. Young .c. FUSRAP NJ.18 Exxon Research and Engineering Company The Former Standard Oil Development Company Linden, New Jersey Site Function In the spring of 1942, Standard Oil Development Company (SODC) was contracted to be in charge of obtaining materials for work being do the Metallurgical Laboratories and subsequently the MED. SODC play

14

OTS NOTE  

Office of Legacy Management (LM)

from further consideration as a candidate for remedial action under FUSRAP and be removed from the FUSRAP considered sites list. cc: C. Young E. Mitchell file FUSRAP MI.13...

15

OT SPECIFIED I OTHER AMENDMENT OF SOLICITATI ON/MODIFICATION OF CONTRACT  

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

OT SPECIFIED I OT SPECIFIED I OTHER AMENDMENT OF SOLICITATI ON/MODIFICATION OF CONTRACT 2 AM EN DMENT/MODIFIC ATION NO 1 B 6 ISSUED BY CODE Oak UrJge u . s . De arcment of Energ y P . O. Box 2001 Oak Ridge TN 37831 3 EFFccnv E DA E Sep Bl c..c.k _6C 00518 8 NAME AND ADDRESS OF CONTRACTOR INo ~/e.' CO Ull/y. Sial. and ZIP Cod.) OAK RIDGE A SOCIATED Ul IVERSITIES , P . O. BOX 117 OAK R-DGE Ttl 37830-6218 N . CODE 0411522 24 FAC ILITY CODE 1 CONTRACT 10 CODE 4 R OUISITIONIPU RCHASr. REO NO IuS lL 7 ADMIN ISTER ED BY rlf QlherlhBn lIem B) Oak Ridge o . s . Dep rtment of Energ y P . O. Box 2001 Oak Ridge TN 37831 (xl 9A AMENDMENT OF SOlICrTATlON NO. 98 DA TEO I SEE ITEM 11) .. 10A MODIFIC ATION OF CO NTRACTIORD ER NO A DE-AC05 - 060R 23 100 l OB DATED (SEE ITEM 13) 12/ 21/ 2005 11 . THIS ITEM ONLY APPLIES TO AMENDMENTS OF SOLICITA

16

Infrared spectrum of the tritiated hydroxyl ion (OT/sup -/) in a neutron-irradiated LiF crystal  

SciTech Connect (OSTI)

Infrared absorption of the tritiated hydroxyl ion (OT/sup -/) in a LiF crystal has been studied. The dominant absorption occurs at 2225 cm/sup -1/. Spectroscopic constants are determined on the basis of the anharmonic oscillator model for a diatomic molecule. The results suggest a smaller anharmonicity of the O-H and O-T stretching vibrations in the LiF crystal compared to those in TiO/sub 2/, ..cap alpha..-Al/sub 2/O/sub 3/, and KTaO/sub 3/. 12 references, 3 figures, 1 table.

Aratono, Y.; Nakashima, M.; Saeki, M.; Tachikawa, E.

1986-04-10T23:59:59.000Z

17

GAUAGHER AND GALLAGHER ATTORmYS AT LAW, P.C. Ot4ECONWRJTIONPUtA  

Office of Legacy Management (LM)

j ; ij 7 iir I,::? ir s1: 141 TL-2 j ; ij 7 iir I,::? ir s1: 141 TL-2 tj .> Ii el)sTorl GAUAGHER AND GALLAGHER ATTORmYS AT LAW, P.C. Ot4ECONWRJTIONPUtA BOSTON. MASS. 02129 March 7, 1990 (617) 241.8aoo ?AX. (617) 141*?6W VIA TELEFAX Park Owen USDOE: Nuclear Facility De commissioning and site Remedial hotion oak Ridge National Laboratory P. 0. Box 2008 Building 2001-6050 Oak Ridge, TN 37831-6050 Re: Wesaahouse, Bloomfield, NJ Our File No.: 15094 (09) near M r. Owen: Pursuant to our telephone conversation of March 7, 1990, P1ca.w fincl the following documents enclo6e.A fnr yot~r perusfil: 1. Report on Radiological Status Building 7 Westinghouse Electric Corp. (Source NJDEP-DHWM-ECRA); 2. Cover Letter and Attachment (NRC to Westinghouse): Report on Radiological status on Westinghouse Building

18

BASIN BLAN CO BLAN CO S OT ERO IGNAC IO-BLANCO AZ TEC BALLAR  

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

BOE Reserve Class BOE Reserve Class No 2001 reserves 0.1 - 10 MBOE 10.1 - 100 MBOE 100.1 - 1,000 MBOE 1,000.1- 10,000 MBOE 10,000.1 - 100,000 MBOE > 100,000 MBOE Basin Outline AZ UT NM CO 1 2 Index Map for 2 Paradox-San Juan Panels 2001 Reserve Summary for All Paradox-San Juan Basin Fields Total Total Total Number Liquid Gas BOE of Reserves Reserves Reserves Fields (Mbbl) (MMcf) (Mbbl) Paradox-San Juan 250 174,193 20,653,622 3,616,464 Basin CO NM IGNAC IO-BLANCO IGNAC IO-BLANCO IGNAC IO-BLANCO IGNAC IO-BLANCO IGNAC IO-BLANCO BASIN BASIN BLAN CO BLAN CO BASIN BASIN BASIN BASIN BASIN BASIN BISTI BAL LAR D BASIN BISTI BLA NCO S OT ERO BAL LAR D LIND RITH W BASIN BLA NCO BLA NCO S BLA NCO S TAPAC ITO GAVIL AN BASIN BLA NCO The mapped oil and gas field boundary outlines were created by the Reserves and Production Division, Office of Oil and Gas, Energy Information Administration pursuant to studies required by

19

BASIN BLAN CO BLAN CO S OT ERO IGNAC IO-BLANCO AZ TEC BALLAR  

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

Gas Reserve Class Gas Reserve Class No 2001 gas reserves 0.1 - 10 MMCF 10.1 - 100 MMCF 100.1 - 1,000 MMCF 1,000.1- 10,000 MMCF 10,000.1 - 100,000 MMCF > 100,000 MMCF Basin Outline AZ UT NM CO 1 2 Index Map for 2 Paradox-San Juan Panels 2001 Reserve Summary for All Paradox-San Juan Basin Fields Total Total Total Number Liquid Gas BOE of Reserves Reserves Reserves Fields (Mbbl) (MMcf) (Mbbl) Paradox-San Juan 250 174,193 20,653,622 3,616,464 Basin CO NM IGNAC IO-BLANCO IGNAC IO-BLANCO IGNAC IO-BLANCO IGNAC IO-BLANCO IGNAC IO-BLANCO BASIN BASIN BLAN CO BLAN CO BASIN BASIN BASIN BASIN BASIN BASIN BISTI BAL LAR D BASIN BISTI BLA NCO S OT ERO BAL LAR D LIND RITH W BASIN BLA NCO BLA NCO S BLA NCO S TAPAC ITO GAVIL AN BASIN BLA NCO The mapped oil and gas field boundary outlines were created by the Reserves and Production Division, Office of Oil and Gas, Energy Information Administration pursuant to studies required by

20

?ot8rh QI ahnloal Corporation In Hart IUnover, Ma86rohusett8,  

Office of Legacy Management (LM)

GE 1 GE 1 ;" qr)-1 s?llq ' p raspy.. c" ifa K. mris I talked with Hr. Wllllm cIF(Iy, Metrllurgist, Wnlon CarbId@ Nuclear cOrp8ny, 08k B&t&$@, Tenne66ee, on April 26, 1961. He informed me th&t the #rtioMl Northern birislon, Ame~ic6.n ?ot8rh QI ahnloal Corporation In Hart IUnover, Ma86rohusett8, la pePfopn1~ lo8lve forming studier for the. ilnion olo)w Wuolem Conpmy "p l7?JHa). The work at National Northern l#rirc.- alon ir under the 6upenl6lon of Ehsll Phillpohuc4~, v of Spealrl Prcbduots. The @ox& to data ha8 been pwfonwd wlth 430 strlnle66 rteel and urma%um metal - both hot snb 0018 wor4c have been performed at pr688u~r fmm 100,000 to 900,000 prl. The shape of the pleu88 na not dlrolored. In 6<lon work ha6 been done with

Note: This page contains sample records for the topic "zn zurn ot" 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

BASIN BLAN CO BLAN CO S OT ERO IGNAC IO-BLANCO AZ TEC BALLAR  

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

Liquids Reserve Class Liquids Reserve Class No 2001 liquids reserves 0.1 - 10 Mbbl 10.1 - 100 Mbbl 100.1 - 1,000 Mbbl 1,000.1- 10,000 Mbbl 10,000.1 - 100,000 Mbbl Basin Outline AZ UT NM CO 1 2 Index Map for 2 Paradox-San Juan Panels 2001 Reserve Summary for All Paradox-San Juan Basin Fields Total Total Total Number Liquid Gas BOE of Reserves Reserves Reserves Fields (Mbbl) (MMcf) (Mbbl) Paradox-San Juan 250 174,193 20,653,622 3,616,464 Basin CO NM IGNAC IO-BLANCO IGNAC IO-BLANCO IGNAC IO-BLANCO IGNAC IO-BLANCO IGNAC IO-BLANCO BASIN BASIN BLAN CO BLAN CO BASIN BASIN BASIN BASIN BASIN BASIN BISTI BAL LAR D BASIN BISTI BLA NCO S OT ERO BAL LAR D LIND RITH W BASIN BLA NCO BLA NCO S BLA NCO S TAPAC ITO GAVIL AN BASIN BLA NCO The mapped oil and gas field boundary outlines were created by the Reserves and Production Division, Office of Oil and Gas, Energy Information Administration pursuant to studies required by

22

AVESTAR Center for operational excellence of clean energy plants and DYNSIM OTS / EyeSim ITS integration  

SciTech Connect (OSTI)

This Power-Point presentation with notes starts with a brief overview of US energy challenging, particularly as regards power generation capacity and clean energy plant operations. It then goes on to present Advanced Virtual Energy Simulation Training And Research (AVESTAR{trademark}) beginning with a statement of its missions and goals, then moves to the subject of Integrated Gasification Combined Cycle (IGCC) with CO{sub 2} Capture, first providing a brief overview of the process, then moving on to Dynamic Simulator/Operator Training System (OTS) and 3D Virtual Immersive Training System (ITS). The presentation continues to describe AVESTAR center facilities, locations, and training systems and to look at future directions for virtual energy simulation.

Provost, G.

2012-01-01T23:59:59.000Z

23

Acceptors in ZnO nanocrystals. | EMSL  

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

in ZnO nanocrystals. Abstract: Zinc oxide (ZnO) has potential for a range of optoelectronic applications. In this work, we studied the defect properties of ZnO nanocrystals,...

24

ZnO nanoclusters: Synthesis and photoluminescence. | EMSL  

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

ZnO nanoclusters: Synthesis and photoluminescence. ZnO nanoclusters: Synthesis and photoluminescence. Abstract: ZnO nanoclusters were prepared and deposited at room temperature...

25

ZnO/Sn:In2O3 and ZnO/CdTe band offsets for extremely thin absorber...  

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

ZnOSn:In2O3 and ZnOCdTe band offsets for extremely thin absorber photovoltaics . ZnOSn:In2O3 and ZnOCdTe band offsets for extremely thin absorber photovoltaics . Abstract: Band...

26

Ultraviolet emission from a multi-layer graphene/MgZnO/ZnO light-emitting diode  

SciTech Connect (OSTI)

We report on ultraviolet emission from a multi-layer graphene (MLG)/MgZnO/ZnO light-emitting diodes (LED). The p-type MLG and MgZnO in the MLG/MgZnO/ZnO LED are used as transparent hole injection and electron blocking layers, respectively. The current-voltage characteristics of the MLG/MgZnO/ZnO LED show that current transport is dominated by tunneling processes in the MgZnO barrier layer under forward bias conditions. The holes injected from p-type MLG recombine efficiently with the electrons accumulated in ZnO, and the MLG/MgZnO/ZnO LED shows strong ultraviolet emission from the band edge of ZnO and weak red-orange emission from the deep levels of ZnO.

Kang, Jang-Won; Choi, Yong-Seok; Goo Kang, Chang; Hun Lee, Byoung [School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Kim, Byeong-Hyeok [Department of Nanobio Materials and Electronics, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Tu, C. W. [Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California 92093-0407 (United States); Park, Seong-Ju, E-mail: sjpark@gist.ac.kr [School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Department of Nanobio Materials and Electronics, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of)

2014-02-03T23:59:59.000Z

27

Zn?Zn Porphyrin Dimer-Sensitized Solar Cells: Toward 3-D Light Harvesting  

Science Journals Connector (OSTI)

Zn?Zn porphyrin dimers have been incorporated into thin dye-sensitized solar cells (DSSCs) to boost their light harvesting efficiency. The photoexcited dimers show efficient and fast electron injection into TiO2 indicating that both photoexcited ...

Attila J. Mozer; Matthew J. Griffith; George Tsekouras; Pawel Wagner; Gordon G. Wallace; Shogo Mori; Kenji Sunahara; Masanori Miyashita; John C. Earles; Keith C. Gordon; Luchao Du; Ryuzi Katoh; Akihiro Furube; David L. Officer

2009-10-09T23:59:59.000Z

28

Crystal structure of the hexagonal (Zn, Mg)4Ho and (Zn, Mg)4Er  

Science Journals Connector (OSTI)

The crystal structure of the hexagonal (Zn, Mg)4Ho/Er was determined by single crystal X-ray diffraction analysis. For the Zn68.4Mg12.7Ho18.9, the structural model, refined to a final R-value of 0.0672, has the composition of Zn69.34Mg12.01Ho18.65, a = 14.259 Å and c = 14.007 Å, and the space group P63/mmc (No. 194). Among the 10 Zn, 2 Mg, and 4 Ho independent sites, 3 Zn sites are icosahedral coordinated whereas 1 Mg is located at the center of a CN15 Kasper deltahedron enclosed by 26 triangles and 15 vertices. In the ?1 0 0? directions, there are four interpenetrated icosahedra, I4(P), within an a period, constituting an icosahedral (0 0 1) layer block in half of the unit-cell. In the [0 0 1] direction, in addition to the two face-sharing icosahedra, I2(F), there is still a CN15 Kasper deltahedron. For the Zn70.8Mg10.6Er18.6, the final refinement led to a R-value of 0.0708. The atom coordinates are very close to those of above (Zn, Mg)4Ho, the largest difference between two corresponding coordinates being only 0.00086. Thus (Zn, Mg)4Er is iso-structural with (Zn, Mg)4Ho. This hexagonal (Zn, Mg)4RE phase has also been found in RE = Y, Sm, Gd, Dy, and Yb cases and they are probably also iso-structural with (Zn, Mg)4Ho/Er. This structure is icosahedrally closely related to the other two known, hexagonal, Zn-rich (Zn, Mg)nRE structures, namely, the Zn6Mg3Y/Sm/Gd [H. Takakura, A. Sato, A. Yamamoto, A.P. Tsai, Phil. Mag. Lett. 78 (1998) 263; K. Sugiyama, K. Yasuda, T. Ohsuna, K. Hiraga, Z. Kristallogr. 213 (1998) 537] and the Zn3MgY [D.W. Deng, K.H. Kuo, Z.P. Luo, D.J. Miller, M.J. Kramer, D.W. Dennis, J. Alloys Compd. 373 (2004) 156]. All these three hexagonal phases coexist with the icosahedral quasicrystal in the Zn–Mg–RE alloys.

M.R. Li; D.W. Deng; K.H. Kuo

2006-01-01T23:59:59.000Z

29

ZnTe: Gibbs free energy  

Science Journals Connector (OSTI)

This document is part of Volume 44 ‘Semiconductors’, Subvolume B ‘New Data and Updates for II-VI Compounds’ of Landolt-Börnstein Group III ‘Condensed Matter’. It contains data on ZnTe (zinc telluride), Element...

J. Gutowski; K. Sebald; T. Voss

2009-01-01T23:59:59.000Z

30

OTS NOTE DATE: TO: FROM:  

Office of Legacy Management (LM)

TO: FROM: March 25, 1991 A. Williams D. stout P SUBJECT: Elimination Recommendation for the Star Cutter Corporation The .attached memorandum and supporting documents are the basis for our recommendation to eliminate the former Star Cutter Corporation site from further consideration under FUSRAP. The site is located in Farmington Hills, Michigan. Documents discovered to date which indicate use or handling of radioactive material by Star Cutter consist of two Analytical Data Sheets, dated June 29, 1956, prepared by the National Lead Company of Ohio (NLO), an Atomic Energy Commission (AEC) prime contractor. The data sheets report the results of radiological monitoring conducted during operation of an oil- cooled drilling/hollowing machine. The sheets record measurements during

31

Alternating Current Driven Electroluminescence from ZnSe/ZnS:Mn/  

E-Print Network [OSTI]

phosphor impurity dopants in ZnSe or other wide band gap host nanocrystals. Lumines- cence of CdS of alternating current thin-film electroluminescent (AC-TFEL) devices using phosphor-doped nanocrystals-TFEL devices consist of a phosphor layer, such as manganese-doped zinc sulfide (ZnS:Mn), vertically sandwiched

32

Structures of nanowires with Zn-ZnO:CuO junctions for detecting ethanol vapors  

Science Journals Connector (OSTI)

The synthesis of ZnO-ZnO:CuO structures in the form of overlapping layers of nanowires of pure and copper oxide-doped zinc oxide is described. These structures are tested as ethanol vapor sensors. The following t...

T. V. Peshkova; D. Ts. Dimitrov; S. S. Nalimova; I. E. Kononova…

2014-05-01T23:59:59.000Z

33

Interaction of CO with Surface PdZn Alloys. | EMSL  

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

Pd(111) surface resulting in the formation of an ordered surface PdZn alloy. Carbon monoxide was found to bond more weakly to the ZnPd(111) alloy surfaces compared to clean...

34

Acceptors in ZnO nanocrystals  

SciTech Connect (OSTI)

Zinc oxide (ZnO) has potential for a range of optoelectronic applications. In this work, we studied the defect properties of ZnO nanocrystals, grown by a solid-state pyrolytic reaction method, using IR and electron paramagnetic resonance (EPR) spectroscopy. A series of IR absorption peaks have been observed at liquid-helium temperatures. These transition lines suggest a hydrogenic acceptor with a hole binding energy of ~ 0.4 - 0.5 eV. EPR measurements in the dark showed the well-known donor line at g = 1.96, and a line at g = 2.003, which we attribute to acceptors that involve a zinc vacancy. A line at g = 2.013, only seen after exposure to light, is assigned to nonaxial zinc vacancy-hydrogen complexes. Given the current lack of suitable acceptor dopants in ZnO, vacancy complexes may provide the best route toward p-type conductivity.

Teklemichael, Samuel T.; Oo, W.M.H.; Matthew, McClusky; Walter, Eric D.; Hoyt, David W.

2011-06-09T23:59:59.000Z

35

Magnetism in Dopant-Free ZnO Nanoplates  

Science Journals Connector (OSTI)

Magnetism in Dopant-Free ZnO Nanoplates ... We found that the chemically synthesized ZnO nanoplates exhibit magnetism even at room temperature. ... First-principles calculations show a growing asymmetry in the spin distribution within the distorted bands formed from Zn (3d) and O (2p) orbitals with the reduction of thickness of the ZnO nanoplates, which is suggested to be responsible for the observed magnetism. ...

Jung-Il Hong; Jiil Choi; Seung Soon Jang; Jiyeong Gu; Yangling Chang; Gregory Wortman; Robert L. Snyder; Zhong Lin Wang

2012-01-03T23:59:59.000Z

36

Development of a Solar-Thermal ZnO/Zn Water-Splitting Thermochemical...  

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

Development of a Solar-thermal ZnOZn Water-splitting Thermochemical Cycle Final Report (DE-PS36-03GO93007 - Subcontract RF-05-SHGR-006) Alan W. Weimer (PI), Christopher Perkins,...

37

Ferromagnetism in CuO-ZnO multilayers  

SciTech Connect (OSTI)

We investigated the magnetic properties of CuO-ZnO heterostructures to elucidate the origin of the ferromagnetic signature in Cu doped ZnO. The CuO and ZnO layer thickness were varied from 15 to 150 nm and from 70 to 350 nm, respectively. Rutherford backscattering experiments showed no significant diffusion of either Cu in ZnO or Zn in CuO layers. Magnetic measurements indicate ferromagnetism at 300 K, which depends on the CuO particle size, but not on the CuO-ZnO interfacial area. Polarized neutron reflectometry measurements show that the observed magnetization cannot be accounted for solely by spins localized near the CuO-ZnO interface or in the CuO layer.

Sudakar, C.; Padmanabhan, K.; Naik, R.; Lawes, G. [Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48201 (United States); Kirby, B. J. [NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Kumar, Sanjiv [NCCCM, Bhabha Atomic Research Centre, ECIL Post, Hyderabad 500062 (India); Naik, V. M. [Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, Michigan 48128 (United States)

2008-07-28T23:59:59.000Z

38

Synthesis and spectroscopic characterisation of aurichalcite (Zn,Cu2+)5(CO3)2(OH)6; implications for Cu–ZnO catalyst precursors  

Science Journals Connector (OSTI)

The Cu–ZnO catalyst precursors with variable Cu:Zn ratio, between Zn-rich and Cu-rich compositions have been investigated by a combination of electronic and vibrational spectroscopy. Synthesized catalyst precu...

B. Jagannadha Reddy; Ray Leslie Frost; Ashley Locke

2008-04-01T23:59:59.000Z

39

Defect induced ferromagnetism in undoped ZnO nanoparticles  

SciTech Connect (OSTI)

Undoped ZnO nanoparticles (NPs) with size ?12?nm were produced using forced hydrolysis methods using diethylene glycol (DEG) [called ZnO-I] or denatured ethanol [called ZnO-II] as the reaction solvent; both using Zn acetate dehydrate as precursor. Both samples showed weak ferromagnetic behavior at 300?K with saturation magnetization M{sub s}?=?0.077 ± 0.002 memu/g and 0.088 ± 0.013 memu/g for ZnO-I and ZnO-II samples, respectively. Fourier transform infrared (FTIR) spectra showed that ZnO-I nanocrystals had DEG fragments linked to their surface. Photoluminescence (PL) data showed a broad emission near 500?nm for ZnO-II which is absent in the ZnO-I samples, presumably due to the blocking of surface traps by the capping molecules. Intentional oxygen vacancies created in the ZnO-I NPs by annealing at 450?°C in flowing Ar gas gradually increased M{sub s} up to 90?min and x-ray photoelectron spectra (XPS) suggested that oxygen vacancies may have a key role in the observed changes in M{sub s}. Finally, PL spectra of ZnO showed the appearance of a blue/violet emission, attributed to Zn interstitials, whose intensity changes with annealing time, similar to the trend seen for M{sub s}. The observed variation in the magnetization of ZnO NP with increasing Ar annealing time seems to depend on the changes in the number of Zn interstitials and oxygen vacancies.

Rainey, K.; Chess, J.; Eixenberger, J.; Tenne, D. A.; Hanna, C. B.; Punnoose, A., E-mail: apunnoos@boisestate.edu [Department of Physics, Boise State University, Boise, Idaho 83725 (United States)

2014-05-07T23:59:59.000Z

40

Strong circular photogalvanic effect in ZnO epitaxial films  

SciTech Connect (OSTI)

A strong circular photogalvanic effect (CPGE) in ZnO epitaxial films was reported under interband excitation. It was observed that CPGE current is as large as 100 nA/W in ZnO, which is about one order in magnitude higher than that in InN film while the CPGE currents in GaN films are not detectable. The possible reasons for the above observations are the strong spin orbit coupling in ZnO or the inversed valence band structure of ZnO.

Zhang, Q.; Wang, X. Q.; Yin, C. M.; Shen, B. [State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Chen, Y. H.; Chang, K. [Laboratory of Semiconductor Materials Science, Institute of Semiconductors, CAS, Beijing 100083 (China); Ge, W. K. [Department of Physics, Tsinghua University, Beijing 100871 (China)

2011-12-23T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" 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

NONLINEAR OPTICAL EFFECTS IN ROTATIONALLY-TWINNED CRYSTALS: AN EVALUATION OF CdTe, ZnTe AND ZnSe  

E-Print Network [OSTI]

405 NONLINEAR OPTICAL EFFECTS IN ROTATIONALLY-TWINNED CRYSTALS: AN EVALUATION OF CdTe, ZnTe AND Zn une loi en N2. On discutera les avantages potentiels en optique non linéaire des cristaux de CdTe, Zn-spaced twin planes the enhancement is proportional to N2. A comparison is made between CdTe, ZnTe, and Zn

Boyer, Edmond

42

Optical/electrical correlations in ZnO: the plasmonic resonance...  

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

Opticalelectrical correlations in ZnO: the plasmonic resonance phase diagram. Opticalelectrical correlations in ZnO: the plasmonic resonance phase diagram. Abstract: Following...

43

Organic Molecule Functionalized Zn3P2 Nanowire Inorganic-Organic...  

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

Organic Molecule Functionalized Zn3P2 Nanowire Inorganic-Organic Hybrid Thermoelectrics Organic Molecule Functionalized Zn3P2 Nanowire Inorganic-Organic Hybrid Thermoelectrics...

44

Thermokinetic investigation of binary Cu/Zn hydroxycarbonates as precursors for Cu/ZnO catalysts  

Science Journals Connector (OSTI)

Abstract A combination of thermogravimetric analysis (TG) and differential scanning calorimetry (DSC) coupled to mass spectrometry has been applied to study the thermal decomposition of Cu/Zn hydroxycarbonates, which are used as a precursor for the active methanol synthesis catalyst. Original TG and DSC profiles and results of a formal kinetic analysis of the calcination process are compared with transformations occurring in the solid phase, which has been studied by means of in situ XRD. A series of hydroxycarbonate precursors with different Cu/Zn molar ratios (40/60, 70/30, 80/20) were synthesized under conditions reported as optimum for catalytic performance. The samples contain primarily two crystalline phases, aurichalcite (Cu,Zn)5(CO3)2(OH)6 and zincian malachite (Cu,Zn)2CO3(OH)2. At least four formal decomposition stages of CO2 and H2O evolution cause the major mass loss in the TG experiments. The best-fit quality for all the studied samples was obtained for a four-step competitive reaction model. The experimental TG dependences are adequately described by the n-th order equation and 3D Jander diffusion equation. The effects of the gas flow, sample mass, and water transfer conditions on the reaction pathway were studied. The presence of H2O vapor in the reaction feed accelerates the decomposition and dramatically changes the reaction TG profile. The decomposition enthalpy of mixed Cu/Zn (80/20) hydroxycarbonate was determined, and the formation enthalpy of the decomposition intermediate, a carbonate-modified oxide, was calculated to be ?Hf° = ?633.7 ± 5.6 kJ/mol.

Andrey Tarasov; Julia Schumann; Frank Girgsdies; Nygil Thomas; Malte Behrens

2014-01-01T23:59:59.000Z

45

Neutral nitrogen acceptors in ZnO: The {sup 67}Zn hyperfine interactions  

SciTech Connect (OSTI)

Electron paramagnetic resonance (EPR) is used to characterize the {sup 67}Zn hyperfine interactions associated with neutral nitrogen acceptors in zinc oxide. Data are obtained from an n-type bulk crystal grown by the seeded chemical vapor transport method. Singly ionized nitrogen acceptors (N{sup ?}) initially present in the crystal are converted to their paramagnetic neutral charge state (N{sup 0}) during exposure at low temperature to 442 or 633?nm laser light. The EPR signals from these N{sup 0} acceptors are best observed near 5?K. Nitrogen substitutes for oxygen ions and has four nearest-neighbor cations. The zinc ion along the [0001] direction is referred to as an axial neighbor and the three equivalent zinc ions in the basal plane are referred to as nonaxial neighbors. For axial neighbors, the {sup 67}Zn hyperfine parameters are A{sub ?}?=?37.0?MHz and A{sub ?}?=?8.4?MHz with the unique direction being [0001]. For nonaxial neighbors, the {sup 67}Zn parameters are A{sub 1}?=?14.5?MHz, A{sub 2}?=?18.3?MHz, and A{sub 3}?=?20.5?MHz with A{sub 3} along a [101{sup ¯}0] direction (i.e., in the basal plane toward the nitrogen) and A{sub 2} along the [0001] direction. These {sup 67}Zn results and the related {sup 14}N hyperfine parameters provide information about the distribution of unpaired spin density at substitutional neutral nitrogen acceptors in ZnO.

Golden, E. M.; Giles, N. C., E-mail: Nancy.Giles@afit.edu [Department of Engineering Physics, Air Force Institute of Technology, Wright-Patterson Air Force Base, Ohio 45433 (United States); Evans, S. M.; Halliburton, L. E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States)

2014-03-14T23:59:59.000Z

46

ZnS-Graphene nanocomposite: Synthesis, characterization and optical properties  

SciTech Connect (OSTI)

A ZnS-Graphene nanocomposite was prepared by a facile one-step hydrothermal method using zinc nitrate hexahydrate, ethylenediamine and carbon disulfide as precursors, graphene oxide as a template. The composite was characterized by X-ray power diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, Fourier transform infrared, Raman spectra and fluorescence spectroscopy. The results show that graphene oxide was reduced to graphene in the hydrothermal reaction process. Simultaneously, the graphene sheets in the composite are exfoliated and decorated with ZnS nanoparticles. Furthermore, Raman and fluorescence properties of the composite were observed. ZnS-Graphene nanocomposite displays surface-enhanced Raman scattering activity for graphene oxide, and fluorescence enhancement property compared with pure ZnS sample. - Graphical abstract: Approach of reaction makes the reduction of grapheme oxide and the deposition of Zns on the grapheme sheets occur simultaneously and overcomes the aggregation of the grapheme sheets and Zns. Highlights: Black-Right-Pointing-Pointer Graphene oxide is reduced to graphene in the hydrothermal reaction process. Black-Right-Pointing-Pointer ZnS nanoparticles are attached onto the almost transparent graphene sheets. Black-Right-Pointing-Pointer ZnS-Graphene system shows surface-enhanced Raman scattering (SERS) activity. Black-Right-Pointing-Pointer ZnS-Graphene system displays relatively better fluorescence property than pure ZnS.

Pan Shugang [Key Laboratory for Soft Chemistry and Functional Materials, Nanjing University of Science and Technology, Ministry of Education, Nanjing 210094 (China); Liu Xiaoheng, E-mail: xhliu@mail.njust.edu.cn [Key Laboratory for Soft Chemistry and Functional Materials, Nanjing University of Science and Technology, Ministry of Education, Nanjing 210094 (China)

2012-07-15T23:59:59.000Z

47

Fluorescent Sensors for Zn2+ Based on a Fluorescein Platform  

E-Print Network [OSTI]

Fluorescent Sensors for Zn2+ Based on a Fluorescein Platform: Synthesis, Properties fluorescent sensors for Zn2+ that utilize fluorescein as a reporting group, Zinpyr-1 and Zinpyr-2, have been. Both Zinpyr sensors have excitation and emission wavelengths in the visible range (500 nm

Tsien, Roger Y.

48

Aerogel tempelated ZnO dye-sensitized solar cells.  

SciTech Connect (OSTI)

Atomic layer deposition is employed to conformally coat low density, high surface area aerogel films with ZnO. The ZnO/aerogel membranes are incorporated as photoanodes in dye-sensitized solar cells, which exhibit excellent power efficiencies of up to 2.4% under 100 mW cm{sup -2} light intensity.

Hamann, T. W.; Martinson , A. B. E.; Elam, J. W.; Pellin, M. J.; Hupp, J. T.; Materials Science Division; Northwestern Univ.

2008-01-01T23:59:59.000Z

49

Pressure-induced crystallization of vitreous ZnCl2  

Science Journals Connector (OSTI)

In situ Raman scattering measurements have been obtained for vitreous ZnCl2 compressed isothermally to 25 GPa. The Raman spectra indicate that, in contrast to other tetrahedral framework glasses, when compressed at room temperature glassy ZnCl2 crystallizes to the high-pressure CdCl2-structured phase between 2.3 and 3.0 GPa; on decompression, the high-pressure phase remains until 1.1 GPa, where it then reverts to ?-ZnCl2. On recompression the ?-ZnCl2 phase converts to the CdCl2 phase at 2.5 GPa and backtransforms at 1.1 GPa upon decompression. We suggest that a density-driven phase separation in the supercooled liquid regime underlies the amorphous-to-crystalline transition of ZnCl2 and other glassy materials.

Cynthia H. Polsky; Luz Maria Martinez; Kurt Leinenweber; Mary A. VerHelst; C. Austen Angell; George H. Wolf

2000-03-01T23:59:59.000Z

50

SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6} - two new Ae-Zn-Sn polar intermetallic compounds (Ae: alkaline earth metal)  

SciTech Connect (OSTI)

SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6}, two closely related new polar intermetallic compounds, were obtained by high temperature reactions of the elements. Their crystal structures were determined with single crystal XRD methods, and their electronic structures were analyzed by means of DFT calculations. The Zn-Sn structure part of SrZn{sub 2}Sn{sub 2} comprises (anti-)PbO-like {l_brace}ZnSn{sub 4/4}{r_brace} and {l_brace}SnZn{sub 4/4}{r_brace} layers. Ca{sub 2}Zn{sub 3}Sn{sub 6} shows similar {l_brace}ZnSn{sub 4/4}{r_brace} layers and {l_brace}Sn{sub 4}Zn{r_brace} slabs constructed of a covalently bonded Sn scaffold capped by Zn atoms. For both phases, the two types of layers are alternatingly stacked and interconnected via Zn-Sn bonds. SrZn{sub 2}Sn{sub 2} adopts the SrPd{sub 2}Bi{sub 2} structure type, and Ca{sub 2}Zn{sub 3}Sn{sub 6} is isotypic to the R{sub 2}Zn{sub 3}Ge{sub 6} compounds (R=La, Ce, Pr, Nd). Band structure calculations indicate that both SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6} are metallic. Analyses of the chemical bonding with the electron localization function (ELF) show lone pair like basins at Sn atoms and Zn-Sn bonding interactions between the layers for both title phases, and covalent Sn-Sn bonding within the {l_brace}Sn{sub 4}Zn{r_brace} layers of Ca{sub 2}Zn{sub 3}Sn{sub 6}. - Graphical abstract: Crystal structures of the new Ae-Zn-Sn polar intermetallic phases SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6}. Highlights: Black-Right-Pointing-Pointer New polar intermetallic phases SrZn{sub 2}Sn{sub 2} and Ca{sub 2}Zn{sub 3}Sn{sub 6}. Black-Right-Pointing-Pointer Obtained by high temperature reactions of the elements. Black-Right-Pointing-Pointer Single crystal XRD structure determination and DFT electronic structure calculations. Black-Right-Pointing-Pointer Closely related crystal and electronic structures. Black-Right-Pointing-Pointer Metallic conductivity coexisting with lone pairs and covalent bonding features.

Stegmaier, Saskia [Department Chemie, Technische Universitaet Muenchen, Lichtenbergstrasse 4, 85747 Garching (Germany); Faessler, Thomas F., E-mail: Thomas.Faessler@lrz.tum.de [Department Chemie, Technische Universitaet Muenchen, Lichtenbergstrasse 4, 85747 Garching (Germany)

2012-08-15T23:59:59.000Z

51

Novel Type-II Zn3P2/ZnO Core/Shell Nanowires: Synthesis, Characteristic, and Photoluminescence Properties  

Science Journals Connector (OSTI)

Besides this, Zn3P2 has many other advantageous physical properties in serving as a photovolatic material, such as a large optical absorption coefficient (>104 cm?1), long minority carrier diffusion length (?13 ?m), abundant and cheap constituent materials, etc.(22, 23) Zinc oxide (ZnO), with a wide direct bandgap of 3.2?3.4 ...

Peicai Wu; Tuo Sun; Yu Dai; Yanghui Sun; Yu Ye; Lun Dai

2011-03-30T23:59:59.000Z

52

Photoluminescence properties of ZnS/CdS/ZnS quantum dot–quantum wells doped with Ag+ ions  

Science Journals Connector (OSTI)

Enhanced photoluminescence and postirradiation luminescence is reported from Ag+-doping ZnS/CdS/ZnS quantum dot–quantum wells (QDQWs)...2O/Heptane system, the size of a QDQW was estimated to be ~6 nm. Compared to...

Hua Qu; Lixin Cao; Wei Liu; Ge Su; Bohua Dong; Hui Zhai

2011-10-01T23:59:59.000Z

53

GaN/ZnO and AlGaN/ZnO heterostructure LEDs: growth, fabrication, optical and electrical characterization  

E-Print Network [OSTI]

radiation hardness than Si, GaAs, CdS and GaN, therefore it should be suitable for space applications. Last novel optoelectronic devices circumventing the problem of p-type doping of ZnO. In such Al devices become reality: the problem of p-type doping of ZnO. So far, there is no way to reliably produce

Wetzel, Christian M.

54

Two dimensional electron gases in polycrystalline MgZnO/ZnO heterostructures grown by rf-sputtering process  

SciTech Connect (OSTI)

This paper reports the formation of two-dimensional electron gas (2DEG) in rf-sputtered defective polycrystalline MgZnO/ZnO heterostructure via the screening of grain boundary potential by polarization-induced charges. As the MgZnO thickness increases, the sheet resistance reduces rapidly and then saturates. The enhancement of the interfacial polarization effect becomes stronger, corresponding to a larger amount of resistance reduction, when the Mg content in the cap layer increases. Monte Carlo method by including grain boundary scattering effect as well as 2D finite-element-method Poisson and drift-diffusion solver is applied to analyze the polycrystalline heterostructure. The experimental and Monte Carlo simulation results show good agreement. From low temperature Hall measurement, the carrier density and mobility are both independent of temperature, indicating the formation of 2DEG with roughness scattering at the MgZnO/ZnO interface.

Chin, Huai-An; Cheng, I-Chun; Huang, Chih-I; Wu, Yuh-Renn [Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan (China); Lu, Wen-Sen; Lee, Wei-Li [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Chen, Jian Z. [Institute of Applied Mechanics, National Taiwan University, Taipei 10617, Taiwan (China); Chiu, Kuo-Chuang; Lin, Tzer-Shen [Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu 31040, Taiwan (China)

2010-09-15T23:59:59.000Z

55

Low-energy muon [LEM] study of Zn-phthalocyanine and ZnO thin films  

Science Journals Connector (OSTI)

Implantation of low-energy muons in zinc-phthalocyanine (ZnPc) thin-films leads to the formation of muoniated radical states, the fast decaying of the ? SR signal at low fields being a clear indication of muonium formation. The formation probability of these paramagnetic states is independent of the implantation depth and amounts, as in the bulk, to approximately 100% of all muons. In these molecular crystals the formation of muonium is a highly local effect and is fairly independent of crystalline structure and defects in the sample. In contrast to that, in vapour-grown ZnO films the paramagnetic signal known from bulk experiments is not observed, even for the deeper implantations. We suggest that in this case muonium is not formed due to the low concentration of free electrons. In these strongly distorted films, electrons are captured at defects and are not available for muonium formation.

H.V. Alberto; J. Piroto Duarte; A. Weidinger; R.C. Vilão; J.M. Gil; N. Ayres de Campos; K. Fostiropoulos; T. Prokscha; A. Suter; E. Morenzoni

2009-01-01T23:59:59.000Z

56

Radioactive contamination of ZnWO4 crystal scintillators  

E-Print Network [OSTI]

The radioactive contamination of ZnWO4 crystal scintillators has been measured deep underground at the Gran Sasso National Laboratory (LNGS) of the INFN in Italy with a total exposure 3197 kg x h. Monte Carlo simulation, time-amplitude and pulse-shape analyses of the data have been applied to estimate the radioactive contamination of the ZnWO4 samples. One of the ZnWO4 crystals has also been tested by ultra-low background gamma spectrometry. The radioactive contaminations of the ZnWO4 samples do not exceed 0.002 -- 0.8 mBq/kg (depending on the radionuclide), the total alpha activity is in the range: 0.2 - 2 mBq/kg. Particular radioactivity, beta active 65Zn and alpha active 180W, has been detected. The effect of the re-crystallization on the radiopurity of the ZnWO4 crystal has been studied. The radioactive contamination of samples of the ceramic details of the set-ups used in the crystals growth has been checked by low background gamma spectrometry. A project scheme on further improvement of the radiopurity level of the ZnWO4 crystal scintillators is briefly addressed.

P. Belli; R. Bernabei; F. Cappella; R. Cerulli; F. A. Danevich; A. M. Dubovik; S. d'Angelo; E. N. Galashov; B. V. Grinyov; A. Incicchitti; V. V. Kobychev; M. Laubenstein; L. L. Nagornaya; F. Nozzoli; D. V. Poda; R. B. Podviyanuk; O. G. Polischuk; D. Prosperi; V. N. Shlegel; V. I. Tretyak; I. A. Tupitsyna; Ya. V. Vasiliev; Yu. Ya. Vostretsov

2010-09-05T23:59:59.000Z

57

Methotrexate intercalated ZnAl-layered double hydroxide  

SciTech Connect (OSTI)

The anticancerous drug methotrexate (MTX) has been intercalated into an ZnAl-layered double hydroxide (LDH) using an anion exchange technique to produce LDH-MTX hybrids having particle sizes in the range of 100-300 nm. X-ray diffraction studies revealed increases in the basal spacings of ZnAl-LDH-MTX hybrid on MTX intercalation. This was corroborated by the transmission electron micrographs, which showed an increase in average interlayer spacing from 8.9 A in pristine LDH to 21.3 A in LDH-MTX hybrid. Thermogravimetric analyses showed an increase in the decomposition temperature for the MTX molecule in the LDH-MTX hybrid indicating enhanced thermal stability of the drug molecule in the LDH nanovehicle. The cumulative release profile of MTX from ZnAl-LDH-MTX hybrids in phosphate buffer saline (PBS) at pH 7.4 was successfully sustained for 48 h following Rigter-Peppas model release kinetics via diffusion. - Graphical abstract: ZnAl-layered double hydroxide intercalated with methotrexate ({approx}34% loading) promises the possibility of use of ZnAl-LDH material as drug carrier and in controlled delivery. Highlights: > ZnAl-layered double hydroxide methotrexate nanohybrid has been synthesized. > XRD and TEM studies on nanohybrid revealed successful intercalation of methotrexate. > TG and CHN analyses showed {approx}34 wt% of methotrexate loading into the nanohybrid. > Possibility of use of ZnAl-LDH material as drug carrier and in delivery.

Chakraborty, Manjusha; Dasgupta, Sudip; Soundrapandian, Chidambaram [Central Glass and Ceramic Research Institute, CSIR, 196 Raja S.C. Mullick Road, Kolkata 700032 (India); Chakraborty, Jui, E-mail: jui@cgcri.res.in [Central Glass and Ceramic Research Institute, CSIR, 196 Raja S.C. Mullick Road, Kolkata 700032 (India); Ghosh, Swapankumar, E-mail: swapankumar.ghosh2@mail.dcu.ie [National Institute for Interdisciplinary Science and Technology (NIIST), CSIR, Trivandrum 695019 (India); Mitra, Manoj K. [Department of Metallurgical and Materials Engineering, Jadavpur University, Kolkata 700032 (India); Basu, Debabrata [Central Glass and Ceramic Research Institute, CSIR, 196 Raja S.C. Mullick Road, Kolkata 700032 (India)

2011-09-15T23:59:59.000Z

58

REGULAR ARTICLE Stability of polar ZnO surfaces studied by pair potential  

E-Print Network [OSTI]

density method Keju Sun � Hai-Yan Su � Wei-Xue Li Received: 1 September 2013 / Accepted: 16 November 2013. The overestimation of the stability of the ZnO(0001)�Zn terminal originates from more distribution of the transferred temperature sublimation processes indicated a higher sublimation rate of the ZnO(0001)�Zn surface compared

Li, Weixue

59

Photocatalytic activity of ZnO films with micro-grid structure  

Science Journals Connector (OSTI)

A layer of zinc oxide (ZnO) micro-grid was deposited on the surface of ZnO ... ZnO film and the regular arrangement of the micro-grid. The microgrid ZnO has a lower specular ... degradation experiments on methyle...

Chunzhi Li; Wenwen Wang; Junying Zhang…

2009-09-01T23:59:59.000Z

60

Green electroluminescence from ZnO/n-InP heterostructure fabricated by metalorganic chemical vapour deposition  

Science Journals Connector (OSTI)

Vertically aligned ZnO films were deposited on n-InP by metalorganic chemical vapour deposition. X-ray diffraction, field emission scanning electron microscopy and photoluminescence measurements demonstrated that the ZnO films had good quality. By evaporating AuZn electrodes on both ZnO and InP surfaces, a ZnO-based light emitting device was fabricated. Under forward voltage, weak green emissions can be observed in darkness.

Huichao Zhu; Baolin Zhang; Xiangping Li; Xin Dong; Wancheng Li; Hesong Guan; Yongguo Cui; Xiaochuan Xia; Tianpeng Yang; Yuchun Chang; Guotong Du

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" 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

CdTe/CdZnTe pixellated radiation detector.  

E-Print Network [OSTI]

??The work in this thesis is focused on the study of CdTe/CdZnTe pixellated detectors. During this research, three main aspects have been covered in the… (more)

Mohd Zain, Rasif

2015-01-01T23:59:59.000Z

62

Compton profile study of polycrystalline ZnBr{sub 2}  

SciTech Connect (OSTI)

The first ever Compton profile study of polycrystalline ZnBr{sub 2} is presented in this paper. The measurement of polycrystalline sample of ZnBr{sub 2} is performed using 59.54 keV gamma-rays emanating from an {sup 241}Am radioisotope. Theoretical calculations are performed following the Ionic model calculations for a number of configurations Zn{sup +x}Br{sub 2}{sup -x/2}(0.0{<=}x{<=}2.0 in step of 0.5) utilizing free atom profiles. The ionic model suggest transfer of 2.0 electrons from 4 s state of Zn to 4 p state of two Br atoms. The autocorrelation function B(z) is also derived from experiment and the most favoured ionic valence Compton profiles.

Dhaka, M. S. [Department of Physics, Engineering College Bikaner, Bikaner, 334004, Rajasthan (India); Sharma, G. [Department of Physics, Bansthali University, Bansthali, 304022, Rajasthan (India); Mishra, M. C.; Kothari, R. K.; Sharma, B. K. [Department of Physics, University of Rajasthan, Jaipur, 302004, Rajasthan (India)

2010-12-01T23:59:59.000Z

63

Aerosol synthesis and Rietveld analysis of tetragonal () PdZn...  

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

method. Detailed structural analysis shows that this material contains little or no vacancies and minimal PdZn disorder. Citation: Peterson EJ, B Halevi, B Kiefer, MN Spilde, AK...

64

Improving conversion efficiency of CdS quantum dots-sensitized TiO2 nanotube arrays by doping with Zn2+ and decorating with ZnO nanoparticles  

Science Journals Connector (OSTI)

Abstract The Zn-doped TiO2 nanotube arrays (TNTs) decorated with ZnO nanoparticles have been prepared via electrochemical anodization and immersing method. Furthermore, the CdS quantum dots (QDs) were deposited on the prepared Zn-doped TNTs-ZnO thin films by chemical bath deposition (CBD) method to fabricate the CdS QDs-sensitized Zn-doped TNTs-ZnO photoelectrodes. The nanostructure, morphology, optical properties and electrochemical properties of the CdS/Zn-doped TNTs-ZnO photoelectrode with comparison to those of the CdS/TNTs photoelectrodes were investigated. It has been found that the Zn-doped TNTs-ZnO photoelectrodes significantly increased the UV–vis light absorption of the CdS/Zn-doped TNTs-ZnO photoelectrodes and reduced the charge recombination at the surfaces of the CdS/Zn-doped TNTs-ZnO photoelectrodes. As a consequence, when the Zn-doped TNTs-ZnO film was adopted instead of the plain \\{TNTs\\} film, the light-chemical energy conversion efficiency of the CdS/Zn-doped TNTs-ZnO photoelectrode was much improved compared with the CdS/TNTs photoelectrode. A maximum energy conversion efficiency achieved for the CdS/Zn-doped TNTs-ZnO photoelectrode is 3.86%, which is a 17% improvement compared with the maximum energy conversion efficiency of 3.29% achieved for the CdS/TNTs photoelectrodes.

Chong Chen; Lei Wang; Fumin Li; Lanyu Ling

2014-01-01T23:59:59.000Z

65

Radioactive contamination of ZnWO4 crystal scintillators  

E-Print Network [OSTI]

The radioactive contamination of ZnWO4 crystal scintillators has been measured deep underground at the Gran Sasso National Laboratory (LNGS) of the INFN in Italy with a total exposure 3197 kg x h. Monte Carlo simulation, time-amplitude and pulse-shape analyses of the data have been applied to estimate the radioactive contamination of the ZnWO4 samples. One of the ZnWO4 crystals has also been tested by ultra-low background gamma spectrometry. The radioactive contaminations of the ZnWO4 samples do not exceed 0.002 â?? 0.8 mBq/kg (depending on the radionuclide), the total alpha activity is in the range: 0.2 - 2 mBq/kg. Particular radioactivity, beta active 65Zn and alpha active 180W, has been detected. The effect of the re-crystallization on the radiopurity of the ZnWO4 crystal has been studied. The radioactive contamination of samples of the ceramic details of the set-ups used in the crystals growth has been checked by low background gamma spectrometry. A project scheme on further improvement of the radiopur...

Belli, P; Cappella, F; Cerulli, R; Danevich, F A; Dubovik, A M; d'Angelo, S; Galashov, E N; Grinyov, B V; Incicchitti, A; Kobychev, V V; Laubenstein, M; Nagornaya, L L; Nozzoli, F; Poda, D V; Podviyanuk, R B; Polischuk, O G; Prosperi, D; Shlegel, V N; Tretyak, V I; Tupitsyna, I A; Vasiliev, Ya V; Vostretsov, Yu Ya

2010-01-01T23:59:59.000Z

66

Nanoscale order in ZnSe:(Mg, O)  

SciTech Connect (OSTI)

Self-assembling of 1O4Mg identical tetrahedral clusters resulting in the nanoscale order in ZnSe:(Mg, O) is presented. Co-doping transforms ZnSe into Mg{sub x}Zn{sub 1?x}O{sub y}Se{sub 1?y} alloy of MgO, MgSe, ZnO and ZnSe. The decrease of a sum of the enthalpies of the constituent compounds and diminution of the strain energy are the causes of this phenomenon. The self-assembling conditions are obtained from the free energy minimum when magnesium and oxygen are in the dilute and ultra dilute limits, correspondingly. The occurrence of 1O4Mg clusters and completion of self-assembling when all oxygen atoms are in clusters are results of the continuous phase transitions. The self-assembling occurrence temperature does not depend on the oxygen content and it is a function of magnesium concentration. Mg{sub x}Zn{sub 1?x}O{sub y}Se{sub 1?y} with all oxygen atoms in clusters can be obtained in temperature ranges from T = 206 °C (x = 0.001, y = 1×10{sup ?4}) to T = 456 °C (x = 0.01, y = 1×10{sup ?4}) and from T = 237 °C (x = 0.001, y = 1×10{sup ?6}) to T = 462 °C (x = 0.01, y = 1×10{sup ?6})

Elyukhin, Vyacheslav A. [Department of Electrical Engineering, Centro de Investigación y de Estudios Avanzados del IPN, Avenida Instituto Politecnico Nacional 2508, 07360 México (Mexico)

2014-02-21T23:59:59.000Z

67

Properties of ZnO/Cu/ZnO multilayer films deposited by simultaneous RF and DC magnetron sputtering at different substrate temperatures  

Science Journals Connector (OSTI)

ZnO/Cu/ZnO transparent conductive multilayer films are prepared by simultaneous RF sputtering of ZnO and DC sputtering of Cu. The properties of the multilayer films are studied at different substrate temperatures. Sheet resistance of the multilayer film ... Keywords: Electrical and optical properties, Multilayer, Sputtering, TCO

D. R. Sahu; Jow-Lay Huang

2007-03-01T23:59:59.000Z

68

DIRECT EVIDENCE OF MG-ZN-P ALLOY FORMATION IN MG/ZN3P2 SOLAR CELLS Gregory M. Kimball  

E-Print Network [OSTI]

Te, CIGS, a-Si) for thin film photovoltaics. The record solar energy conversion efficiency for Zn3P2 cells] or liquid contacts,[5] with Mg/Zn3P2 Schottky diodes having exhibited >6% solar energy-conversion efficiency], and long (5-10 m) minority-carrier diffusion lengths [2]. To date, Zn3P2 has been produced almost

Kimball, Gregory

69

Solar Syngas Production via H2O/CO2-Splitting Thermochemical Cycles with Zn/ZnO and FeO/Fe3O4 Redox Reactions  

Science Journals Connector (OSTI)

Solar Syngas Production via H2O/CO2-Splitting Thermochemical Cycles with Zn/ZnO and FeO/Fe3O4 Redox Reactions† ... The first step, driven by concentrated solar radiation, is the endothermic thermolysis of ZnO producing a gaseous mixture of O2 and ... ...

A. Stamatiou; P. G. Loutzenhiser; A. Steinfeld

2009-08-28T23:59:59.000Z

70

Ordered zinc-vacancy induced Zn0.75Ox nanophase structure Yong Ding, Rusen Yang, Zhong Lin Wang *  

E-Print Network [OSTI]

Ordered zinc-vacancy induced Zn0.75Ox nanophase structure Yong Ding, Rusen Yang, Zhong Lin Wang induced by Zn-vacancy has been discovered to grow on wurtzite ZnO nanobelts. The superstructure grows parameters of ZnO. The superstructured phase is resulted from high-density Zn vacancies orderly distributed

Wang, Zhong L.

71

Synthesis of reduced graphene oxide/ZnO nanorods composites on graphene coated PET flexible substrates  

SciTech Connect (OSTI)

Graphical abstract: - Highlights: • ZnO nanorods synthesized on CVD-graphene and rGO surfaces, respectively. • ZnO/CVD-graphene and ZnO/rGO form a distinctive porous 3D structure. • rGO/ZnO nanostructures possibility in energy storage devices. - Abstract: In this work, reduced graphene oxide (rGO)/ZnO nanorods composites were synthesized on graphene coated PET flexible substrates. Both chemical vapor deposition (CVD) graphene and reduced graphene oxide (rGO) films were prepared following by hydrothermal growth of vertical aligned ZnO nanorods. Reduced graphene sheets were then spun coated on the ZnO materials to form a three dimensional (3D) porous nanostructure. The morphologies of the ZnO/CVD graphene and ZnO/rGO were investigated by SEM, which shows that the ZnO nanorods grown on rGO are larger in diameters and have lower density compared with those grown on CVD graphene substrate. As a result of fact, the rough surface of nano-scale ZnO on rGO film allows rGO droplets to seep into the large voids of ZnO nanorods, then to form the rGO/ZnO hierarchical structure. By comparison of the different results, we conclude that rGO/ZnO 3D nanostructure is more desirable for the application of energy storage devices.

Huang, Lei, E-mail: leihuang@shnu.edu.cn; Guo, Guilue; Liu, Yang; Chang, Quanhong; Shi, Wangzhou

2013-10-15T23:59:59.000Z

72

Phase-Pure Cu,Zn,Al Hydrotalcite-like Materials as Precursors for Copper rich Cu/ZnO/Al2O3 Catalysts  

Science Journals Connector (OSTI)

Zincian malachite or rosasite (Cu,Zn)2(CO3)(OH), aurichalcite (Cu,Zn)5(CO3)2(OH)6, and hydrotalcite-like (htl) materials of the general composition ((Cu,Zn)1?xAlx)(OH)2(CO3)x/2·m H2O are the typical hydroxy carbonate precursor phases for such catalysts. ... (5) The relevance of the individual precursor phases for applied Cu/ZnO/Al2O3 or binary Cu/ZnO model catalysts is controversially discussed in the literature and aurichalcite,(6) rosasite,(7) zincian malachite,(1, 8) or a phase mixture of rosasite and hydrotalcite(9) have been suggested as desired precursor phases leading to highly active catalysts. ... (52) It is noted that such carbonate species have also been observed for the binary CuZn precursors zincian malachite and aurichalcite in course of the preparation of Cu/ZnO catalysts. ...

Malte Behrens; Igor Kasatkin; Stefanie Kühl; Gisela Weinberg

2009-12-22T23:59:59.000Z

73

Photoluminescence study of the substitution of Cd by Zn during the growth by atomic layer epitaxy of alternate CdSe and ZnSe monolayers  

SciTech Connect (OSTI)

We present a study of the substitution of Cd atoms by Zn atoms during the growth of alternate ZnSe and CdSe compound monolayers (ML) by atomic layer epitaxy (ALE) as a function of substrate temperature. Samples contained two quantum wells (QWs), each one made of alternate CdSe and ZnSe monolayers with total thickness of 12 ML but different growth parameters. The QWs were studied by low temperature photoluminescence (PL) spectroscopy. We show that the Cd content of underlying CdSe layers is affected by the exposure of the quantum well film to the Zn flux during the growth of ZnSe monolayers. The amount of Cd of the quantum well film decreases with higher exposures to the Zn flux. A brief discussion about the difficulties to grow the Zn{sub 0.5}Cd{sub 0.5}Se ordered alloy (CuAu-I type) by ALE is presented.

Hernández-Calderón, I. [Physics Department,Cinvestav, Ave. IPN2508, 07360, México City, DF. (Mexico); Salcedo-Reyes, J. C. [Thin Films Group, Physics Department, Pontificia Universidad Javeriana, Cr. 7 No. 43-82, Ed. 53, Lab. 404, Bogotá, D.C. (Colombia)

2014-05-15T23:59:59.000Z

74

Photodynamic action of curcumin derived polymer modified ZnO nanocomposites  

SciTech Connect (OSTI)

Highlights: ? ZnO/PVA nano sensitized with curcumin and its metal complex were synthesized by vacuum evaporation method. ? M/cur sensitized on ZnO/PVA nanocomposites were characterized. ? Generation of {sup 1}O{sub 2} and ROS were detected by optical and EPR-spin trapping method. ? It was found that photoinduced cleavage of DNA using Zn/cur–ZnO/PVA was superior. ? Photodegradation of MB in water catalyzed by ZnO/PVA–Zn/cur was also superior under visible light. -- Abstract: The photodynamic action of ZnO nano can be improved by modifying the surface by PVA and encapsulating the natural product, curcumin. The synthesized ZnO/PVA nanocomposites have been characterized using XRD, SEM, TEM, FTIR, TG–DTA, etc. Here we are reporting the photodynamic effect of ZnO nanocomposites on pUC18 DNA. Based on optical and EPR measurements, singlet oxygen and other ROS were responsible for photocleavage of DNA. Most importantly, derived curcumin modified ZnO/PVA nanocomposites were comparatively more effective than derived curcumin complex against HeLa cell lines under in vitro condition. In addition, photodegradation of methylene blue (MB) in water catalyzed by nano ZnO/PVA–curcumin derivative was investigated at room temperature. Under visible irradiation photocatalytic activity of ZnO nanomaterial sensitized curcumin was higher than those of curcumin and nano ZnO.

Hariharan, R.; Senthilkumar, S. [P.G. Department of Chemistry, Cardamom Planters’ Association College, Bodinayakanur 625513, Tamil Nadu (India)] [P.G. Department of Chemistry, Cardamom Planters’ Association College, Bodinayakanur 625513, Tamil Nadu (India); Suganthi, A., E-mail: suganthiphd09@gmail.com [P.G. and Research Department of Chemistry, Thiagarajar College, Madurai 625009, Tamil Nadu (India); Rajarajan, M., E-mail: rajarajan_1962@yahoo.com [P.G. Department of Chemistry, Cardamom Planters’ Association College, Bodinayakanur 625513, Tamil Nadu (India)

2012-11-15T23:59:59.000Z

75

Structure of liquid and glassy ZnCl2  

Science Journals Connector (OSTI)

The method of isotope substitution in neutron diffraction was used to measure the structure of liquid ZnCl2 at 332(5)?°C and glassy ZnCl2 at 25(1)?°C. The partial structure factors were obtained from the measured diffraction patterns by using the method of singular value decomposition and by using the reverse Monte Carlo procedure. The partial structure factors reproduce the diffraction patterns measured by high-energy x-ray diffraction once a correction for the resolution function of the neutron diffractometer has been made. The results show that the predominant structural motif in both phases is the corner sharing ZnCl4 tetrahedron and that there is a small number of edge-sharing configurations, these being more abundant in the liquid. The tetrahedra organize on an intermediate length scale to give a first sharp diffraction peak in the measured diffraction patterns at a scattering vector kFSDP?1?Å?1 that is most prominent for the Zn-Zn correlations. The results support the notion that the relative fragility of tetrahedral glass forming MX2 liquids is related to the occurrence of edge-sharing units.

Anita Zeidler; Philip S. Salmon; Richard A. Martin; Takeshi Usuki; Philip E. Mason; Gabriel J. Cuello; Shinji Kohara; Henry E. Fischer

2010-09-23T23:59:59.000Z

76

Enhanced photoelectrochemical responses of ZnO films through Ga and N codoping  

SciTech Connect (OSTI)

We report on the crystallinity and photoelectrochemical (PEC) response of ZnO thin films codoped by Ga and N. The ZnO:(Ga,N) thin films were deposited by cosputtering at room temperature and followed by postannealing at 500 deg. C in air for 2 h. We found that ZnO:(Ga,N) thin films exhibited significantly enhanced crystallinity compared to ZnO doped solely with N at the same growth conditions. Furthermore, ZnO:(Ga,N) thin films exhibited enhanced N incorporation over ZnO doped solely with N at high temperatures. As a result, ZnO:(Ga,N) thin films achieved dramatically improved PEC response, compared to ZnO thin films doped solely with N at any conditions. Our results suggest a general way to improve PEC response for wide-band-gap oxides.

Ahn, Kwang-Soon; Yan, Yanfa; Shet, Sudhakar; Deutsch, Todd; Turner, John; Al-Jassim, Mowafak [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

2007-12-03T23:59:59.000Z

77

Structural Studies of Al:ZnO Powders and Thin Films | Stanford...  

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

Ingham, Associate Investigator, MacDiarmid Institute for Advanced Materials & Nanotechnology Al-doped ZnO (Al:ZnO) is a promising transparent conducting oxide. We have used...

78

E-Print Network 3.0 - applied zn fe Sample Search Results  

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

carbonate and other Zn-containing compounds1 Graldine Sarret, Emiko Harada, Yong-Eui Choi*, Marie... to toxic levels of zinc. Zn exposure resulted in toxicity signs in...

79

Pressure Behaviour of the UV and Green Emission Bands in ZnO...  

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

Pressure Behaviour of the UV and Green Emission Bands in ZnO Micro-rods. Pressure Behaviour of the UV and Green Emission Bands in ZnO Micro-rods. Abstract: The pressure behavior of...

80

Graphene sheets decorated with ZnO nanoparticles as anode materials for lithium ion batteries  

Science Journals Connector (OSTI)

ZnO/graphene composites were synthesized using a facile solution- ... 4 nm were densely and homogeneously deposited on graphene sheets. As the anode material for the lithium ion batteries, the ZnO/graphene compos...

Ling-Li Xu; Shao-Wei Bian; Kang-Lin Song

2014-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" 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

E-Print Network 3.0 - al pb zn Sample Search Results  

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

et al., 1993; Dejonghe, 1998), resulting in elevated concentrations of Zn, Pb... by atomic absorption spectroscopy (AAS) for Zn, Pb, Mn, Fe, Ca, Mg, K and Al, and by...

82

Electrodeposition of ZnO Nanorods in the Presence of Metal Ions...  

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

of the hexagonal ZnO rods to be larger than in defect-free single-crystalline ZnO. SIMS measurements indicate impurity incorporation and doping in the bulk of the nanorods....

83

Predictive GIS model for potential mapping of Cu, Pb, Zn mineralization  

Science Journals Connector (OSTI)

The geologic features indicative of Cu, Pb, Zn mineral deposits in a area are fractures (structure), and host rock sediments. Datasets used include Cu, Pb, Zn deposit points record, geological data, remote sensin...

Tarik B. Benomar Ph. D.; Bian Fuling

2006-06-01T23:59:59.000Z

84

Structural, optical and photocatalytic properties of ZnO thin films and  

E-Print Network [OSTI]

emitting diodes, gas sensors and transparent conducting thin films for solar cells. In this work, Zn an electronic furnace. Fig. 1. Grain size (black) and RMS variations (blue) of 1-6 layered ZnO films vs

85

Fluorescent Dye Encapsulated ZnO Particles with Cell-specific...  

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

Dye Encapsulated ZnO Particles with Cell-specific Toxicity for Potential use in Biomedical Applications. Fluorescent Dye Encapsulated ZnO Particles with Cell-specific Toxicity...

86

Microsoft Word - Zn-DTPA Insert_2 Pages.doc  

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

zinc trisodium injection contains the sodium salt of zinc diethylenetriaminepentaacetate. Pentetate zinc zinc trisodium injection contains the sodium salt of zinc diethylenetriaminepentaacetate. Pentetate zinc trisodium is also known as trisodium zinc diethylenetriaminepentaacetate and is commonly referred to as Zn- DTPA. It has a molecular formula of Na3ZnC14H18N3O10 and a molecular weight of 522.7 Daltons. It is represented by the following structural formula: Zn-DTPA is supplied as a clear, colorless, hyperosmolar (1260 mOsmol/kg) solution in a colorless ampoule containing 5 mL. The ampoule contents are sterile, non-pyrogenic and suitable for intravenous administration. Each mL of solution contains the equivalent of 200 mg pentetate zinc trisodium (obtained from 150.51 mg pentetic acid, 31.14 mg zinc oxide and NaOH) and water for injection, USP. The pH of the solution is adjusted

87

Dehydrogenation of Ethanol Over Cu/ZnO Catalysts Prepared from Various Coprecipitated Precursors  

Science Journals Connector (OSTI)

For the title reaction, Cu/ZnO catalysts prepared from aurichalcite were more active than those prepared from...2

Shin-ichiro Fujita; Nobuhiro Iwasa; Hiroaki Tani…

88

Structure and luminescence of annealed nanoparticles of ZnS:Mn A. D. Dinsmore,a)  

E-Print Network [OSTI]

,10 Y2O3:Eu,11­13 LaPO4:Eu, Ce and Tb,14 CdS:Mn,15 CdSe:Mn,16 ZnS:Cu,17 ZnS:Tb,18 and ZnS:Mn,19­32 which temperatures5,6 and pressures.7,8 In addition to their funda- mental interest, doped semiconductor describe experimental studies of the structure and luminescence of nanoparticles of ZnS doped with Mn

Dinsmore, Tony

89

Structural recovery of ion implanted ZnO nanowires G. Perillat-Merceroz,1, 2, a)  

E-Print Network [OSTI]

applications, ZnO nanowires are studied for making light- emitting diodes (LEDs) because of the advantages

Boyer, Edmond

90

Characterization of CdZnTe ambient temperature detectors  

SciTech Connect (OSTI)

A great deal of interest has been generated in the use of cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) detectors for ambient temperature detection of radionuclides. The addition of zinc to CdTe provides several benefits that enhance the materials operational characteristics at ambient temperature. Recent movement in the industry is to produce larger volume detectors using CdZnTe without much known about the effects of larger geometry on performance. The purpose of this study is to get an idea of the relationship of detector performance to both area and thickness variations.

Lavietes, A.

1994-09-01T23:59:59.000Z

91

Heavy Quasiparticles in the Ferromagnetic Superconductor ZrZn2  

Science Journals Connector (OSTI)

We report a study of the de Haas–van Alphen effect in the normal state of the ferromagnetic superconductor ZrZn2. Our results are generally consistent with a linear muffin-tin orbital band structure which predicts four exchange-split Fermi surface sheets. Quasiparticle effective masses are enhanced by a factor of 4.9 implying a strong coupling to magnetic excitations or phonons. ZrZn2 is unique among metallic ferromagnets in that it has a very large density of states in the ferromagnetic phase.

S. J. C. Yates; G. Santi; S. M. Hayden; P. J. Meeson; S. B. Dugdale

2003-02-06T23:59:59.000Z

92

Influence of Zn(II) on the Adsorption of Arsenate onto Ferrihydrite  

Science Journals Connector (OSTI)

The bands were assigned to the stretching of hydroxyl groups of the solid phase similar to IR data available for some zinc hydroxide carbonate minerals such as rosasite ((Cu,Zn)2(CO3)(OH)2), hydrozincite (Zn5(CO3)(OH)2), or aurichalcite ((Zn,Cu)5(CO3)2(OH)6). ...

Ivan Carabante; Mattias Grahn; Allan Holmgren; Jurate Kumpiene; Jonas Hedlund

2012-11-21T23:59:59.000Z

93

Corrosion of, and cellular responses to MgZnCa bulk metallic glasses Xuenan Gu a  

E-Print Network [OSTI]

Corrosion of, and cellular responses to Mg­Zn­Ca bulk metallic glasses Xuenan Gu a , Yufeng Zheng a: Magnesium alloy Bulk metallic glass Mechanical property Corrosion Cytotoxicity a b s t r a c t Mg­Zn­Ca bulk, mechanical testing, corrosion and cytotoxicity tests. It was found that the Mg66Zn30Ca4 sample presents

Zheng, Yufeng

94

Low temperature growth of ZnTe by synchroton radiation using metalorganic sources  

Science Journals Connector (OSTI)

The use of synchrotron radiation to convert diethylzinc and diethyltelluride molecules into ZnTe has been employed for ZnTe growth. The formation of ZnTe epitaxial layer on (100) oriented GaAs substrate at room temperature is experimentally demonstrated. It is shown by x?ray photoelectron spectroscopy that no carbon is included in the film. ?

Makoto Ikejiri; Toshihiro Ogata; Hiroshi Ogawa; Mitsuhiro Nishio; Akira Yoshida

1994-01-01T23:59:59.000Z

95

Spectroscopic studies on Zn-doped CdS nanopowders prepared by simple coprecipitation method  

Science Journals Connector (OSTI)

A series of Zn-doped cadmium sulfide (CdS:Zn) nanopowders were prepared by a simple ... nanosize and cubic structure at room temperature. Doping with Zn in CdS does not lead to any structural phase ... the lattic...

H. Sekhar; D. Narayana Rao

2012-02-01T23:59:59.000Z

96

Study of stability of ZnO nanoparticles and growth mechanisms of colloidal ZnO nanorods  

E-Print Network [OSTI]

that the intraparticle diffusion is different from normal Ostwald ripening because it occurs at lower monomer concentration and by monomer migration from small to larger ones. 19 2.6 Selectively binding of surface ligands It is also reported that changes...O concentration in the precursor solution at 60 ?C or higher. As for the mechanisms for the growth of ZnO nanorods, ?Ostwald ripening? and ?oriented attachment? were proposed to explain the formation of ZnO nanorods [30]. In here, ?oriented attachment...

Lee, Kwang Jik

2006-10-30T23:59:59.000Z

97

ZnO/Sn:In2O3 and ZnO/CdTe band offsets for extremely thin absorber photovoltaics  

SciTech Connect (OSTI)

Band alignments were measured by x-ray photoelectron spectroscopy for thin films of ZnO on polycrystalline Sn:In2O3 (ITO) and single crystal CdTe. Hybrid density functional theory calculations of epitaxial zinc blende ZnO(001) on CdTe(001) were performed to compare with experiment. A conduction band offset of -0.6 eV was measured for ZnO/ITO, which is larger than desired for efficient electron injection. For ZnO/CdTe, the experimental conduction band offset of 0.25 eV is smaller than the calculated value of 0.67 eV, likely due to the TeOx layer at the ZnO/CdTe interface. The measured conduction band offset for ZnO/CdTe is favorable for photovoltaic devices.

Kaspar, Tiffany C.; Droubay, Timothy C.; Jaffe, John E.

2011-12-28T23:59:59.000Z

98

ZnO/ZnS(O,OH)/Cu(In,Ga)Se2/Mo SOLAR CELL WITH 18.6% EFFICIENCY M.A. Contreras, 2  

E-Print Network [OSTI]

) photovoltaic technology is motivated primarily by the potential to enhance solar cell current generationZnO/ZnS(O,OH)/Cu(In,Ga)Se2/Mo SOLAR CELL WITH 18.6% EFFICIENCY 1 M.A. Contreras, 2 T. Nakada, 2 M of 18.6% for Cu(In,Ga)Se2 solar cells that incorporate a ZnS(O,OH) buffer layer as an alternative to Cd

Sites, James R.

99

Atomic Absorption Method Guide Zn in Copper Alloys  

E-Print Network [OSTI]

Atomic Absorption Method Guide Zn in Copper Alloys Principle The sample is digested in nitric/hydrochloric acid, and zinc is determined by flame atomic absorption spectrometry using an air-acetylene flame · Copper Alloys · Zinc · Flame · Atomic Absorption Method Guide: 40158 #12;©2008 Thermo Fisher Scientific

Wells, Mathew G. - Department of Physical and Environmental Sciences, University of Toronto

100

Scintillating bolometers based on ZnMoO$_4$ and Zn$^{100}$MoO$_4$ crystals to search for 0$\  

E-Print Network [OSTI]

The technology of scintillating bolometers based on zinc molybdate (ZnMoO$_4$) crystals is under development within the LUMINEU project to search for 0$\

Poda, D V; Arnaud, Q; Augier, C; Benoît, A; Bergé, L; Boiko, R S; Bergmann, T; Blümer, J; Broniatowski, A; Brudanin, V; Camus, P; Cazes, A; Censier, B; Chapellier, M; Charlieux, F; Chernyak, D M; Coron, N; Coulter, P; Cox, G A; Danevich, F A; de Boissière, T; Decourt, R; De Jesus, M; Devoyon, L; Drillien, A -A; Dumoulin, L; Eitel, K; Enss, C; Filosofov, D; Fleischmann, A; Fourches, N; Gascon, J; Gastaldo, L; Gerbier, G; Giuliani, A; Gros, M; Hehn, L; Henry, S; Hervé, S; Heuermann, G; Humbert, V; Ivanov, I M; Juillard, A; Kéfélian, C; Kleifges, M; Kluck, H; Kobychev, V V; Koskas, F; Kozlov, V; Kraus, H; Kudryavtsev, V A; Sueur, H Le; Loidl, M; Magnier, P; Makarov, E P; Mancuso, M; de Marcillac, P; Marnieros, S; Marrache-Kikuchi, C; Menshikov, A; Nasonov, S G; Navick, X-F; Nones, C; Olivieri, E; Pari, P; Paul, B; Penichot, Y; Pessina, G; Piro, M C; Plantevin, O; Redon, T; Robinson, M; Rodrigues, M; Rozov, S; Sanglard, V; Schmidt, B; Shlegel, V N; Siebenborn, B; Strazzer, O; Tcherniakhovski, D; Tenconi, M; Torres, L; Tretyak, V I; Vagneron, L; Vasiliev, Ya V; Velazquez, M; Viraphong, O; Walker, R J; Weber, M; Yakushev, E; Zhang, X; Zhdankov, V N

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" 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

Search for non-Newtonian gravitation—a gravimetric experiment in a hydroelectric lake  

Science Journals Connector (OSTI)

......gravitation-a gravimetric experiment in a hydroelectric lake G. Muller 1 W. Zurn 2 K. Lindner...gravitation-a gravimetric experiment in a hydroelectric lake G. Muller', W. Zurn2, K...are moved in dry rocks, locks and hydroelectric lakes, they often have a well-defined......

G. Müller; W. Zürn; K. Lindner; N. Rösch

1990-05-01T23:59:59.000Z

102

Inelastic neutron scattering from single crystal Zn under high pressure  

Science Journals Connector (OSTI)

Inelastic neutron-scattering experiments have been performed for single crystals of Zn under pressures up to 8.8 GPa at 300 K. The phonon modes q/qmax=?=0.075 and ?=0.10 were measured in the transverse acoustic branch ?3, where q=0 corresponds with the elastic constant C44. The phonon energy showed a substantial hardening with increasing pressure. The experimental data below 6.8 GPa for ?=0.075 yield a constant Grüneisen mode ?i=-ln?i/lnV of 2.25 in good agreement with a previous calculation [H. Ledbetter, Phys. Status Solidi B 181, 81 (1994)]. Above 6.8 GPa, there is a very rapid increase of ?i which is indicative of the presence of a giant Kohn anomaly. This rapid divergence at high pressure indicates that a phonon softening may occur at pressures higher than 8.8 GPa caused by the collapse of the giant Kohn anomaly via an electronic topological transition (ETT). In an earlier Mössbauer Zn study at 4 K [W. Potzel et al., Phys. Rev. Lett. 74, 1139 (1994)], a drastic drop of the Lamb-Mössbauer factor was observed at 6.6 GPa, which was interpreted as being due to phonon softening, indicating this ETT had occurred. This paper also compares the compressibility data for single crystal Zn and Zn powder using neutron scattering. The results were found to be similar to an earlier x-ray Zn powder experiment [O. Schulte et al., High Pressure Res. 6, 169 (1991)]. © 1996 The American Physical Society.

J. G. Morgan; R. B. Von Dreele; P. Wochner; S. M. Shapiro

1996-07-01T23:59:59.000Z

103

A simple photolytic reactor employing Ag-doped ZnO nanowires for water purification  

Science Journals Connector (OSTI)

Abstract Well-aligned native zinc oxide (ZnO) and silver-doped ZnO (Ag-ZnO) films were deposited on borosilicate glass via a simple, low-cost, low-temperature, scalable hydrothermal process. The as-synthesized ZnO and Ag-ZnO films were characterized by X-ray diffraction; scanning electron microscopy, UV–visible spectroscopy, and Fourier transform infrared spectroscopy. A simple photolytic reactor was fabricated and later used to find the optimum experimental conditions for photocatalytic performance. The photodegradation of methyl orange in water was investigated using as-prepared ZnO and Ag-ZnO nanowires, and was compared to P25 (a commercial photocatalyst) in both visible and UV radiations. The P25 and Ag-ZnO showed a similar photodegradation performance under UV light, but Ag-ZnO demonstrated superior photocatalytic activity under visible irradiation. The optimized doping of Ag in Ag-ZnO enhanced photocatalytic activity in a simple reactor design and indicated potential applicability of Ag-ZnO for large-scale purification of water under solar irradiation.

Innocent Udom; Yangyang Zhang; Manoj K. Ram; Elias K. Stefanakos; Aloysius F. Hepp; Radwan Elzein; Rudy Schlaf; D. Yogi Goswami

2014-01-01T23:59:59.000Z

104

Facile synthesis of graphene/ZnO nanocomposites by low temperature hydrothermal method  

SciTech Connect (OSTI)

Highlights: ? Graphene/ZnO nanocomposites were prepared by low temperature hydrothermal method. ? Rhodamine-B degraded by using graphene/ZnO nanocomposites. ? ZnO anchored well on the surface of graphene. -- Abstract: Graphene/ZnO nanocomposites have been synthesized using hydrothermal method at two different temperatures 80 and 90 °C. The structure, morphology and optical properties of as synthesized nanocomposites were analyzed through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy, transmission electron microscopy (TEM) and UV–vis absorbance spectroscopy. The XRD pattern confirmed the formation of graphene decorated by hexagonal ZnO with high crystallinity. FESEM image revealed that the sheet like graphene decorated with ZnO in homogeneously. Decoration of quasi-spherical ZnO nanoparticles on graphene sheet was confirmed by TEM. The characteristic absorbance peaks of graphene/ZnO nanocomposites were observed in UV visible spectra. The photocatalytic degradation experiment was performed against rhodamine-B dye and showed good catalytic activity for both samples. The graphene/ZnO nanocomposites showed higher catalytic activity then ZnO nanoparticles. The GZN-90 sample showed more catalytic activity than GZN-80 due to higher density of ZnO in graphene surface generates large number of photo-induced electron.

Saravanakumar, Balasubramaniam; Mohan, Rajneesh [Nanomaterials and System Lab, Department of Mechatronics Engineering, Jeju National University, Jeju 690-756 (Korea, Republic of)] [Nanomaterials and System Lab, Department of Mechatronics Engineering, Jeju National University, Jeju 690-756 (Korea, Republic of); Kim, Sang-Jae, E-mail: kimsangj@jejunu.ac.kr [Nanomaterials and System Lab, Department of Mechatronics Engineering, Jeju National University, Jeju 690-756 (Korea, Republic of)] [Nanomaterials and System Lab, Department of Mechatronics Engineering, Jeju National University, Jeju 690-756 (Korea, Republic of)

2013-02-15T23:59:59.000Z

105

Structural Studies of Al:ZnO Powders and Thin Films | Stanford Synchrotron  

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

Structural Studies of Al:ZnO Powders and Thin Films Structural Studies of Al:ZnO Powders and Thin Films Monday, June 18, 2012 - 2:00pm SSRL Main Conference Room 137-322 Dr. Bridget Ingham, Associate Investigator, MacDiarmid Institute for Advanced Materials & Nanotechnology Al-doped ZnO (Al:ZnO) is a promising transparent conducting oxide. We have used complementary synchrotron and laboratory techniques to study the incorporation of Al within the ZnO lattice, and measure its effect on the crystallinity of thin films prepared by sol-gel techniques, with an aim to understand how these properties affect the film conductivity. I will present recent results from Al:ZnO powders and thin films, prepared with varying Al concentrations and calcination temperatures. Solid state 27Al NMR and ex situ X-ray diffraction (XRD) were performed on Al:ZnO

106

Structural and optical properties of MgO doped ZnO  

SciTech Connect (OSTI)

Samples of ZnO, Zn{sub 0.5}Mg{sub 0.5}O and MgO were prepared by co-precipitation method. X-ray diffraction (XRD) pattern infers that the sample of ZnO is in single-phase wurtzite structure (hexagonal phase, space group P6{sub 3}mc), MgO crystallizes in cubic Fd3m space group and Zn{sub 0.5}Mg{sub 0.5}O represents mixed nature of ZnO and MgO lattices. Similar features were observed from Raman spectroscopy. The energy band gaps estimated from UV-Vis spectroscopy are found to be 4.21 and 3.42 eV for ZnO and Zn{sub 0.5}Mg{sub 0.5}O samples respectively.

Verma, Kavita; Shukla, S.; Varshney, Dinesh, E-mail: vdinesh33@rediffmail.com [School of Physics, Vigyan Bhavan, Devi Ahilya University, Khandwa Road Campus, Indore-452001 (India); Varshney, M. [Department of Physics, M. B. Khalsa College, Raj Mohallah, Indore-452002 (India); Asthana, A. [Department of Chemistry, Govt. B. V. T. PG Autonomous College, Durg- 491001 (India)

2014-04-24T23:59:59.000Z

107

Optical transitions and multiphonon Raman scattering of Cu doped ZnO and MgZnO ceramics  

E-Print Network [OSTI]

of the Cu ion, Cu doped ZnO is a p-type semiconductor.13 Additionally, ferromagnetic behavior due were then dried and cold pressed at up to 3 tons for approximately 30 min, followed by annealing at a temperature of 10 K using a Bomem DA8 Fourier transform IR spectrometer and InSb detector. The micro

McCluskey, Matthew

108

Structural properties and spatial ordering in multilayered ZnMgTe/ZnSe type-II quantum dot structures  

SciTech Connect (OSTI)

We report the structural properties and spatial ordering of multilayer ZnMgTe quantum dots (QDs) embedded in ZnSe, where sub-monolayer quantities of Mg were introduced periodically during growth in order to reduce the valence band offset of ZnTe QDs. The periodicity, period dispersion, individual layer thickness, and the composition of the multilayer structures were determined by comparing the experimental high resolution x-ray diffraction (HRXRD) spectra to simulated ones for the allowed (004) and quasi-forbidden (002) reflections in combination with transmission electron microscopy (TEM) results. Secondary ion mass spectroscopy (SIMS) profiles confirmed the incorporation of Mg inside the QD layers, and the HRXRD analysis revealed that there is approximately 32% Mg in the ZnMgTe QDs. The presence of Mg contributes to higher scattering intensity of the HRXRD, leading to the observation of higher order superlattice peaks in both the (004) and (002) reflections. The distribution of scattered intensity in the reciprocal space map (RSM) shows that the diffuse scattered intensity is elongated along the q{sub x} axis, indicating a vertical correlation of the dots, which is found to be less defined for the sample with larger periodicity. The diffuse scattered intensity is also found to be weakly correlated along the q{sub z} direction indicating a weak lateral correlation of the dots.

Manna, U.; Noyan, I. C.; Neumark, G. F. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); Zhang, Q.; Moug, R. [Department of Chemistry, City College of CUNY, New York, New York 10031 (United States); Salakhutdinov, I. F. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); Department of Physics, Queens College of CUNY, Flushing, New York 11367 (United States); Dunn, K. A.; Novak, S. W. [College of Nanoscale Science and Engineering, University at Albany-SUNY, Albany, New York 12203 (United States); Tamargo, M. C. [Department of Chemistry, City College of CUNY, New York, New York 10031 (United States); Graduate Center of CUNY, New York, New York 10016 (United States); Kuskovsky, I. L. [Department of Physics, Queens College of CUNY, Flushing, New York 11367 (United States); Graduate Center of CUNY, New York, New York 10016 (United States)

2012-02-01T23:59:59.000Z

109

Cu–ZnO and Cu–ZnO/Al2O3 Catalysts for the Reverse Water-Gas Shift Reaction. The Effect of the Cu/Zn Ratio on Precursor Characteristics and on the Activity of the Derived Catalysts  

Science Journals Connector (OSTI)

Comparison is made between Cu–ZnO and alumina-supported Cu–ZnO as catalysts for the reverse water-gas shift (RWGS) reaction. For both types of catalyst the Cu/Zn ratio has been varied between Cu-rich and Zn-ri...

Frank S. Stone; David Waller

2003-04-01T23:59:59.000Z

110

The influence of Zn vacancy on thermal conductivity of {beta}-Zn{sub 4}Sb{sub 3}: A molecular dynamics study  

SciTech Connect (OSTI)

The influence of Zn vacancy on lattice thermal conductivity of {beta}-Zn{sub 4}Sb{sub 3} is studied by non-equilibrium molecular dynamics approach. The lattice thermal conductivity of single-crystal bulk {beta}-Zn{sub 4}Sb{sub 3} decreases rapidly when there is Zn vacancy, and then when the vacancy grows, the lattice thermal conductivity decreases further but rather slowly, which suggests a scaling law of k{sub v}{approx}n{sub v}{sup -{alpha}} of Zn atom vacancy (n{sub v}) to lattice thermal conductivity (k{sub vac}). This phenomenon is attributed to the fact that the existence of vacancy scattering can significantly decrease the mean free path. When the Zn atom vacant proportion reaches 10%, that is the vacancy model of {beta}-Zn{sub 4}Sb{sub 3}, the lattice thermal conductivity is 1.32 W/mk along the x-axis and 1.62 W/mk along the z-axis, respectively, which drops by {approx}90% that of its full occupancy model. Therefore, our calculations show that the 10% Zn atom vacancy in {beta}-Zn{sub 4}Sb{sub 3} is the main reason for its exceptionally low thermal conductivity, and the interstitial Zn atoms have little effect on the thermal conductivity of single-crystal {beta}-Zn{sub 4}Sb{sub 3}. - Graphical abstract: The bulk thermal conductivity (k{sub pure}) is 11.88 W/mk along the x-axis and 20.00 W/mk the z-axis. When it is 10% vacancy, namely the vacancy model of {beta}-Zn{sub 4}Sb{sub 3}, the thermal conductivity of {beta}-Zn{sub 4}Sb{sub 3} is 1.32 W/mk along the x-axis and 1.62 W/mk along the z-axis, respectively, which reduces by {approx}90% that of its full occupancy model. Our calculations show that the 10% Zn atom vacancy in the crystal structure of {beta}-Zn{sub 4}Sb{sub 3} is the main reason for its exceptionally low thermal conductivity, and the interstitial Zn atoms have little effect on the thermal conductivity of single-crystal {beta}-Zn{sub 4}Sb{sub 3}. Highlights: Black-Right-Pointing-Pointer The lattice stability of {beta}-Zn{sub 4}Sb{sub 3} decreases remarkably with the growing vacancy. Black-Right-Pointing-Pointer 10% Zn vacancy leads to its low thermal conductivity and structural instability. Black-Right-Pointing-Pointer Interstitial Zn atoms in {beta}-Zn{sub 4}Sb{sub 3} mainly stabilize the crystal structure.

Zhai, Pengcheng [Department of Engineering Structure and Mechanics, Wuhan University of Technology, Wuhan 430070 (China) [Department of Engineering Structure and Mechanics, Wuhan University of Technology, Wuhan 430070 (China); State Key Laboratory of Advanced Technology of Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Li, Guodong; Wen, Pengfei [Department of Engineering Structure and Mechanics, Wuhan University of Technology, Wuhan 430070 (China)] [Department of Engineering Structure and Mechanics, Wuhan University of Technology, Wuhan 430070 (China); Li, Yao, E-mail: liyao06@126.com [Department of Engineering Structure and Mechanics, Wuhan University of Technology, Wuhan 430070 (China)] [Department of Engineering Structure and Mechanics, Wuhan University of Technology, Wuhan 430070 (China); Zhang, Qingjie; Liu, Lisheng [State Key Laboratory of Advanced Technology of Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)] [State Key Laboratory of Advanced Technology of Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

2012-09-15T23:59:59.000Z

111

Synthesis and electronic properties of ZnO/CoZnO core-shell nanowires Song Han, Daihua Zhang, and Chongwu Zhoua  

E-Print Network [OSTI]

of interesting DMS nanowires including Mn-doped GaN,18,19 CdS, and ZnS Ref. 19 have been synthesized- hibit ferromagnetism above room temperature when doped with substitutional Mn2+ ions and sufficiently high levels of p-type dopants. Sato et al.8 further revealed that n-type Co- doped ZnO would remain

Zhou, Chongwu

112

Point Defect Characterization in CdZnTe  

SciTech Connect (OSTI)

Measurements of the defect levels and performance testing of CdZnTe detectors were performed by means of Current Deep Level Transient Spectroscopy (I-DLTS), Transient Charge Technique (TCT), Current versus Voltage measurements (I-V), and gamma-ray spectroscopy. CdZnTe crystals were acquired from different commercial vendors and characterized for their point defects. I-DLTS studies included measurements of defect parameters such as energy levels in the band gap, carrier capture cross sections, and defect densities. The induced current due to laser-generated carriers was measured using TCT. The data were used to determine the transport properties of the detectors under study. A good correlation was found between the point defects in the detectors and their performance.

Gul,R.; Li, Z.; Bolotnikov, A.; Keeter, K.; Rodriguez, R.; James, R.

2009-03-24T23:59:59.000Z

113

XAFS Debye-Waller factors for Zn metalloproteins  

SciTech Connect (OSTI)

An accurate and practical method for the calculation and use of thermal x-ray absorption fine structure (XAFS) Debye-Waller factors (DWFs) in active sites of metalloproteins is presented. These factors are calculated on model clusters within the local density functional approximation with nonlocal corrections. The DWFs are mapped out and parametrized as a function of the first shell distance and an angle (where applicable), for all significant single and multiple scattering paths, as well as the sample temperature. This approach is applied to the biologically essential but spectroscopically silent Zn{sup +2} active sites composed of histidines, cysteines, and carboxylate ligands in homogeneous and heterogeneous environments. Detailed analysis of the relative scattering paths for Zn metalloproteins using projected vibrational density of states further explain why these paths are not detectable by XAFS for first shell metal-ligand distances above a 'cutoff' value.

Dimakis, Nicholas; Bunker, Grant [Illinois Institute of Technology, 3300 South Federal Street, Chicago, Illinois 60616-3793 (United States)

2004-11-15T23:59:59.000Z

114

Experimental evidence of V{sub O}?Zn{sub i} complex to be intrinsic donor in bulk ZnO  

SciTech Connect (OSTI)

Theoretical evidence of V{sub O}?Zn{sub i} to be a native donor in bulk ZnO has been under debate. To resolve the issue, we annealed several pieces of as grown zinc rich n-type ZnO thin film having N{sub D} ? 3.26 × 10{sup 17} cm{sup ?3} grown by molecular beam epitaxy on Si (001) substrate in oxygen environment at 500°C – 800°C, keeping a step of 100°C for one hour, each. Room temperature Hall measurements demonstrated that free donor concentration decreased exponentially and Arrhenius plot yielded activation energy to be 1.2±0.02 eV. This value is in an agreement with the theoretically reported activation energy of V{sub O}?Zn{sub i} donor complex in ZnO.

Asghar, M.; Mahmood, K. [Department of Physics, The Islamia University of Bahawalpur 63100 (Pakistan); Hasan, M.-A; Tsu, R.; Ferguson, I. T. [Department of Electrical and Computer Engineering, University of North Carolina Charlotte, NC 28223 (United States)

2014-02-21T23:59:59.000Z

115

Metal contacts on ZnSe and GaN  

SciTech Connect (OSTI)

Recently, considerable interest has been focused on the development of blue light emitting materials and devices. The focus has been on GaN and ZnSe, direct band gap semiconductors with bands gaps of 3.4 and 2.6 eV, respectively. To have efficient, reliable devices it is necessary to have thermally and electrically stable Ohmic contacts. This requires knowledge of the metal-semiconductor reaction behavior. To date few studies have investigated this behavior. Much information has accumulated over the years on the behavior of metals on Si and GaAs. This thesis provides new knowledge for the more ionic wide band gap semiconductors. The initial reaction temperatures, first phases formed, and phase stability of Pt, Pd, and Ni on both semiconductors were investigated. The reactions of these metals on ZnSe and GaN are discussed in detail and correlated with predicted behavior. In addition, comparisons are made between these highly ionic semiconductors and Si and GaAs. The trends observed here should also be applicable to other II-VI and III-Nitride semiconductor systems, while the information on phase formation and stability should be useful in the development of contacts for ZnSe and GaN devices.

Duxstad, K.J. [Univ. of California, Berkeley, CA (United States). Materials Science and Mineral Engineering; [Lawrence Berkeley National Lab., CA (United States). Materials Sciences Div.

1997-05-01T23:59:59.000Z

116

Photoelectron spectroscopic study of band alignment of polymer/ZnO photovoltaic device structure  

SciTech Connect (OSTI)

Using x-ray photoelectron spectroscopy, we investigated the band alignment of a Ag/poly(3-hexylthiophene-2,5-diyl) (P3HT)/ZnO photovoltaic structure. At the P3HT/ZnO interface, a band bending of P3HT and a short surface depletion layer of ZnO were observed. The offset between the highest occupied molecular orbital of P3HT and the conduction band minimum of ZnO at the interface contributed to the open circuit voltage (Voc) was estimated to be approximately 1.5 {+-} 0.1 eV, which was bigger than that of the electrically measured effective Voc of P3HT/ZnO photovoltaic devices, meaning that the P3HT/ZnO photovoltaic structure has the potential to provide improved photovoltaic properties.

Nagata, T.; Chikyow, T. [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan)] [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); Oh, S.; Wakayama, Y. [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan) [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); Department of Chemistry and Biochemistry, Faculty of Engineering, Kyushu University, 1-1 Namiki, Tsukuba 305-0044 (Japan); Yamashita, Y. [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan) [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); NIMS Beamline Station at SPring-8, National Institute for Materials Science, 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Yoshikawa, H.; Kobayashi, K. [NIMS Beamline Station at SPring-8, National Institute for Materials Science, 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)] [NIMS Beamline Station at SPring-8, National Institute for Materials Science, 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Ikeno, N. [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan) [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); Nanotechnology Laboratory, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan)

2013-01-28T23:59:59.000Z

117

As-doped p -type ZnO produced by an evaporation?sputtering process  

Science Journals Connector (OSTI)

Strongly p -type ZnO is produced by the following sequence of steps: (1) evaporation of Zn 3 As 2 on a fused-quartz substrate at 350 ° C ; and (2) sputtering of ZnO with substrate held at 450 ° C . The electrical characteristics include: resistivity of 0.4 ? cm a mobility of 4 cm 2 ? V s and a hole concentration of about 4 × 10 18 cm ? 3 . This resistivity is among the best (lowest) ever reported for p -type ZnO. Secondary-ion mass spectroscopic analysis gives an average As concentration about 5 × 10 19 cm ? 3 and a simple one-band fit of the temperature-dependent mobility curve yields an acceptor concentration of about 9 × 10 19 cm ? 3 . This is strong evidence that the p -type dopant involves As although it is not clear whether the acceptor is simply As O or the recently suggested As Zn ? 2 V Zn .

D. C. Look; G. M. Renlund; R. H. Burgener II; J. R. Sizelove

2004-01-01T23:59:59.000Z

118

Study of interatomic potential and thermal structural properties of ?-Zn{sub 4}Sb{sub 3}  

SciTech Connect (OSTI)

Highlights: ? The multi-body interatomic potentials of various models of ?-Zn{sub 4}Sb{sub 3} have been developed to describe atomic interactions. ? The radial distribution function shows that the 10% vacancy of Zn site leads to the disorder of ?-Zn{sub 4}Sb{sub 3}. ? The 10% vacancy of Zn site is the main cause of the exceptional low thermal conductivity. -- Abstract: Previous experimental research shows that the disordered Zn atoms in ?-Zn{sub 4}Sb{sub 3} may have an important influence on its exceptionally low thermal conductivity and easily occurred phase transition. So the present work aims to study the influence of disordered Zn atoms on thermodynamics properties of ?-Zn{sub 4}Sb{sub 3} by using molecular dynamics (MD) method. Firstly, based on first principles calculation and experimental results, the interatomic potentials of ?-Zn{sub 4}Sb{sub 3} and MD analysis method are established, and the feasibility is verified. Then, the influence of disordered Zn atoms on thermal conductivity of ?-Zn{sub 4}Sb{sub 3} is studied in detail. The simulation results indicate that the 10% vacant Zn atoms is the main reason for the exceptionally low thermal conductivity of ?-Zn{sub 4}Sb{sub 3}, and it seems that the interstitial Zn atoms have little effect on its thermal conductivity.

Li, Guodong [Department of Engineering Structure and Mechanics, Wuhan University of Technology, Wuhan 430070 (China)] [Department of Engineering Structure and Mechanics, Wuhan University of Technology, Wuhan 430070 (China); Li, Yao, E-mail: liyao06@126.com [Department of Engineering Structure and Mechanics, Wuhan University of Technology, Wuhan 430070 (China)] [Department of Engineering Structure and Mechanics, Wuhan University of Technology, Wuhan 430070 (China); Liu, Lisheng; Zhang, Qingjie; Zhai, Pengcheng [State Key Laboratory of Advanced Technology of Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)] [State Key Laboratory of Advanced Technology of Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

2012-11-15T23:59:59.000Z

119

IR spectroscopy of lattice vibrations and comparative analysis of the ZnTe/CdTe quantum-dot superlattices on the GaAs substrate and with the ZnTe and CdTe buffer layers  

SciTech Connect (OSTI)

A comparative analysis of multiperiod ZnTe/CdTe superlattices with the CdTe quantum dots grown by molecular beam epitaxy on the GaAs substrate with the ZnTe and CdTe buffer layers is carried out. The elastic-stress-induced shifts of eigenfrequencies of the modes of the CdTe- and ZnTe-like vibrations of materials forming similar superlattices but grown on different buffer ZnTe and CdTe layers are compared. The conditions of formation of quantum dots in the ZnTe/CdTe superlattices on the ZnTe and CdTe buffer layers differ radically.

Kozyrev, S. P. [Russian Academy of Sciences, Lebedev Institute of Physics (Russian Federation)], E-mail: skozyrev@sci.lebedev.ru

2009-07-15T23:59:59.000Z

120

Methanol synthesis from CO2 over Cu/ZnO catalysts prepared from various coprecipitated precursors  

Science Journals Connector (OSTI)

Various precursors of Cu/ZnO catalysts were prepared by coprecipitation methods. By varying the conditions of coprecipitation, precursors having different structures (aurichalcite, malachite, hydrozincite, or their mixture) were obtained at given Cu/Zn ratios, ranging from 30/70 to 70/30. In a wide range of the Cu/Zn ratios, the catalysts derived from the precursors containing aurichalcite exhibited high performance in the methanol synthesis from CO2.

Shin-ichiro Fujita; Yoshinori Kanamori; Agus Muhamad Satriyo; Nobutsune Takezawa

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
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121

Magnetism in undoped ZnS studied from density functional theory  

SciTech Connect (OSTI)

The magnetic property induced by the native defects in ZnS bulk, thin film, and quantum dots are investigated comprehensively based on density functional theory within the generalized gradient approximation + Hubbard U (GGA?+?U) approach. We find the origin of magnetism is closely related to the introduction of hole into ZnS systems. The relative localization of S-3p orbitals is another key to resulting in unpaired p-electron, due to Hund's rule. For almost all the ZnS systems under study, the magnetic moment arises from the S-dangling bonds generated by Zn vacancies. The charge-neutral Zn vacancy, Zn vacancy in 1? charge sate, and S vacancy in the 1+ charge sate produce a local magnetic moment of 2.0, 1.0, and 1.0??{sub B}, respectively. The Zn vacancy in the neutral and 1? charge sates are the important cause for the ferromagnetism in ZnS bulk, with a Curie temperature (T{sub C}) above room temperature. For ZnS thin film with clean (111) surfaces, the spins on each surface are ferromagnetically coupled but antiferromagnetically coupled between two surfaces, which is attributable to the internal electric field between the two polar (111) surfaces of the thin film. Only surface Zn vacancies can yield local magnetic moment for ZnS thin film and quantum dot, which is ascribed to the surface effect. Interactions between magnetic moments on S-3p states induced by hole-doping are responsible for the ferromagnetism observed experimentally in various ZnS samples.

Xiao, Wen-Zhi, E-mail: xiaowenzhi@hnu.edu.cn, E-mail: llwang@hun.edu.cn; Rong, Qing-Yan; Xiao, Gang [Department of Physics and Mathematics, Hunan Institute of Engineering, Xiangtan 411104 (China); Wang, Ling-ling, E-mail: xiaowenzhi@hnu.edu.cn, E-mail: llwang@hun.edu.cn [School of Physics and Microelectronics and Key Lab for Micro-Nano Physics and Technology of Hunan Province, Hunan University, Changsha 410082 (China); Meng, Bo [College of Physics and Electronic Engineering, Caili University, Kaili 556011 (China)

2014-06-07T23:59:59.000Z

122

Supporting information for: Na-doped p-type ZnO , Faxian Xiu2  

E-Print Network [OSTI]

S1 Supporting information for: Na-doped p-type ZnO microwires Wei Liu1* , Faxian Xiu2 , Ke Sun1 flow was switched to argon followed by cooling to room temperature. After the growth, high-density Zn distribution of the Na Doped ZnO microwire 1.3 EDX line scans spectra #12;S3 Figure S3 a) a typical TEM image

Yang, Zheng

123

Zinc Stannate (Zn2SnO4) Dye-Sensitized Solar Cells  

Science Journals Connector (OSTI)

Atomic-Scale Imaging of Cation Ordering in Inverse Spinel Zn2SnO4 Nanowires ... Atomic-Scale Imaging of Cation Ordering in Inverse Spinel Zn2SnO4 Nanowires ... By using high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) coupled with density functional theory (DFT) calculations, we demonstrate the atomic-level imaging of cation ordering in inverse spinel Zn2SnO4 nanowires. ...

Bing Tan; Elizabeth Toman; Yanguang Li; Yiying Wu

2007-03-20T23:59:59.000Z

124

Effect of Zn, Mn, and Fe on Cd accumulation in phytoplankton ...  

Science Journals Connector (OSTI)

We examined the effect of important controlling factors (free ion concentrations of Cd, Zn, and Mn and Fe limitation of growth rate) on Cd accumulation by an ...

125

Crystal growth behaviour in Au-ZnO nanocomposite under different annealing environments and photoswitchability  

SciTech Connect (OSTI)

The growth of gold nanoparticles and ZnO nanorods in atom beam co-sputtered Au-ZnO nanocomposite (NC) system by annealing at two different ambient conditions is demonstrated in this work. Annealing in a furnace at 600 Degree-Sign C (air environment) confirmed the formation of ZnO nanorods surrounded with Au nanoparticles. In-situ annealing inside a transmission electron microscope (TEM) led to the formation of gold nanocrystals with different polygonal shapes. TEM micrographs were obtained in real time at intermediate temperatures of 300 Degree-Sign C, 420 Degree-Sign C, and 600 Degree-Sign C under vacuum. The growth mechanisms of Au nanocrystals and ZnO nanorods are discussed in the framework of Au-Zn eutectic and Zn-melting temperatures in vacuum and air, respectively. Current-voltage responses of Au-ZnO NC nanorods in dark as well as under light illumination have been investigated and photoswitching in Au-ZnO NC system is reported. The photoswitching has been discussed in terms of Au-ZnO band-diagram.

Mishra, Y. K.; Adelung, R. [Functional Nanomaterials, Institute for Materials Science, University of Kiel, Kaiserstrasse 2, 24143 Kiel (Germany); Chakravadhanula, V. S. K.; Hrkac, V.; Kienle, L. [Synthesis and Real Structure, Institute for Materials Science, University of Kiel, Kaiserstrasse 2, 24143 Kiel (Germany); Jebril, S. [Multicomponent Materials, Institute for Materials Science, University of Kiel, Kaiserstrasse 2, 24143 Kiel (Germany); Agarwal, D. C.; Avasthi, D. K. [Inter University Accelerator Centre, Post Box 10502, New Delhi 110067 (India); Mohapatra, S. [University School of Basic and Applied Sciences, GGS Indraprastha University, Dwaraka, New Delhi 110075 (India)

2012-09-15T23:59:59.000Z

126

E-Print Network 3.0 - av zn cu Sample Search Results  

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

to promote efficiency of CuZnOAl2O3 catalysts, producing hydrogen with low carbon monoxide levels 13 Source: Mukasyan, Alexander - Department of Chemical and Biomolecular...

127

E-Print Network 3.0 - active site zn Sample Search Results  

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

carbonate and other Zn-containing compounds1 Graldine Sarret, Emiko Harada, Yong-Eui ... Source: Ecole Polytechnique, Centre de mathmatiques Collection: Mathematics 29...

128

Diluted ferromagnetic semiconductor Li(Zn,Mn)P with decoupled charge and spin doping  

Science Journals Connector (OSTI)

We report the discovery of a diluted magnetic semiconductor, Li(Zn,Mn)P, in which charge and spin are introduced independently via lithium off-stoichiometry and the isovalent substitution of Mn2+ for Zn2+, respectively. Isostructural to (Ga,Mn)As, Li(Zn,Mn)P was found to be a p-type ferromagnetic semiconductor with excess lithium providing charge doping. First-principles calculations indicate that excess Li is favored to partially occupy the Zn site, leading to hole doping. Ferromagnetism with Curie temperature up to 34 K is achieved while the system still shows semiconducting transport behavior.

Z. Deng; K. Zhao; B. Gu; W. Han; J. L. Zhu; X. C. Wang; X. Li; Q. Q. Liu; R. C. Yu; T. Goko; B. Frandsen; L. Liu; Jinsong Zhang; Yayu Wang; F. L. Ning; S. Maekawa; Y. J. Uemura; C. Q. Jin

2013-08-21T23:59:59.000Z

129

The Role of ZnO Nanoparticle Electrostatic Properties in Cancer Cell Cytotoxicity.  

E-Print Network [OSTI]

??ZnO nanoparticles have previously been shown to exhibit selective cytotoxicity against certain types of cancerous cells, suggesting their potential use in biomedical applications. In this… (more)

Louka, Panagiota

2012-01-01T23:59:59.000Z

130

Transport and magnetotransport study of Mg doped ZnO thin films  

SciTech Connect (OSTI)

We report negative magnetoresistance in pulsed laser deposited single phase ZnO and Mg{sub 0.268}Zn{sub 0.732}O films and attribute it to the presence of oxygen interstitials (O{sub i}) and zinc interstitials (Zn{sub i}) as observed in the X-ray photoelectron spectra of the films. An interesting feature of reduction of negative magnetoresistance at low temperatures and large fields in Mg{sub 0.268}Zn{sub 0.732}O film is observed and is explained by taking into account the localized scattering.

Agrawal, Arpana; Dar, Tanveer A., E-mail: tanveerphysics@gmail.com; Sen, Pratima [Laser Bhawan, School of Physics, Devi Ahilya University, Indore 452 017 (India); Phase, Deodatta M. [UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore 452017 (India)

2014-04-14T23:59:59.000Z

131

Optical and morphological properties of graphene sheets decorated with ZnO nanowires via polyol enhancement  

SciTech Connect (OSTI)

Graphene-ZnO nanocomposites have proven to be very useful materials for photovoltaic and sensor applications. Here, we report a facile, one-step in situ polymerization method for synthesis of graphene sheets randomly decorated with zinc oxide nanowires using ethylene glycol as solvent. We have used hydrothermal treatment for growth of ZnO nanowires. UV-visible spectra peak shifting around 288nm and 307 nm shows the presence of ZnO on graphene structure. Photoluminiscence spectra (PL) in 400nm-500nm region exhibits the luminescence quenching effect. Scanning electron microscopy (SEM) image confirms the growth of ZnO nanowires on graphene sheets.

Sharma, Vinay, E-mail: winn201@gmail.com; Rajaura, Rajveer Singh, E-mail: winn201@gmail.com [Centre for Converging Technologies, University of Rajasthan, Jaipur - 302004 (India); Sharma, Preetam K.; Srivastava, Subodh; Vijay, Y. K. [Department of Physics, Thin Film and Membrane Science Lab., University of Rajasthan, Jaipur - 302004 (India); Sharma, S. S. [Department of Physics, Govt. Women Engineering College, Ajmer- 305002 (India)

2014-04-24T23:59:59.000Z

132

Visualization of Peroxynitrite-Induced Changes of Labile Zn[superscript 2+] in the Endoplasmic Reticulum with Benzoresorufin-based Fluorescent Probes  

E-Print Network [OSTI]

Zn[superscript 2+] plays essential roles in biology, and the homeostasis of Zn[superscript 2+] is tightly regulated in all cells. Subcellular distribution and trafficking of labile Zn[superscript 2+], and its inter-relation ...

Lin, Wei

133

Impact of high-oxygen thermal annealing on the structural, optical and electrical properties of ZnO discs made from 20-nm ZnO nanoparticles  

Science Journals Connector (OSTI)

20-nm nanoparticles of zinc oxide (ZnO) were used to make high-density ZnO discs by uniaxial pressing at 4 ton/cm2 pressure and sintering at 1200 °C for 1 hour. High-oxygen thermal annealing performed on the ZnO discs was found to have a profound impact especially enhanced grain growth even at a low annealing temperature of only 400 °C. Moreover we observed a unique secondary growth of ZnO nanoparticles and growth of multilayer grains that have not been reported elsewhere. The strong solid state reaction during annealing was probably attributed to the high surface area of the 20-nm ZnO nanoparticles that promoted strong surface reaction even at low annealing temperatures. The ZnO discs have been found to contain a very high concentration of structural defects (oxygen vacancies and zinc/oxygen interstitials) that was indicated by the dominant and broad visible photoluminescence (PL) emission in the green band with peaks at (519 - 533) nm and it was found that this visible emission was greatly increased after annealing treatment especially at 800 °C. Annealing treatment also was found to improved the grain crystallinity as illustrated by the lowering of intrinsic compressive stress based on the XRD lattice constant and full-wave half-maximum (FWHM) data. The electrical properties of the ZnO discs were also greatly influenced by the annealing treatment especially a big drop in the breakdown voltage from 362 V (as-grown sample) to 170 V (800 °C sample). The resistivity also experienced a dramatic drop from 267 k?.cm (as-grown sample) to 74.6 k?.cm (800 °C sample). High-oxygen thermal annealing can be employed as a new technique in controlling the breakdown voltage of ZnO discs made from ZnO nanoparticles with improved structural properties.

Rabab Khalid Sendi; Shahrom Mahmud

2012-01-01T23:59:59.000Z

134

Mineral formation from aqueous solution. Part III. The stability of aurichalcite, (Zn,Cu)5(CO3)2(OH)6, and rosasite (Cu,Zn)2(CO3)(OH)2  

Science Journals Connector (OSTI)

The stabilities of rosasite, (Cu, Zn)2 (CO3)(OH)2, and aurichalcite, (Zn, Cu)5(CO3)2(OH)6, have been determined by solution experiments with computer calculations of aqueous species in equilibrium with the solid ...

Alwan K. Alwan; J. H. Thomas; Peter A. Williams

1980-01-01T23:59:59.000Z

135

Structural Phase Transition in AuZn Alloys  

SciTech Connect (OSTI)

AuxZn1-x alloys undergo a shape memory martensitic transformation whose temperature and nature (continuous or discontinuous) is strongly composition dependent. Neutron diffraction experiments were performed on single crystals of x=50 and 52 to explore the structural changes occurring at the transition temperature. A transverse modulation with wavevector q0=(1/3,1/3,0) develops below the transition temperature, with no observable change in lattice parameter. However, the Bragg peak width shows a broadening suggesting an unresolved rhombohedral distortion similar to what has been observed in NiTi-Fe alloys.

Winn,B.L.; Shapiro, S.M.; Lashley, J.C.; Opeil, C.; Ratcliff, W.

2009-05-03T23:59:59.000Z

136

Piezospectroscopic study of substitutional Ni in ZnO  

SciTech Connect (OSTI)

The effect of uniaxial stress on the electronic {sup 3}T{sub 1}(F)?{sup 3}T{sub 2}(F) transitions of Ni{sup 2+} in ZnO at 4216, 4240, and 4247 cm{sup ?1} is investigated by means of Fourier transform IR absorption spectroscopy. A stress Hamiltonian is constructed which accounts for the behavior of these transitions under uniaxial stress. It is shown that the split pattern and polarization properties of these IR absorption lines are consistent with a dynamic Jahn-Teller effect in the {sup 3}T{sub 2}(F) state of Ni.

Lavrov, E. V.; Herklotz, F. [Technische Universität Dresden, 01062 Dresden (Germany); Kutin, Y. S. [Kazan Federal University, Federal Center of Shared Facilities, 420008 Kazan (Russian Federation)

2014-02-21T23:59:59.000Z

137

Mechanism of the formation of precursors for the Cu/ZnO methanol synthesis catalysts by a coprecipitation method  

Science Journals Connector (OSTI)

Precursors of Cu/ZnO catalysts with various Cu/Zn molar ratios were prepared by a coprecipitation method. It was found that amorphous copper hydroxycarbonate and sodium zinc carbonate were intermediates for the f...

Shin-ichiro Fujita; Agus Muhamad Satriyo; Guo Cheng Shen…

1995-01-01T23:59:59.000Z

138

The effect of ZnO in methanol synthesis catalysts on Cu dispersion and the specific activity  

Science Journals Connector (OSTI)

The effect of ZnO in Cu/ZnO catalysts prepared by the coprecipitation method has been studied using measurements of the surface area of Cu, the specific activity for the methanol synthesis by hydrogenation of CO2

T. Fujitani; J. Nakamura

139

An ethanol vapor detection probe based on a ZnO nanorod coated optical fiber long period grating  

Science Journals Connector (OSTI)

A new ethanol vapor detection probe based on an optical fiber long period grating overlaid with a zinc oxide (ZnO) nanorods layer is presented. The ZnO nanorod layer was developed onto...

Konstantaki, Maria; Klini, Argyro; Anglos, Demetrios; Pissadakis, Stavros

2012-01-01T23:59:59.000Z

140

Growth mechanism and properties of ZnO nanorods synthesized by plasma-enhanced chemical vapor deposition  

E-Print Network [OSTI]

and ul- traviolet (UV) optoelectronic devices. ZnO can be found easily as n-type because of Zn. Trans- parent electrodes in optoelectronic devices should have high visible transmittance, low

Cao, Hui

Note: This page contains sample records for the topic "zn zurn ot" 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

Infrared spectroscopy of lattice vibrations in ZnTe/CdTe superlattices with quantum dots on the GaAs substrate with the ZnTe buffer layer  

SciTech Connect (OSTI)

The results of the analysis of the infrared lattice reflectance spectra of multiperiod ZnTe/CdTe superlattices with CdTe quantum dots are reported. The samples are grown by molecular beam epitaxy on the GaAs substrate with the ZnTe buffer layer. Due to the large number of periods of the superlattices, it is possible to observe CdTe-like vibration modes in the quantum dots, i.e., the dislocation-free stressed islands formed during the growth due to relaxation of elastic stresses between the ZnTe and CdTe layers are markedly different in their lattice parameters. From the frequency shifts of the CdTe- and ZnTe-like vibration modes with respect to the corresponding modes in the unstressed materials, it is possible to estimate the level of elastic stresses.

Kozyrev, S. P. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)], E-mail: skozyrev@sci.lebedev.ru

2009-03-15T23:59:59.000Z

142

Preparation of patterned graphene-ZnO hybrid nanoflower and nanorods on ITO surface  

SciTech Connect (OSTI)

Hybrid ZnO nanostructure with controlled morphology have been proved to enhance the physical and chemical properties of the material and used as photodiode and sensor. In this paper, hybrid graphene-ZnO nanoflower and nanorods have been successfully synthesized via a seed mediated method with micropatterned ZnO nanoseed treated with multilayer graphene (MLG) in a hydrothermal process. In typical process, the ZnO nanoseeds with and without resists were spin coated with a multilayer graphene prior to the growth process. The treated seed was then used to grow the ZnO nanostructures in the growth solution that contained equimolar (0.04 M) of zinc nitrate hexahydrate and hexamethylenetetramine. The growth process was carried out inside an autoclave at temperature 70 °C. The growth time was 4 h. It was proved that the MLG treatment on micropatterning substrate may induce new morphology formation of ZnO nanostructure. It is expected that the heteroepitaxy reaction occurred between the MLG and ZnO interface. This presence method can be used as an alternative approach to control the morphology of hybrid ZnO nanostructure growth.

Tan, Sin Tee; Umar, Marjoni Imamora Ali; Ginting, Riski Titian; Yahaya, Muhammad; Yap, Chi Chin [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Umar, Akrajas Ali; Salleh, Muhamad Mat; Majlis, Burhanuddin Yeop; Naumar, Fitri Yenni [Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

2013-11-27T23:59:59.000Z

143

Degradation of ZnO Window Layer for CIGS by Damp-Heat Exposure: Preprint  

SciTech Connect (OSTI)

This paper summarizes our work with more details and an emphasis on the DH-induced degradation of Al-doped ZnO and Zn1-xMgxO alloys. The other two TCOs, ITO and F:SnO2, are not included here.

Pern, F.J.; To, B.; DeHart, C.; Li, X.; Glick, S. H.; Noufi, R.

2008-08-01T23:59:59.000Z

144

Recycling ZnTe, CdTe, and Other Compound Semiconductors by Ambipolar Electrolysis  

E-Print Network [OSTI]

The electrochemical behavior of ZnTe and CdTe compound semiconductors dissolved in molten ZnCl[subscript 2] and equimolar CdCl[subscript 2]–KCl, respectively, was examined. In these melts dissolved Te is present as the ...

Osswald, Sebastian

145

ZnO Nanostructures Single-Crystal Hexagonal Disks and Rings of  

E-Print Network [OSTI]

ZnO Nanostructures Single-Crystal Hexagonal Disks and Rings of ZnO: Low-Temperature, Large of Chemistry University of New Orleans New Orleans, LA 70148 (USA) Fax: (+1)504-280-6860 E-mail: fli@uno.edu Dr to ellipsoids to disks, and even much more complex shapes, by adjusting experimental parameters,[33] we can

Wang, Zhong L.

146

Hybrid Electrochromic Fluorescent Poly(DNTD)/CdSe@ZnS Composite Films  

E-Print Network [OSTI]

Hybrid Electrochromic Fluorescent Poly(DNTD)/CdSe@ZnS Composite Films Huige Wei, Xingru Yan, Springdale, Arkansas 72764, United States ABSTRACT: Hybrid electrochromic poly(DNTD)/CdSe@ZnS quantum dots of an electrical current after the application of an appropriate electrode potential.15-17 The electrochromic

Guo, John Zhanhu

147

Tunable White-Light-Emitting Mn-Doped ZnSe Nanocrystals Vijay Kumar Sharma,  

E-Print Network [OSTI]

Tunable White-Light-Emitting Mn-Doped ZnSe Nanocrystals Vijay Kumar Sharma, Burak Guzelturk, Talha report white-light-emitting Mn-doped ZnSe nanocrystals (NCs) that are synthesized using modified orange emission (580 nm), allowed us to achieve excitation wavelength tailorable white-light generation

Demir, Hilmi Volkan

148

Photoluminescence-based measurements of the energy gap and diffusion length of Zn3P2  

E-Print Network [OSTI]

or liquid contacts,5 with p-Zn3P2/Mg Schottky diodes having exhibited 6% solar energy-conversion efficiencyPhotoluminescence-based measurements of the energy gap and diffusion length of Zn3P2 Gregory M ellipsometric measurements. Bulk minority carrier lifetimes of 20 ns were observed by time

Kimball, Gregory

149

Water adsorption on stepped ZnO surfaces from MD simulation David Raymand a  

E-Print Network [OSTI]

Water adsorption on stepped ZnO surfaces from MD simulation David Raymand a , Adri C.T. van Duin b Keywords: Zinc oxide Water Solid­gas interfaces Construction and use of effective interatomic interactions force-field for use in molecular dynamics simulations of the ZnO­ water system. The force

Goddard III, William A.

150

The possibility of improving the structural perfection of the new heterojunctions GaAs-(Ge2)1? x (ZnSe)x, Ge-(Ge2)1?x (ZnSe)x, GaP-(Ge2)1?x (ZnSe)x, and Si-(Ge2)1?x (ZnSe)x  

Science Journals Connector (OSTI)

Based on morphological investigations, as well as on a study of the scanning patterns and diffraction spectra of the heterostructures GaAs-(Ge2)1?x (ZnSe)x, Ge-(Ge2)1?x (ZnSe)x, Ga...

A. S. Saidov; É. A. Koshchanov; A. Sh. Razzakov

1998-01-01T23:59:59.000Z

151

Luminescence studies of localized gap states in colloidal ZnS nanocrystals D. Denzler, M. Olschewski, and K. Sattlera)  

E-Print Network [OSTI]

form are the II-VI semi- conductor compounds CdS and ZnS.14 ZnS has a band gap of 3.6 eV at 300 K spectra show a broad ultraviolet peak at around 420 nm. ZnS can be doped with Mn very easily, where few Mn atoms substitute for Zn atoms.18 This doping causes a visible orange luminescence at about 590 nm. Both

Sattler, Klaus

152

Direct kinetic correlation of carriers and ferromagnetism in Co2+ : ZnO  

SciTech Connect (OSTI)

We report the use of controlled introduction and removal of Zni to test the hypothesis that high-Curie-temperature ferromagnetism in cobalt-doped ZnO (Co2+:ZnO) is mediated by carriers. Using oriented epitaxial Co2+:ZnO films grown by chemical vapor deposition, kinetics measurements were used to correlate the oxidative quenching of ferromagnetism with the diffusion and oxidation of interstitial zinc. These results demonstrate controlled systematic variation of a key parameter involved in the ferromagnetism of Co2+:ZnO, namely interstitial zinc, and in the process unambiguously reveal this ferromagnetism to be dependent upon carriers. The distinction between defect-bound and free carriers in Co2+:ZnO is discussed

Kittilstved, Kevin R.; Schwartz, Dana A.; Tuan, Allan C.; Heald, Steve M.; Chambers, Scott A.; Gamelin, Daniel R.

2006-07-21T23:59:59.000Z

153

Synthesis and photocatalytic activity of ZnO/TiO2 nanoparticle  

Science Journals Connector (OSTI)

ZnO/TiO2 photocatalysts were synthesised via wet-chemical techniques. These can subsequently be used as efficient photocatalysts which can effectively degrade organic contaminants. Photocatalysts prepared with these techniques were characterised with X-ray diffraction (XRD), infrared (FTIR) spectrophotometer, UV-visible spectroscopy and photo luminescence. XRD confirmed the formation of ZnO/TiO2 nanoparticle. UV-visible spectroscopy showed significant difference in the optical absorption. Enhancement in optical absorption of ZnO/TiO2 indicated that it can be used as an efficient photocatalyst under UV irradiation. The photo-reduction activities of photocatalysts were evaluated using methyl orange as organic contaminant. The experiment demonstrated that the photo-degradation value of ZnO/TiO2 was significantly higher than that of ZnO.

R. Parimaladevi; K. Sumathi

2014-01-01T23:59:59.000Z

154

Atomic layer deposition of ZnO on ultralow-density nanoporous silica aerogel monoliths  

Science Journals Connector (OSTI)

We report on atomic layer deposition of an ? 2 -nm-thick ZnO layer on the inner surface of ultralow-density ( ? 0.5 % of the full density) nanoporoussilica aerogel monoliths with an extremely large effective aspect ratio of ? 10 5 (defined as the ratio of the monolith thickness to the average pore size). The resultant monoliths are formed by amorphous- SiO 2 core/wurtzite-ZnO shell nanoparticles which are randomly oriented and interconnected into an open-cell network with an apparent density of ? 3 % and a surface area of ? 10 0 m 2 g ? 1 . Secondary ion mass spectrometry and high-resolution transmission electron microscopy imaging reveal excellent uniformity and crystallinity of ZnO coating. Oxygen K -edge and Zn L 3 -edge soft x-ray absorption near-edge structure spectroscopy shows broadened O p - as well as Zn s - and d -projected densities of states in the conduction band.

S. O. Kucheyev; J. Biener; Y. M. Wang; T. F. Baumann; K. J. Wu; T. van Buuren; A. V. Hamza; J. H. Satcher Jr.; J. W. Elam; M. J. Pellin

2005-01-01T23:59:59.000Z

155

Nitrogen doping in pulsed laser deposited ZnO thin films using dense plasma focus  

Science Journals Connector (OSTI)

Pulsed laser deposition synthesized ZnO thin films, grown at 400 °C substrate temperature in different oxygen gas pressures, were irradiated with 6 shots of pulsed nitrogen ions obtained from 2.94 kJ dense plasma focus to achieve the nitrogen doping in ZnO. Structural, compositional and optical properties of as-deposited and nitrogen ion irradiated ZnO thin films were investigated to confirm the successful doping of nitrogen in irradiated samples. Spectral changes have been seen in the nitrogen irradiated ZnO thin film samples from the low temperature PL measurements. Free electron to acceptor emissions can be observed from the irradiated samples, which hints towards the successful nitrogen doping in films. Compositional analysis by X-ray photoelectron spectroscopy and corresponding shifts in binding energy core peaks of oxygen and nitrogen confirmed the successful use of plasma focus device as a novel source for nitrogen ion doping in ZnO thin films.

S. Karamat; R.S. Rawat; T.L. Tan; P. Lee; S.V. Springham; E. Ghareshabani; R. Chen; H.D. Sun

2011-01-01T23:59:59.000Z

156

Carboxylic-containing copolymer as template to prepare CdS, ZnS and doped nanoparticles  

Science Journals Connector (OSTI)

CdS, CdS:Mn, ZnS, ZnS:Mn and ZnS: ... Average particle size, 2.5 nm for CdS nanoparticles, is deduced from UV-vis absorption ... observation of TEM. Characteristic emissions of the doping ions can be observed and...

Lingdong Sun; Bo Xu; Xuefeng Fu; Mingwen Wang…

2001-02-01T23:59:59.000Z

157

Room temperature ferromagnetism in undoped and Fe doped ZnO nanorods: Microwave-assisted synthesis  

SciTech Connect (OSTI)

One-dimensional (1D) undoped and Fe doped ZnO nanorods of average length {approx}1 {mu}m and diameter {approx}50 nm have been obtained using a microwave-assisted synthesis. The magnetization (M) and coercivity (H{sub c}) value obtained for undoped ZnO nanorods at room temperature is {approx}5x10{sup -3} emu/g and {approx}150 Oe, respectively. The Fe doped ZnO samples show significant changes in M -H loop with increasing doping concentration. Both undoped and Fe doped ZnO nanorods exhibit a Curie transition temperature (T{sub c}) above 390 K. Electron spin resonance and Moessbauer spectra indicate the presence of ferric ions. The origin of ferromagnetism in undoped ZnO nanorods is attributed to localized electron spin moments resulting from surface defects/vacancies, where as in Fe doped samples is explained by F center exchange mechanism. -- Graphical abstract: Room temperature ferromagnetism has been reported in undoped and Fe doped ZnO nanorods of average length {approx}1 {mu}m and diameter {approx}50 nm. Display Omitted Research Highlights: {yields} Microwave-assisted synthesis of undoped and Fe doped ZnO nanorods. {yields} Observation of room temperature ferromagnetism in undoped and Fe doped ZnO nanorods. {yields} Transition temperature (T{sub c}) obtained in undoped and doped samples is above 390 K. {yields} In undoped ZnO origin of ferromagnetism is explained in terms of defects/vacancies. {yields} Ferromagnetism in Fe doped ZnO is explained by F-center exchange mechanism.

Limaye, Mukta V.; Singh, Shashi B. [DST unit on Nanoscience, Department of Physics, University of Pune, Pune 411007 (India); Das, Raja; Poddar, Pankaj [Physical and Materials Chemistry Division, National Chemical Laboratory, Pune 411 008 (India); Kulkarni, Sulabha K., E-mail: s.kulkarni@iiserpune.ac.i [DST unit on Nanoscience, Indian Institute of Science Education and Research, Pune 411021 (India)

2011-02-15T23:59:59.000Z

158

Catalyst-free growth of ZnO nanorods and their nanodevice applications  

Science Journals Connector (OSTI)

We review recent research activities on catalyst-free growth of ZnO nanorods and their nanodevice applications. Since ZnO nanomaterials add excellent chemical sensing characteristics due to their large surface-to-volume ratio to intrinsic ZnO properties including semiconducting and piezoelectric properties, a wide direct band gap energy, and a large exciton binding energy, they are expected to become one of the most ideal materials for future high performance nanodevice applications. There have been extensive research activities for synthesis of high quality ZnO nanomaterials for nanodevice applications. Among the numerous growth methods, we have focused on catalyst-free metal-organic chemical vapour deposition, since this enables us to grow vertically aligned ZnO nanorods on various substrates, including Si and glass, without any special substrate treatment. This catalyst-free approach yields high purity and single crystalline nanostructures, and does not require a subsequent catalyst removal process. Furthermore, we established techniques for fabricating ZnO nanorod heterostructures with composition modulations along either radial or axial direction, which can provide more opportunities for novel optical and electronic device development. Furthermore, we briefly describe our activities on ZnO nanorod device fabrication and evaluation, including field-effect transistors, biological molecule sensors, Schottky diodes, and light emitting devices. We also address the remaining scientific issues and technical challenges, required to fully understand the device characteristics and to realise integrated nanodevices.

Won Il Park; Dong-Wook Kim; Sug Woo Jung; Gyu-Chul Yi

2006-01-01T23:59:59.000Z

159

Identification of As-vacancy complexes in Zn-diffused GaAs  

SciTech Connect (OSTI)

We have used positron annihilation spectroscopy to study the introduction of point defects in Zn-diffused semi-insulating GaAs. The diffusion was performed by annealing the samples for 2 h at 950 Degree-Sign C. The samples were etched in steps of 7 {mu}m. Both Doppler broadening using slow positron beam and lifetime spectroscopy studies were performed after each etching step. Both techniques showed the existence of vacancy-type defects in a layer of about 45 {mu}m. Secondary ion mass spectroscopy measurements illustrated the presence of Zn at high level in the sample almost up to the same depth. Vacancy-like defects as well as shallow positron traps were observed by lifetime measurements. We distinguish two kinds of defects: As vacancy belongs to defect complex, bound to most likely one Zn atom incorporated on Ga sublattice, and negative-ion-type positron traps. Zn acceptors explained the observation of shallow traps. The effect of Zn was evidenced by probing GaAs samples annealed under similar conditions but without Zn treatment. A defect-free bulk lifetime value is detected in this sample. Moreover, our positron annihilation spectroscopy measurements demonstrate that Zn diffusion in GaAs system is governed by kick-out mechanism.

Elsayed, M. [Department of Physics, Martin Luther University Halle, 06099 Halle (Germany); Department of Physics, Faculty of Science, Minia University, 61519 Minia (Egypt); Krause-Rehberg, R. [Department of Physics, Martin Luther University Halle, 06099 Halle (Germany); Korff, B. [Bremen Center for Computational Materials Science, University Bremen, 28359 Bremen (Germany); Richter, S. [Fraunhofer Center for Silicon Photovoltaics CSP, 06120 Halle (Saale) (Germany); Leipner, H. S. [Center of Materials Science, Martin Luther University Halle, 06099 Halle (Germany)

2013-03-07T23:59:59.000Z

160

Water-gas shift reaction over Cu/ZnO and Cu/ZnO/Al2O3 catalysts prepared by homogeneous precipitation  

Science Journals Connector (OSTI)

Both binary Cu/ZnO and ternary Cu/ZnO/Al2O3 catalysts were prepared by homogeneous precipitation (hp) using urea hydrolysis. The structure and the activity for the water-gas shift reaction of these catalysts were studied compared with those prepared by coprecipitation (cp). The binary precursors contained hydroxycarbonates such as malachite and aurichalcite phases, whereas the ternary precursors were composed of hydrotalcite, malachite and aurichalcite phases depending on the metal composition. After thermal decomposition, both catalysts contained apparently CuO and ZnO as crystalline phase. No phase derived from Al was observed, since the amount of Al was small as 10 at.% in the ternary catalysts. After reduction pretreatment with hydrogen, the catalysts were tested for the shift reaction between 150 and 300 °C. The activity of hp-catalysts was higher than that of cp-catalysts; binary hp-Cu/ZnO showed higher activity than ternary hp-Cu/ZnO/Al2O3 catalysts none the less the surface area was larger for the latter than for the former. The activity apparently depended on the surface area of Cu metal formed on the surface of hp-catalysts and a good correlation was observed between the Cu metal particle size and the activation energy of the shift reaction. However, more precise evaluation of the activity based on turn-over frequency strongly suggested the formation of Cu+ species as the active sites at the boundary between Cu metal particles and ZnO particles. Even after the pre-reduction at the high temperature, 250 °C, hp-Cu/ZnO catalyst showed no significant deactivation as well as no detectable sintering of the Cu metal particles during 50 h of the reaction, indicating that the hp-preparation method afforded the Cu catalysts with high sustainability in the shift reaction.

Tetsuya Shishido; Manabu Yamamoto; Dalin Li; Yan Tian; Hiroyuki Morioka; Masahide Honda; Tsuneji Sano; Katsuomi Takehira

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" 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

Precise calibration of Mg concentration in Mg{sub x}Zn{sub 1-x}O thin films grown on ZnO substrates  

SciTech Connect (OSTI)

The growth techniques for Mg{sub x}Zn{sub 1-x}O thin films have advanced at a rapid pace in recent years, enabling the application of this material to a wide range of optical and electrical applications. In designing structures and optimizing device performances, it is crucial that the Mg content of the alloy be controllable and precisely determined. In this study, we have established laboratory-based methods to determine the Mg content of Mg{sub x}Zn{sub 1-x}O thin films grown on ZnO substrates, ranging from the solubility limit of x {approx} 0.4 to the dilute limit of x < 0.01. For the absolute determination of Mg content, Rutherford backscattering spectroscopy is used for the high Mg region above x = 0.14, while secondary ion mass spectroscopy is employed to quantify low Mg content. As a lab-based method to determine the Mg content, c-axis length is measured by x-ray diffraction and is well associated with Mg content. The interpolation enables the determination of Mg content to x = 0.023, where the peak from the ZnO substrate overlaps the Mg{sub x}Zn{sub 1-x}O peak in standard laboratory equipment, and thus limits quantitative determination. At dilute Mg contents below x = 0.023, the localized exciton peak energy of the Mg{sub x}Zn{sub 1-x}O films as measured by photoluminescence is found to show a linear Mg content dependence, which is well resolved from the free exciton peak of ZnO substrate down to x = 0.0043. Our results demonstrate that x-ray diffraction and photoluminescence in combination are appropriate methods to determine Mg content in a wide Mg range from x = 0.004 to 0.40 in a laboratory environment.

Kozuka, Y.; Falson, J.; Tsukazaki, A. [Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656 (Japan); Segawa, Y.; Makino, T. [Cross-Correlated Materials Research Group (CMRG) and Correlated Electron Research Group (CERG), RIKEN-Advanced Science Institute, Wako 351-0198 (Japan); Kawasaki, M. [Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656 (Japan); Cross-Correlated Materials Research Group (CMRG) and Correlated Electron Research Group (CERG), RIKEN-Advanced Science Institute, Wako 351-0198 (Japan)

2012-08-15T23:59:59.000Z

162

Photoelectrochemical performance of DSSC with monodisperse and polydisperse ZnO SPs  

SciTech Connect (OSTI)

Zinc oxide, ZnO, is one of oxide semiconductors being used in DSSC. ZnO is promising material for having fairly higher energy band gap and much higher bulk electron mobility than that of anatase TiO{sub 2}, the most widely used semiconductor for DSSC photoelectrode. This study introduces the synthesis of ZnO by precipitation method. The synthesis involves ZnAc dihydrate and diethylene glycol (DEG) for the chemicals. Various size of ZnO spherical particles (SPs) are obtained in polydisperse and monodisperse particles. Monolayer and bilayer DSSCs are fabricated in sandwich structure and sensitized with N719 dye for 3 and 5 hours. Monolayer DSSC using monodisperse particles (422 nm) is able to generate highest conversion efficiency of 0.569% (V{sub oc} = 541.3 mV, J{sub sc} = 1.92 mA/cm{sup 2}, and fill factor of 54.78%). Bilayer DSSC, i.e. combined 422 - 185 nm ZnO layer, can optimize the photocurrent action spectra in UV regime leading to high conversion efficiency of 0.568 (V{sub oc} = 568.2 mV, J{sub sc} = 2.22 mA/cm{sup 2}, and fill factor of 47.25%). The longer sensitizing time does not always produce better conversion efficiency since it can induce the dissolution of Zn atoms and formation of Zn{sup 2+} - dye resisting the electron transport from dye to ZnO photoelectrode.

Wahyuono, Ruri Agung, E-mail: r-agung-w@ep.its.ac.id; Risanti, Doty D., E-mail: r-agung-w@ep.its.ac.id [Department of Engineering Physics, Institut Teknologi Sepuluh Nopember (Indonesia); Shirosaki, Tomohiro; Nagaoka, Shoji [Kumamoto Industrial Research Institute (Japan); Takafuji, Makoto; Ihara, Hirotaka [Department of Applied Chemistry and Biochemistry, Kumamoto University (Japan)

2014-02-24T23:59:59.000Z

163

Z(N) model of grain-boundary wetting  

Science Journals Connector (OSTI)

Even though van der Waals forces should prevent the wetting of a grain boundary by a liquid at the melting temperature, experiment and simulations indicate an instability in grain-boundary structure in the vicinity of this temperature. We study the structure of analogous boundaries in a Z(N) model in which a region of solid with a given orientation is replaced by a spin in that orientation. Different interfacial behaviors are found for different regions of a model parameter which is related to N. For the value appropriate to grain boundaries, our model suggests that boundaries of a sufficiently large angle should be unstable, not to the intrusion of a layer of liquid, however, but to the intrusion of solid of intermediate orientation. Such an intrusion can occur below the melting temperature.

M. Schick and Wei-Heng Shih

1987-04-01T23:59:59.000Z

164

Inverse spin Hall effect induced by spin pumping into semiconducting ZnO  

SciTech Connect (OSTI)

The inverse spin Hall effect (ISHE) of n-type semiconductor ZnO thin films with weak spin-orbit coupling has been observed by utilizing the spin pumping method. In the ferromagnetic resonance condition, the spin pumping driven by the dynamical exchange interaction of a permalloy film injects a pure spin current into the adjacent ZnO layer. This spin current gives rise to a DC voltage through the ISHE in the ZnO layer, and the DC voltage is proportional to the microwave excitation power. The effect is sizeable even when the spin backflow is considered.

Lee, Jung-Chuan [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Huang, Leng-Wei [Graduate Institute of Applied Physics, National Chengchi University, Taipei 11605, Taiwan (China); Hung, Dung-Shing, E-mail: dshung@mail.mcu.edu.tw [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Department of Information and Telecommunications Engineering, Ming Chuan University, Taipei 111, Taiwan (China); Chiang, Tung-Han [Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan (China); Huang, J. C. A., E-mail: jcahuang@mail.ncku.edu.tw [Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan (China); Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Liang, Jun-Zhi [Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Department of Physics, Fu Jen Catholic University, Taipei 242, Taiwan (China); Lee, Shang-Fan, E-mail: leesf@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Graduate Institute of Applied Physics, National Chengchi University, Taipei 11605, Taiwan (China)

2014-02-03T23:59:59.000Z

165

Nonlinear optical properties of ZnO/poly (vinyl alcohol) nanocomposite films  

SciTech Connect (OSTI)

Extensive studies have already been reported on the optical characteristics of ZnO/polymer nanocomposite films, using a variety of polymers including transparent polymers such as polystyrene, polymethyl methacrylate etc and many interesting results have been established regarding the non linear optical characteristics of these systems. Poly (vinyl alcohol)(PVA) is a water soluble polymer. Though the structural and optical studies of ZnO/PVA nanocomposite films have already been investigated, there are no detailed reports on the nonlinear optical characteristics of ZnO/PVA nanocomposite films, irrespective of the fact that these nanocomposite films can be synthesized using quite easy and cost effective methods. The present work is an attempt to study in detail the nonlinear optical behaviour of ZnO/PVA nanocomposite films using Z-scan technique. Highly transparent ZnO/PVA nanocomposite films were prepared from the ZnO incorporated PVA solution in water using spin coating technique. The ZnO nanoparticles were synthesized by the simple chemical route at room temperature. High-resolution transmission electron microscopy studies show that the ZnO nanoparticles are of size around 10 nm. The ZnO/PVA nanocomposite films were structurally characterized by X-ray diffraction technique, from which the presence of both PVA and ZnO in the nanocomposite was established. The optical absorptive nonlinearity in the nanocomposite films was investigated using open aperture Z-scan technique. The results indicate optical limiting type nonlinearity in the films due to two photon absorption in ZnO with efficiency more than 50%. These films also show a self defocusing type negative nonlinear refraction in closed aperture Z-scan experiment. The present studies indicate that, highly transparent and homogeneous films of ZnO/PVA nanocomposite can be obtained on glass substrates using simple methods, in a highly cost effective way, since PVA is water soluble. These nanocomposite films offer prospects of application as efficient optical limiters to protect light sensitive devices from the possible damage on exposure to high intensity radiation.

Jeeju, P. P., E-mail: jeejupp@gmail.com [Department of Physics, S N M College, Maliankara, Ernakulam, Kerala (India); Jayalekshmi, S., E-mail: jayalekshmi@cusat.ac.in [Division for Research in Advanced Materials, Department of Physics, Cochin University of Science and Technology, Kochi 682 022 (India); Chandrasekharan, K. [Department of Physics, National Institute of Technology, Calicut, Kerala (India)

2014-01-28T23:59:59.000Z

166

Evaluation of Melt-Grown, ZnO Single Crystals for Use as Alpha-Particle Detectors  

SciTech Connect (OSTI)

As part of an ongoing investigation of the scintillation properties of zinc-oxide-based scintillators, several melt-grown, ZnO single crystals have been characterized using -particle excitation, infrared reflectance, and room temperature photoluminescence. The crystals, grown by Cermet, Inc. using a pressurized melt growth process, were doped with Group 1 elements (Li), Group 2 elements (Mg), Group 3 elements (Ga, In) and Lanthanides (Gd, Er, Tm). The goals of these studies are to better understand the scintillation mechanisms associated with various members of the ZnO scintillator family and to then use this knowledge to improve the radiation detection capabilities of ZnO-based scintillators. One application for which ZnO is particularly well suited as a scintillator is as the associated particle detector in a deuterium-tritium (D-T) neutron generator. Application requirements include the exclusion of organic materials, outstanding timing resolution, and high radiation resistance. ZnO(Ga) and ZnO(In) have demonstrated fast (sub-nanosecond) decay times with relatively low light yields, and ZnO(Ga) has been used in a powder form as the associated particle detector for a D-T neutron generator. Four promising candidate materials, ZnO, ZnO:Ga, ZnO:In,Li, and ZnO:Er,Li, were identified in this study. These four samples demonstrated sub-nanosecond decay times and alpha particle excited luminescence comparable to BC-400 fast plastic scintillator. The ZnO:Mg,Ga, ZnO:Gd, and ZnO:Li samples demonstrated appreciable slow (microsecond) decay components that would be incompatible with high-counting-rate applications.

Neal, John S [ORNL; Giles, N. C. [West Virginia University; Yang, Xiaocheng [West Virginia University; Wall, R. Andrew [Wake Forest University, Winston-Salem, NC; Ucer, Burak [Wake Forest University, Winston-Salem, NC; Williams, Richard T. [Wake Forest University, Winston-Salem, NC; Wisniewski, Dariusz J [ORNL; Boatner, Lynn A [ORNL; Rengarajan, Varatharajan [ORNL; Nause, Jeff E [ORNL; Nemeth, Bell [Cermet, Inc., Atlanta

2008-01-01T23:59:59.000Z

167

New Materials of Co-Doped ZnO for LEDs and Thin Films Solar Cells  

Science Journals Connector (OSTI)

Zr-Al co-doped ZnO were prepared by DC magnetron sputtering on glass substrates. Microstructure, optoelectrical properties of the films were investigated. The films with resistivity...

Yuan, Yuzhen; Wang, Hui

168

Efficient light emitting devices utilizing CdSe(ZnS) quantum dots in organic host matrices  

E-Print Network [OSTI]

We demonstrate efficient electroluminescence from thin film structures containing core-shell CdSe(ZnS) quantum dots dispersed in molecular organic host materials. In the most efficient devices, excitons are created on the ...

Coe-Sullivan, Seth (Seth Alexander)

2002-01-01T23:59:59.000Z

169

Mg-Doped ZnO Nanoparticles for Efficient Sunlight-Driven Photocatalysis  

Science Journals Connector (OSTI)

Magnesium-doped ZnO (ZMO) nanoparticles were synthesized through an oxalate coprecipitation method. Crystallization of ZMO upon thermal decomposition of the oxalate precursors was investigated using differential scanning calorimetry (DSC) and X-ray ...

Vinodkumar Etacheri; Roshith Roshan; Vishwanathan Kumar

2012-05-03T23:59:59.000Z

170

Zn3P2 and Cu2O substrates for solar energy conversion.  

E-Print Network [OSTI]

??Zinc phosphide (Zn3P2) and cuprous oxide (Cu2O) are promising and earth-abundant alternatives to traditional thin film photovoltaics materials such as CIGS, CdTe, and a-Si. We… (more)

Kimball, Gregory Michael

2012-01-01T23:59:59.000Z

171

Graphene mode-locked Cr:ZnS laser with 41 fs pulse duration  

Science Journals Connector (OSTI)

We report the ultrashort-pulse Cr:ZnS laser mode-locked by graphene-based saturable absorber mirror. Using the combination of bulk material and a chirped mirror, we demonstrate the...

Tolstik, Nikolai; Sorokin, Evgeni; Sorokina, Irina T

2014-01-01T23:59:59.000Z

172

Synthesis of ZnO decorated graphene nanocomposite for enhanced photocatalytic properties  

SciTech Connect (OSTI)

Zinc oxide/Graphene (GZ) composites with different concentrations of ZnO were successfully synthesized through simple chemical precipitation method. The X-ray diffraction pattern and the micro-Raman spectroscopic technique revealed the formation of GZ composite, and the energy dispersive X-ray spectrometry analysis showed the purity of the prepared samples. The ZnO nanoparticles decorated graphene sheets were clearly visible in the field emission scanning electron micrograph. Raman mapping was employed to analyze the homogeneity of the prepared samples. The diffuse-reflectance spectra clearly indicated that the formation of GZ composites promoted the absorption in the visible region also. The photocatalytic activity of ZnO and GZ composites was studied by the photodegradation of Methylene blue dye. The results revealed that the GZ composites exhibited a higher photocatalytic activity than pristine ZnO. Hence, we proposed a simple wet chemical method to synthesize GZ composite and its application on photocatalysis was demonstrated.

Gayathri, S.; Jayabal, P. [Department of Laser Studies, School of Physics, Madurai Kamaraj University, Madurai 625021, Tamilnadu (India); Kottaisamy, M. [Department of Chemistry, Thiagarajar College of Engineering, Madurai 625014, Tamilnadu (India); Ramakrishnan, V., E-mail: vr.optics1@gmail.com [Department of Laser Studies, School of Physics, Madurai Kamaraj University, Madurai 625021, Tamilnadu (India); Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram 695016, Kerala (India)

2014-05-07T23:59:59.000Z

173

Polymeric precursor derived nanocrystalline ZnO thin films using EDTA as chelating agent  

E-Print Network [OSTI]

properties, ZnO has plausible electro-optical applications, such as, solar cells [1, 2], light- emitting diodes [3, 4], UV lasers [5], thin film transistors [6,7], and UV photodetectors [8]. Besides

Mohanty, Saraju P.

174

Effects of La–Zn substitution on microstructure and magnetic properties of strontium ferrite nanofibers  

Science Journals Connector (OSTI)

Sr1?x La x Zn x Fe12?x O19/poly(vinylpyrrolidone) (PVP) (0.0?x?0.5) precursor nanofibers were prepared by the so...

Xiangqian Shen; Mingquan Liu; Fuzhan Song; Yongwei Zhu

2011-07-01T23:59:59.000Z

175

PROCESS DEVELOPMENT FOR ZnO-BASED DEVICES KELLY PUI SZE IP  

E-Print Network [OSTI]

PROCESS DEVELOPMENT FOR ZnO-BASED DEVICES By KELLY PUI SZE IP A DISSERTATION PRESENTED OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2005 #12;Copyright 2005 by Kelly Pui Sze Ip #12;To my family

Pearton, Stephen J.

176

Incorporation of V, Zn and Pb into the crystalline phases of Portland clinker  

SciTech Connect (OSTI)

Burning of industrial wastes in cement kilns has an increasing environmental importance, brought about by the incorporation of potentially hazardous elements into clinker crystalline phases and partial substitution of primary fuel and raw materials. In this study, experimental clinkers were synthesized, with the addition of V, Zn and Pb to a standard raw meal, from which a control clinker was obtained for comparison. The three metals were chosen as they are present in the alternative fuel petcoke (V) and in industrial wastes (Zn, Pb) commonly burned in cement kilns. Electron microprobe and scanning electron microscope analysis revealed the preferential partition of these metals among the clinker crystalline phases. It was observed that V has shown a preferential partition towards C{sub 2}S. Zn appears in higher amounts in periclase, and C{sub 3}S has higher Zn contents than C{sub 2}S. Pb concentrates in minute spherules and partitions toward C{sub 3}S in small amounts.

Andrade, F.R.D.; Maringolo, V.; Kihara, Y

2003-01-01T23:59:59.000Z

177

Synthesis and Luminescence of ZnMgS:Mn2+ Nanoparticles. | EMSL  

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

of green light emitting diodes. Citation: Zhang J, F Su, W Chen, R Sammynaiken, SL Westcott, DE McCready, G Li, and AG Joly.2005."Synthesis and Luminescence of ZnMgS:Mn2+...

178

Development of ZnO Based Light Emitting Diodes and Laser Diodes.  

E-Print Network [OSTI]

??ZnO based homojunction light emitting diode, double heterojunction light emitting diode, embedded heterojunction random laser diode and Fabry-Perot nanowire laser devices were fabricated and characterized.… (more)

Kong, Jieying

2012-01-01T23:59:59.000Z

179

Si, CdTe and CdZnTe radiation detectors for imaging applications.  

E-Print Network [OSTI]

??The structure and operation of CdTe, CdZnTe and Si pixel detectors based on crystalline semiconductors, bump bonding and CMOS technology and developed mainly at Oy… (more)

Schulman, Tom

2006-01-01T23:59:59.000Z

180

Photo-driven autonomous hydrogen generation system based on hierarchically shelled ZnO nanostructures  

SciTech Connect (OSTI)

A quantum dot semiconductor sensitized hierarchically shelled one-dimensional ZnO nanostructure has been applied as a quasi-artificial leaf for hydrogen generation. The optimized ZnO nanostructure consists of one dimensional nanowire as a core and two-dimensional nanosheet on the nanowire surface. Furthermore, the quantum dot semiconductors deposited on the ZnO nanostructures provide visible light harvesting properties. To realize the artificial leaf, we applied the ZnO based nanostructure as a photoelectrode with non-wired Z-scheme system. The demonstrated un-assisted photoelectrochemical system showed the hydrogen generation properties under 1 sun condition irradiation. In addition, the quantum dot modified photoelectrode showed 2 mA/cm{sup 2} current density at the un-assisted condition.

Kim, Heejin; Yong, Kijung [Surface Chemistry Laboratory of Electronic Materials, Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of)] [Surface Chemistry Laboratory of Electronic Materials, Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of)

2013-11-25T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" 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.


181

ZnO nanorefrigerant in R152a refrigeration system for energy conservation and green environment  

Science Journals Connector (OSTI)

In this paper the reliability and performance of a vapour compression refrigeration system with ZnO nanoparticles in the working fluid was investigated experimentally. Nanorefrigerant was synthesized on the basis...

D. Sendil Kumar; R. Elansezhian

2014-03-01T23:59:59.000Z

182

Luminescence and electrical properties of single ZnO/MgO core/shell nanowires  

SciTech Connect (OSTI)

To neutralise the influence of the surface of ZnO nanowires for photonics and optoelectronic applications, we have covered them with insulating MgO film and individually contacted them for electrical characterisation. We show that such a metal-insulator-semiconductor-type nanodevice exhibits a high diode ideality factor of 3.4 below 1?V. MgO shell passivates ZnO surface states and provides confining barriers to electrons and holes within the ZnO core, favouring excitonic ultraviolet radiative recombination, while suppressing defect-related luminescence in the visible and improving electrical conductivity. The results indicate the potential use of ZnO/MgO nanowires as a convenient building block for nano-optoelectronic devices.

Grinblat, Gustavo; Comedi, David [Laboratorio de Física del Sólido, Dep. de Física, FACET, Universidad Nacional de Tucumán, Tucumán, and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina)] [Laboratorio de Física del Sólido, Dep. de Física, FACET, Universidad Nacional de Tucumán, Tucumán, and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Bern, Francis; Barzola-Quiquia, José; Esquinazi, Pablo, E-mail: esquin@physik.uni-leipzig.de [Division of Superconductivity and Magnetism, Institute for Experimental Physics II, University of Leipzig, D-04103 Leipzig (Germany)] [Division of Superconductivity and Magnetism, Institute for Experimental Physics II, University of Leipzig, D-04103 Leipzig (Germany); Tirado, Mónica [Laboratorio de Nanomateriales y Propiedades Dieléctricas, Dep. de Física, FACET, Universidad Nacional de Tucumán, Tucumán (Argentina)] [Laboratorio de Nanomateriales y Propiedades Dieléctricas, Dep. de Física, FACET, Universidad Nacional de Tucumán, Tucumán (Argentina)

2014-03-10T23:59:59.000Z

183

Band offsets for mismatched interfaces: The special case of ZnO...  

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

Abstract: High-quality planar interfaces between ZnO and CdTe would be useful in optoelectronic applications, but appear difficult to achieve given the rather different crystal...

184

Metalorganic chemical vapor deposition of carbon-free ZnO using...  

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

Metalorganic chemical vapor deposition of carbon-free ZnO using the bis(2,2,6,6-tetramethyl-3,5-heptanedionato)zinc precursor. Metalorganic chemical vapor deposition of carbon-free...

185

Optimizing the Power Output of a ZnO Photocell by Piezopotential  

E-Print Network [OSTI]

properties of ZnO make it an ideal choice for applications in nanogenerators10 13 for converting mechanical together with the thermionic emission theory has explained the four kinds of relationships observed

Wang, Zhong L.

186

Donor bound excitons in ZnSe nanoresonators - Applications in quantum information science  

SciTech Connect (OSTI)

Here we summarize the advantages of excitons bound to isolated fluorine donor in ZnSe/ZnMgSe quantum well nano-structures. Devices based on these semiconductors, are particularly suited to implement concepts of the optical manipulation of quantum states in solid-state material. The fluorine donor in ZnSe provides a physical qubit with potential advantages over previously researched qubits. In this context we show several initial demonstrations of devices, such as a low-threshold microdisk laser and an indistinguishable single photon source. Additionally we demonstrate the realization of a controllable three-level-system qubit consisting of a single Fluorine donor in a ZnSe nano-pillar, which provides an optical accessible single electon spin qubit.

Pawlis, A. [Department of Physics, University of Paderborn, Warburger Str. 100, 33098 Paderborn, Germany and Edward L. Ginzton Laboratory, Stanford University, Stanford, California 94305-4088 (United States); Lischka, K. [Department of Physics, University of Paderborn, Warburger Str. 100, 33098 Paderborn (Germany); Sanaka, K.; Yamamoto, Y. [Edward L. Ginzton Laboratory, Stanford University, Stanford, California 94305-4088, USA and National Institute of Informatics, 2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo 101-8430 (Japan); Sleiter, D. [Edward L. Ginzton Laboratory, Stanford University, Stanford, California 94305-4088 (United States)

2014-05-15T23:59:59.000Z

187

Determination of the spontaneous polarization of wurtzite (Mg,Zn)O  

SciTech Connect (OSTI)

We report on the experimental determination of the spontaneous polarization of wurtzite-(Mg,Zn)O by examination of the recombination dynamics of polar ZnO/(Mg,Zn)O quantum wells (QWs). The thickness-dependent decay time of the unscreened single-exciton states inside the QWs was modeled by a self-consistent solution of Schrödinger- and Poisson-equation to deduce the total polarization across the QW for different Mg-contents inside the barriers. By the separation of the piezoelectric components of the polarization, a linear increase in spontaneous polarization with increasing Mg-content x of P/x?=?(0.151?±?0.015) C/m{sup 2} was determined for Mg{sub x} Zn{sub 1?x} O.

Stölzel, Marko, E-mail: stoelzel@physik.uni-leipzig.de; Müller, Alexander; Benndorf, Gabriele; Lorenz, Michael; Grundmann, Marius [Institut für Experimentelle Physik II, Universität Leipzig, Linnéstr. 5, 04103 Leipzig (Germany); Patzig, Christian; Höche, Thomas [Fraunhofer Institute for Mechanics of Materials IWM, Center for Applied Microstructure Diagnostics, Walter-Huelse-Straße 1, 06120 Halle (Saale) (Germany)

2014-05-12T23:59:59.000Z

188

Nitrogen-Doped ZnO Nanowire Arrays for Photoelectrochemical Water Splitting  

E-Print Network [OSTI]

fuel of the future.1-3 However, currently the main production of hydrogen comes from steam reforming in ammonia to incorporate N as a dopant. Nanowires with a controlled N concentration (atomic ratio of N to Zn

Li, Yat

189

Electronic structure and optical properties of ZnSe from first-principles calculations  

Science Journals Connector (OSTI)

We have performed the first-principles calculations in the framework of density functional theory to determine the electronic structure and optical properties of zinc-blende ZnSe.

Yu, Zhiqiang; Xu, Zhimou; Wu, Xinghui; Ma, Zhichao

190

Analysis of biodegradation performance of furfural and 5-hydroxymethylfurfural by Amorphotheca resinae ZN1  

Science Journals Connector (OSTI)

Furfural and 5-hydroxymethylfurfural (HMF) are the degradation products of...Amorphotheca resinae ZN1 had demonstrated its excellent capacity on degrading lignocellulose derived inhibitors and helped the fermenta...

Hong Ran; Jian Zhang; Qiuqiang Gao; Zhanglin Lin; Jie Bao

2014-04-01T23:59:59.000Z

191

ZnO nano-rods synthesized by nano-particle-assisted pulsed-laser deposition  

Science Journals Connector (OSTI)

We succeeded in synthesizing ZnO nanorods by nanoparticle assisted pulsed-laser deposition (PLD) without using any catalyst where nanoparticles formed by condensation of ablated particles play an important rol...

T. Okada; B.H. Agung; Y. Nakata

2004-09-01T23:59:59.000Z

192

Photoionization spectra of silver dimers adsorbed on the surface of a ZnS single crystal  

Science Journals Connector (OSTI)

We use the photostimulated luminescence flash method to measure photoionization spectra of Ag2 clusters adsorbed on the surface of a ZnS single crystal. Adsorbed dimers of silver are prepared by treatment of the ...

O. V. Ovchinnikov; D. A. Minakov; M. S. Smirnov…

2007-07-01T23:59:59.000Z

193

Design of Shallow P-Type Dopants in ZnO: Preprint  

SciTech Connect (OSTI)

This paper describes approaches to lower the acceptor ionization energy in ZnO by codoping acceptors with donor or isovalent atoms and proposes a universal approach to overcome the doping polarity problem for wide-band-gap semiconductors.

Wei, S.-H.; Li, J.; Yan, Y.

2008-05-01T23:59:59.000Z

194

ELEMENTARY DIFFUSION PROCESSES IN AL-CU-ZN ALLOYS: AN AB INITIO STUDY  

E-Print Network [OSTI]

ELEMENTARY DIFFUSION PROCESSES IN AL-CU-ZN ALLOYS: AN AB INITIO STUDY S. GRABOWSKI AND P. ENTEL of alloys such as mechanical strength and toughness, creep and corrosion resistance are essentially

Entel, P.

195

Use of a capillary X-ray focused beam to investigate the chemical composition of CdZnTe wafers with high resolution CdZnTe detectors  

SciTech Connect (OSTI)

The control of the concentration of Zn and its fluctuation in the high pressure Bridgman grown CdZnTe crystals is part of the characterization work on the ternary grown ingots grown in house. In order to reach both high sensitivity and high position resolution, the authors have developed a new system consisting of a X-ray generator, coupled to a focusing X-ray capillary, delivering intense beams in the micron scale, since the intensity gain is around a factor of 100 compared to conventional methods. The characteristic X-rays are measured through a high resolution CdZnTe detector (225 eV at 5.9 keV FWHM) cooled by a Peltier system. The results of the investigations on different kinds of crystals will be discussed.

Fougeres, P. [EURORAD, Strasbourg (France); Burggraf, Ch.; Burggraf, Chr.; Koebel, J.M.; Regal, R.; Hage-Ali, M.; Krauth, A.; Siffert, P. [CNRS, Strasbourg (France). Lab. PHASE; Koenig, C. [Univ. Louis Pasteur, Schiltigheim (France)

1998-12-31T23:59:59.000Z

196

Graphene Cathode-Based ZnO Nanowire Hybrid Solar Cells  

Science Journals Connector (OSTI)

Graphene Cathode-Based ZnO Nanowire Hybrid Solar Cells ... On the basis of this structure, we then demonstrate graphene cathode-based hybrid solar cells using two different photoactive materials, PbS quantum dots and the conjugated polymer P3HT, with AM 1.5G power conversion efficiencies of 4.2% and 0.5%, respectively, approaching the performance of ITO-based devices with similar architectures. ... graphene; ZnO nanowires; solar cells; ITO ...

Hyesung Park; Sehoon Chang; Joel Jean; Jayce J. Cheng; Paulo T. Araujo; Mingsheng Wang; Moungi G. Bawendi; Mildred S. Dresselhaus; Vladimir Bulovi?; Jing Kong; Silvija Grade?ak

2012-12-03T23:59:59.000Z

197

Electron transfer and capture dynamics in ZnSe quantum wells grown on GaAs  

SciTech Connect (OSTI)

We investigate the transfer and capture dynamics of electrons in phase coherent photorefractive ZnSe quantum wells grown on GaAs using degenerate three-beam four-wave-mixing. The measurements reveal electron capture times by the quantum well in the order of several tens of picoseconds and a transit time of approximately 5 picoseconds from the GaAs substrate through the ZnMgSe barrier.

Dongol, A.; Wagner, H. P. [Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221 (United States)

2013-12-04T23:59:59.000Z

198

Morphological and electrochemical characterization of electrodeposited Zn–Ag nanoparticle composite coatings  

SciTech Connect (OSTI)

Silver nanoparticles with an average size of 23 nm were chemically synthesized and used to fabricate Zn–Ag composite coatings. The Zn–Ag composite coatings were generated by electrodeposition method using a simple sulfate plating bath dispersed with 0.5, 1 and 1.5 g/l of Ag nanoparticles. Scanning electron microscopy, X-ray diffraction and texture co-efficient calculations revealed that Ag nanoparticles appreciably influenced the morphology, micro-structure and texture of the deposit. It was also noticed that agglomerates of Ag nanoparticles, in the case of high bath load conditions, produced defects and dislocations on the deposit surface. Ag nanoparticles altered the corrosion resistance property of Zn–Ag composite coatings as observed from Tafel polarization, electrochemical impedance analysis and an immersion test. Reduction in corrosion rate with increased charge transfer resistance was observed for Zn–Ag composite coatings when compared to a pure Zn coating. However, the particle concentration in the plating bath and their agglomeration state directly influenced the surface morphology and the subsequent corrosion behavior of the deposits. - Highlights: • Synthesis of Ag nanoparticles with an average size of 23 nm • Fabrication of Zn/nano Ag composite coating on mild steel • Composite coatings showed better corrosion resistance. • Optimization of particle concentration is necessary.

Punith Kumar, M.K.; Srivastava, Chandan, E-mail: csrivastava@materials.iisc.ernet.in

2013-11-15T23:59:59.000Z

199

As-doped p-type ZnO produced by an evaporation/sputtering process  

SciTech Connect (OSTI)

Strongly p-type ZnO is produced by the following sequence of steps: (1) evaporation of Zn{sub 3}As{sub 2} on a fused-quartz substrate at 350 deg. C; and (2) sputtering of ZnO with substrate held at 450 deg. C. The electrical characteristics include: resistivity of 0.4 {omega} cm, a mobility of 4 cm{sup 2}/V s, and a hole concentration of about 4x10{sup 18} cm{sup -3}. This resistivity is among the best (lowest) ever reported for p-type ZnO. Secondary-ion mass spectroscopic analysis gives an average As concentration about 5x10{sup 19} cm{sup -3}, and a simple one-band fit of the temperature-dependent mobility curve yields an acceptor concentration of about 9x10{sup 19} cm{sup -3}. This is strong evidence that the p-type dopant involves As, although it is not clear whether the acceptor is simply As{sub O} or the recently suggested As{sub Zn}-2V{sub Zn}.

Look, D.C.; Renlund, G.M.; Burgener, R.H. II; Sizelove, J.R. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 and Semiconductor Research Center, Wright State University, Dayton, Ohio 45435 (United States); ON International, Inc., 418 West Winchester Street, Salt Lake City, Utah 84107 (United States); Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States)

2004-11-29T23:59:59.000Z

200

Magnetic properties and loss separation in iron-silicone-MnZn ferrite soft magnetic composites  

SciTech Connect (OSTI)

This paper investigates the magnetic and structural properties of iron-based soft magnetic composites coated with silicone-MnZn ferrite hybrid. The organic silicone resin was added to improve the flexibility of the insulated iron powder and causes better adhesion between particles to increase the mechanical properties. Scanning electron microscopy and distribution maps show that the iron particle surface is covered with a thin layer of silicone-MnZn ferrite. Silicone-MnZn ferrite coated samples have higher permeability when compared with the non-magnetic silicone resin coated compacts. The real part of permeability increases by 34.18% when compared with the silicone resin coated samples at 20 kHz. In this work, a formula for calculating the total loss component by loss separation method is presented and finally the different parts of total losses are calculated. The results show that the eddy current loss coefficient is close to each other for the silicone-MnZn ferrite, silicone resin and MnZn ferrite coated samples (0.0078Zn ferrite coated sample (k{sub 2} =1.4058) in comparison with other samples.

Wu, Shen; Sun, Aizhi; Xu, Wenhuan; Zou, Chao; Yang, Jun; Dong, Juan [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing (China)

2013-12-16T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" 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.


201

Effects of Bi doping on the thermoelectric properties of ? -Zn 4 Sb 3  

Science Journals Connector (OSTI)

The thermoelectricproperties of Bi-doped compounds ( Zn 1 ? x Bi x ) 4 Sb 3 ( x = 0 0.0025 0.005 0.01 ) were studied experimentally as well as theoretically. The results indicate that low-temperature ( T 9975 Bi 0.0025 ) 4 Sb 3 reduces remarkably as compared with that of Zn 4 Sb 3 due to enhanced phonon scattering of impurity (dopant).Electrical resistivity and Seebeck coefficient increase monotonically with increase in the Bi content resulting mainly from decrease in carrier concentration. Moreover first-principle calculations were performed on the occupation options of Bi atoms in ? -Zn 4 Sb 3 which show that Bi will preferentially occupy the Zn sites and not Sb sites and act as donors being consistent with the experimental observations. In addition the lightly doped compound ( Zn 0.9975 Bi 0.0025 ) 4 Sb 3 exhibits the best thermoelectric performance due to the improvement in both its thermal conductivity and Seebeck coefficient whose figure of merit Z T is about 1.5 times larger than that of ? -Zn 4 Sb 3 at 300 K.

X. Y. Qin; M. Liu; L. Pan; H. X. Xin; J. H. Sun; Q. Q. Wang

2011-01-01T23:59:59.000Z

202

Ion beam assisted sputter deposition of ZnO for silicon thin-film solar cells  

Science Journals Connector (OSTI)

Ion beam assisted deposition (IBAD) is a promising technique for improving the material quality of ZnO-based thin films. The operation of an auxiliary Ar+ ion source during deposition of ZnO?:?Ga thin films by dc magnetron sputtering led to an improvement in crystalline texture, especially at low temperatures due to momentum transfer from the ions to the growing film. Etching of IBAD-ZnO?:?Ga films in diluted HCl revealed crater-like surface structures with crater diameters of up to 600 nm. These structures are usually achieved after deposition at high substrate temperatures. This is an indication that the grain structure was remarkably changed by bombarding these films during deposition in terms of increasing the compactness of the ZnO?:?Ga films. Subsequent annealing procedures led to an improvement in the electrical and optical properties. Hydrogenated microcrystalline silicon (µc-Si?:?H) solar cells exhibited enhanced efficiency as compared to cells on other low-temperature sputtered reference ZnO films. This improvement was ascribed to light trapping by the modified etching behaviour of the IBAD-ZnO?:?Ga films as well as improved transparency after the vacuum annealing step.

M Warzecha; D Köhl; M Wuttig; J Hüpkes

2014-01-01T23:59:59.000Z

203

DEVELOPMENT OF CdZnTe RADIATION DETECTORS  

SciTech Connect (OSTI)

Cadmium Zinc Telluride (CdZnTe or CZT) is a very attractive material for room-temperature semiconductor detectors because of its wide band-gap and high atomic number. Despite these advantages, CZT still presents some material limitations and poor hole mobility. In the past decade most of the developing CZT detectors focused on designing different electrode configurations, mainly to minimize the deleterious effect due to the poor hole mobility. A few different electrode geometries were designed and fabricated, such as pixelated anodes and Frisch-grid detectors developed at Brookhaven National Lab (BNL). However, crystal defects in CZT materials still limit the yield of detector-grade crystals, and, in general, dominate the detector's performance. In the past few years, our group's research extended to characterizing the CZT materials at the micro-scale, and to correlating crystal defects with the detector's performance. We built a set of unique tools for this purpose, including infrared (IR) transmission microscopy, X-ray micro-scale mapping using synchrotron light source, X-ray transmission- and reflection-topography, current deep level transient spectroscopy (I-DLTS), and photoluminescence measurements. Our most recent work on CZT detectors was directed towards detailing various crystal defects, studying the internal electrical field, and delineating the effects of thermal annealing on improving the material properties. In this paper, we report our most recent results.

BOLOTNIKOV, A.; CAMARDA, G.; HOSSAIN, A.; KIM, K.H.; YANG, G.; GUL, R.; CUI, Y.; AND JAMES, R.B.

2011-10-23T23:59:59.000Z

204

Physica B 340342 (2003) 933938 EPR and electrical studies of native point defects in ZnSiP2  

E-Print Network [OSTI]

Physica B 340­342 (2003) 933­938 EPR and electrical studies of native point defects in ZnSiP2 Abstract We present the first detection of native defects in ZnSiP2. Similar to p-type ZnGeP2, the EPR lattice sites is reflected in the differences of the EPR parameters in both lattices. In both materials, V

Nabben, Reinhard

205

Synthesis and Treatment Parameters for Controlling Metal Particle Size and Composition in Cu/ZnO Materials—First Evidence of Cu3Zn Alloy Formation  

Science Journals Connector (OSTI)

This paper deals with the study of the conditions of obtention of small metal copper particles on ZnO using easy synthesis methods and activation treatments, which were found “efficient” for the preparation of copper particles on silica, that is, ...

Salim Derrouiche; Hélène Lauron-Pernot; Catherine Louis

2012-05-18T23:59:59.000Z

206

Enhanced photovoltaic performance of nanocrystalline CdTe/ZnO solar cells using sol-gel ZnO and positive bias treatment  

SciTech Connect (OSTI)

The effect of doping and porosity of the n-type ZnO layer on the performance of solution-processed, sintered p-CdTe/n-ZnO nanocrystal photovoltaic (PV) devices is investigated. Amorphous sol-gel ZnO is found to be the best candidate with overall energy conversion efficiencies above 8% obtained if the ZnO is also indium doped. We demonstrate that when such PV devices are left under forward bias (in dark or light), the device efficiency values are raised to at least 9.8%, due to a substantially increased open-circuit voltage and fill-factor. This drastic enhancement is attributed to improved band alignment at the ITO/CdTe interface. The forward-bias treatment is slowly reversed over a period of days to weeks on standing under open circuit conditions, but is readily restored with further voltage treatment. The moderate processing conditions and high efficiency of such devices demonstrate that nanocrystal-based systems are a promising technology for photovoltaics.

MacDonald, B. I. [CSIRO Materials Science and Engineering, Bayview Avenue, Clayton, Victoria 3168 (Australia); School of Chemistry and Bio21 Institute, The University of Melbourne, Parkville, Victoria 3010 (Australia); Della Gaspera, E.; Watkins, S. E.; Jasieniak, J. J., E-mail: Jacek.Jasieniak@csiro.au [CSIRO Materials Science and Engineering, Bayview Avenue, Clayton, Victoria 3168 (Australia); Mulvaney, P. [School of Chemistry and Bio21 Institute, The University of Melbourne, Parkville, Victoria 3010 (Australia)

2014-05-14T23:59:59.000Z

207

A comparison of ZnO films deposited on indium tin oxide and soda lime glass under identical conditions  

SciTech Connect (OSTI)

ZnO films have been grown via a vapour phase transport (VPT) on soda lime glass (SLG) and indium-tin oxide (ITO) coated glass. ZnO film on ITO had traces of Zn and C which gives them a dark appearance while that appears yellowish-white on SLG. X-ray photoelectron spectroscopy studies confirm the traces of C in the form of C-O. The photoluminescence studies reveal a prominent green luminescence band for ZnO film on ITO.

Deka, Angshuman; Nanda, Karuna Kar [Materials Research Centre, Indian Institute of Science, Bangalore - 560012 (India)

2013-06-15T23:59:59.000Z

208

Swift heavy ion irradiation of ZnO nanoparticles embedded in silica: Radiation-induced deoxidation and shape elongation  

SciTech Connect (OSTI)

ZnO nanoparticles (NPs) embedded in amorphous SiO{sub 2} were irradiated with 200 MeV Xe{sup 14+} swift heavy ions (SHIs) to a fluence of 5.0 × 10{sup 13} ions/cm{sup 2}. Optical linear dichroism was induced in the samples by the irradiation, indicating shape transformation of the NPs from spheres to anisotropic ones. Transmission electron microscopy observations revealed that some NPs were elongated to prolate shapes; the elongated NPs consisted not of ZnO but of Zn metal. The SHI irradiation induced deoxidation of small ZnO NPs and successive shape elongation of the deoxidized metal NPs.

Amekura, H.; Tsuya, D.; Mitsuishi, K.; Nakayama, Y. [National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0003 (Japan)] [National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0003 (Japan); Okubo, N.; Ishikawa, N. [Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki (Japan)] [Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki (Japan); Singh, U. B.; Khan, S. A.; Avasthi, D. K. [Inter-University Accelerator Centre (IUAC), New Delhi (India)] [Inter-University Accelerator Centre (IUAC), New Delhi (India); Mohapatra, S. [Guru Gobind Singh Indraprastha University, New Delhi (India)] [Guru Gobind Singh Indraprastha University, New Delhi (India)

2013-11-11T23:59:59.000Z

209

Submicrosized Rods, Cables, and Tubes of ZnE (E = S, Se, Te): Exterior?Interior Boron-Chalcogen Conversions and Optical Properties  

Science Journals Connector (OSTI)

Submicrosized Rods, Cables, and Tubes of ZnE (E = S, Se, Te): Exterior?Interior Boron-Chalcogen Conversions and Optical Properties ... The absence of ZnO judging from the XRD (part d of Figure 3) and the disappearance of the core as shown in the SEM images (parts c and d of Figure 5) allow us to conclude that the intermediate product is heterostructure with ZnO as core and ZnS as sheath, that is, the ZnO/ZnS cable. ...

Yi-Zhi Huang; Ling Chen; Li-Ming Wu

2008-10-15T23:59:59.000Z

210

Interdiffusion and impurity diffusion in polycrystalline Mg solid solution with Al or Zn  

SciTech Connect (OSTI)

Interdiffusion and impurity diffusion in Mg binary solid solutions, Mg(Al) and Mg(Zn) were investigated at temperatures ranging from 623 to 723 K. Interdiffusion coef cients were determined via the Boltzmann Matano Method using solid-to-solid diffusion couples assembled with polycrystalline Mg and Mg(Al) or Mg(Zn) solid solutions. In addition, the Hall method was employed to extrapolate the impurity diffusion coef cients of Al and Zn in pure polycrystalline Mg. For all diffusion couples, electron micro-probe analysis was utilized for the measurement of concentration pro les. The interdiffusion coef cient in Mg(Zn) was higher than that of Mg(Al) by an order of magnitude. Additionally, the interdiffusion coef cient increased signi cantly as a function of Al content in Mg(Al) solid solution, but very little with Zn content in Mg(Zn) solid solution. The activation energy and pre-exponential factor for the average effective interdiffusion coef cient in Mg(Al) solid solution were determined to be 186.8 ( 0.9) kJ/mol and 7.69 x 10-1 ( 1.80 x 10-1) m2/s, respectively, while those determined for Mg(Zn) solid solution were 139.5 ( 4.0) kJ/mol and 1.48 x 10-3 ( 1.13 x 10-3) m2/s. In Mg, the Zn impurity diffusion coef cient was an order of magnitude higher than the Al impurity diffusion coef cient. The activation energy and pre-exponential factor for diffusion of Al impurity in Mg were determined to be 139.3 ( 14.8) kJ/mol and 6.25 x 10-5 ( 5.37 x 10-4) m2/s, respectively, while those for diffusion of Zn impurity in Mg were determined to be 118.6 ( 6.3) kJ/mol and 2.90 x 10-5 ( 4.41 x 10-5) m2/s.

Kammerer, Catherine [University of Central Florida, Orlando; Kulkarni, Nagraj S [ORNL; Warmack, Robert J Bruce [ORNL; Sohn, Yong Ho [University of Central Florida

2014-01-01T23:59:59.000Z

211

Relaxation in ZnO (1010), (0001), and (0001) surfaces and the adsorption of CO  

SciTech Connect (OSTI)

An atom superposition and electron delocalization molecular orbital study using cluster models shows surface zinc and oxygen ions relax into the (0001), (0001), and (1010) surfaces. The unsaturated zinc ions present surface states consisting of empty 4s, 4p hybridized orbitals with energy levels beneath the empty 4s, 4p band. The filled bands are O 2p nonbonding, Zn 4s + O 2p bonding, and Zn 3d, in order of increasing ionization potential. A study of CO adsorption to an unsaturated zinc ion on the (1010) surface produces an adsorption energy of 12 kcal/mol, a CO bond length decrease of 0.02 A, and an increase in the CO stretching force constant. The zinc ion unrelaxes to a position above the bulk-like position when CO is coordinated to it. The bonding of CO to zinc consists in closed shell sigma donation interactions of the CO 5sigma orbital with the filled Zn 3d and Zn 4s + O 2p bands with the antibonding counterpart stabilized by the Zn 4s, 4p surface state orbital. This 5sigma donation strengthens the CO bond and transfers charge to the surface. These results support a number of experimental structural, vibrational, and electronic studies in the literature.

Anderson, A.B.; Nichols, J.A.

1986-04-02T23:59:59.000Z

212

Synthesis and catalytic performance of graphene modified CuO-ZnO-Al2O3 for CO2 hydrogenation to methanol  

Science Journals Connector (OSTI)

CuO-ZnO-Al2O3 and graphene nanosheet (GNS) were synthesized by coprecipitation route and reduction of exfoliated graphite oxides method, respectively. GNS modified CuO-ZnO-Al2O3 nanocomposites were synthesized ...

Zheng-juan Liu, Xing-jiang Tang, Shan Xu, Xiao-lai Wang

2014-01-01T23:59:59.000Z

213

FINAL REPORT OF RESEARCH ON CuxS/ (Cd,Zn)S PHOTOVOLTAIC SOLAR ENERGY CONVERTERS 3/77 - 9/79  

E-Print Network [OSTI]

and (Cd,Zn)S/CuxS photovoltaic cells. The approach was tothe CuxS/(Cd,Zn)S photovoltaic cell in order to betterstudying CdS/CuxS photovoltaic cells, films prepared by the

Chin, B.L.

2013-01-01T23:59:59.000Z

214

MG DOPING AND ALLOYING IN ZN3P2 HETEROJUNCTION SOLAR CELLS Gregory M. Kimball, Nathan S. Lewis, Harry A. Atwater  

E-Print Network [OSTI]

], or liquid contacts [5], with Mg/Zn3P2 Schottky diodes having exhibited >6% solar energy-conversion (5-10 IJm) minority-carrier diffusion lengths [2). To date, Zn3P2 has been produced almost

Kimball, Gregory

215

A facile bubble-assisted synthesis of porous Zn ferrite hollow microsphere and their excellent performance as an anode in lithium ion battery  

Science Journals Connector (OSTI)

Pure porous hollow Zn ferrite (ZnFe2O4) microspheres have been successfully synthesized by a facile bubble assisted method in the presence of ammonium acetate (NH4Ac) as an anode material in lithium ion battery. ...

Lingmin Yao; Xianhua Hou; Shejun Hu; Qiang Ru…

2013-07-01T23:59:59.000Z

216

On the variations of optical property and electronic structure in heavily Al-doped ZnO films during double-step growth process  

SciTech Connect (OSTI)

We have investigated the variations of optical property and electronic structure in heavily Al-doped ZnO (AZO) films during the growth process, which were formed by first creating Zn vacancies in O{sub 2}-rich atmosphere and second filling the vacancies with Zn atoms in Zn-vapor atmosphere. After the first step, the high-resistance AZO films have the same optical bandgap with nominally undoped ZnO, indicating that negligible variations in the fundamental bandgap happened to the AZO films although Al atom was incorporated into the ZnO lattice. After the second step, once free electrons were brought into the lattice by Zn-filling, the optical transition energy blueshifts due to the band-filling effect. X-ray absorption fine structure measurements suggest that Zn-filling process decreased the unoccupied states of the conduction band, but not raised the conduction band minimum.

Hu, Q. C.; Ding, K., E-mail: kding@fjirsm.ac.cn; Zhang, J. Y.; Yan, F. P.; Pan, D. M.; Huang, F., E-mail: fhuang@fjirsm.ac.cn [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Chiou, J. W., E-mail: jwchiou@nuk.edu.tw [Department of Applied Physics, National University of Kaohsiung, Kaohsiung 811, Taiwan (China)

2014-01-13T23:59:59.000Z

217

Homojunction p-n photodiodes based on As-doped single ZnO nanowire  

SciTech Connect (OSTI)

Photovoltaic device was successfully grown solely based on the single ZnO p-n homojunction nanowire. The ZnO nanowire p-n diode consists of an as-grown n-type segment and an in-situ arsenic doped p-type segment. This p-n homojunction acts as a good photovoltaic cell, producing a photocurrent almost 45 times larger than the dark current under reverse-biased condition. Our results demonstrate that present ZnO p-n homojunction nanowire can be used as a self-powered ultraviolet photodetector as well as a photovoltaic cell, which can also be used as an ultralow electrical power source for nano-scale electronic, optoelectronic, and medical devices.

Cho, H. D.; Zakirov, A. S.; Yuldashev, Sh. U.; Kang, T. W. [Quantum-Functional Semiconductor Research Center, Dongguk Univ.-Seoul, Seoul 100-715 (Korea, Republic of); Ahn, C. W. [Nano-materials Lab. National Nanofab Center at KAIST, 335 Gwahangno, Daejeon 305-806 (Korea, Republic of); Yeo, Y. K. [Department of Engineering Physics, Air Force Institute of Technology,Wright-Patterson AFB, OH 45433 (United States)

2013-12-04T23:59:59.000Z

218

Photovoltaic device on a single ZnO nanowire p–n homojunction  

Science Journals Connector (OSTI)

A photovoltaic device was successfully grown solely based on the single ZnO p–n homojunction nanowire. The ZnO nanowire p–n diode consists of an as-grown n-type segment and an in situ arsenic-doped p-type segment. This p–n homojunction acts as a good photovoltaic cell, producing a photocurrent almost 45 times larger than the dark current under reverse-biased conditions. Our results demonstrate that the present ZnO p–n homojunction nanowire can be used as a self-powered ultraviolet photodetector as well as a photovoltaic cell, which can also be used as an ultralow electrical power source for nanoscale electronic, optoelectronic and medical devices.

Hak Dong Cho; Anvar S Zakirov; Shavkat U Yuldashev; Chi Won Ahn; Yung Kee Yeo; Tae Won Kang

2012-01-01T23:59:59.000Z

219

Optical properties of single ZnTe nanowires grown at low temperature  

SciTech Connect (OSTI)

Optically active gold-catalyzed ZnTe nanowires have been grown by molecular beam epitaxy, on a ZnTe(111) buffer layer, at low temperature (350 °C) under Te rich conditions, and at ultra-low density (from 1 to 5 nanowires per ?m{sup 2}). The crystalline structure is zinc blende as identified by transmission electron microscopy. All nanowires are tapered and the majority of them are <111> oriented. Low temperature micro-photoluminescence and cathodoluminescence experiments have been performed on single nanowires. We observe a narrow emission line with a blue-shift of 2 or 3 meV with respect to the exciton energy in bulk ZnTe. This shift is attributed to the strain induced by a 5 nm-thick oxide layer covering the nanowires, and this assumption is supported by a quantitative estimation of the strain in the nanowires.

Artioli, A.; Stepanov, P.; Den Hertog, M.; Bougerol, C.; Genuist, Y.; Donatini, F.; André, R.; Nogues, G.; Tatarenko, S.; Ferrand, D.; Cibert, J. [Inst NEEL, Universiy of Grenoble Alpes, F-38042 Grenoble (France) [Inst NEEL, Universiy of Grenoble Alpes, F-38042 Grenoble (France); Inst NEEL, CNRS, F-38042 Grenoble (France); Rueda-Fonseca, P. [Inst NEEL, Universiy of Grenoble Alpes, F-38042 Grenoble (France) [Inst NEEL, Universiy of Grenoble Alpes, F-38042 Grenoble (France); Inst NEEL, CNRS, F-38042 Grenoble (France); INAC, CEA and Université de Grenoble, 17 rue des Martyrs, 38054 Grenoble (France); Bellet-Amalric, E.; Kheng, K. [INAC, CEA and Université de Grenoble, 17 rue des Martyrs, 38054 Grenoble (France)] [INAC, CEA and Université de Grenoble, 17 rue des Martyrs, 38054 Grenoble (France)

2013-11-25T23:59:59.000Z

220

Mothproofing of wool fabric utilizing ZnO nanoparticles optimized by statistical models  

Science Journals Connector (OSTI)

Abstract Wool with high strength, elasticity, and resiliency has good dye-ability and comfort however could be digested by keratinolytic enzymes. In this research, wool fabric pre-treated with BTCA and then treated with nano ZnO. The treated fabrics showed mothproofing activity against the larvae of carpet beetle, Anthrenus verbasci, as feeding protein fibers. The role of both BTCA and nano ZnO concentrations on mothproofing properties of the wool fabric were optimized using statistical model of response surface methodology (RSM). Mothproofing was investigated through assessing wool weight loss during feeding by A. verbasci. The analysis of variance (ANOVA) was utilized to obtain the optimum models for wool with mothproofing properties. The damages on the wool surface confirmed with scanning electron microscopy and digital camera images. Further transmission and absorbance spectra approved the UV protection properties of the nano ZnO treated wool in both UVA and UVB.

Ali Nazari; Majid Montazer; Mehdi Dehghani-Zahedani

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" 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

Spectroscopy peculiarities of thermal plasma of electric arc discharge between electrodes with Zn admixtures  

Science Journals Connector (OSTI)

Abstract Plasma of the free burning electric arc between Ag–SnO2–ZnO composite electrodes as well as brass electrodes were investigated. The plasma temperature distributions were obtained by Boltzmann plot method involving Cu I, Ag I or Zn I spectral line emissions. The electron density distributions were obtained from the width and from absolute intensity of spectral lines. The laser absorption spectroscopy was used for measurement of copper atom concentration in plasma. Plasma equilibrium composition was calculated using two independent groups of experimental values (temperature and copper atom concentration, temperature and electron density). It was found that plasma of the free burning electric arc between brass electrodes is in local thermodynamical equilibrium. The experimental verification of the spectroscopic data of Zn I spectral lines was carried out.

R.V. Semenyshyn; A.N. Veklich; I.L. Babich; V.F. Boretskij

2014-01-01T23:59:59.000Z

222

Electrical transport properties in nitrogen-doped p-type ZnO thin film  

Science Journals Connector (OSTI)

Electrical transport properties of p-type ZnO:N films grown by thermal activation of the nitrogen dopant were investigated via the temperature-dependent Hall effect. The Hall mobility increases with decreasing temperature. Varied scattering mechanisms have been analysed including lattice vibration scattering, ionized impurity scattering and dislocation scattering. A fit of the theory to temperature-dependent hole mobility experimental data in p-type ZnO:N films gives dislocation densities in the order of 1012 cm?2. The analysis shows dislocation scattering is indeed important for the p-type ZnO films grown on the mismatched substrate. The thermal ionization energy of the nitrogen acceptor is estimated to be 170 meV in terms of the temperature-dependent hole concentration. On the other hand, the emission related to the acceptors is observed in PL spectra.

Z Y Xiao; Y C Liu; B H Li; J Y Zhang; D X Zhao; Y M Lu; D Z Shen; X W Fan

2006-01-01T23:59:59.000Z

223

Growth and optical properties of CdTe quantum dots in ZnTe nanowires  

SciTech Connect (OSTI)

We report on the formation of optically active CdTe quantum dots in ZnTe nanowires. The CdTe/ZnTe nanostructures have been grown by a gold nanocatalyst assisted molecular beam epitaxy in a vapor-liquid solid growth process. The presence of CdTe insertions in ZnTe nanowire results in the appearance of a strong photoluminescence band in the 2.0 eV-2.25 eV energy range. Spatially resolved photoluminescence measurements reveal that this broad emission consists of several sharp lines with the spectral width of about 2 meV. The large degree of linear polarization of these individual emission lines confirms their nanowire origin, whereas the zero-dimensional confinement is proved by photon correlation spectroscopy.

Wojnar, Piotr; Janik, Elzbieta; Baczewski, Lech T.; Kret, Slawomir; Karczewski, G.; Wojtowicz, Tomasz [Institute of Physics, Polish Academy of Sciences, Al Lotnikow 32/46, 02-668 Warsaw (Poland); Goryca, Mateusz; Kazimierczuk, Tomasz; Kossacki, Piotr [Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul Hoza 69, 00-681 Warsaw (Poland)

2011-09-12T23:59:59.000Z

224

Band offsets in HfO{sub 2}/InGaZnO{sub 4} heterojunctions  

SciTech Connect (OSTI)

The valence band discontinuity ({Delta}E{sub V}) of sputter deposited HfO{sub 2}/InZnGaO{sub 4} (IGZO) heterostructures was obtained from x-ray photoelectron spectroscopy measurements. The HfO{sub 2} exhibited a bandgap of 6.07 eV from absorption measurements. A value of {Delta}E{sub V} = 0.48 {+-} 0.025 eV was obtained by using the Ga 2p{sub 3/2}, Zn 2p{sub 3/2}, and In 3d{sub 5/2} energy levels as references. This implies a conduction band offset {Delta}E{sub C} of 2.39 eV in HfO{sub 2}/InGaZnO{sub 4} heterostructures and a nested interface band alignment.

Cho, Hyun [Department of Nanomechatronics Engineering, Pusan National University, Gyeongnam 627-706 (Korea, Republic of); Douglas, E. A.; Gila, B. P.; Craciun, V.; Lambers, E. S.; Pearton, S. J. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Ren Fan [Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611 (United States)

2012-01-02T23:59:59.000Z

225

Mechanism and kinetics of Zn(II) removal from wastewater by immobilised beads of SRB sludge  

Science Journals Connector (OSTI)

The treatment of Zn(II)-bearing wastewater by immobilised Sulfate Reducing Bacteria (SRB) sludge beads of inner cohesive nutrient source was investigated, by which the traditional problems in SRB methods were resolved. The mechanism and kinetics model on Zn(II) removal were studied. The results showed that SO42? was reduced to S2? on the surface of SRB sludge beads, and Zn(II) precipitated outside beads. The effect of internal diffusion could be neglected, and the chemical reaction was the rate determining step. The reaction kinetics was followed by Micaelis-Menten formula, and the constants, Ks and vmax were 8.99 mg?L?1 and 0.018 mg?L?1?s?1, respectively.

Liyuan Chai; Xiaobo Min; Ning Tang; Yunyan Wang

2009-01-01T23:59:59.000Z

226

Measuring size dependent electrical properties from nanoneedle structures: Pt/ZnO Schottky diodes  

SciTech Connect (OSTI)

This work reports the fabrication and testing of nanoneedle devices with well-defined interfaces that are amenable to a variety of structural and electrical characterization, including transmission electron microscopy. Single Pt/ZnO nanoneedle Schottky diodes were fabricated by a top down method using a combination of electro-polishing, sputtering, and focused ion beam milling. The resulting structures contained nanoscale planar heterojunctions with low ideality factors, the dimensions of which were tuned to study size-dependent electrical properties. The diameter dependence of the Pt/ZnO diode barrier height is explained by a joule heating effect and/or electronic inhomogeneity in the Pt/ZnO contact area.

Mao, Shimin; Anderson, Daniel D. [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Shang, Tao [Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Park, Byoungnam [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Department of Materials Science and Engineering, Hongik University, 72-1 Sangsu-dong, Mapo-gu, Seoul 121-791 (Korea, Republic of); Dillon, Shen J., E-mail: sdillon@illinois.edu [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

2014-04-14T23:59:59.000Z

227

Al-doped ZnO powdered materials: Al solubility limit and IR absorption properties  

Science Journals Connector (OSTI)

Al-doped ZnO powder was synthesized via the Pechini route with a doping rate varying from 1 to 4 mol.%. A solubility limit has been estimated under 0.3 mol.% of Al using X-ray diffraction refinements. The incorporation of aluminium into the ZnO lattice was investigated by 27Al NMR, which suggests an extremely low amount of Al in a distribution of sites in ZnO. In order to assess the impact of such a low dopant amount, diffuse reflection experiments were performed for a wavelength range from 200 to 2500 nm. If the effect of doping was negligible for samples prepared at 850 °C, annealing at 1200 °C clearly reveals enhanced IR absorption properties for the doped samples, which are similar whatever be the nominal Al content.

Hélène Serier; Manuel Gaudon; Michel Ménétrier

2009-01-01T23:59:59.000Z

228

Enhanced photocatalytic hydrogen evolution under visible light over Cd x Zn1?x S solid solution by ruthenium doping  

Science Journals Connector (OSTI)

Cd x Zn1?x S and Ru3+ doped Ru(m)/Cd0.5Zn0.5S photocatalysts were prepared by a simple hydrothermal method, and characterized by X-ray diffraction, UV–Vis absorpt...

Shaoqin Peng; Ran An; Zhisheng Wu…

2012-10-01T23:59:59.000Z

229

Reversible Modification of CdSe-CdS/ZnS Quantum Dot Fluorescence by Surrounding Ca2+  

E-Print Network [OSTI]

Reversible Modification of CdSe-CdS/ZnS Quantum Dot Fluorescence by Surrounding Ca2+ Ions Li Li (3-MPA) coated CdSe-CdS/ZnS core-multishell QDs when free Ca2+ ions were added to and subsequently removed from the QD solution. It was found that QD fluorescence intensity was reduced when Ca2+ ions were

Haviland, David

230

Synthesis and Characterization of Ag-or Sb-Doped ZnO Nanorods by a Facile Hydrothermal Route  

E-Print Network [OSTI]

Synthesis and Characterization of Ag- or Sb-Doped ZnO Nanorods by a Facile Hydrothermal Route Oleg Stefan Cel Mare BouleVard, MD-2004 Chisinau, Republic of MoldoVa, AdVanced Materials Processing ZnO nanorods doped with Ag and Sb have been synthesized by a facile hydrothermal technique. Crystal

Kik, Pieter

231

Effects of temperature on the optical and electrical properties of ZnO nanoparticles synthesized by sol-gel method  

Science Journals Connector (OSTI)

ZnO nanoparticles for different thermal treatment temperatures were prepared by using sol-gel method under supercritical drying of ethyl alcohol. The structural properties showed that the ZnO nanoparticles exhibit hexagonal wurtzite structure. Thus, ... Keywords: Electrical conductivity, Nanoparticles, Optical materials, Sol-gel, Zinc oxide

K. Omri, I. Najeh, R. Dhahri, J. El Ghoul, L. El Mir

2014-10-01T23:59:59.000Z

232

Determination of secondary ion mass spectrometry relative sensitivity factors for polar and non-polar ZnO  

SciTech Connect (OSTI)

Zinc oxide (ZnO) is regarded as a promising material for optoelectronic devices, due to its electronic properties. Solely, the difficulty in obtaining p-type ZnO impedes further progress. In this connection, the identification and quantification of impurities is a major demand. For quantitative information using secondary ion mass spectrometry (SIMS), so-called relative sensitivity factors (RSF) are mandatory. Such conversion factors did not yet exist for ZnO. In this work, we present the determined RSF values for ZnO using primary (ion implanted) as well as secondary (bulk doped) standards. These RSFs have been applied to commercially available ZnO substrates of different surface termination (a-plane, Zn-face, and O-face) to quantify the contained impurities. Although these ZnO substrates originate from the same single-crystal, we observe discrepancies in the impurity concentrations. These results cannot be attributed to surface termination dependent RSF values for ZnO.

Laufer, Andreas; Volbers, Niklas; Eisermann, Sebastian; Meyer, Bruno K. [Physikalisches Institut, Justus-Liebig-Universitaet Giessen, Heinrich-Buff-Ring 16, 35392 Giessen (Germany); Potzger, Kay [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden (Germany); Geburt, Sebastian; Ronning, Carsten [Institut fuer Festkoerperphysik, Universitaet Jena, Max-Wien-Platz 1, 07743 Jena (Germany)

2011-11-01T23:59:59.000Z

233

Fabrication of ZnO/Cu2O heterojunctions in atmospheric conditions: improved interface quality and solar cell performance  

E-Print Network [OSTI]

Zn_1-xMg_xO/Cu_2O heterojunctions were successfully fabricated in open-air at low temperatures via atmospheric atomic layer deposition of Zn_1-xMg_xO on thermally oxidized cuprous oxide. Solar cells employing these heterojunctions demonstrated a...

Ievskaya, Y.; Hoye, R. L. Z.; Sadhanala, A.; Musselman, K.; MacManus-Driscoll, J. L.

2014-01-01T23:59:59.000Z

234

Enhanced ethanol sensing properties of TiO2/ZnO core–shell nanorod sensors  

Science Journals Connector (OSTI)

TiO2-core/ZnO-shell nanorods were synthesized using a two-step process: the synthesis of TiO2 nanorods using a hydrothermal method followed by atomic layer deposition of ZnO. The mean diameter and length of the n...

Sunghoon Park; Soyeon An; Hyunsung Ko; Sangmin Lee; Hyoun Woo Kim…

2014-06-01T23:59:59.000Z

235

Microfluidic pumps employing surface acoustic waves generated in ZnO thin films  

SciTech Connect (OSTI)

ZnO thin film based surface acoustic wave (SAW) devices have been utilized to fabricate microfluidic pumps. The SAW devices were fabricated on nanocrystalline ZnO piezoelectric thin films deposited on Si substrates using rf magnetron sputtering and use a Sezawa wave mode for effective droplet motion. The as-deposited ZnO surface is hydrophilic, with a water contact angle of {approx}75 deg., which prevents droplet pumping. Therefore, the ZnO surface was coated using a self-assembled monolayer of octadecyltrichlorosilane which forms a hydrophobic surface with a water contact angle of {approx}110 deg. Liquid droplets between 0.5 and 1 {mu}l in volume were successfully pumped on the hydrophobic ZnO surface at velocities up to 1 cm s{sup -1}. Under acoustic pressure, the water droplet on an hydrophilic surface becomes deformed, and the asymmetry in the contact angle at the trailing and leading edges allow the force acting upon the droplet to be calculated. These forces, which increase with input voltage above a threshold level, are found to be in the range of {approx}100 {mu}N. A pulsed rf signal has also been used to demonstrate precision manipulation of the liquid droplets. Furthermore, a SAW device structure is demonstrated in which the ZnO piezoelectric only exists under the input and output transducers. This structure still permits pumping, while avoiding direct contact between the piezoelectric material and the fluid. This is of particular importance for biological laboratory-on-a-chip applications.

Du, X. Y.; Flewitt, A. J.; Milne, W. I. [Electrical Engineering Division, Department of Engineering, University of Cambridge, JJ Thomson Ave., Cambridge CB3 0FA (United Kingdom); Fu, Y. Q. [Electrical Engineering Division, Department of Engineering, University of Cambridge, JJ Thomson Ave., Cambridge CB3 0FA (United Kingdom); Department of Mechanical Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Luo, J. K. [Electrical Engineering Division, Department of Engineering, University of Cambridge, JJ Thomson Ave., Cambridge CB3 0FA (United Kingdom); Centre for Material Research and Innovation, University of Bolton, Deane Road, Bolton BL3 5AB (United Kingdom)

2009-01-15T23:59:59.000Z

236

Resource Letter: OTS-1: Observations and theory of supernovae  

Science Journals Connector (OSTI)

This Resource Letter provides a guide to the literature on the observations of supernovae and the theory of their explosion mechanisms. Journal articles and books are cited for the following topics: observations of the spectra spectropolarimetry and light curves of supernovae of various types theory of thermonuclear explosions core collapse and radioactive decay applications to cosmology and possible connections to gamma-ray bursts.

J. Craig Wheeler

2003-01-01T23:59:59.000Z

237

Complete genome sequence of Haliscomenobacter hydrossis type strain (OT)  

SciTech Connect (OSTI)

Haliscomenobacter hydrossis van Veen et al. 1973 is the type species of the genus Halisco- menobacter, which belongs to order 'Sphingobacteriales'. The species is of interest because of its isolated phylogenetic location in the tree of life, especially the so far genomically un- charted part of it, and because the organism grows in a thin, hardly visible hyaline sheath. Members of the species were isolated from fresh water of lakes and from ditch water. The genome of H. hydrossis is the first completed genome sequence reported from a member of the family 'Saprospiraceae'. The 8,771,651 bp long genome with its three plasmids of 92 kbp, 144 kbp and 164 kbp length contains 6,848 protein-coding and 60 RNA genes, and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

Daligault, Hajnalka E. [Los Alamos National Laboratory (LANL); Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Zeytun, Ahmet [Los Alamos National Laboratory (LANL); Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Glavina Del Rio, Tijana [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [U.S. Department of Energy, Joint Genome Institute; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Liolios, Konstantinos [U.S. Department of Energy, Joint Genome Institute; Pagani, Ioanna [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Huntemann, Marcel [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [U.S. Department of Energy, Joint Genome Institute; Palaniappan, Krishna [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Brambilla, Evelyne-Marie [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Rohde, Manfred [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Verbarg, Susanne [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Eisen, Jonathan [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute

2011-01-01T23:59:59.000Z

238

Missouri Ordnance Works Becomes Bureau ot Mines Demonstration Plant  

Science Journals Connector (OSTI)

The Bureau of Mines estimates that the United States has about 3 trillion tons of coal reserves—enough to supply the nation with both solid and liquid fuels for at least 1,000 years. ... The Bureau of Mines will take over the Missouri Ordnance Works, near Louisiana, Mo., a $17,500,000 plant that made synthetic ammonia during the war, and convert it into a demonstration plant for the production of gasoline and oil from coal and lignite. ...

1946-01-10T23:59:59.000Z

239

Synthesis of Mixed Copper?Zinc Basic Carbonates and Zn-Doped Tenorite by Homogeneous Alkalinization  

Science Journals Connector (OSTI)

In the range 0.50 ? XZn > 0.30, on the other hand, only aurichalcite forms; the final solid composition is essentially that of the starting solution. ... Mixtures of aurichalcite, zincian?malachites and Zn-doped tenorite, in varying proportions, form at intermediate XZn values. ... 18-21These procedures, in which coprecipitation takes place at very large supersaturations, usually give rise to mixed copper?zinc hydroxycarbonate phases, mainly aurichalcite and zincian?malachites;22-26subsequent thermal decomposition, which leads to what is believed to be a fine CuO?ZnO interdispersion, followed by reduction yields the final catalysts. ...

Galo J. de A. A. Soler-Illia; Roberto J. Candal; Alberto E. Regazzoni; Miguel A. Blesa

1997-01-16T23:59:59.000Z

240

Analysis of the thermoelectric properties of n-type ZnO  

SciTech Connect (OSTI)

We report an investigation of the temperature- and doping-dependent thermoelectric behavior of n-type ZnO. The results are based on a combination of experimental data from the literature and calculated transport functions obtained from Boltzmann transport theory applied to the first-principles electronic structure. From this we obtain the dependence of the figure of merit ZT on doping and temperature. We find that improvement of the lattice thermal conductivity is essential for obtaining high ZT in n-type ZnO.

Ong, Khuong P [IHPC, Singapore; Singh, David J [ORNL; Wu, Ping [IHPC, Singapore

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" 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

Microstructure and electrical properties of p-type phosphorus-doped ZnO films  

Science Journals Connector (OSTI)

The microscopic defects and their effects on the electrical properties of phosphorus-doped ZnO films epitaxially grown on (0?0?0?1) sapphire and ZnO substrates by pulsed laser deposition are studied. While threading dislocations were observed only in heteroepitaxial films, a high density of partial dislocations associated with interstitial dislocation loops was observed in films grown on both substrates. These dislocations provide sinks to quench native donors and favour the injection of zinc vacancies to form acceptor-complex defects, thus leading to p-type conductivity.

A Allenic; W Guo; Y B Chen; Y Che; Z D Hu; B Liu; X Q Pan

2008-01-01T23:59:59.000Z

242

Impact of transparent electrode on photoresponse of ZnO-based phototransistor  

SciTech Connect (OSTI)

ZnO-based photo-thin film transistors with enhanced photoresponse were developed using transparent conductive oxide contacts. Changing the electrode from opaque Mo to transparent In-Zn-O increases the photocurrent by five orders of magnitude. By changing the opacity of each source and drain electrode, we could observe how the photoresponse is affected. We deduce that the photocurrent generation mechanism is based on an energy band change due to the photon irradiation. More importantly, we reveal that the photocurrent is determined by the energy barrier of injected electrons at the interface between the source electrode and the active layer.

Lee, Seunghyup; Ahn, Seung-Eon, E-mail: seungeon.ahn@samsung.com; Jeon, Yongwoo; Ahn, Ji-Hoon; Song, Ihun; Kim, Jungwoo; Choi, Hyung; Chung, U-in; Park, Jaechul [Advanced Device Laboratory, Samsung Advanced Institute of Technology, Samsung Electronics Corporation, Yongin-Si, Gyeonggi-Do 446-712 (Korea, Republic of)] [Advanced Device Laboratory, Samsung Advanced Institute of Technology, Samsung Electronics Corporation, Yongin-Si, Gyeonggi-Do 446-712 (Korea, Republic of); Jeon, Sanghun [Department of Display and Semiconductor Physics and Department of Applied Physics, Korea University, 2511, Sejongro, Sejong, 339–700 (Korea, Republic of)] [Department of Display and Semiconductor Physics and Department of Applied Physics, Korea University, 2511, Sejongro, Sejong, 339–700 (Korea, Republic of); Yun, Dong-Jin [Analytical Science Group, Samsung Advanced Institute of Technology, Samsung Electronics Corporation, Yongin-Si, Gyeonggi-Do 446-712 (Korea, Republic of)] [Analytical Science Group, Samsung Advanced Institute of Technology, Samsung Electronics Corporation, Yongin-Si, Gyeonggi-Do 446-712 (Korea, Republic of)

2013-12-16T23:59:59.000Z

243

Fracture Behavior of a Laser Beam Welded High-strength Al-Zn Alloy  

Science Journals Connector (OSTI)

Abstract Laser beam welding of butt joints made of the newly developed high-strength Al-Zn alloy PA734 is conducted. A new approach of the Helmholtz-Zentrum Geesthacht is used to solve the problems of weldability and softening. The results of the fatigue, fatigue crack propagation and fracture toughness tests are discussed relating to the microstructural characteristics and the mechanical properties of the laser welded joints and compared to the base material. The obtained data can be used for the assessment of the damage tolerance behaviour of the laser welded integral aircraft structures made of Al-Zn alloys.

J. Enz; H. Iwan; S. Riekehr; V. Ventzke; N. Kashaev

2014-01-01T23:59:59.000Z

244

Remote plasma enhanced atomic layer deposition of ZnO for thin film electronic applications  

Science Journals Connector (OSTI)

This paper describes a systematic approach to analyze the simultaneous impact of various reactant plasma parameters of remote plasma enhanced ALD (PEALD) on the ZnO thin film properties. Particular emphasis is placed on the film stoichiometry which affects the electrical properties of the thin film. Design of Experiment (DOE) is used to study the impact of the oxygen plasma parameters such as the RF power, pressure and plasma time to realize semiconductor quality of ZnO thin film. Based on the optimized plasma condition, staggered bottom-gate \\{TFTs\\} were fabricated and its electrical characteristics were measured.

S.M. Sultan; O.D. Clark; T.B. Masaud; Q. Fang; R. Gunn; M.M.A. Hakim; K. Sun; P. Ashburn; H.M.H. Chong

2012-01-01T23:59:59.000Z

245

Effects of nitrogen on the growth and optical properties of ZnO thin films grown by pulsed laser deposition  

Science Journals Connector (OSTI)

ZnO thin films were grown using pulsed laser deposition by ablating a Zn target in various mixtures of O2 and N2. The presence of N2 during deposition was found to affect the growth of the ZnO thin films and their optical properties. Small N2 concentrations during growth led to strong acceptor-related photoluminescence (PL), while larger concentrations affected both the intensity and temperature dependence of the emission peaks. In addition, the PL properties of the annealed ZnO thin films are associated with the N2 concentration during their growth. The possible role of nitrogen in ZnO growth and annealing is discussed.

J B Cui; M A Thomas; Y C Soo; H Kandel; T P Chen

2009-01-01T23:59:59.000Z

246

Development of High-Efficiency Cd-Free Cu(In,Ga)Se2 Solar Cells Using Chemically Deposited ZnS Film  

Science Journals Connector (OSTI)

A ZnS film covered completely the CIGS surface without pinholes. The thickness of the ZnS film could be controlled according to the cycle number of the CBD process. As the thickness of the ZnS film increased, ...

Dong Hyeop Shin; Seung Tae Kim…

2014-01-01T23:59:59.000Z

247

Role of copper in the regulation of CU, ZN-superoxide dismutase in human K562 erythroleukemia cells and human fibroblasts  

E-Print Network [OSTI]

Activation of the enzyme CU2Zn2-SUperoxide dismutase (CuZnSOD) by its copper cofactor was studied in K562 erythroleukemia cells and skin fibroblasts. K562 cells were incubated in medium supplemented with 0-50 IIM CUC12 or ZnCI2 for 24 h and extracts...

Yu, Dan

1994-01-01T23:59:59.000Z

248

Effects of Mg composition on open circuit voltage of Cu2OMgxZn1xO heterojunction solar cells  

E-Print Network [OSTI]

(ZnO) Cuprous oxide (Cu2O) Solar cells Electrodeposition MOCVD (metal-organic chemical vapor solar cells, where Ag and FTO are used as top and bottom electrodes, respectively. An enhancement on the MgxZn1�xO (x¼10%) based solar cell. & 2011 Elsevier B.V. All rights reserved. 1. Introduction Zn

Garfunkel, Eric

249

An organic hydrogel film with micron-sized pillar array for real-time and indicator-free detection of Zn2+  

E-Print Network [OSTI]

-time and indicator-free detection of Zn2+ is developed by embedding a fluorescent indicator 11,16-bis(phenyl)-6 in the hippocampus, amygdale, cortex gray, and olfactory bulb regions [2]. Most of Zn2+ are bound to proteins;Fluorescent microscopy is conventionally used to detect Zn2+ with the help of fluorescent indicators since

Meng, Hsin-Fei

250

Characteristics of Ga and Ag-doped ZnO-based nanowires for an ethanol gas sensor prepared by hot-walled pulsed laser deposition  

Science Journals Connector (OSTI)

Pure ZnO and Ga (3 % w/w) and Ag (3 % w/w...)-doped ZnO nanowires (NWs) have been grown by use of the hot-walled pulse laser deposition technique. The doping characteristics of Ga and Ag in ZnO NWs were analyzed ...

Dawn Jeong; Kyoungwon Kim; Sung-ik Park…

2014-01-01T23:59:59.000Z

251

Surface complexation and precipitate geometry for aqueous Zn(II) sorption on ferrihydrite I: X-ray absorption extended fine structure spectroscopy analysis  

Science Journals Connector (OSTI)

“Two-line” ferrihydrite samples precipitated and then exposed to a range of aqueous Zn solutions (10?5 to 10?3 M), and also coprecipitated in similar Zn solutions (pH 6.5), have been examined by Zn and Fe K-edge X-ray absorption spectroscopy. Typical Zn complexes on the surface have Zn-O distances of 1.97(.02) Å and coordination numbers of about 4.0(0.5), consistent with tetrahedral oxygen coordination. This contrasts with Zn-O distances of 2.11(.02) Å and coordination numbers of 6 to 7 in the aqueous Zn solutions used in sample preparation. X-ray absorption extended fine structure spectroscopy (EXAFS) fits to the second shell of cation neighbors indicate as many as 4 Zn-Fe neighbors at 3.44(.04) Å in coprecipitated samples, and about two Zn-Fe neighbors at the same distance in adsorption samples. In both sets of samples, the fitted coordination number of second shell cations decreases as sorption density increases, indicating changes in the number and type of available complexing sites or the onset of competitive precipitation processes. Comparison of our results with the possible geometries for surface complexes and precipitates suggests that the Zn sorption complexes are inner sphere and at lowest adsorption densities are bidentate, sharing apical oxygens with adjacent edge-sharing Fe(O,OH)6 octahedra. Coprecipitation samples have complexes with similar geometry, but these are polydentate, sharing apices with more than two adjacent edge-sharing Fe(O,OH)6 polyhedra. The results are inconsistent with Zn entering the ferrihydrite structure (i.e., solid solution formation) or formation of other Zn-Fe precipitates. The fitted Zn-Fe coordination numbers drop with increasing Zn density with a minimum of about 0.8(.2) at Zn/(Zn + Fe) of 0.08 or more. This change appears to be attributable to the onset of precipitation of zinc hydroxide polymers with mainly tetrahedral Zn coordination. At the highest loadings studied, the nature of the complexes changes further, and a second type of precipitate forms. This has a structure based on a brucite layer topology, with mainly octahedral Zn coordination. Amorphous zinc hydroxide samples prepared for comparison had a closely similar local structure. Analysis of the Fe K-edge EXAFS is consistent with surface complexation reactions and surface precipitation at high Zn loadings with little or no Fe-Zn solid solution formation. The formation of Zn-containing precipitates at solution conditions two or more orders of magnitude below their solubility limit is compared with other sorption and spectroscopic studies that describe similar behavior.

G.A Waychunas; C.C Fuller; J.A Davis

2002-01-01T23:59:59.000Z

252

Microwave-assisted synthesis of CuO/ZnO and CuO/ZnO/Al2O3 precursors using urea hydrolysis  

Science Journals Connector (OSTI)

Binary CuO/ZnO and ternary CuO/ZnO/Al2O3 catalysts have been rapidly synthesized in a multimode microwave oven by the homogeneous precipitation of aurichalcite and hydrotalcite-like precursors using urea hydrolysis. For purposes of comparison, the same catalysts were prepared under conventional heating. The corresponding metal nitrates were mixed with various amounts of urea to yield different urea/(?M+) molar ratios. The precipitation proceeded stepwise, copper being the first metal to be hydrolyzed. It was found that the higher the urea content, the higher the alkalinization of the solution, an effect which favored the precipitation of Zn (II) (the most pH dependent metal), and in turn, the synthesis of aurichalcite and hydrotalcite-like precursors. Microwave-synthesized catalysts presented similar characteristics to those obtained under conventional heating, but in considerably reduced aging times. Microwave radiation proved to be more efficient than conventional heating under harsh conditions of precipitation, i.e., lower molar ratios of urea with respect to the metal cations in the solution.

Y. Fernández; J.A. Menéndez; A. Arenillas; E. Fuente; J.H. Peng; Z.B. Zhang; W. Li; Z.Y. Zhang

2009-01-01T23:59:59.000Z

253

Energy level alignment of polythiophene/ZnO hybrid solar cells  

E-Print Network [OSTI]

Energy level alignment of polythiophene/ZnO hybrid solar cells W. Feng,a S. Rangan,b Y. Cao,c E between energy level alignment and photovoltaic properties of a model bilayer hybrid solar cell. Galoppini,c R. A. Bartynskib and E. Garfunkel*ab Energy level alignment at interfaces is critical

Garfunkel, Eric

254

Resonance transitions of Zn-like ions from the multiconfiguration relativistic random-phase approximation  

Science Journals Connector (OSTI)

Excitation energies and oscillator strengths from the 1S0 ground state to the first 1P°1 and 3P°1 excited states of Zn-like ions are calculated by using the multiconfiguration relativistic random-phase approximation. Results are compared with those from other theories and with experiment. Predicted values for highly stripped ions are listed.

Te-Chun Cheng and Keh-Ning Huang

1992-04-01T23:59:59.000Z

255

Growth of anisotropic one-dimensional ZnS nanostructures{ Daniel Moore and Zhong L. Wang*  

E-Print Network [OSTI]

is the most stable structure for CdS and CdSe and the other II­VI School of Materials Science and Engineering, and nano- combs.7,10,16­26 Recently, ZnS nanobelts have been doped with manganese for possible application

Wang, Zhong L.

256

Chemical bath deposition of CdS thin films doped with Zn and Cu  

Science Journals Connector (OSTI)

Zn- and Cu-doped CdS thin films were deposited onto glass substrates...2 and CuCl2...were incorporated as dopant agents into the conventional CdS chemical bath in order to promote the CdS doping process. The effe...

A I OLIVA; J E CORONA; R PATIÑO; A I OLIVA-AVILÉS

2014-04-01T23:59:59.000Z

257

Narrow band defect luminescence from Al-doped ZnO probed by scanning tunneling cathodoluminescence  

E-Print Network [OSTI]

Institute of Physics. Related Articles Effect of CdS film thickness on the photoexcited carrier lifetime of TiO2/CdS core-shell nanowires Appl. Phys. Lett. 99, 153111 (2011) Current underestimationNarrow band defect luminescence from Al-doped ZnO probed by scanning tunneling cathodoluminescence

Russell, Kasey

258

Scalable production of microbially-mediated ZnS nanoparticles and application to functional thin films  

SciTech Connect (OSTI)

A series of semiconducting zinc sulfide (ZnS) nanoparticles were scalably, reproducibly, controllably, and economically synthesized with anaerobic metal-reducing Thermoanaerobacter species. They reduced partially oxidized sulfur sources to sulfides that extracellularly and thermodynamically incorporated with zinc ions to produce sparingly soluble ZnS nanoparticles with ~5 nm crystallites at yields of ~5 g l 1 month 1. A predominant sphalerite formation was facilitated by rapid precipitation kinetics, low cation/anion ratio, higher zinc concentration, water stabilization, or some combination of the four. The sphalerite ZnS nanoparticles exhibited narrow size distribution, high emission intensity, and few native defects. Scale-up and emission tunability using copper-doping were confirmed spectroscopically. Surface characterization was determined using Fourier transform infrared and X-ray photoelectron spectroscopies, which confirmed amine and carboxylic acid not only maintaining a nano-dimensional average crystallite size, but also increasing aggregation. Application of ZnS nanoparticle ink to a functional thin film was successfully tested for potential future applications.

Moon, Ji Won [ORNL; Ivanov, Ilia N [ORNL; Joshi, Pooran C [ORNL; Armstrong, Beth L [ORNL; Wang, Wei [ORNL; Jung, Hyunsung [ORNL; Rondinone, Adam Justin [ORNL; Jellison Jr, Gerald Earle [ORNL; Meyer III, Harry M [ORNL; Jang, Gyoung Gug [Oak Ridge National Laboratory (ORNL); Meisner, Roberta [Oak Ridge National Laboratory (ORNL); Duty, Chad E [ORNL; Phelps, Tommy Joe [ORNL

2014-01-01T23:59:59.000Z

259

Study of hydrogen and carbon monoxide adsorption on modified Zn/Cr catalysts by adsorption calorimetry  

SciTech Connect (OSTI)

Differential heat of adsorption (q) of hydrogen (a) and carbon monoxide (b) as a function of the adsorbed amount (a) on Zn/Cr catalysts at 463/sup 0/K; 1) unpromoted catalyst, 2) catalyst promoted with 2.5% of K/sub 2/O.

Yoshin, S.V.; Klyacho, A.L.; Kondrat'ev, L.T.; Leonov, V.E.; Skripchenko, G.B.; Sushchaya, L.E.

1986-08-01T23:59:59.000Z

260

Fabrication of inverted opal ZnO photonic crystals by atomic layer deposition  

E-Print Network [OSTI]

Fabrication of inverted opal ZnO photonic crystals by atomic layer deposition M. Scharrer, X. Wu, A method to fabricate so-called "inverted opal" structures which have the long-range order, high filling into opal or inverted opal backbones.3,5,13,14 Recently, atomic layer deposition ALD has been pro- posed

Cao, Hui

Note: This page contains sample records for the topic "zn zurn ot" 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

Electrical and optical properties of p-type ZnO  

Science Journals Connector (OSTI)

ZnO has ideal qualities for bright, efficient UV light emitting diodes and laser diodes, based on p–n junctions. However, while high quality n-type ZnO has been available for many years, the development of good p-type material is a much more recent phenomenon. The most successful acceptor dopants have been the group V elements, N, P and As; N substitutes on the O site, but the exact structures of the P and As acceptors have not yet been established. Resistivities as low as 0.4 ? cm have been measured, and some UV heterojunction and homojunction LEDs have been fabricated. Optical fingerprints of p-type ZnO often include a photoluminescence line at 3.31 eV, and strong donor-bound exciton lines at 3.357 and 3.367 eV, both of which are well known from previous studies of n-type ZnO.

David C Look

2005-01-01T23:59:59.000Z

262

Current-scattered (?) detrital remanence directions in the Zn-rich Pennsylvanian Stark black shale, USA  

Science Journals Connector (OSTI)

......thermal analyses, however, the oil was not completely removed because...surface water in Zn, V and other heavy minerals that were subsequently...Pennsylvanian black shales of Missouri and Kansas, Econ. Geol...2004. Paleozoic Succession in Missouri, Part 5-Pennsylvanian Subsystem......

K. Kawasaki; D. T. A. Symons; R. M. Coveney; Jr.

2007-11-01T23:59:59.000Z

263

Mn, Fe, Zn and As speciation in a fast-growing ferromanganese marine nodule  

SciTech Connect (OSTI)

The speciation of Mn, Fe, As and Zn in a fast-growing (0.02mm/yr), shallow-marine ferromanganese nodule has been examined by micro X-ray fluorescence, micro X-ray diffraction, and micro X-ray absorption spectroscopy. This nodule exhibits alternating Fe-rich and Mn-rich layers reflecting redox variations in water chemistry. Fe occurs as two-line ferrihydrite. The As is strictly associated with Fe and is mostly pentavalent, with an environment similar to that of As sorbed on or coprecipitated with synthetic ferrihydrite. The Mn is in the form of turbostratic birnessite with {approx} 10 percent trivalent manganese in the layers and probably {approx} 8 percent corner-sharing metal octahedra in the interlayers. The Zn is enriched on the rim of the nodule, associated with Mn. The Zn is completely (>90 percent) tetrahedrally coordinated and sorbed in the interlayers of birnessite on vacant layer Mn sites. The Zn and Mn species are similar to ones found in soils, suggesting common structural principles, despite the differing formation conditions in these systems.

Marcus, Matthew A.; Manceau, Alain; Kersten, Michael

2004-04-01T23:59:59.000Z

264

Fabrication of ZnO nanorod using spray-pyrolysis and chemical bath deposition method  

SciTech Connect (OSTI)

ZnO thin films with nanorod structure were deposited using Ultrasonic Spray Pyrolysis method for seed growth, and Chemical Bath Deposition (CBD) for nanorod growth. High purity Zn-hydrate and Urea are used to control Ph were dissolved in ethanol and aqua bidest in Ultrasonic Spray Pyrolysis process. Glass substrate was placed above the heater plate of reaction chamber, and subsequently sprayed with the range duration of 5, 10 and 20 minutes at the temperatures of 3500 C. As for the Chemical Bath Deposition, the glass substrate with ZnO seed on the surface was immerse to Zn-hydrate, HMTA (Hexa Methylene Tetra Amine) and deionized water solution for duration of 3, 5 and 7 hour and temperatures of 600 C, washed in distilled water, dried, and annealed at 3500 C for an hour. The characterization of samples was carried out to reveal the surface morphology using Scanning Electron Microscopy (SEM). From the data, the combination of 5 minutes of Ultrasonic Spray Pyrolysis process and 3 hour of CBD has showed the best structure of nanorod. Meanwhile the longer Spraying process and CBD yield the bigger nanorod structure that have been made, and it makes the films more dense which make the nanorod collide each other and as a result produce unsymetric nanorod structure.

Ramadhani, Muhammad F., E-mail: brian@tf.itb.ac.id; Pasaribu, Maruli A. H., E-mail: brian@tf.itb.ac.id; Yuliarto, Brian, E-mail: brian@tf.itb.ac.id; Nugraha, E-mail: brian@tf.itb.ac.id [Advanced Functional Materials Laboratory, Engineering Physics Department Faculty of Industrial Technology, Institut Teknologi Bandung (Indonesia)

2014-02-24T23:59:59.000Z

265

Acceptors in ZnO nanocrystals: A reinterpretation W. Gehlhoff and A. Hoffmann  

E-Print Network [OSTI]

et al. reported on the identification of an uncompensated acceptor in ZnO nanocrystals using infrared and valence band splitting. VC 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4773524] Bulk. Recently, Teklemichael, Hlaing Oo, McCluskey et al.5 (THC) reported on the identification

Nabben, Reinhard

266

Nondestructive In Situ Identification of Crystal Orientation of Anisotropic ZnO  

E-Print Network [OSTI]

Nondestructive In Situ Identification of Crystal Orientation of Anisotropic ZnO Nanostructures to their unique mechanical, electrical, and optical proper- ties compared to their bulk counterparts.1 4 Important, a fast, unambiguous, and nondestructive technique for identification of the crystalline orientation

Wang, Zhong L.

267

Rapid degradation of CdSe/ZnS colloidal quantum dots exposed to gamma irradiation  

E-Print Network [OSTI]

on irradiation dose. CdSe/ZnS quantum dots show poor radiation hardness, and severely degrade after less than 20 of light sources to ionizing radiation, it is important to know the levels of irradiation that would de of applica- tions ranging from optoelectronic through photocatalytic to biomedical, including applications

New Mexico, University of

268

CO2 gas sensing properties of DC reactive magnetron sputtered ZnO thin film  

Science Journals Connector (OSTI)

Abstract Nanostructured ZnO thin films were deposited on glass substrates using a DC reactive magnetron sputtering technique. Thin films of three different thicknesses viz 40, 100 and 300 nm were prepared and subsequently annealed at 450 °C. The structural, topographical, and optical characteristics of all the three annealed films were studied using X-ray diffractometer (XRD), Atomic Force Microscope (AFM) UV–visible and photoluminescence spectrophotometers. The carbon dioxide (CO2) gas sensing behavior of these films was investigated in detail in the concentration range of 500–10,000 ppm. The sensing performance was optimized with respect to the ZnO film thickness as well as the operating temperature. ZnO film with 40 nm thickness showed better response characteristics at the operating temperature of 300 °C than that of thicker ZnO films. A maximum sensitivity (%) of 1.13 with a response and recovery time of 20 s was observed towards 1000 ppm of CO2.

Padmanathan Karthick Kannan; Ramiah Saraswathi; John Bosco Balaguru Rayappan

2014-01-01T23:59:59.000Z

269

Supporting Information Oligo-and Poly-thiophene/ZnO Hybrid Nanowire Solar Cells  

E-Print Network [OSTI]

1 Supporting Information Oligo- and Poly-thiophene/ZnO Hybrid Nanowire Solar Cells Alejandro L with 1M HCl. The ether was evaporated to yield crude product that was purified by column chromatography and the organic phase washed with 1M HCl. The #12;2 dichloromethane was removed under reduced pressure to yield

Yang, Peidong

270

The electrochemical lithium reactions of monoclinic ZnP2 material{{ Haesuk Hwang,a  

E-Print Network [OSTI]

The electrochemical lithium reactions of monoclinic ZnP2 material{{ Haesuk Hwang,a Min Gyu Kim was developed, and out to 545 mAh g21 , only topotactic lithium ion intercalation into the molecule pores was observed. The excess Li ion uptake beyond simple Li intercalation (.545 mAh g21 ) into molecular pores can

Cho, Jaephil

271

Hierarchically Structured ZnO Nanorods-Nanosheets for Improved Quantum-Dot-Sensitized Solar Cells  

E-Print Network [OSTI]

). This hierarchical structure had two advantages in improving the power conversion efficiency (PCE) of the solar cells. INTRODUCTION The establishment of low-cost and high-performance solar cells for sustainable energy sourcesHierarchically Structured ZnO Nanorods-Nanosheets for Improved Quantum-Dot-Sensitized Solar Cells

Cao, Guozhong

272

Factors Affecting Ni and Zn Hydroxide Precipitate Formation in Soils. (S02-peltier222185-oral)  

E-Print Network [OSTI]

Factors Affecting Ni and Zn Hydroxide Precipitate Formation in Soils. (S02-peltier222185-oral) Authors: E.F. Peltier* - Univ. of Delaware D.L. Sparks - Univ. of Delaware Abstract: The formation matter in the soil. Speaker Information: Edward Peltier, Univ. of Delaware, Dept. of Plant and Soil

Sparks, Donald L.

273

Hydrogen at zinc vacancy of ZnO: An EPR and ESEEM study  

SciTech Connect (OSTI)

An electron paramagnetic resonance (EPR) spectrum, labeled S1, with small-splitting doublet accompanied by weak satellites is observed in ZnO irradiated with 2 MeV electrons. The obtained structure is shown to be the hyperfine structure due to the dipolar interaction between an unpaired electron spin and a nuclear spin of hydrogen (H). The observation of the nuclear Zeeman frequency of H in electron spin echo envelope modulation experiments further confirmed the presence of a hydrogen atom in S1. From the observed spin-Hamiltonian parameters, S1 is identified to be the partly H-passivated Zn vacancy, V{sub Zn}{sup ?}H{sup +}, with the H{sup +} ion making a short O-H bond with only one nearest O neighbor of V{sub Zn} in the basal plane, being off the substitutional site, while the unpaired electron spin, which gives rise to the observed EPR signal, is localized on the p orbital of another O neighbor also in the basal plane.

Son, N. T.; Ivanov, I. G.; Janzén, E. [Department Physics, Chemistry and Biology, Linköping University, SE-58183 Linköping (Sweden); Isoya, J. [Graduate School of Library, Information and Media Studies, University of Tsukuba, Tsukuba, Ibaraki 305-8550 (Japan); Ohshima, T. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan)

2014-02-21T23:59:59.000Z

274

Aqueous synthesis and characterization of CdSe/ZnO core-shell nanoparticles  

Science Journals Connector (OSTI)

Core-shell nanomaterials based on CdSe as the core and ZnO as the shell were prepared using an aqueous route involving the use of Cd salt and NaBH4 in reaction with Se to generate CdSe in the presence of thioglycerol (TG) as a stabilizer. ...

B. P. Rakgalakane; M. J. Moloto

2011-01-01T23:59:59.000Z

275

Microwave accelerated one-minute synthesis of luminescent ZnO quantum dots  

Science Journals Connector (OSTI)

In this paper we present microwave assisted non-aqueous synthesis of ZnO quantum dots (QDs) by hydrolyzing zinc acetate with lithium hydroxide in ethanol under microwave heating. The processing time for QDs was reduced to few minutes when compared with time consuming sol–gel chemistry. The prepared QDs show good colloidal stability along with stable visible emission.

Adersh Asok; A. R. Kulkarni; Mayuri N. Gandhi

2013-01-01T23:59:59.000Z

276

Short communication Measuring the aspect ratios of ZnO nanobelts  

E-Print Network [OSTI]

^ 15 nm for ZnO at 200 kV. The thicknesses of the thinner nanobelts are then determined by EELS using in that they are almost void of dislocations and other line-defects, making them important for electronic and shape (Wang, 1999). The width of the nanobelts can be precisely determined by transmission electron

Wang, Zhong L.

277

Bandgap engineering of CdxZn1xTe nanowires Keivan Davami,a  

E-Print Network [OSTI]

junction. These structures have been used in solar cells2,3 and eld effect transistors.4 Alloy nanowires device fabrication. Alloy nano- wires in various systems have been used to construct solar cells into a furnace. In a set of trial experiments, ZnTe (99.99% Aldrich) and CdTe (99.99% Aldrich) source powders

Cuniberti, Gianaurelio

278

Crystallographic Orientation-Aligned ZnO Nanorods Grown by a Tin Catalyst  

E-Print Network [OSTI]

, has a wide range of applications in solar cells,1 sensors,2-4 optoelectronic devices, and surface a horizontal tube furnace, a rotary pump system, and a gas supply system. A mixture of commercial ZnO, SnO2). The entire length of the tube furnace is 50 cm. The desired nanostruc- tures were deposited onto an alumina

Wang, Zhong L.

279

Interpenetrative and transverse growth process of self-catalyzed ZnO nanorods  

E-Print Network [OSTI]

for short-wavelength optoelectronics [1] and transparent con- ducting windows for solar cells [2 evaporation process in a horizontal tube furnace. Commercial grade ZnO powder was place in the center of a single zone tube furnace and evacuated for several hours to purge oxygen in the chamber. Polycrystalline

Wang, Zhong L.

280

Microstructure and nanohardness distribution in a polycrystalline Zn deformed by high strain rate impact  

E-Print Network [OSTI]

-Munitions, 7 route de Guerry, 18023 Bourges Cedex, France c Department of Materials Physics, Eötvös Loránd grain size of 20 m surrounded by a fine-grained rim with an average grain size of 6 m. Transmission in high purity polycrystal- line Zn. The evolution of the microstructure due to the impact loading

Gubicza, Jenõ

Note: This page contains sample records for the topic "zn zurn ot" 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

E-Print Network 3.0 - aleaciones cu-zn-al estabilidad Sample...  

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

C2, suppl6mentau Journal de Physique 111,Volume 5, f6vrier 1995 Summary: The shape memory alloys which are industrially used are based upon NiTi, CuZnAl and CuAlNi to which...

282

Cu2ZnSnS4 nanocrystals and graphene quantum dots for photovoltaics Xukai Xinab  

E-Print Network [OSTI]

Cu2ZnSnS4 nanocrystals and graphene quantum dots for photovoltaics Jun Wang,a Xukai Xinab advances in the synthesis and utilization of CZTS nanocrystals and colloidal GQDs for photovoltaics emerged to achieve low cost, high perfor- mance photovoltaics, including organic solar cells,2­6 dye

Lin, Zhiqun

283

Cu/Zn-based catalysts improved by adding magnesium for water–gas shift reaction  

Science Journals Connector (OSTI)

Ternary Cu/MeO/ZnO (Me: alkaline-earth metal, Mg, Ca, Sr and Ba) catalysts were prepared by homogeneous precipitation (hp) using urea hydrolysis. The structure and the activity for the water–gas shift reaction of these catalysts were studied compared with those of the catalysts prepared by coprecipitation (cp). The highest activity was obtained over hp-Cu/MgO/ZnO among the catalysts tested. The catalyst precursors after the precipitation contained mainly aurichalcite, (Cu,Zn)5(CO3)2(OH)16, while the decomposed products after the calcination contained apparently CuO and ZnO as crystalline phases, since the amount of Mg actually included in the catalyst was less than 1.0 at.%. The Cu metal surface area was larger and the particle size of Cu metal was smaller on the hp-catalysts than those on the cp-catalysts; nonetheless the BET surface area was sometimes larger on the latter than on the former. The addition of ?0.1 at.% of Mg was the most effective, resulting in the highest activity as well as the lowest activation energy. A good correlation was observed between the amount of Cu+ species and the activation energy of the shift reaction, suggesting that MgO significantly enhanced the formation of Cu+ species as the active sites. Even after the pre-reduction at the high temperature, 250 °C, hp-Cu/MgO/ZnO catalyst showed no significant decrease in the activity as well as no detectable sintering in the Cu metal particles during 50 h of the reaction. It was supposed that the shift reaction proceeds by a reduction–oxidation mechanism between Cu0 ? Cu+.

Tetsuya Shishido; Manabu Yamamoto; Ikuo Atake; Dalin Li; Yan Tian; Hiroyuki Morioka; Masahide Honda; Tsuneji Sano; Katsuomi Takehira

2006-01-01T23:59:59.000Z

284

Simulations of phase transitions in Rb2ZnCl4  

Science Journals Connector (OSTI)

Structural relaxations, molecular-dynamics simulations, and lattice-dynamics calculations were performed to study the phase transitions in Rb2ZnCl4, using intermolecular and intramolecular potentials generated from ab initio quantum-chemistry calculations for the whole molecular ion ZnCl42-. Compared with an earlier treatment of the system by a polarizable-ion model, the present approach emphasizes the static effect of the electron covalency within the molecular ions that affects strongly both the intermolecular and intramolecular interactions. The calculations gave a close agreement with experiment on the static structures of the Pnam and the Pna21 phases and the transition temperature from the former to the latter. For the lower-temperature, monoclinic phase of Rb2ZnCl4, the detailed structure of which is unknown, our simulations predict a structure with C1c1 space-group symmetry, which doubles the Pna21 structure along both the b and c axes and thus has 48 formula units per unit cell. The lattice-dynamics calculations for the Pna21 structure clearly revealed the lattice instability responsible for the Pna21-monoclinic transition and provided a more convincing explanation of a previous Raman measurement. We have shown that the potential-energy surface in Rb2ZnCl4 pertinent to the phase transitions contains a double-well structure, very similar to that of K2SeO4, except that the double well is much deeper, causing the much more severe disordering in the Pnam structure of Rb2ZnCl4 observed experimentally.

H. M. Lu and J. R. Hardy

1992-04-01T23:59:59.000Z

285

Acceptor formation mechanisms determination from electrical and optical properties of p-type ZnO doped with lithium and nitrogen  

Science Journals Connector (OSTI)

A lithium (Li) and nitrogen (N) dual-doped p-type ZnO film (ZnO?:?(Li,N)) was deposited on c-plane sapphire by RF-magnetron sputtering of Zn–2?at.% Li alloy using mixed gases of oxygen and nitrogen and then annealing in N2 flow. It has a carrier concentration of 3.07 ? 1016?cm?3 and Hall mobility of 1.74?cm2?V?1?s?1. XPS measurement shows that there are LiZn–N complexes in the p-type ZnO?:?(Li,N), which are demonstrated by photoluminescence measured at various temperatures and different excitation powers to be acceptors and responsible for p-type conductivity of the ZnO?:?(Li,N). The optical level of the LiZn–N complex acceptor is estimated to be about 126?meV by measurement of emission energy of free electron to the acceptor level.

X H Wang; B Yao; Z P Wei; D Z Sheng; Z Z Zhang; B H Li; Y M Lu; D X Zhao; J Y Zhang; X W Fan; L X Guan; C X Cong

2006-01-01T23:59:59.000Z

286

Room-Temperature Ferromagnetism in a II-VI Diluted Magnetic Semiconductor Zn1-xCrxTe  

Science Journals Connector (OSTI)

The magnetic and magneto-optical properties of a Cr-doped II-VI semiconductor ZnTe were investigated. Magnetic circular dichroism measurements showed a strong interaction between the sp carriers and localized d spins, indicating that Zn1-xCrxTe is a diluted magnetic semiconductor. The Curie temperature of the film with x=0.20 was estimated to be 300±10???K, which is the highest value ever reported for a diluted magnetic semiconductor in which sp-d interactions were confirmed. In spite of its high Curie temperature, Zn1-xCrxTe film shows semiconducting electrical transport properties.

H. Saito; V. Zayets; S. Yamagata; K. Ando

2003-05-20T23:59:59.000Z

287

Zn-Doping Dependence of Stripe Order in La1.905Ba0.095CuO4  

SciTech Connect (OSTI)

The effect of Zn-doping on the stripe order in La{sub 1.905}Ba{sub 0.095}CuO{sub 4} has been studied by means of x-ray and neutron diffraction as well as magnetization measurements. While 1% Zn leads to an increase of the spin stripe order, it unexpectedly causes a wipe out of the visibility of the charge stripe order. A magnetic field of 10 Tesla applied along the c-axis has no reversing effect on the charge order. We compare this observation with the Zn-doping dependence of the crystal structure, superconductivity, and normal state magnetism.

Hucker, M.; Zimmermann, M.v.; Xu, Z.J.; Wen, J.S.; Gu, G.D.; Tian, W.; Zarestky, J.; Tranquada, J.M.

2011-04-01T23:59:59.000Z

288

Band structure engineering for solar energy applications: ZnO1-xSex films and devices  

E-Print Network [OSTI]

W. Walukiewicz, and J. Wu, Solar Energy Materials and Solarand M. J. Carter, Solar Energy Materials and Solar Cells 51,structure engineering for solar energy applications: ZnO 1-x

Mayer, Marie Annette

2012-01-01T23:59:59.000Z

289

Influence of N-doping on the thermal stability and switching speed of Zn15Sb85 phase change material  

Science Journals Connector (OSTI)

The phase change characteristics of nitrogen doping Zn15Sb85 thin films were investigated by in situ film resistance measurements. The crystallization temperature and activation energy for crystallization of thin...

Xiaoqin Zhu; Yifeng Hu; Hua Zou…

2014-11-01T23:59:59.000Z

290

Cross-Linked ZnO nanowalls immobilized onto bamboo surface and their use as recyclable photocatalysts  

Science Journals Connector (OSTI)

A novel recyclable photocatalyst was fabricated by hydrothermal method to immobilize the cross-linked ZnO nanowalls on the bamboo surface. The resultant samples were characterized by using scanning electron microscopy (SEM), X-ray diffraction (XRD), ...

Chunde Jin, Jingpeng Li, Jin Wang, Shenjie Han, Zhe Wang, Qingfeng Sun

2014-01-01T23:59:59.000Z

291

A Study of the Zn-based Desulfurization Sorbents for H2S Removal in the IGCC  

Science Journals Connector (OSTI)

Recently, the possibility for the simultaneous removal of H2S and NH3...on the Zn–Ti-based sorbents has been tested by various researchers using several additives like Co, Ni, Fe, Mo and ... W. However, the resea...

Suk Yong Jung; Soo Chool Lee; Hee Kwon Jun; Jae Chang Kim

2013-06-01T23:59:59.000Z

292

Rujevac Sb-Pb-Zn-As polymetallic deposit, Boranja orefield, Western Serbia: native arsenic and arsenic mineralization  

Science Journals Connector (OSTI)

Rujevac is a low-temperature hydrothermal polymetallic Sb-Pb-Zn-As vein-type ore deposit, hosted within a volcanogenic-sedimentary zone situated in the Rujevac-Crvene Stene-Brezovica Diabase-Chert Formation (D...

Slobodan A. Radosavljevi?; Jovica N. Stojanovi?…

2014-02-01T23:59:59.000Z

293

Comment on 'The diatomic dication CuZn{sup 2+} in the gas phase' [J. Chem. Phys. 135, 034306 (2011)  

SciTech Connect (OSTI)

In this Comment, the density functional theory (DFT) calculations carried out by Diez et al. [J. Chem. Phys. 135, 034306 (2011)] are revised within the framework of the coupled-cluster single double triple method. These more sophisticated calculations allow us to show that the {sup 2}{Sigma}{sup +} electronic ground state of CuZn{sup 2+}, characterized as the metastable ground state by DFT calculations, is a repulsive state instead. The {sup 2}{Delta} and {sup 2}{Pi} metastable states of CuZn{sup 2+}, on the other hand, should be responsible for the formation mechanism of the dication through the near-resonant electron transfer CuZn{sup +}+ Ar{sup +}{yields} CuZn{sup 2+}+ Ar reaction.

Fiser, Jiri [Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030, 128 40 Prague 2 (Czech Republic); Diez, Reinaldo Pis [Departamento de Quimica, CEQUINOR, Centro de Quimica Inorganica (CONICET, UNLP), Facultad de Ciencias Exactas, UNLP, CC 962, 1900 La Plata (Argentina); Franzreb, Klaus [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287 (United States); Alonso, Julio A. [Departamento de Fisica Teorica, Universidad de Valladolid, E-47011 Valladolid (Spain)

2013-02-21T23:59:59.000Z

294

Use of separate ZnTe interface layers to form ohmic contacts to p-CdTe films  

DOE Patents [OSTI]

A method of is disclosed improving electrical contact to a thin film of a p-type tellurium-containing II-VI semiconductor comprising: depositing a first undoped layer of ZnTe on a thin film of p-type tellurium containing II-VI semiconductor with material properties selected to limit the formation of potential barriers at the interface between the p-CdTe and the undoped layer, to a thickness sufficient to control diffusion of the metallic-doped ZnTe into the p-type tellurium-containing II-VI semiconductor, but thin enough to minimize affects of series resistance; depositing a second heavy doped p-type ZnTe layer to the first layer using an appropriate dopant; and depositing an appropriate metal onto the outer-most surface of the doped ZnTe layer for connecting an external electrical conductor to an ohmic contact. 11 figs.

Gessert, T.A.

1999-06-01T23:59:59.000Z

295

Improvement of CIGS thin-film solar cell performance by optimization of Zn(O,S) buffer layer parameters  

Science Journals Connector (OSTI)

The effects of Zn(O,S) buffer layer parameters on CuInGaSe (CIGS) cell performance are investigated using a physically based solar cell model. The key issue for CIGS solar cells is to remove destructive effec...

Samaneh Sharbati; Sayyed Hossein Keshmiri; J. Tyler McGoffin…

2014-10-01T23:59:59.000Z

296

Temperature-dependent photoluminescence of undoped, N-doped and N-In codoped ZnO thin films  

Science Journals Connector (OSTI)

Temperature-dependent photoluminescence properties of undoped, N-doped and N-In codoped p-type ZnO thin films have been investigated in detail. The yielded temperature dependences of ultraviolet peak energy, width and intensity for several resolved emissions exhibit the different carrier recombination processes associated with doping mechanisms. We have revealed the acceptor binding energy of 113?meV, 140?meV and 112?meV and donor one of 56?meV, 82?meV and 112?meV for undoped, N-doped and N-In codoped ZnO, respectively, together with the broadening of the acceptor levels in N-doped and N-In codoped ZnO. We have also clarified the origin of the ZnO deep-level visible emission.

H B Ye; J F Kong; W Z Shen; J L Zhao; X M Li

2007-01-01T23:59:59.000Z

297

Zn(II)–Cr(III) mixed oxide as efficient bifunctional catalyst for dehydroisomerisation of ?-pinene to p-cymene  

Science Journals Connector (OSTI)

Zn(II)–Cr(III) mixed oxide possessing acid and dehydrogenation functions is an efficient, noble-metal-free catalyst for the one-step dehydroisomerisation of ?-pinene to p-cymene. This reaction is a good example of the use of heterogeneous multifunctional catalysis for the conversion of renewable feedstock into value-added chemicals. It involves acid-catalysed ?-pinene isomerisation followed by dehydrogenation of p-cymene precursor(s). The reaction is carried out over a fixed catalyst bed in the gas phase at 350 °C. Amongst Zn–Cr oxides studied (Zn/Cr = 20:1–1:30), the preferred catalyst is Zn–Cr (1:1) oxide which produces p-cymene with a 78% yield at 100% ?-pinene conversion. This catalyst shows stable performance for over 30 h without co-feeding hydrogen to the reactor.

Fahd Al-Wadaani; Elena F. Kozhevnikova; Ivan V. Kozhevnikov

2009-01-01T23:59:59.000Z

298

Electronic structure of Al- and Ga-doped ZnO films studied by hard X-ray photoelectron spectroscopy  

SciTech Connect (OSTI)

Al- and Ga-doped sputtered ZnO films (AZO, GZO) are semiconducting and metallic, respectively, despite the same electronic valence structure of the dopants. Using hard X-ray photoelectron spectroscopy we observe that both dopants induce a band in the electronic structure near the Fermi level, accompanied by a narrowing of the Zn 3d/O 2p gap in the valence band and, in the case of GZO, a substantial shift in the Zn 3d. Ga occupies substitutional sites, whereas Al dopants are in both substitutional and interstitial sites. The latter could induce O and Zn defects, which act as acceptors explaining the semiconducting character of AZO and the lack of variation in the optical gap. By contrast, mainly substitutional doping is consistent with the metallic-like behavior of GZO.

Gabás, M.; Ramos Barrado, José R. [Lab. de Materiales and Superficies, Dpto. de Física Aplicada I, Universidad de Málaga, 29071 Málaga (Spain); Torelli, P. [Laboratorio TASC, IOM-CNR, S.S. 14 km 163.5, Basovizza, I-34149 Trieste (Italy); Barrett, N. T. [CEA, DSM/IRAMIS/SPCSI, F-91191 Gif-sur-Yvette Cedex (France); Sacchi, M. [Synchrotron SOLEIL, BP 48, 91192 Gif-sur-Yvette, France and Institut des NanoSciences de Paris, UPMC Paris 06, CNRS UMR 7588, 4 Place Jussieu, 75005 Paris (France)

2014-01-01T23:59:59.000Z

299

Characteristics of light-induced electron transport from P3HT to ZnO-nanowire field-effect transistors  

SciTech Connect (OSTI)

We fabricated ZnO-nanowire (NW) field-effect transistors (FETs) coated with poly(3-hexylthiophene) (P3HT) and characterized the electron-transfer characteristics from the P3HT to the ZnO NWs. Under irradiation by laser light with a wavelength of 532?nm, photo-induced electrons were created in the P3HT and then transported to the ZnO NWs, constituting a source-drain current in the initially enhancement-mode P3HT-coated ZnO-NW FETs. As the intensity of the light increased, the current increased, and its threshold voltage shifted to the negative gate-bias direction. We estimated the photo-induced electron density and the electron-transfer characteristics, which will be helpful for understanding organic-inorganic hybrid optoelectronic devices.

Choe, Minhyeok; Hoon Lee, Byoung; Park, Woojin; Kang, Jang-Won; Jeong, Sehee; Hun Lee, Byoung; Lee, Kwanghee; Park, Seong-Ju, E-mail: sjpark@gist.ac.kr [School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of)] [School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Cho, Kyungjune; Lee, Takhee, E-mail: tlee@snu.ac.kr [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)] [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Hong, Woong-Ki [Jeonju Center, Korea Basic Science Institute, Jeonju 561-756 (Korea, Republic of)] [Jeonju Center, Korea Basic Science Institute, Jeonju 561-756 (Korea, Republic of)

2013-11-25T23:59:59.000Z

300

ZnWO4 nanocrystals/reduced graphene oxide hybrids: Synthesis and their application for Li ion batteries  

Science Journals Connector (OSTI)

ZnWO4..., as an environment-friendly and economic material, has the potential for Li ion batteries (LIB) application. In this paper,...4 supported on the reduced graphene oxide (RGO) to improve its LIB...4 nanocr...

Xiao Wang; BoLong Li; DaPeng Liu; HuanMing Xiong

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" 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

Structural, electronic and optical properties of CdxZn1 ? xS alloys from first-principles calculations  

Science Journals Connector (OSTI)

Abstract Structural, electronic and optical properties as well as structural phase transitions of ternary alloy CdxZn1 ? xS have been investigated using the first-principles calculations based on the density functional theory. We found that the crystal structure of CdxZn1 ? xS alloys transforms from wurtzite to zinc blende as Cd content of x = 0.83 . Effect of Cd content on electronic structures of CdxZn1 ? xS alloys has been studied. The bandgaps of CdxZn1 ? xS alloys with wurtzite and zinc blende structures decrease with the increase of Cd content. Furthermore, dielectric constant and absorption coefficient also have been discussed in detail.

Meiling Xu; Yongfeng Li; Bin Yao; Zhanhui Ding; Gang Yang

2014-01-01T23:59:59.000Z

302

Comparative Study of Zn(O,S) Buffer Layers and CIGS Solar Cells Fabricated by CBD, ALD, and Sputtering: Preprint  

SciTech Connect (OSTI)

Zn(O,S) thin films were deposited by chemical bath deposition (CBD), atomic layer deposition, and sputtering. Composition of the films and band gap were measured and found to follow the trends described in the literature. CBD Zn(O,S) parameters were optimized and resulted in an 18.5% efficiency cell that did not require post annealing, light soaking, or an undoped ZnO layer. Promising results were obtained with sputtering. A 13% efficiency cell was obtained for a Zn(O,S) emitter layer deposited with 0.5%O2. With further optimization of process parameters and an analysis of the loss mechanisms, it should be possible to increase the efficiency.

Ramanathan, K.; Mann, J.; Glynn, S.; Christensen, S.; Pankow, J.; Li, J.; Scharf, J.; Mansfield, L. M.; Contreras, M. A.; Noufi, R.

2012-06-01T23:59:59.000Z

303

Bipolar resistive switching characteristics of low temperature grown ZnO thin films by plasma-enhanced atomic layer deposition  

SciTech Connect (OSTI)

ZnO films deposited by plasma-enhanced atomic layer deposition (PEALD) have been used to investigate resistive memory behavior. The bipolar resistance switching properties were observed in the Al/PEALD-ZnO/Pt devices. The resistance ratio for the high and low resistance states (HRS/LRS) is more than 10{sup 3}, better than ZnO devices deposited by other methods. The dominant conduction mechanisms of HRS and LRS are trap-controlled space charge limited current and Ohmic behavior, respectively. The resistive switching behavior is induced upon the formation/disruption of conducting filaments. This study demonstrated that the PEALD-ZnO films have better properties for the application in 3D resistance random access memory.

Zhang Jian; Yang Hui; Zhang Qilong [Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China)] [Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Dong Shurong [Department of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027 (China)] [Department of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027 (China); Luo, J. K. [Department of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027 (China) [Department of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027 (China); Institute of Material Research and Innovation, Bolton University, Deane Road, Bolton BL3 5AB (United Kingdom)

2013-01-07T23:59:59.000Z

304

Use of separate ZnTe interface layers to form OHMIC contacts to p-CdTe films  

DOE Patents [OSTI]

A method of improving electrical contact to a thin film of a p-type tellurium-containing II-VI semiconductor comprising: depositing a first undoped layer of ZnTe on a thin film of p-type tellurium containing II-VI semiconductor with material properties selected to limit the formation of potential barriers at the interface between the p-CdTe and the undoped layer, to a thickness sufficient to control diffusion of the metallic-doped ZnTe into the p-type tellurim-containing II-VI semiconductor, but thin enough to minimize affects of series resistance; depositing a second heavy doped p-type ZnTe layer to the first layer using an appropriate dopant; and depositing an appropriate metal onto the outer-most surface of the doped ZnTe layer for connecting an external electrical conductor to an ohmic contact.

Gessert, Timothy A. (Conifer, CO)

1999-01-01T23:59:59.000Z

305

Atomic scattering spectroscopy for determination of the polarity of semipolar AlN grown on ZnO  

SciTech Connect (OSTI)

Determination of the polarity of insulating semipolar AlN layers was achieved via atomic scattering spectroscopy. The back scattering of neutralized He atoms on AlN surfaces revealed the atomic alignment of the topmost layers of semipolar AlN and the ZnO substrate. Pole figures of the scattering intensity were used to readily determine the polarity of these wurtzite-type semipolar materials. In addition, we found that +R-plane AlN epitaxially grows on ?R-plane ZnO, indicating that the polarity flips at the semipolar AlN/ZnO interface. This polarity flipping is possibly explained by the appearance of ?c and m-faces on the ?R ZnO surfaces, which was also revealed by atomic scattering spectroscopy.

Kobayashi, Atsushi; Ohta, Jitsuo [Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505 (Japan)] [Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505 (Japan); Ueno, Kohei; Oshima, Masaharu [Department of Applied Chemistry, The University of Tokyo, Tokyo 113-8656 (Japan) [Department of Applied Chemistry, The University of Tokyo, Tokyo 113-8656 (Japan); Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo 113-8656 (Japan); Fujioka, Hiroshi, E-mail: hfujioka@iis.u-tokyo.ac.jp [Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505 (Japan) [Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505 (Japan); CREST, Japan Science and Technology Agency (JST), Tokyo 102-0076 (Japan)

2013-11-04T23:59:59.000Z

306

Cu–Zn–Al mixed metal oxides derived from hydroxycarbonate precursors for H2S removal at low temperature  

Science Journals Connector (OSTI)

One series of Cu–Zn and two series of Cu–Zn–Al hydroxycarbonate precursors with varying metal molar ratios were prepared via co-precipitation or multi-precipitation method, and the mixed metal oxides obtained by calcination of the precursor materials were used as adsorbents for H2S removal in the range of 25–100 °C. The results of H2S adsorption tests showed that these mixed oxides, especially two series of Cu–Zn–Al mixed metal oxides exhibited markedly high breakthrough sulfur capacities (ranging from 4.4 to 25.7 g S/100 g-sorbent with increase of Cu/Zn molar ratio) at 40 °C. Incorporation Cu and/or Al decreased the mean crystalline sizes of ZnO and CuO species in the Cu–Zn and Cu–Zn–Al mixed metal oxide adsorbents by decreasing of mean crystalline sizes of hydroxycarbanate phases mainly including hydrozincite, aurichalcite and malachite, segregation of Al phase, etc. Higher breakthrough sulfur capacity of each adsorbent in two ternary series than that of the corresponding adsorbent in binary series should be ascribed to the enhancement of the dispersion of ZnO and/or CuO species with incorporation of aluminum, thereby increasing the overall rate of reaction between the adsorbent and H2S by reducing the thickness of potential sulfide shell on the outer layer of the oxide crystalline grains and increasing the area of the interface for the exchange of HS?/S2? and O2?. For each series of adsorbents, the breakthrough sulfur capacity increased with the increase of Cu/Zn molar ratio regardless of changes of the dispersion of CuO and/or ZnO. This phenomenon might be mainly attributed to faster rate of the lattice diffusion of HS?, S2? and O2? or exchange of HS?/S2? and O2? during the sulfidation of CuO than that during the sulfidation of ZnO due to less rearrangement of the anion lattice.

Dahao Jiang; Lianghu Su; Lei Ma; Nan Yao; Xiaoliang Xu; Haodong Tang; Xiaonian Li

2010-01-01T23:59:59.000Z

307

Effective MgO surface doping of Cu/Zn/Al oxides as water–gas shift catalysts  

Science Journals Connector (OSTI)

Trace amounts of MgO were doped on Cu/ZnO/Al2O3 catalysts with the Cu/Zn/Al molar ratio of 45/45/10 and tested for the water–gas shift (WGS) reaction. A mixture of Zn(Cu)–Al hydrotalcite (HT) and Cu/Zn aurichalcite was prepared by co-precipitation (cp) of the metal nitrates and calcined at 300 °C to form the catalyst precursor. When the precursor was dispersed in an aqueous solution of Mg(II) nitrate, HT was reconstituted by the “memory effect.” During this procedure, the catalyst particle surface was modified by MgO-doping, leading to a high sustainability. Contrarily, cp-Mg/Cu/Zn/Al prepared by Mg2+, Cu2+, Zn2+ and Al3+ co-precipitation as a control exhibited high activity but low sustainability. Mg2+ ions were enriched in the surface layer of m-Mg–Cu/Zn/Al, whereas Mg2+ ions were homogeneously distributed throughout the particles of cp-Mg/Cu/Zn/Al. CuO particles were significantly sintered on the m-catalyst during the dispersion, whereas CuO particles were highly dispersed on the cp-catalyst. However, the m-catalyst was more sustainable against sintering than the cp-catalyst. Judging from TOF, the surface doping of MgO more efficiently enhanced an intrinsic activity of the m-catalyst than the cp-catalyst. Trace amounts of MgO on the catalyst surface were enough to enhance both activity and sustainability of the m-catalyst by accelerating the reduction–oxidation between Cu0 and Cu+ and by suppressing Cu0 (or Cu+) oxidation to Cu2+.

Kazufumi Nishida; Dalin Li; Yingying Zhan; Tetsuya Shishido; Yasunori Oumi; Tsuneji Sano; Katsuomi Takehira

2009-01-01T23:59:59.000Z

308

Dynamic Cu/Zn Interaction in SiO2 Supported Methanol Synthesis Catalysts Unraveled by in Situ XAFS  

Science Journals Connector (OSTI)

Fujitani et al.(15) already observed that formation of an intimately mixed Cu/Zn/carbonate aurichalcite phase during the preparation stage enhanced the creation of a Cu–Zn alloy, which they identified as the main active site in methanol synthesis after calcination and reduction. ... method through a precursor of aurichalcite is ascribed to both improvements in the Cu surface area and the specific activity. ...

Didier Grandjean; Vladimir Pelipenko; Erdni D. Batyrev; Johannes C. van den Heuvel; Alexander A. Khassin; Tamara. M. Yurieva; Bert M. Weckhuysen

2011-08-30T23:59:59.000Z

309

Johillerit, Na(Mg, Zn)3 Cu(AsO4)3, ein neues Mineral aus Tsumeb, Namibia  

Science Journals Connector (OSTI)

Electron microprobe analysis of the new mineral johillerite gave Na2O 5.4, MgO 18.3, ZnO 5.4, CuO 15.8, and As2O5 55.8, total 100.7%. From this result, the ideal formula is given as Na(Mg, Zn)3 Cu(AsO4)3. Johille...

Prof. Dr. P. Keller; Prof. Dr. H. Hess…

1982-01-01T23:59:59.000Z

310

Effects of zinc anneals in the (400-550 C) range on the acceptor concentration in ZnTe  

E-Print Network [OSTI]

: dans le coeur des échantillons, on libère les impuretés cuivre et lithium qui passent en site accepteur-550 °C gives two effects : within the bulk of the samples, impurities (copper and lithium) are released from the Te excess and act as CuZn and LiZn. On the surface, an elec- trically compensated zone

Boyer, Edmond

311

Optically optimal wavelength-scale patterned ITO/ZnO composite coatings for thin film solar cells  

E-Print Network [OSTI]

A new methodology is proposed for finding structures that are, optically speaking, locally optimal : a physical analysis of much simpler structures is used to constrain the optimization process. The obtained designs are based on a flat amorphous silicon layer (to minimize recombination) with a patterned anti-reflective coating made of ITO or ZnO, or a composite ITO/ZnO coating. These latter structures are realistic and present good performances despite very thin active layers.

Moreau, Antoine; Centeno, Emmanuel; Seassal, Christian

2012-01-01T23:59:59.000Z

312

Spectral photoresponse of ZnSe/GaAs(001) heterostructures with CdSe ultra-thin quantum well insertions  

SciTech Connect (OSTI)

We present a study of the spectral photoresponse (SPR) of ZnSe/GaAs(001) heterostructures for different ZnSe film thickness with and without CdSe ultra-thin quantum well (UTQW) insertions. We observe a significant increase of the SPR of heterostructures containing 3 monolayer thick CdSe UTQW insertions; these results encourage their use in photodetectors and solar cells.

Valverde-Chávez, D. A.; Sutara, F.; Hernández-Calderón, I. [Physics Department, Cinvestav-IPN, Av. IPN 2508, 07360 México, DF (Mexico)

2014-05-15T23:59:59.000Z

313

Cobalt(II/III) Redox Electrolyte in ZnO Nanowire-Based Dye-Sensitized Solar Cells  

Science Journals Connector (OSTI)

Thus the present study opens new opportunities to improve energy conversion efficiency in ZnO-based DSCs. ... This allows the rational design and development of hierarchical ZnO nanostructures able to simultaneously optimize charge carrier path and dye loading. ... Finally, a series of Co(II)/Co(III) complexes are systematically investigated to gauge the impact of ligand substitution and of metal coordination (tris-bidentate vs. bis-tridentate) on the HS/LS energy difference and reorganization energies. ...

Jiandong Fan; Yan Hao; Andreu Cabot; Erik M. J. Johansson; Gerrit Boschloo; Anders Hagfeldt

2013-02-28T23:59:59.000Z

314

First-principles study of electronic structures and photocatalytic activity of low-Miller-index surfaces of ZnO  

SciTech Connect (OSTI)

First-principles calculations have been performed to investigate the electronic structures and optical properties of the main low-Miller-index surfaces of ZnO: nonpolar (1010) and (1120) surfaces as well as polar (0001)-Zn and (0001)-O surfaces. According to the structure optimization results, there are similar relaxation behaviors for the (1010) and (1120) surfaces, both with a strong tilting of the surface Zn-O dimers and an obvious contraction of the surface bonds. For the polar surfaces, the surface double layers both tend to relax inwards, but the largest relaxation is found on the (0001)-O surfaces. The calculated band gaps are 0.56, 0.89, 0.21, and 0.71 eV for (1010), (1120), (0001)-Zn and (0001)-O surfaces, respectively. For the nonpolar (1010) and 1120 surfaces, the Fermi levels locate at the valence band maximum, which are similar to that of bulk ZnO. The surface states in the conduction band lead to the increased Fermi level and cause the n-type conduction behavior for (0001)-Zn surface. For the (0001)-O surface, the Fermi level shifts down a little into the valence band, leading to the p-type conduction behavior. From the optical properties calculations, absorption regions of all the four surfaces are quite wide and the main absorption peaks locate in the UV region. For the (0001)-Zn surface, it has the strongest absorptions in the near UV-light range and a remarkable red-shift phenomenon of the absorption edge. This indicates that (0001)-Zn surface has the highest photocatalytic activity among the four surfaces as the low excitation energy is required theoretically. The computed results are in accordance with the experimental observations.

Zhang Haifeng; Lu Shixiang; Xu Wenguo; Yuan Feng [School of Chemistry, Beijing Institute of Technology, Beijing 100081 (China)

2013-01-21T23:59:59.000Z

315

Thermal treatment induced change of diluted oxygen doped ZnTe films grown by metal-organic chemical vapor deposition  

Science Journals Connector (OSTI)

In this paper the authors report the growth of diluted oxygen doped ZnTe films (ZnTe:O) by metal-organic chemical vapor deposition (MOCVD). The effect of a post thermal annealing on the properties of the highly mismatched films has been investigated. It is found that the in-situ doping leads to an effective incorporation of oxygen into ZnTe films with different occupation configurations either on Zn or on Te site. The subsequent annealing process in a vacuum ambient leads to an enhancement of the oxygen incorporation into the ZnTe:O films due to the diffusion of the residual oxygen while the annealing with the same as-grown sample covered on top of the surface (denoted as “face-to-face” annealing in the text) is beneficial to the improvement of the film quality with manifest intermediate band emission at around 1.9?eV as revealed by the low-temperature photoluminescence. This study indicates that the mass-productive MOCVD technique may be suitable for the growth of highly mismatched ZnTe:O films for the application of the intermediate band solar cell.

2014-01-01T23:59:59.000Z

316

Application of the soluble salt-assisted route to scalable synthesis of ZnO nanopowder with repeated photocatalytic activity  

Science Journals Connector (OSTI)

In this paper, the soluble salt-assisted route has been extended to the low-cost and scalable preparation of ZnO nanostructures via the simple oxidation of Zn–Na2SO4 mixture followed by washing with water. The as-prepared ZnO nanopowders are of nanoscaled size, hexagonal phase, and pure, without being stained by Na2SO4. Their optical band gap is 3.22 eV, exhibiting a red-shift of 0.15 eV in comparison with pure ZnO bulk, and their optical absorbance is strong in the region of 200–400 nm, suggesting their full utilization of most of the UV light in sunlight. The product shows evident photocatalytic activity in degradation of RhB under solar light irradiation, and then its solar light degradation efficiency is close to that under UV irradiation, indicating that there is a possibility of practical application. More importantly, the obtained ZnO nanoparticles, because of the quick precipitation by themselves in solution with no stirring, could be easily recycled without any accessorial means such as high-speed centrifuge. The low-cost and scalable preparation, high photocatalytic activity, and convenient recycling of this ZnO nanomaterial gives it potential in purifying waste water. Hence the interesting results in this study indicate the wide range of the soluble salt-assisted route for the industrial preparation of many other advanced nanomaterials.

Yingying Lv; Leshu Yu; Heyong Huang; Yuying Feng; Dongzhen Chen; Xin Xie

2012-01-01T23:59:59.000Z

317

First-principles study of the electronic and structural properties of (CdTe)n/(ZnTe)n superlattices  

Science Journals Connector (OSTI)

Abstract We present the results of a first-principles study of the electronic and structural properties of binary CdTe and ZnTe compounds and their (CdTe)n/(ZnTe)n superlattices (SLs). The computational method is based on the full-potential linear muffin tin orbitals method (FP-LMTO) augmented by a plane-wave basis (PLW). The exchange and correlation energy is described in the local density approximation (LDA) using the Perdew–Wang parameterization including a generalized gradient approximation (GGA). The calculated structural properties of CdTe and ZnTe compounds are in good agreement with available experimental and theoretical data. We have also carried out band-structure calculations for the binary CdTe and ZnTe compounds and their (CdTe)n/(ZnTe)n superlattices (SLs). From the results of the electronic properties, we find that the parent material CdTe and ZnTe and their superlattices have a direct band gaps. The fundamental band gap decreases with increasing the number of monolayer n.

M. Boucharef; S. Benalia; D. Rached; M. Merabet; L. Djoudi; B. Abidri; N. Benkhettou

2014-01-01T23:59:59.000Z

318

Soil and Mold Influences on Fe and Zn Concentrations of Sorghum Grain in Mali, West Africa  

E-Print Network [OSTI]

+ from soil and DTPA similarly complexes these labile forms. Several recent studies involving crops other than sorghum have shown that the concentration of Fe and Zn in the grain does not always consistently reflect DTPA- extractable Fe and Zn...) 22.6 (18.4) 6.60 (3.99) 2.16 (1.20) 15-30 5.96 (0.54) 0.13 (0.13) 0.69 (0.15) 533 (89.9) -- 5.43 (1.44) 0.95 (0.55) Tiguere Field 1 0-15 6.24 (0.58) -- 1.33 (0.08) 590 (54.6) 12.8 (5.7) 7.75 (4.28) 2.78 (1.77) 15-30 5.61 (0...

Verbree, Cheryl

2012-10-19T23:59:59.000Z

319

Quantum Phase Transitions in the Itinerant Ferromagnet ZrZn2  

Science Journals Connector (OSTI)

We report a study of the ferromagnetism of ZrZn2, the most promising material to exhibit ferromagnetic quantum criticality, at low temperatures T as a function of pressure p. We find that the ordered ferromagnetic moment disappears discontinuously at pc=16.5???kbar. Thus a tricritical point separates a line of first order ferromagnetic transitions from second order (continuous) transitions at higher temperature. We also identify two lines of transitions of the magnetization isotherms up to 12 T in the p-T plane where the derivative of the magnetization changes rapidly. These quantum phase transitions (QPT) establish a high sensitivity to local minima in the free energy in ZrZn2, thus strongly suggesting that QPT in itinerant ferromagnets are always first order.

M. Uhlarz; C. Pfleiderer; S. M. Hayden

2004-12-14T23:59:59.000Z

320

Phase assembly and photo-induced current in CdTe-ZnO nanocomposite thin films  

SciTech Connect (OSTI)

Sequential radio-frequency sputtering was used to produce CdTe-ZnO nanocomposite thin films with varied semiconductor-phase extended structures. Control of the spatial distribution of CdTe nanoparticles within the ZnO embedding phase was used to influence the semiconductor phase connectivity, contributing to both changes in quantum confinement induced spectral absorption and carrier transport characteristics of the resulting nanocomposite. An increased number density of CdTe particles deposited along the applied field direction produced an enhancement in the photo-induced current observed. These results highlight the opportunity to employ long-range phase assembly as a means to control optoelectronic properties of significant interest for photovoltaic applications.

Beal, R. J.; Kana Kana, J. B. [Department of Materials Science and Engineering, University of Arizona, Tucson, Arizona 85721 (United States); Potter, B. G. Jr. [Department of Materials Science and Engineering, University of Arizona, Tucson, Arizona 85721 (United States); College of Optical Sciences, University of Arizona, Tucson, Arizona 85721 (United States)

2012-07-16T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" 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

Enhanced ultraviolet photoconductivity in semiconducting ZnGa{sub 2}O{sub 4} thin films  

SciTech Connect (OSTI)

We have investigated the conductivity and photoconductivity response of undoped and Li-doped ZnGa{sub 2}O{sub 4} epitaxial films grown using pulsed-laser deposition. A significant enhancement of the ultraviolet (UV) photoresponse is observed with Li doping that also correlates with an enhanced luminescent intensity. The wavelength dependence observed for creation of free carriers under UV excitation suggests that the transition is either band-to-band or involves a defect level near the band edge. Moderate n-type dark conductivity is observed for undoped films processed under reducing conditions. With Li doping, dark conductivity is reduced, suggesting that lithium ions in the zinc gallate lattice serve as deep acceptors. In addition, Li doping effectively eliminates persistent photoconductivity that is commonly observed in undoped films, suggesting the possible use of Li-doped ZnGa{sub 2}O{sub 4} as a visible wavelength blind UV photodetector.

Lee, Yong Eui; Norton, David P.; Budai, John D.; Wei, Yayi

2001-10-15T23:59:59.000Z

322

Modification of the optical properties of ZnO thin films by proton implantation  

SciTech Connect (OSTI)

Highlights: ? Optical properties of proton-implanted ZnO thin film prepared by rf magneton sputtering were studied. ? Increase in the ordinary refractive index after proton implantation was explained by the polarizability. ? A slight decrease in the optical bandgap by proton implantation was identified. -- Abstract: Optical properties of proton-implanted ZnO thin film prepared by radio-frequency (rf) magneton sputtering have been studied, the optical constants being obtained from the reflectance measurements by employing Cauchy–Urbach model. Increase in the ordinary refractive index after proton implantation was explained by that in the polarizability. Besides, a slight increase in the optical band gap by proton implantation was identified and discussed in terms of the hydrogen shallow donors introduced by the proton implantation.

Ham, Yong Ju; Park, Jun Kue; Lee, W. [Department of Physics and Institute for Nano Science, Korea University, Seoul 136-713 (Korea, Republic of)] [Department of Physics and Institute for Nano Science, Korea University, Seoul 136-713 (Korea, Republic of); Lee, Cheol Eui, E-mail: rscel@korea.ac.kr [Department of Physics and Institute for Nano Science, Korea University, Seoul 136-713 (Korea, Republic of); Park, W. [Graduate School of Management of Technology, Korea University, Seoul 136-713 (Korea, Republic of)] [Graduate School of Management of Technology, Korea University, Seoul 136-713 (Korea, Republic of)

2012-09-15T23:59:59.000Z

323

Evaluation of CdZnTe detectors for soft x-ray applications  

SciTech Connect (OSTI)

High resistivity CdZnTe is a very promising material for X-ray detection at room temperature or slightly below. Cooling a Cd[sub 0.8]Zn[sub 0.2]Te crystal down to [minus]30 C reduces the leakage current to the picoamp level, which enables the use of low-noise pulsed optical feedback instead of noisier resistive feedback preamplifiers. Also, longer shaping time constants at the linear amplifier can be used for the optimum resolution. The authors have obtained resolutions of 240 eV (FWHM) for the 5.9-keV [sup 55]Fe line at [minus]40 C and of 282 eV at [minus]30 C. The Fano factor for the material at [minus]40 C was calculated to be 0.14. These results compare well with the results obtained with peltier-cooled HgI[sub 2] detectors.

Niemelae, A.; Sipilae, H. (Outokumpu Instruments Oy, Espoo (Finland))

1994-08-01T23:59:59.000Z

324

ZnO buffer layer for metal films on silicon substrates  

DOE Patents [OSTI]

Dramatic improvements in metallization integrity and electroceramic thin film performance can be achieved by the use of the ZnO buffer layer to minimize interfacial energy between metallization and adhesion layers. In particular, the invention provides a substrate metallization method utilizing a ZnO adhesion layer that has a high work of adhesion, which in turn enables processing under thermal budgets typically reserved for more exotic ceramic, single-crystal, or metal foil substrates. Embodiments of the present invention can be used in a broad range of applications beyond ferroelectric capacitors, including microelectromechanical systems, micro-printed heaters and sensors, and electrochemical energy storage, where integrity of metallized silicon to high temperatures is necessary.

Ihlefeld, Jon

2014-09-16T23:59:59.000Z

325

Synthesis and thermoelectric properties of Cu excess Cu2ZnSnSe4  

SciTech Connect (OSTI)

Quaternary stannites with an excess of copper were successfully synthesized by reacting the constituent elements and subsequent solid state annealing, followed by densification by hot-pressing. The composition for each specimen was confirmed with a combination of Rietveld refinement and elemental analysis. Their high temperature thermoelectric properties were measured from 300 K to 800 K and compared with that of Cu2ZnSnSe4. The thermal conductivity decreases significantly with increasing Cu content at elevated temperatures due to the crystal structure of this material system. A maximum ZT value of 0.86 was obtained at 800 K for the specimen with the highest Cu content, Cu2.2Zn0.8SnSe4.

Dong, Yongkwan [University of South Florida, Tampa (USF); Wang, Hsin [ORNL; Nolas, G [University of South Florida, Tampa

2014-01-01T23:59:59.000Z

326

Microstructural and optical studies on sonochemically synthesized Cu doped ZnO nanoparticles  

SciTech Connect (OSTI)

Copper doped ZnO nanoparticles were synthesized by sonochemical method varying the concentration of the impurity. Systematic investigations like X-ray diffraction (XRD) and Transmission electron microscopy (TEM) were carried out to understand the microstructural properties. The average particle sizes and all the crystallographic parameters were calculated from XRD results. This shows the formation of wurtzite phase of ZnO with average size of the particles as 53 nm and an increase of particle size with dopant concentration was also been observed. UV absorption and Fourier transformed infrared spectroscopy (FTIR) spectra revealed the absorption at wavelength < 370 nm with a remarkable red shift of absorption band and a linear decrease of transmittance with increase in doping concentrations respectively.

Sahu, Dojalisa, E-mail: dojalisa.sahu@gmail.com; Panda, Nihar Ranjan, E-mail: dojalisa.sahu@gmail.com; Panda, A. K. [Sambalpur University, Jyoti Vihar, Burla -768019, Odisha (India); Acharya, B. S. [C.V. Raman College of Engineering, Bhubaneswar-752054, Odisha (India)

2014-04-24T23:59:59.000Z

327

Formation of ZnS nanorods entrapped in polyacrylic acid (PAA) film  

Science Journals Connector (OSTI)

A simplistic approach for synthesis of zinc sulphide (ZnS) nanorods is reported. The synthesis of ZnS nanoparticles involved mixing of zinc acetate, sodium sulphide and acrylic acid in appropriate ratio at proper conditions, which formed the core. These nanoparticles were trapped in PAA by in-situ polymerization of acrylic acid and carefully casted into the film which resulted into entrapped nanorods in the polymer matrix. The nanoparticles as well as nanorods entrapped in PAA were characterized using high resolution scanning electron microscopy (SEM) for morphological investigations; energy dispersive X-ray analysis (EDAX) for composition and its crystalinity was checked using X-ray diffraction (XRD). The length of nanorods was in the range of 2–4 ?m and thickness between 50–200 nm.

Hemant P. Soni; Diptesh Parmar; Narendra Patel; Mukesh Chawda; Dhananjay Bodas

2008-01-01T23:59:59.000Z

328

Microstructural aspects of nanocrystalline LiZn ferrites densified with chemically derived additives  

SciTech Connect (OSTI)

Densification behavior and microstructural characteristics of nanocrystalline LiZn ferrites with chemically derived additives were investigated. Nanocrystalline Li{sub 0.3}Zn{sub 0.4}Fe{sub 2.3}O{sub 4} powders having a {approx} 15 nm size were prepared at a low temperature of 450 C by a chemical synthesis using a combustible polyacrylic acid (PAA). Small amounts of Si, Ca and Mn were incorporated into the nanocrystalline ferrites via sol-gel reactions utilizing tetraethyl orthosilicate, calcium isopropoxide and manganese acetate. This process was believed to give a homogeneous distribution of the additives over the nanocrystalline ferrites. A uniform microstructure was obtained without any evidence of exaggerated grain growth after sintering at 1,100 C. Saturation magnetization and coercive force were found to increase with the chemical additives. The results were compared with those of the same composition, but processed by the conventional batch-mixing of corresponding oxide additives.

Cho, Y.S.; Burdick, V.L.; Amarakoon, V.R.W. [Alfred Univ., NY (United States). New York State Coll. of Ceramics; Underhill, E.; Brissette, L. [Electromagnetic Science Technologies Inc., Norcross, GA (United States)

1998-12-31T23:59:59.000Z

329

Excited states of acceptors in CdTe and ZnTe  

Science Journals Connector (OSTI)

Higher excited states of acceptors in CdTe and ZnTe are obtained by using the Baldereschi and Lipari spherical model including the cubic correction and the central-cell effect. This is done by solving the coupled radial equations by the finite-element method with Arnoldi's algorithm, which gives several (?20) low-lying states simultaneously. Our procedure allows one to determine very accurately the host band-structure parameters. In the case of CdTe we obtain the Luttinger parameters ?1 = 5.30, ?2 = 1.62, ?3 = 2.10 and the dielectric constant ?0 = 9.3. For ZnTe we obtain ?1 = 3.80, ?2 = 0.86, ?3 = 1.32 and ?0 = 9.4.

M. Said; M.A. Kanehisa

1990-01-01T23:59:59.000Z

330

Recombination dynamics and carrier lifetimes in highly mismatched ZnTeO alloys  

SciTech Connect (OSTI)

This study investigates the recombination dynamics in highly mismatched ZnTeO alloys using time-resolved photoluminescence (PL) spectroscopy. The large PL energy redshift with increasing O content and the disappearance of the ZnTe emission verify the O-induced conduction band anticrossing effect. The incorporation of O generates electron localization below the E{sub ?} conduction subband tail, which provide additional optical transitions and cause complex recombination mechanisms. Photoexcited free electrons in both the E{sub +} and the E{sub ?} conduction subbands favor rapid relaxation to low energy states. Additionally, temperature-independent long carrier lifetimes (>130.0?ns) that are induced by localized electrons increase with O concentration.

Lin, Yan-Cheng, E-mail: bryanlin@mail.nctu.edu.tw, E-mail: wuchingchou@mail.nctu.edu.tw; Tasi, Ming-Jui; Chou, Wu-Ching, E-mail: bryanlin@mail.nctu.edu.tw, E-mail: wuchingchou@mail.nctu.edu.tw; Chang, Wen-Hao; Chen, Wei-Kuo [Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan (China)] [Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan (China); Tanaka, Tooru [Department of Electrical and Electronic Engineering, Saga University, Saga 840-8502 (Japan) [Department of Electrical and Electronic Engineering, Saga University, Saga 840-8502 (Japan); PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012 (Japan); Guo, Qixin [Synchrotron Light Application Center, Saga University, 1 Honjo, Saga 840-8502 (Japan)] [Synchrotron Light Application Center, Saga University, 1 Honjo, Saga 840-8502 (Japan); Nishio, Mitsuhiro [Department of Electrical and Electronic Engineering, Saga University, Saga 840-8502 (Japan)] [Department of Electrical and Electronic Engineering, Saga University, Saga 840-8502 (Japan)

2013-12-23T23:59:59.000Z

331

Point Defects in CdZnTe Crystals Grown by Different Techniques  

SciTech Connect (OSTI)

We studied, by current deep-level transient spectroscopy (I-DLTS), point defects in CdZnTe detectors grown by different techniques. We identified 12 different traps with energy levels from 7 meV to 1.1 eV. Although the levels of most of the identified defects were independent of the crystal growth techniques, nevertheless there were some associated differences in the traps energies and densities.

R Gul; A Bolotnikov; H Kim; R Rodriguez; K Keeter; Z Li; G Gu; R James

2011-12-31T23:59:59.000Z

332

Point Defects in CdZnTe Crystals Grown by Different Techniques  

SciTech Connect (OSTI)

We studied, by current deep-level transient spectroscopy (I-DLTS), point defects in CdZnTe detectors grown by different techniques. We identified 12 different traps with energy levels from 7 meV to 1.1 eV. Although the levels of most of the identified defects were independent of the crystal growth techniques, nevertheless there were some associated differences in the traps energies and densities.

Gul, R.; Bolotnikov, A.; Kim, H.K.; Rodriguez, R.; Keeter, K.; Li, Z.; Gu, G.; and James, R.B.

2011-02-02T23:59:59.000Z

333

The 63Cu(?, p)66Zn cross section and the corresponding thermonuclear reaction rate  

Science Journals Connector (OSTI)

Differential cross sections and excitation functions for the reaction 63Cu(?, p)66Zn have been measured over the energy range E? = 6–10 MeV. Results of statistical model calculations are compared to the excitation functions for individual proton groups and are found to give good representations to within about a factor of two. The data and the calculated cross sections are used to determine the thermonuclear reaction rates for temperatures of astrophysical interest.

M.S. Islam; R.N. Boyd; P.B. Corn; D.P. Rath; X. Gu; G.W. Kolnicki

1989-01-01T23:59:59.000Z

334

Tuning of defects in ZnO nanorod arrays used in bulk heterojunction solar cells  

E-Print Network [OSTI]

in nanostructured form [9-13]. Low-cost manufacturing routes for metal oxides, such as electrochemical deposition and hydrothermal pro- treatments are necessary to reduce defect concentrations and to prevent high series resistance in the final photo- voltaic device... being around 5%). Scanning electron microscopy images were taken using a LEO VP-1530 field emission scanning electron micro- scope (Peabody, MA, USA). Photovoltaic cell processing ZnO nanorod arrays were incorporated in inverted poly (3-hexylthiophene...

Iza, Diana C; Muñoz-Rojas, David; Jia, Quanxi; Swartzentruber, Brian; MacManus-Driscoll, Judith L

2012-11-27T23:59:59.000Z

335

Simple method for antireflection coating ZnSe in the 20 m wavelength range  

E-Print Network [OSTI]

of this dewar assembly provide a good vacuum seal. The window material must have sufficient mechanical strength to withstand the pressure gradient across it, be able to form a vacuum tight seal with the dewar assembly be expressed as r n2 - n1 n2 n1 ; t 2n1 n2 n1 : 1 In the case of ZnSe­air/vacuum boundaries, as- suming

Naylor, David A.

336

Nonradiative processes in the Zn1-xCoxSe system  

Science Journals Connector (OSTI)

We report the photoacoustic investigations of the Zn1-xCoxSe system. The qualitative analysis of possible nonradiative deexcitation paths in the Co2+ ion is performed. It is shown that the pseudo-Jahn-Teller effect is responsible for accumulation of the electron-lattice interaction energy in the lowest 2T1 state. As a result, the effective path for nonradiative deexcitation of the system is opened.

Marek Grinberg; A. C. Felici; T. Papa; M. Piacentini

1999-09-15T23:59:59.000Z

337

Modulated Structures, Nanocrystals and Quasicrystals in Mg-Zn-Y Alloys Anandh Subramaniam and S. Ranganathan  

E-Print Network [OSTI]

operating at 30 kV and with a step angle of 0.02 o was used for identification of the phases. Cu K radiation. In the present work, using TEM (Transmission Electron Microscope) as the main tool, the formation of nanocrystals-Zn-Y system were investigated. One alloy is chosen on the e/a = 2.02 line, four alloys close to the e/a = 2

Subramaniam, Anandh

338

Basic study for the application of Cu supported ZnS and ZnO photocatalysts for the CO{sub 2} conversion into alcohol  

SciTech Connect (OSTI)

Transformation of CO{sub 2} into alcohol by using photocatalysts is one of the “green” methods to solve the environmental problem. In this study, to increase the activity, condition of Cu co-catalysts onto the substrate (Zn photocatalysts) were precisely controlled by obeying to relationship between the surface potential of substrate and the condition of metal complexes in solution by applying the metal complexes calculation using critical stability constants. By obeying to calculation results, Cu metal complexes with positively charged species, [(Cu{sup 2+})(MEA){sub 2}] and [(Cu{sup 2+})(MEA){sub 3}] and/or negatively charged species, [(Cu{sup 2+})(OH{sup ?})(cit{sup 3?})] monomer and dimmer, were stably synthesized. Absorption amount of Cu species was successfully controlled by using these solutions since surface potential of ZnO was negative. When the concentration of Cu in the solution was same, the difference of adsorption amount led the difference of the number of nuclear site of Cu particles. As a result, the size of co-catalysts in the case of MEA became smaller.

Kajino, Yasuharu, E-mail: hideyuki@mail.kankyo.tohoku.ac.jp; Takahashi, Hideyuki, E-mail: hideyuki@mail.kankyo.tohoku.ac.jp; Tohji, Kazuyuki, E-mail: hideyuki@mail.kankyo.tohoku.ac.jp [Graduate School of Environmental Studies, Tohoku University 6-6-20, Aramaki, Aoba-ku, Sendai, 980-8579 (Japan)

2013-12-10T23:59:59.000Z

339

A violet emission in ZnS:Mn,Eu: Luminescence and applications for radiation detection  

SciTech Connect (OSTI)

We prepared manganese and europium co-doped zinc sulfide (ZnS:Mn,Eu) phosphors and used them for radiation detection. In addition to the red fluorescence at 583?nm due to the d-d transition of Mn ions, an intense violet emission at 420?nm is newly observed in ZnS:Mn,Eu phosphors. The emission is related to Eu{sup 2+} doping but only appears at certain Eu{sup 2+} concentrations. It is found that the intensity of the 420?nm violet fluorescence is X-ray does-dependent, while the red fluorescence of 583?nm is not. The ratio of fluorescence intensities at 420?nm and 583?nm has been monitored as a function of X-ray doses that exposed upon the ZnS:Mn,Eu phosphors. Empirical formulas are provided to estimate the doses of applied X-ray irradiation. Finally, possible mechanisms of X-ray irradiation induced fluorescence quenching are discussed. The intense 420?nm emission not only provides a violet light for solid state lighting but also offers a very sensitive method for radiation detection.

Ma, Lun; Chen, Wei, E-mail: weichen@uta.edu [Department of Physics and the SAVANT Center, The University of Texas at Arlington, Arlington, Texas 76019-0059 (United States); Jiang, Ke [Center for Biofrontiers Institute, University of Colorado at Colorado Springs, 1420 Austin Bluffs Pkwy., Colorado Springs, Colorado 80918 (United States); Liu, Xiao-tang [Department of Physics and the SAVANT Center, The University of Texas at Arlington, Arlington, Texas 76019-0059 (United States); Department of Applied Chemistry, College of Science, South China Agricultural University, Guangzhou 510642 (China)

2014-03-14T23:59:59.000Z

340

Effect of compressive stress on stability of N-doped p-type ZnO  

SciTech Connect (OSTI)

Nitrogen-doped p-type zinc oxide (p-ZnO:N) thin films were fabricated on a-/c-plane sapphire (a-/c-Al{sub 2}O{sub 3}) by plasma-assisted molecular beam epitaxy. Hall-effect measurements show that the p-type ZnO:N on c-Al{sub 2}O{sub 3} degenerated into n-type after a preservation time; however, the one grown on a-Al{sub 2}O{sub 3} showed good stability. The conversion of conductivity in the one grown on c-Al{sub 2}O{sub 3} ascribed to the faster disappearance of N{sub O} and the growing N{sub 2(O)}, which is demonstrated by x-ray photoelectron spectroscopy (XPS). Compressive stress, caused by lattice misfit, was revealed by Raman spectra and optical absorption spectra, and it was regarded as the root of the instability in ZnO:N.

Chen Xingyou [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 Dongnanhu Road, Changchun 130033 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Zhang Zhenzhong; Jiang Mingming; Wang Shuangpeng; Li Binghui; Shan Chongxin; Liu Lei; Zhao Dongxu; Shen Dezhen [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 Dongnanhu Road, Changchun 130033 (China); Yao Bin [State Key Laboratory of Superhard Materials and College of Physics, Jilin University, Changchun 130023 (China)

2011-08-29T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" 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

Determination of the transport mechanisms in mixed conduction of reactively sputtered ZnO thin films  

Science Journals Connector (OSTI)

Material grown at highly Zn-rich conditions in reactive sputtering of ZnO thin films resulted in mixed conduction, indicating that stable p-type ZnO can be produced. In n-type conductivity, neutral flaw scattering transport mechanism via centres seems to be dominant due to the existence of oxygen vacancies in high concentrations. An exponential decrease in electron mobility is observed upon cooling from room temperature to 210?K while the concentration of the inactive state increases. This is also a cause of p-type conduction in the low temperature range ( scattering. Quantitative evaluations of VO centres show that fractional distribution of , and charge states are, respectively, around 4%, 95% and 1% of the total [VO] at the room temperature conditions. The energy of phonons interacting with the centre is estimated to be 38.5?meV which is a local phonon mode relaxation, most probably resulting in negative-U behaviour of VO centres.

S Tüzemen; Emre Gür; S Do?an

2008-01-01T23:59:59.000Z

342

Rejection of randomly coinciding events in ZnMoO$_4$ scintillating bolometers  

E-Print Network [OSTI]

Random coincidence of events (particularly from two neutrino double beta decay) could be one of the main sources of background in the search for neutrinoless double beta decay with cryogenic bolometers due to their poor time resolution. Pulse-shape discrimination by using front edge analysis, mean-time and $\\chi^2$ methods was applied to discriminate randomly coinciding events in ZnMoO$_4$ cryogenic scintillating bolometers. These events can be effectively rejected at the level of 99% by the analysis of the heat signals with rise-time of about 14 ms and signal-to-noise ratio of 900, and at the level of 92% by the analysis of the light signals with rise-time of about 3 ms and signal-to-noise ratio of 30, under the requirement to detect 95% of single events. These rejection efficiencies are compatible with extremely low background levels in the region of interest of neutrinoless double beta decay of $^{100}$Mo for enriched ZnMoO$_4$ detectors, of the order of $10^{-4}$ counts/(y keV kg). Pulse-shape parameters have been chosen on the basis of the performance of a real massive ZnMoO$_4$ scintillating bolometer. Importance of the signal-to-noise ratio, correct finding of the signal start and choice of an appropriate sampling frequency are discussed.

D. M. Chernyak; F. A. Danevich; A. Giuliani; M. Mancuso; C. Nones; E. Olivieri; M. Tenconi; V. I. Tretyak

2014-04-04T23:59:59.000Z

343

High density nanoparticle Mn-Zn ferrite synthesis, characterisation and magnetic properties  

Science Journals Connector (OSTI)

The amazing magnetic properties exhibited by nanoparticles Mn-Zn ferrites and their promising technological and medical applications have attracted much interest in recent years. Nanoparticle Mnx Zn(1-x)Fe2O4 spinel ferrites with x = 0.6/0.63/0.65/0.67/0.7 were synthesised by the nitrilotriacetate precursor method employing microwave combustion synthesis. Powder X-ray diffractometry (XRD) confirmed the formation of the ferrite phase in all samples. IR analysis was done to verify formation of spinel structure. Elemental analysis using EDS confirmed the nanoparticle composition. The crystallite size was calculated from peak widths using the Scherrer formula, yielding a size in the range of 10â??25 nm. Transmission electron microscopy was also performed on the samples to testify formation of nanosized crystallites in the sample. Saturation magnetisation (Mr), retentivity (Ms) and coercivity (Hc) measurements were carried out on the samples using standard hysteresis loop tracer equipment. The saturation magnetisation values were found to be in the range of 58.6â??63.2 emu/g with very low values for (Mr/Ms). Variation of specific magnetisation with temperature and Curie temperature measurements were carried out using pulse field AC susceptibility measuring equipment. These measurements indicated formation of single domain (SD) material with dependence of Curie temperature on Zn concentration. The density of the samples was found to be high.

R.B. Tangsali; J.S. Budkuley; S.H. Keluskar; G.K. Naik; S.C. Watave

2011-01-01T23:59:59.000Z

344

Paper deacidification and UV protection using ZnO atomic layer deposition  

Science Journals Connector (OSTI)

Acid degradation of cellulosic paper in archival books periodicals and historic documents is a serious and widespread problem. Using acidic page samples from ?40 year old books we demonstrate that atomic layer deposition (ALD) ZnO can adjust and controllably neutralize the paper acid content. The paper samples were collected and analyzed in accordance with recognized Technical Association of the Pulp and Paper Industry (TAPPI) test standards. The average pH of the starting paper was 3.7?±?0.4 and 4.4?±?0.1 as determined using the TAPPI surface probe and cold water extraction methods respectively. After 50 ALD ZnO cycles the same tests on the coated paper produced an average pH of 7.39?±?0.08 and 7.3?±?0.4 respectively. Scanning electron microscopy confirmed that the cellulose structure remained intact during ALD. Additional tests of recently printed newspaper samples coated with ALD ZnO also show that ALD can effectively prevent paper discoloration and embrittlement caused by UV sunlight photoexposure. While there are many known methods for paper preservation including others using diethyl zinc the control afforded by ALD provides attractive advantages over other known approaches for preservation of archival paper and other natural fibrous materials.

C. A. Hanson; C. J. Oldham; G. N. Parsons

2012-01-01T23:59:59.000Z

345

Factors Affecting the Hydrogen Environment Assisted Cracking Resistance of an AL-Zn-Mg-(Cu) Alloy  

SciTech Connect (OSTI)

Precipitation hardenable Al-Zn-Mg alloys are susceptible to hydrogen environment assisted cracking (HEAC) when exposed to aqueous environments. In Al-Zn-Mg-Cu alloys, overaged tempers are used to increase HEAC resistance at the expense of strength but overaging has little benefit in low copper alloys. However, the mechanism or mechanisms by which overaging imparts HEAC resistance is poorly understood. The present research investigated hydrogen uptake, diffusion, and crack growth rate in 90% relative humidity (RH) air for both a commercial copper bearing Al-Zn-Mg-Cu alloy (AA 7050) and a low copper variant of this alloy in order to better understand the factors which affect HEAC resistance. Experimental methods used to evaluate hydrogen concentrations local to a surface and near a crack tip include nuclear reaction analysis (NRA), focused ion beam, secondary ion mass spectroscopy (FIB/SIMS) and thermal desorption spectroscopy (TDS). Results show that overaging the copper bearing alloys both inhibits hydrogen ingress from oxide covered surfaces and decreases the apparent hydrogen diffusion rates in the metal.

G.A. Young; J.R. Scully

2002-04-09T23:59:59.000Z

346

Ultrafast intramolecular relaxation dynamics of Mg- and Zn-bacteriochlorophyll a  

SciTech Connect (OSTI)

Ultrafast excited-state dynamics of the photosynthetic pigment (Mg-)bacteriochlorophyll a and its Zn-substituted form were investigated by steady-state absorption/fluorescence and femtosecond pump-probe spectroscopic measurements. The obtained steady-state absorption and fluorescence spectra of bacteriochlorophyll a in solution showed that the central metal compound significantly affects the energy of the Q{sub x} state, but has almost no effect on the Q{sub y} state. Photo-induced absorption spectra were recorded upon excitation of Mg- and Zn-bacteriochlorophyll a into either their Q{sub x} or Q{sub y} state. By comparing the kinetic traces of transient absorption, ground-state beaching, and stimulated emission after excitation to the Q{sub x} or Q{sub y} state, we showed that the Q{sub x} state was substantially incorporated in the ultrafast excited-state dynamics of bacteriochlorophyll a. Based on these observations, the lifetime of the Q{sub x} state was determined to be 50 and 70 fs for Mg- and Zn-bacteriochlorophyll a, respectively, indicating that the lifetime was influenced by the central metal atom due to the change of the energy gap between the Q{sub x} and Q{sub y} states.

Kosumi, Daisuke [Osaka City University Advanced Research Institute for Natural Science and Technology, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan); CREST/JST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Nakagawa, Katsunori; Sakai, Shunsuke [Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Nagaoka, Yuya; Maruta, Satoshi; Sugisaki, Mitsuru [CREST/JST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Department of Physics, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan); Dewa, Takehisa [Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); PRESTO/JST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Nango, Mamoru [The Osaka City University Advanced Research Institute for Natural Science and Technology, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan); CREST/JST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Hashimoto, Hideki [The Osaka City University Advanced Research Institute for Natural Science and Technology, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan); CREST/JST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Department of Physics, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan)

2013-07-21T23:59:59.000Z

347

Band alignment and interfacial structure of ZnO/Si heterojunction with Al{sub 2}O{sub 3} and HfO{sub 2} as interlayers  

SciTech Connect (OSTI)

Energy band alignment of ZnO/Si heterojunction with thin interlayers Al{sub 2}O{sub 3} and HfO{sub 2} grown by atomic layer deposition has been studied using x-ray photoelectron spectroscopy. The valence band offsets of ZnO/Al{sub 2}O{sub 3} and ZnO/HfO{sub 2} heterojunctions have been determined to be 0.43 and 0.22?eV, respectively. Accordingly, the band alignment ZnO/Si heterojunction is then modified to be 0.34 and 0.50?eV through inserting a thin Al{sub 2}O{sub 3} and HfO{sub 2} layer, respectively. The feasibility to tune the band structure of ZnO/Si heterojunction by selecting a proper interlayer shows great advantage in improving the performance of the ZnO-based optoelectronic devices.

Lu, Hong-Liang, E-mail: honglianglu@fudan.edu.cn; Yang, Ming; Xie, Zhang-Yi; Geng, Yang; Zhang, Yuan; Wang, Peng-Fei; Sun, Qing-Qing; Ding, Shi-Jin; Wei Zhang, David [State Key Laboratory of ASIC and System, Institute of Advanced Nanodevices, School of Microelectronics, Fudan University, Shanghai 200433 (China)

2014-04-21T23:59:59.000Z

348

Synthesis of Methanol and Dimethyl Ether from Syngas over Pd/ZnO/Al2O3 Catalysts  

SciTech Connect (OSTI)

A Pd/ZnO/Al2O3 catalyst was developed for the synthesis of methanol and dimethyl ether (DME) from syngas. Studied were temperatures of operation ranging from 250°C to 380°C. High temperatures (e.g. 380°C) are necessary when combining methanol and DME synthesis with a methanol to gasoline (MTG) process in a single reactor bed. A commercial Cu/ZnO/Al2O3 catalyst, utilized industrially for the synthesis of methanol at 220-280°C, suffers from a rapid deactivation when the reaction is conducted at high temperature (>320°C). On the contrary, a Pd/ZnO/Al2O3 catalyst was found to be highly stable for methanol and DME synthesis at 380°C. The Pd/ZnO/Al2O3 catalyst was thus further investigated for methanol and DME synthesis at P=34-69 bars, T= 250-380°C, GHSV= 5 000-18 000 h-1, and molar feeds H2/CO= 1, 2, and 3. Selectivity to DME increased with decreasing operating temperature, and increasing operating pressure. Increased GHSV’s and H2/CO syngas feed ratios also enhanced DME selectivity. Undesirable CH4 formation was observed, however, can be minimized through choice of process conditions and by catalyst design. By studying the effect of the Pd loading and the Pd:Zn molar ratio the formulation of the Pd/ZnO/Al2O3 catalyst was optimized. A catalyst with 5% Pd and a Pd:Zn molar ratio of 0.25:1 has been identified as the preferred catalyst. Results indicate that PdZn particles are more active than Pdº particles for the synthesis of methanol and less active for CH4 formation. A correlation between DME selectivity and the concentration of acid sites of the catalysts has been established. Hence, two types of sites are required for the direct conversion of syngas to DME: 1) PdZn particles are active for the synthesis of methanol from syngas, and 2) acid sites which are active for the conversion of methanol to DME. Additionally, CO2 formation was problematic as PdZn was found to be active for the water-gas-shift (WGS) reaction, under all the conditions evaluated.

Lebarbier, Vanessa MC; Dagle, Robert A.; Kovarik, Libor; Lizarazo Adarme, Jair A.; King, David L.; Palo, Daniel R.

2012-10-01T23:59:59.000Z

349

Relations between structural parameters and physical properties in CdTe and Cd0.96Zn0.04Te alloys  

E-Print Network [OSTI]

481 Relations between structural parameters and physical properties in CdTe and Cd0.96Zn0.04Te cristaux de CdTe et de Cd0,96Zn0,04Te, de densité de dislocations variant entre 5 x 104 et 6 x 105 cm-2. La and photoluminescence experiments were performed on several CdTe and Cd0.96Zn0.04Te crystals with dislocation density

Paris-Sud XI, Université de

350

Development and validation of TOF-SIMS and CLSM imaging method for cytotoxicity study of ZnO nanoparticles in HaCaT cells  

Science Journals Connector (OSTI)

Abstract Zinc oxide nanoparticles (ZnO NPs) exhibit novel physiochemical properties and have found increasing use in sunscreen products and cosmetics. The potential toxicity is of increasing concern due to their close association with human skin. A time-of-flight secondary ion mass spectrometry (TOF-SIMS) and confocal laser scanning microscopy (CLSM) imaging method was developed and validated for rapid and sensitive cytotoxicity study of ZnO \\{NPs\\} using human skin equivalent HaCaT cells as a model system. Assorted material, chemical, and toxicological analysis methods were used to confirm their shape, size, crystalline structure, and aggregation properties as well as dissolution behavior and effect on HaCaT cell viability in the presence of various concentrations of ZnO \\{NPs\\} in aqueous media. Comparative and correlative analyses of aforementioned results with TOF-SIMS and CLSM imaging results exhibit reasonable and acceptable outcome. A marked drop in survival rate was observed with 50 ?g/ml ZnO NPs. The CLSM images reveal the absorption and localization of ZnO \\{NPs\\} in cytoplasm and nuclei. The TOF-SIMS images demonstrate elevated levels of intracellular ZnO concentration and associated Zn concentration-dependent 40Ca/39K ratio, presumably caused by the dissolution behavior of ZnO NPs. Additional validation by using stable isotope-labeled 68ZnO \\{NPs\\} as tracers under the same experimental conditions yields similar cytotoxicity effect. The imaging results demonstrate spatially-resolved cytotoxicity relationship between intracellular ZnO NPs, 40Ca/39K ratio, phosphocholine fragments, and glutathione fragments. The trend of change in TOF-SIMS spectra and images of ZnO \\{NPs\\} treated HaCaT cells demonstrate the possible mode of actions by ZnO NP involves cell membrane disruption, cytotoxic response, and ROS mediated apoptosis.

Pei-Ling Lee; Bo-Chia Chen; Ganesh Gollavelli; Sin-Yu Shen; Yu-Sheng Yin; Shiu-Ling Lei; Cian-Ling Jhang; Woan-Ruoh Lee; Yong-Chien Ling

2014-01-01T23:59:59.000Z

351

FINAL REPORT OF RESEARCH ON CuxS/ (Cd,Zn)S PHOTOVOLTAIC SOLAR ENERGY CONVERTERS 3/77 - 9/79  

E-Print Network [OSTI]

S/(Cd,Zn)S PHOTOVOLTAIC SOLAR ENERGY CONVERTERS 3/77 - 9/79Research on Photovoltaic Solar Energy Converters CuxSI(Cd~

Chin, B.L.

2013-01-01T23:59:59.000Z

352

A kinetic study of methanol synthesis in a slurry reactor using a CuO/ZnO/Al2O3 catalyst  

E-Print Network [OSTI]

with the CuO/ZnO, CuO/ZnO/Cr203 and CuO/ZnO/A1203 catalysts, other catalysts are being investigated for practical use. Maj et al. (1985) prepared and characterized ?Th02 snd NH4-Th02 catalysts for methanol production that produced CO conversions of 3'/o.../Thx were reported to demonstrate activity towards methanol synthesis. Recently, Stiles et al. (1991) prepared a catalyst system (~Zn/Co/Cr/(K+Cs) = 4/3/1/0. 028/(15 wt. '/o+4. 0 wt '/o)) with high activity for producing higher alcohols. 1. 2 Objectives...

Al-Adwani, Hamad Abdulwahab

1992-01-01T23:59:59.000Z

353

SnO{sub 2}/ZnO composite structure for the lithium-ion battery electrode  

SciTech Connect (OSTI)

In this article, SnO{sub 2}/ZnO composite structures have been synthesized by two steps hydrothermal method and investigated their lithium storage capacity as compared with pure ZnO. It has been found that these composite structures combining the large specific surface area, stability and catalytic activity of SnO{sub 2} micro-crystals, demonstrate the higher initial discharge capacity of 1540 mA h g{sup -1} with a Coulombic efficiency of 68% at a rate of 120 mA h g{sup -1} between 0.02 and 2 V and found much better than that of any previously reported ZnO based composite anodes. In addition, a significantly enhanced cycling performance, i.e., a reversible capacity of 497 mA h g{sup -1} is retained after 40 cycles. The improved lithium storage capacity and cycle life is attributed to the addition of SnO{sub 2} structure, which act as good electronic conductors and better accommodation of the large volume change during lithiation/delithiation process. - Graphical abstract: SnO{sub 2}/ZnO composite structures demonstrate the improved lithium storage capacity and cycle life as compared with pure ZnO nanostructure. Highlights: Black-Right-Pointing-Pointer Synthesis of SnO{sub 2}/ZnO composite structures by two steps hydrothermal approach. Black-Right-Pointing-Pointer Investigation of lithium storage capacity. Black-Right-Pointing-Pointer Excellent lithium storage capacity and cycle life of SnO{sub 2}/ZnO composite structures.

Ahmad, Mashkoor, E-mail: mashkoorahmad2003@yahoo.com [Beijing National Center for Electron Microscopy, The State Key Laboratory of New Ceramics and Fine Processing, Laboratory of Advanced Material, China Iron and Steel Research Institute Group, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China) [Beijing National Center for Electron Microscopy, The State Key Laboratory of New Ceramics and Fine Processing, Laboratory of Advanced Material, China Iron and Steel Research Institute Group, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China); Nanomaterial Research Group, Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); Yingying, Shi [Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)] [Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Sun, Hongyu [Beijing National Center for Electron Microscopy, The State Key Laboratory of New Ceramics and Fine Processing, Laboratory of Advanced Material, China Iron and Steel Research Institute Group, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China)] [Beijing National Center for Electron Microscopy, The State Key Laboratory of New Ceramics and Fine Processing, Laboratory of Advanced Material, China Iron and Steel Research Institute Group, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China); Shen, Wanci [Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)] [Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Zhu, Jing, E-mail: jzhu@mail.tsinghua.edu.cn [Beijing National Center for Electron Microscopy, The State Key Laboratory of New Ceramics and Fine Processing, Laboratory of Advanced Material, China Iron and Steel Research Institute Group, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China)] [Beijing National Center for Electron Microscopy, The State Key Laboratory of New Ceramics and Fine Processing, Laboratory of Advanced Material, China Iron and Steel Research Institute Group, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China)

2012-12-15T23:59:59.000Z

354

Crystal structure and bonding characteristics of In-doped {beta}-Zn{sub 4}Sb{sub 3}  

SciTech Connect (OSTI)

The effects of indium impurity on the crystal structure and bonding characteristics of In-doped {beta}-Zn{sub 4}Sb{sub 3} were investigated by powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The XRD Rietveld refinement indicates that the indium impurity preferentially substitutes one of Sb atoms in Sb-Sb dimer at the 12c Sb(2) site and simultaneously leads to the increase of Zn occupancy. The observations of binding energy shift and a new valence state in Sb 3d core-level XPS spectra can be attributed to the charge transfer from In and Zn to Sb. As a result, more electropositive Zn atoms are needed to maintain the charge balance. The reduction of the lattice thermal conductivity is ascribed to the formation of the asymmetric Sb-In bond, resulting in much low lattice thermal conductivity of 0.49 W{sup -1} K{sup -1} of Zn{sub 4}Sb{sub 2.96}In{sub 0.04}. - Graphical abstract: The indium impurity substitutes one of Sb atoms in Sb-Sb dimer, resulting the charge transfer from In to Sb, which leads to the binding energy of Sb 3d core level XPS spectra shift to low value. Highlights: Black-Right-Pointing-Pointer The indium impurity preferentially substitutes one of Sb atoms in Sb-Sb dimer at the 12c Sb(2) site. Black-Right-Pointing-Pointer The occupancy of Zn increases by the In substitution for Sb, whereas that of Sb keeps constant. Black-Right-Pointing-Pointer The binding energy of Sb 3d shifts to low value. Black-Right-Pointing-Pointer The charge transfer occurs from In and Zn to Sb.

Tang, Dingguo [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China) [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Key Laboratory of Catalysis and Materials Science of the State Ethnic Affair Commission and Ministry of Education, South-Central University for Nationalities, Wuhan 430074 (China); Zhao, Wenyu, E-mail: wyzhao@whut.edu.cn [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)] [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Cheng, Sudan; Wei, Ping; Yu, Jian [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)] [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Zhang, Qingjie, E-mail: zhangqj@whut.edu.cn [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)] [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

2012-09-15T23:59:59.000Z

355

Chemical reactions at Cu/ZnS(001) and In/ZnS(001) heterojunctions: A comparison of photoelectron and S L{sub 2,3} x-ray emission spectroscopy  

SciTech Connect (OSTI)

Occurrence and extent of chemical reactions at Cu/ZnS(001) and In/ZnS(001) heterojunctions have been investigated by S L{sub 2,3} x-ray emission spectroscopy as well as photoelectron spectroscopy. With the formation of metal-sulfur bonds, spectral features originating from shallow metal d core levels (Zn 3d, In 4d) or valence states (Cu 3d)) may appear in the S L{sub 2,3} emission spectra. Thus the x-ray emission spectroscopy was employed to detect chemical reactions at the heterojunctions, together with conventional photoelectron spectroscopy. Considerable reactions at the Cu/ZnS(001) interface are more clearly indicated in the S L emission spectrum than in the Cu 2p{sub 3sol2} or S 2p core level spectra, whereas relatively confined reactions at the In/ZnS(001) interface can only be probed in the In 3d{sub 5sol2} core level spectra. The partial densities of states calculated for a reference CuInS{sub 2} on the basis of density functional theory agree well with features occurring in its S L{sub 2,3} emission spectrum.

Zhang, L.; Wett, D.; Schulze, D.; Szargan, R.; Nagel, M.; Peisert, H.; Chasse, T. [Institut fuer Physikalische und Theoretische Chemie, Universitaet Tuebingen, Auf der Morgenstelle 8, 72076 Tuebingen (Germany); Wilhelm-Ostwald-Institut fuer Physikalische und Theoretische Chemie, Universitaet Leipzig, Linnestrasse 2, 04103 Leipzig (Germany); Wilhelm-Ostwald-Institut fuer Physikalische und Theoretische Chemie, Universitaet Leipzig, Linnestrasse 2, 04103 Leipzig (Germany); Institut fuer Physikalische und Theoretische Chemie, Universitaet Tuebingen, Auf der Morgenstelle 8, 72076 Tuebingen (Germany)

2005-01-03T23:59:59.000Z

356

Promoting effect of polyoxyethylene octylphenol ether on Cu/ZnO catalysts for low-temperature methanol synthesis  

Science Journals Connector (OSTI)

Cu/ZnO catalysts were prepared by the co-precipitation method with the addition of OP-10 (polyoxyethylene octylphenol ether) and were chemically and structurally characterized by means of XRD, BET, H2-TPR, CO-TPD and N2O-titration. The effect of OP-10 addition on the activity of Cu/ZnO for the slurry phase methanol synthesis at 150 °C was evaluated. The results showed that Cu/ZnO prepared with addition of 8% OP-10 (denoted as C8) exhibited the promoted activity for the methanol synthesis. The conversion of CO and the STY (space time yield) of methanol were 42.5% and 74.6% higher than those of Cu/ZnO prepared without addition of OP-10 (denoted as C0), respectively. The precursor of C8 contained more aurichalcite and rosasite, and the concerted effect of Cu-Zn in C8 was found to be stronger than that in C0. Compared with C0, C8 showed smaller particle size, lower reduction temperature and larger BET and Cu surface areas.

Ling Liu; Tiansheng Zhao; Qingxiang Ma; Yufang Shen

2009-01-01T23:59:59.000Z

357

Influence of preparation methods and Zr and Y promoters on Cu/ZnO catalysts used for methanol steam reforming  

Science Journals Connector (OSTI)

Binary Cu/ZnO catalysts were prepared using three different methods (coprecipitation, sequential precipitation and homogeneous precipitation) and tested in a methanol steam reforming reaction. Zirconium and yttrium were tested as promoters, and their effects were evaluated in the same reaction. The studied preparation methods influenced the surface area of the Cu-based catalysts and consequently their catalytic activity; however, we verified that surface area was not the only factor influencing activity. Different structural changes in the aurichalcite precursor resulted from the different preparation methods used, and these differences were also observed in the reduced catalysts. An expansion of the Cu lattice with an increase in microstrain were identified and attributed to the formation of a Cu–Zn alloy. Based on the correlation found between these structural changes and the catalytic activity, the Cu–Zn alloy was proposed as active site. We concluded that the preparation methods used influenced Cu dispersion and overall catalyst structure, and Cu–Zn alloy formation resulted from the incorporation of Zn atoms into the Cu lattice. This influence was more pronounced in the catalysts prepared by homogeneous precipitation and coprecipitation. The yttrium promoter did not provide textural or structural advantages. In contrast, the incorporation of Zr promoted both greater Cu dispersion and structural changes in the Cu lattice.

S.G. Sanches; J. Huertas Flores; R.R. de Avillez; M.I. Pais da Silva

2012-01-01T23:59:59.000Z

358

Zinc vacancy and erbium cluster jointly promote ferromagnetism in erbium-doped ZnO thin film  

SciTech Connect (OSTI)

Zn{sub 1-x}Er{sub x}O (0.005 ? x ? 0.04) thin films have been prepared by inductively coupled plasma enhanced physical vapor deposition method. Ferromagnetism, crystal structure, microstructure and photoluminescence properties of the films were characterized. It is found that the chemical valence state of Er is trivalent, and the Er{sup 3+} cations play an important role in ferromagnetism. Both saturated magnetization (M{sub s}) and zinc vacancy (V{sub Zn}) are decreased with the increase of x from 0.005 to 0.03. However, further increasing x to 0.04, the M{sub s} is quenched due to the generation of Er clusters. It reveals that the intensity of M{sub s} is not only associated with the V{sub Zn} concentration, but also related to the Er clusters. The V{sub Zn} concentration and the Er clusters can jointly boost the ferromagnetism in the Zn{sub 1-x}Er{sub x}O thin films.

Chen, Hong-Ming; Zhou, Ren-Wei; Li, Fei [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 215 Chengbei Road, Shanghai 201800 (China) [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 215 Chengbei Road, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Xue-Chao, E-mail: xcliu@mail.sic.ac.cn; Zhuo, Shi-Yi; Shi, Er-Wei [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 215 Chengbei Road, Shanghai 201800 (China)] [Shanghai Institute of Ceramics, Chinese Academy of Sciences, 215 Chengbei Road, Shanghai 201800 (China); Xiong, Ze [Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong (China)] [Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong (China)

2014-04-15T23:59:59.000Z

359

Mechanism of methanol synthesis on Cu(100) and Zn/Cu(100) surfaces: Comparative dipped adcluster model study  

SciTech Connect (OSTI)

The mechanism of methanol synthesis from CO{sub 2} and H{sub 2} on Cu(100) and Zn/Cu(100) surfaces was studied using the dipped adcluster model (DAM) combined with ab initio Hartree-Fock (HF) and second-order Moeller-Plesset (MP2) calculations. On clean Cu(100) surface, calculations show that five successive hydrogenations are involved in the hydrogenation of adsorbed CO{sub 2} to methanol, and the intermediates are formate, dioxomethylene, formaldehyde, and methoxy. The rate-limiting step is the hydrogenation of formate to formaldehyde, and the Cu-Cu site is responsible for the reaction on Cu(100). The roles of Zn on Zn/Cu(100) catalyst are to modify the rate-limiting step of the reaction: to lower the activation energies of this step and to stabilize the dioxomethylene intermediate at the Cu-Zn site. The present comparative results indicate that the Cu-Zn site is the active site, which cooperates with the Cu-Cu site to catalyze methanol synthesis on a Cu-based catalyst. Electron transfer from surface to adsorbates is the most important factor in affecting the reactivity of these surface catalysts.

Nakatsuji, Hiroshi; Hu, Zhenming

2000-03-05T23:59:59.000Z

360

Characterization of Al-As codoped p-type ZnO films by magnetron cosputtering deposition  

SciTech Connect (OSTI)

We report the preparation of Al-As codoped p-type ZnO films by rf magnetron cosputtering deposition. The p-type conductivity of the films was revealed by Hall measurements, x-ray photoelectron spectroscopy (XPS), and photoluminescence measurements after being annealed in O{sub 2}. It was observed by XPS that Al content increased with increasing AlAs target power from 80 to 160 W and reached a maximum value at an AlAs target power of 160 W. Hole concentration decreased with increasing Al content. With increasing AlAs target power greater than 160 W, the samples exhibit increases in As and O contents and decreases in Al and Zn contents, which contribute to the increase in hole concentration. A high hole concentration of 2.354x10{sup 20} cm{sup -3}, a low resistivity of 2.122x10{sup -2} {omega} cm, and a Hall mobility of 0.13 cm{sup 2}/V s for the films with high As content of 16.59% were obtained. XPS has also been used to address the unresolved issues related to the p-type formation mechanism of As-doped ZnO, supporting that the acceptor is As{sub Zn}-2V{sub Zn}.

Yun, Eui-Jung; Park, Hyeong-Sik [Department of Semiconductor and Display Engineering and Department of System and Control Engineering, Hoseo University, Asan, Chungnam 336-795 (Korea, Republic of); Lee, Kyu H.; Nam, Hyoung G. [Electronic Engineering Division, Sun Moon University, Asan, Chungnam 336-708 (Korea, Republic of); Jung, Myunghee [Department of Digital Media Engineering, Anyang University, Anyang-si, Kyunggi-do 430-714 (Korea, Republic of)

2008-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
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361

Removal of As, Cd, Cu, Ni, Pb, and Zn from a highly contaminated industrial soil using surfactant enhanced soil washing  

Science Journals Connector (OSTI)

Surfactant enhanced soil washing (SESW) was applied to an industrial contaminated soil. A preliminary characterization of the soil regarding the alkaline-earth metals, Na, K, Ca and Mg took values of 2866, 2036, 2783 and 4149 mg/kg. The heavy metals As, Cd, Cu, Pb, Ni and Zn, had values of 4019, 14, 35582, 70, 2603, and 261 mg/kg, respectively. When using different surfactants, high removal of Cu, Ni and Zn were found, and medium removals for Pb, As and Cd. In the case of these three metals, tap water removed more than the surfactant solutions, except for the case of As. There were surfactants with average removals (this is, the removal for all the metals studied) of 67.1% (Tween 80), 64.9% (Surfacpol 14104) and 61.2% (Emulgin W600). There were exceptional removals using Texapon N-40 (83.2%, 82.8% and 86.6% for Cu, Ni and Zn), Tween 80 (85.9, 85.4 and 81.5 for Cd, Zn and Cu), Polafix CAPB (79%, 83.2% and 49.7% for Ni, Zn and As). The worst results were obtained with POLAFIX LO with a global removal of 45%, well below of the average removal with tap water (50.2%).All removal efficiencies are reported for a one step washing using 0.5% surfactant solutions, except for the case of mezquite gum, where a 0.1% solution was employed.

Luis G. Torres; Rosario B. Lopez; Margarita Beltran

2012-01-01T23:59:59.000Z

362

Oxygen plasma power dependence on ZnO grown on porous silicon substrates by plasma-assisted molecular beam epitaxy  

SciTech Connect (OSTI)

ZnO thin films were deposited on porous silicon by plasma-assisted molecular beam epitaxy using different radio frequency power settings. Optical emission spectrometry was applied to study the characteristics of the oxygen plasma, and the effects of the radio frequency power on the properties of the ZnO thin films were evaluated by X-ray diffraction, scanning electron microscopy, and photoluminescence. The grain sizes for radio frequency powers of 100, 200, and 300 W were 46, 48, and 62 nm, respectively. In addition, the photoluminescence intensities of the ultraviolet and the visible range increased at 300 W, because the density of the atomic oxygen transitions increased. The quality of the ZnO thin films was enhanced, but the deep-level emission peaks increased with increasing radio frequency power. The structural and optical properties of the ZnO thin films were improved at the radio frequency power of 300 W. Moreover, the optical properties of the ZnO thin films were improved with porous silicon, instead of Si.

Nam, Giwoong [Department of Nano Engineering, Inje University, Gimhae, Gyungnam 621-749 (Korea, Republic of)] [Department of Nano Engineering, Inje University, Gimhae, Gyungnam 621-749 (Korea, Republic of); Kim, Min Su [Department of Nano Systems Engineering, Center for Nano Manufacturing, Inje University, Gimhae, Gyungnam 621-749 (Korea, Republic of)] [Department of Nano Systems Engineering, Center for Nano Manufacturing, Inje University, Gimhae, Gyungnam 621-749 (Korea, Republic of); Kim, Do Yeob [Holcombe Department of Electrical and Computer Engineering, Center for Optical Materials Science and Engineering Technologies, Clemson University, Clemson, SC 29634 (United States)] [Holcombe Department of Electrical and Computer Engineering, Center for Optical Materials Science and Engineering Technologies, Clemson University, Clemson, SC 29634 (United States); Yim, Kwang Gug [Department of Nano Systems Engineering, Center for Nano Manufacturing, Inje University, Gimhae, Gyungnam 621-749 (Korea, Republic of)] [Department of Nano Systems Engineering, Center for Nano Manufacturing, Inje University, Gimhae, Gyungnam 621-749 (Korea, Republic of); Kim, Soaram [Department of Nano Engineering, Inje University, Gimhae, Gyungnam 621-749 (Korea, Republic of)] [Department of Nano Engineering, Inje University, Gimhae, Gyungnam 621-749 (Korea, Republic of); Kim, Sung-O. [Holcombe Department of Electrical and Computer Engineering, Center for Optical Materials Science and Engineering Technologies, Clemson University, Clemson, SC 29634 (United States)] [Holcombe Department of Electrical and Computer Engineering, Center for Optical Materials Science and Engineering Technologies, Clemson University, Clemson, SC 29634 (United States); Lee, Dong-Yul [Epi R and D Team, Samsung LED Co. Ltd., Suwon, Gyeonggi-do 443-373 (Korea, Republic of)] [Epi R and D Team, Samsung LED Co. Ltd., Suwon, Gyeonggi-do 443-373 (Korea, Republic of); Leem, Jae-Young, E-mail: jyleem@inje.ac.kr [Department of Nano Engineering, Inje University, Gimhae, Gyungnam 621-749 (Korea, Republic of) [Department of Nano Engineering, Inje University, Gimhae, Gyungnam 621-749 (Korea, Republic of); Department of Nano Systems Engineering, Center for Nano Manufacturing, Inje University, Gimhae, Gyungnam 621-749 (Korea, Republic of)

2012-10-15T23:59:59.000Z

363

Photoluminescence properties and energy levels of RE (RE?=?Pr, Sm, Er, Tm) in layered-CaZnOS oxysulfide  

SciTech Connect (OSTI)

RE{sup 3+} (RE?=?Pr, Sm, Er, Tm)-activated CaZnOS samples were prepared by a solid-state reaction method at high temperature, and their photoluminescence properties were investigated. Doping with RE{sup 3+} (RE?=?Pr, Sm, Er, Tm) into layered-CaZnOS resulted in typical RE{sup 3+} (RE?=?Pr, Sm, Er, Tm) f-f line absorptions and emissions, as well as the charge transfer band of Sm{sup 3+} at about 3.3?eV. The energy level scheme containing the position of the 4f and 5d levels of all divalent and trivalent lanthanide ions with respect to the valence and conduction bands of CaZnOS has been constructed based on the new data presented in this work, together with the data from literature on Ce{sup 3+} and Eu{sup 2+} doping in CaZnOS. The detailed energy level scheme provides a platform for interpreting the optical spectra and could be used to comment on the valence stability of the lanthanide ions in CaZnOS.

Zhang, Zhi-Jun, E-mail: zhangzj@mail.sic.ac.cn [Key Laboratory of Transparent Opto-Functional Inorganic Materials of Chinese Academy of Sciences, Shanghai Institute of Ceramics, Shanghai 200050 (China); Feng, Ang; Chen, Xiang-Yang [Key Laboratory of Transparent Opto-Functional Inorganic Materials of Chinese Academy of Sciences, Shanghai Institute of Ceramics, Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Zhao, Jing-Tai, E-mail: jtzhao@mail.sic.ac.cn [Key Laboratory of Transparent Opto-Functional Inorganic Materials of Chinese Academy of Sciences, Shanghai Institute of Ceramics, Shanghai 200050 (China); School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China)

2013-12-07T23:59:59.000Z

364

Pt/ZnO nanoarray nanogenerator as self-powered active gas sensor with linear ethanol sensing at room temperature  

Science Journals Connector (OSTI)

A self-powered gas sensor that can actively detect ethanol at room temperature has been realized from a Pt/ZnO nanoarray nanogenerator. Pt nanoparticles are uniformly distributed on the whole surface of ZnO nanowires. The piezoelectric output of Pt/ZnO nanoarrays can act not only as a power source, but also as a response signal to ethanol at room temperature. Upon exposure to dry air and 1500 ppm ethanol at room temperature, the piezoelectric output of the device under the same compressive strain is 0.672 and 0.419 V, respectively. Moreover, a linear dependence of the sensitivity on the ethanol concentration is observed. Such a linear ethanol sensing at room temperature can be attributed to the atmosphere-dependent variety of the screen effect on the piezoelectric output of ZnO nanowires, the catalytic properties of Pt nanoparticles, and the Schottky barriers at Pt/ZnO interfaces. The present results can stimulate research in the direction of designing new material systems for self-powered room-temperature gas sensing.

Yayu Zhao; Xuan Lai; Ping Deng; Yuxin Nie; Yan Zhang; Lili Xing; Xinyu Xue

2014-01-01T23:59:59.000Z

365

Comparative Study of the Defect Point Physics and Luminescence of the Kesterites Cu2ZnSnS4 and Cu2ZnSnSe4 and Chalcopyrite Cu(In,Ga)Se2: Preprint  

SciTech Connect (OSTI)

In this contribution, we present a comparative study of the luminescence of the kesterites Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe) and their related chalcopyrite Cu(In,Ga)Se2 (CIGSe). Luminescence spectroscopy suggests that the electronic properties of Zn-rich, Cu-poor kesterites (both CZTS and CZTSe) and Cu-poor CIGSe are dictated by fluctuations of the electrostatic and chemical potentials. The large redshift in the luminescence of grain boundaries in CIGSe, associated with the formation of a neutral barrier is clearly observed in CZTSe, and, to some extent, in CZTS. Kesterites can therefore replicate the fundamental electronic properties of CIGSe.

Romero, M. J.; Repins, I.; Teeter, G.; Contreras, M.; Al-Jassim, M.; Noufi, R.

2012-08-01T23:59:59.000Z

366

Transparent and conducting ZnO films grown by spray pyrolysis  

Science Journals Connector (OSTI)

ZnO films were prepared using the simple, flexible and cost-effective spray pyrolysis technique at different substrate temperatures and precursor molarity values. The films' structural, optical and electrical properties were investigated by x-ray diffraction, UV–VIS transmittance spectroscopy, profilometry and voltage–current–temperature (VIT) measurements. The films prepared at substrate temperatures above 400 °C appear better crystallized with (0?0?2) preferred orientation and exhibit higher visible transmittance (65–80%), higher electrical n-type semiconductor conductivity (10–50 (? cm)?1), lower activation energy (

Lazhar Hadjeris; Labidi Herissi; M Badreddine Assouar; Thomas Easwarakhanthan; Jamal Bougdira; Nadhir Attaf; M Salah Aida

2009-01-01T23:59:59.000Z

367

Nanoparticle-coated n-ZnO/p-Si photodiodes with improved photoresponsivities and  

Science Journals Connector (OSTI)

In this work, n-ZnO/p-Si photodiodes were fabricated and characterized to explore their potential applications in solar cells. With a coating of silica nanoparticles, we observed the enhancement of photoresponsivity and acceptance angle at a wavelength between 400 and 650 nm. The 17.6% increase of the photoresponsivity over the conventional device is due to the improved optical transmission toward the semiconductor through the silica nanoparticles. Furthermore, the acceptance angle of the nanoparticle coated device is dramatically increased, which is attributed to the effect of Bragg diffraction.

Cheng-Pin Chen; Pei-Hsuan Lin; Liang-Yi Chen; Min-Yung Ke; Yun-Wei Cheng; JianJang Huang

2009-01-01T23:59:59.000Z

368

Core-shell ITO/ZnO/CdS/CdTe nanowire solar cells  

SciTech Connect (OSTI)

Radial p-n junction nanowire (NW) solar cells with high densities of CdTe NWs coated with indium tin oxide (ITO)/ZnO/CdS triple shells were grown with excellent heterointerfaces. The optical reflectance of the devices was lower than for equivalent planar films by a factor of 100. The best efficiency for the NW solar cells was ??=?2.49%, with current transport being dominated by recombination, and the conversion efficiencies being limited by a back contact barrier (?{sub B}?=?0.52?eV) and low shunt resistances (R{sub SH}?

Williams, B. L.; Phillips, L.; Major, J. D.; Durose, K. [Stephenson Institute for Renewable Energy, University of Liverpool, Chadwick Building, Peach St., Liverpool L69 7ZF (United Kingdom); Taylor, A. A.; Mendis, B. G.; Bowen, L. [G. J. Russell Microscopy Facility, University of Durham, South Road, Durham DH1 3LE (United Kingdom)

2014-02-03T23:59:59.000Z

369

Blue photoluminescence in ZnGa{sub 2}O{sub 4} thin-film phosphors  

SciTech Connect (OSTI)

The growth and properties of luminescent ZnGa{sub 2}O{sub 4} thin films using pulsed laser ablation has been investigated. As-deposited films on glass and (100) MgO substrates exhibit blue-white photoluminescence with a broad emission band under ultraviolet excitation. In situ epitaxial films obtained on single crystal (100) MgO substrates possess enhanced luminescent intensity as compared to polycrystalline films on glass substrates. The enhanced luminescence in epitaxial films presumably reflects lower defect densities due to growth on low energy surfaces.

Lee, Yong Eui; Norton, David P.; Park, Chan; Rouleau, Christopher M.

2001-02-01T23:59:59.000Z

370

Injection photodiodes based on low-resistivity ZnS single crystals  

SciTech Connect (OSTI)

Results of an experimental study of Ni-n-n{sup +}-In photodiode structures fabricated from a low-resistivity ZnS:Al crystal (n{sup +}-region) are reported. The high-resistivity compensated n-type layer is produced by thermal diffusion of silver. The photodiodes exhibit an injection amplification of the photocurrent under a forward bias of 1-10 V. The dependence of the currents through the diodes on the thickness of the n-type layer in the dark and under UV irradiation is determined. The photosensitivity is at a maximum in the fundamental absorption range in a narrow spectral band.

Losev, V. V., E-mail: morozova-tamara@mail.ru [Moscow State Institute (Technical University) of Electronic Engineering (Russian Federation)

2009-12-15T23:59:59.000Z

371

Sediment-water exchange of Mn, Fe, Ni and Zn in Galveston Bay, Texas  

Science Journals Connector (OSTI)

In-situ benthic flux studies were conducted at three stations in Upper Galveston Bay twice during March 1996 to directly measure release rates of dissolved Mn, Fe, Ni and Zn from the sediments. Results showed reproducible increases with time in both replicate light and light–dark benthic chambers, resulting in average fluxes of ?1200±780, ?17±12, ?1.6±0.6 and ?2.4±0.79 ?mol m?2 day?1 for Mn, Fe, Ni and Zn, respectively. Sediment cores collected during 1994–1996 showed that surficial pore water concentrations were elevated compared to overlying water column concentrations, suggesting diffusive release from the sediments. Diffusive flux estimates of Mn and Zn agreed in direction with chamber fluxes measured on the same date, but only accounted for 5–38% of the measured flux. Diffusive fluxes of Fe agreed with measured fluxes at the near Trinity River station but overestimated actual release in the mid and outer Trinity Bay regions, possibly due to inaccurate determination of the Fe pore water gradients or rapid oxidation processes in the overlying water at these stations. In general, measured fluxes of Mn and Ni were higher in the mid Trinity Bay region and suggested a mechanism for the elevated trace metal concentrations previously reported for this region of Galveston Bay. However, the fluxes of Fe were highest in close proximity to the Trinity River, supporting the elevated Fe concentrations measured in this region during this and other studies, and decreased towards middle and outer Trinity Bay. Trace metal turnover times were between 0.1 and 1.2 days for Mn, between 1.3 and 4.6 days for Fe, and between 27 and 100 days for Ni and 12–20 days Zn, and were considerably shorter than the average Trinity Bay water residence time (1.5 years) for this period. Comparing area averaged benthic inputs to Trinity River inputs shows the sediments to be a significant source of trace metals to Galveston Bay. However, while benthic inputs of trace metals were measured, water column concentrations remained low despite rapid turnover times for Mn and Fe, suggesting removal of these metals from the water column after release from the sediments.

Kent W Warnken; Gary A Gill; Lawrence L Griffin; Peter H Santschi

2001-01-01T23:59:59.000Z

372

Growth, disorder, and physical properties of ZnSnN{sub 2}  

SciTech Connect (OSTI)

We examine ZnSnN{sub 2}, a member of the class of materials contemporarily termed “earth-abundant element semiconductors,” with an emphasis on evaluating its suitability for photovoltaic applications. It is predicted to crystallize in an orthorhombic lattice with an energy gap of 2 eV. Instead, using molecular beam epitaxy to deposit high-purity, single crystal as well as highly textured polycrystalline thin films, only a monoclinic structure is observed experimentally. Far from being detrimental, we demonstrate that the cation sublattice disorder which inhibits the orthorhombic lattice has a profound effect on the energy gap, obviating the need for alloying to match the solar spectrum.

Feldberg, N.; Aldous, J. D. [Department of Physics, University at Buffalo, Buffalo, New York 14260 (United States)] [Department of Physics, University at Buffalo, Buffalo, New York 14260 (United States); Linhart, W. M.; Phillips, L. J.; Durose, K.; Veal, T. D. [Stephenson Institute for Renewable Energy and Department of Physics, University of Liverpool, Liverpool L69 7ZF (United Kingdom)] [Stephenson Institute for Renewable Energy and Department of Physics, University of Liverpool, Liverpool L69 7ZF (United Kingdom); Stampe, P. A.; Kennedy, R. J. [Department of Physics, Florida A and M University, Tallahassee, Florida 32307 (United States)] [Department of Physics, Florida A and M University, Tallahassee, Florida 32307 (United States); Scanlon, D. O. [University College London, Kathleen Lonsdale Materials Chemistry, Department of Chemistry, 20 Gordon Street, London WC1H 0AJ (United Kingdom)] [University College London, Kathleen Lonsdale Materials Chemistry, Department of Chemistry, 20 Gordon Street, London WC1H 0AJ (United Kingdom); Vardar, G.; Field, R. L. III; Jen, T. Y.; Goldman, R. S. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Durbin, S. M. [Department of Physics, University at Buffalo, Buffalo, New York 14260 (United States) [Department of Physics, University at Buffalo, Buffalo, New York 14260 (United States); Department of Electrical Engineering, University at Buffalo, Buffalo, New York 14260 (United States)

2013-07-22T23:59:59.000Z

373

Formation of Smooth, Conformal Molecular Layers on ZnO Surfaces via Photochemical Grafting  

Science Journals Connector (OSTI)

While the surface chemistry of bulk single crystals of ZnO has been explored in some detail, these studies focused almost exclusively on small molecules in ultrahigh vacuum,(29-33) where the absence of water and associated solvation may substantially alter reactivity. ... (36-40) Recently this method has also been extended to ionic semiconductors to form stable, functional layers on gallium nitride(41) and titanium dioxide. ... For example, hydrophobic or hydrophilic ligands can control wetting and solubility properties, while functional groups such as amines can be used for subsequent covalent chemistry. ...

Rose E. Ruther; Ryan Franking; Alex M. Huhn; Jaritza Gomez-Zayas; Robert J. Hamers

2011-07-21T23:59:59.000Z

374

High Resolution Optically Addressed Spatial Light Modulator based on ZnO Nanoparticles  

E-Print Network [OSTI]

temperatures. (d) Temporal current response with and without illumination. Samples are illuminated by 10 mW cm -2 of 365 nm light emitting diode with 6 V dc being applied throughout. Electrical characterization For conductivity measurement, two rectangular... of the corresponding dark/photo currents of the ITO-ZnO-ITO structures are carried out using Agilent 4156 together with a 365 nm light emitting diode light source of 2 mW cm-2. The conductivity, ? , of the sample is calculated as, dI LtV? ? (2) where, d...

Shrestha, Pawan Kumar; Chun, Young Tea; Chu, Daping

2015-01-01T23:59:59.000Z

375

Low-temperature recrystallization of Ge nanolayers on ZnSe  

SciTech Connect (OSTI)

The in situ X-ray photoelectron spectroscopy observation of low-temperature recrystallization of an amorphous Ge layer deposited on a ZnSe film at room temperature is reported. It is shown that the experimentally measured shifts of the Ge 3d core level are consistent with the changes observed in the crystal structure of the layer by the high-energy electron diffraction technique in the reflection mode of measurements. The shifts can be attributed to successive nanometer-scaled structural changes in the Ge layer with increasing temperature.

Suprun, S. P., E-mail: suprun@thermo.isp.nsc.ru; Fedosenko, E. V. [Russian Academy of Sciences, Institute of Semiconductor Physics, Siberian Division (Russian Federation)

2007-05-15T23:59:59.000Z

376

Heat Capacity of ?-CuZn Alloys below 4.2°K  

Science Journals Connector (OSTI)

Low-temperature heat capacity measurements have been made on a series of high-purity specimens covering the entire ? phase of the Cu-Zn system. The electronic heat capacity decreases rapidly with increasing zinc concentration, thereby lending support to the hypothesis that the ? brasses are electron compounds. An excellent fit to the data may be obtained by assuming that the Fermi surface of these alloys is spherical and makes contact with the large Brillouin zone of the ?-brass structure. The Debye temperature of the alloys is 433°K and is approximately independent of zinc concentration.

Boyd W. Veal and John A. Rayne

1963-11-15T23:59:59.000Z

377

Characterization of ZnSe scintillating bolometers for Double Beta Decay  

E-Print Network [OSTI]

ZnSe scintillating bolometers are good candidates for future Double Beta Decay searches, because of the 82Se high Q-value and thanks to the possibility of alpha background rejection on the basis of the scintillation signal. In this paper we report the characteristics and the anomalies observed in an extensive study of these devices. Among them, an unexpected high emission from alpha particles, accompanied with an unusual pattern of the light vs. heat scatter plot. The perspectives for the application of this kind of detectors to search for the Neutrinoless Double Beta Decay of 82Se are presented.

C. Arnaboldi; S. Capelli; O. Cremonesi; L. Gironi; M. Pavan; G. Pessina; S. Pirro

2010-06-14T23:59:59.000Z

378

Hydrothermally Grown Upright-Standing Nanoporous Nanosheets of Iodine-Doped ZnO (ZnO:I) Nanocrystallites for a High-Efficiency Dye-Sensitized Solar Cell  

Science Journals Connector (OSTI)

Nanoporous nanosheets of ZnO and ZnO:I nanocrsytallites were washed with DI water and baked in air at 350 °C for 30 min in order to remove any residual organics and optimize solar cell performance. ... The proposed growth process is a simple and low-cost approach for the large scale production of nanomaterials with high conversion efficiency to fabricate DSSCs and hybrid solar cells. ... This method is also anticipated to be equally applicable to other semiconductor photoelectrodes in DSSCs and organic–inorganic hybrid solar cells. ...

Khalid Mahmood; Hyun Wook Kang; Seung Bin Park; Hyung Jin Sung

2013-03-19T23:59:59.000Z

379

Growth of p-type ZnO thin films by (N, Ga) co-doping using DMHy dopant  

Science Journals Connector (OSTI)

We investigate p-type doping in ZnO prepared by metal-organic chemical vapour deposition with dimethylhydrazine (DMHy) as the nitrogen dopant source. Results obtained by x-ray photoelectron spectroscopy show that DMHy exhibits a narrow temperature window from 500 to 550?°C for efficient nitrogen incorporation and that nitrogen doping is critically influenced by growth conditions, e.g. the N/Ga flux ratio in growth. Within an appropriate N/Ga flux ratio range, p-type ZnO can be realized. The effect of the N/Ga flux ratio on the conductivity conversion of ZnO is reported. The extrinsic nitrogen acceptor level is calculated to be about 160?meV from low-temperature photoluminescence spectra.

H Wang; H P Ho; K C Lo; K W Cheah

2007-01-01T23:59:59.000Z

380

Reduction of surface leakage current by surface passivation of CdZn Te and other materials using hyperthermal oxygen atoms  

DOE Patents [OSTI]

Reduction of surface leakage current by surface passivation of Cd.sub.1-x Zn.sub.x Te and other materials using hyperthermal oxygen atoms. Surface effects are important in the performance of CdZnTe room-temperature radiation detectors used as spectrometers since the dark current is often dominated by surface leakage. A process using high-kinetic-energy, neutral oxygen atoms (.about.3 eV) to treat the surface of CdZnTe detectors at or near ambient temperatures is described. Improvements in detector performance include significantly reduced leakage current which results in lower detector noise and greater energy resolution for radiation measurements of gamma- and X-rays, thereby increasing the accuracy and sensitivity of measurements of radionuclides having complex gamma-ray spectra, including special nuclear materials.

Hoffbauer, Mark A. (Los Alamos, NM); Prettyman, Thomas H. (Los Alamos, NM)

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" 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

One-photon band gap engineering of borate glass doped with ZnO for photonics applications  

SciTech Connect (OSTI)

Lithium tungsten borate glass of the composition (0.56-x)B{sub 2}O{sub 3}-0.4Li{sub 2}O-xZnO-0.04WO{sub 3} (0 {<=}x{<=} 0.1 mol. %) is prepared for photonics applications. The glass is doped with ZnO to tune the glass absorption characteristics in a wide spectrum range (200-2500 nm). Chemical bond approach, including chemical structure, electronegativity, bond ionicity, nearest-neighbor coordination, and other chemical bonding aspect, is used to analyze and to explain the obtained glass properties such as: transmittance, absorption, electronic structure parameters (bandgap, Fermi level, and Urbach exciton-phonon coupling), Wannier free excitons excitation (applying Elliott's model), and two-photon absorption coefficient as a result of replacement of B{sub 2}O{sub 3} by ZnO.

Abdel-Baki, Manal [Glass Department, National Research Centre, Dokki 12311 Giza (Egypt); Abdel-Wahab, Fathy A.; El-Diasty, Fouad [Physics Department, Faculty of Science, Ain Shams University, Abbasia, 11566 Cairo (Egypt)

2012-04-01T23:59:59.000Z

382

Performance of ZnMoO4 crystal as cryogenic scintillating bolometer to search for double beta decay of molybdenum  

E-Print Network [OSTI]

Zinc molybdate (ZnMoO4) single crystals were grown for the first time by the Czochralski method and their luminescence was measured under X ray excitation in the temperature range 85-400 K. Properties of ZnMoO4 crystal as cryogenic low temperature scintillator were checked for the first time. Radioactive contamination of the ZnMoO4 crystal was estimated as <0.3 mBq/kg (228-Th) and 8 mBq/kg (226-Ra). Thanks to the simultaneous measurement of the scintillation light and the phonon signal, the alpha particles can be discriminated from the gamma/beta interactions, making this compound extremely promising for the search of neutrinoless Double Beta Decay of 100-Mo. We also report on the ability to discriminate the alpha-induced background without the light measurement, thanks to a different shape of the thermal signal that characterizes gamma/beta and alpha particle interactions.

L. Gironi; C. Arnaboldi; J. W. Beeman; O. Cremonesi; F. A. Danevich; V. Ya. Degoda; L. I. Ivleva; L. L. Nagornaya; M. Pavan; G. Pessina; S. Pirro; V. I. Tretyak; I. A. Tupitsyna

2010-10-01T23:59:59.000Z

383

Interaction between O{sub 2} and ZnO films probed by time-dependent second-harmonic generation  

SciTech Connect (OSTI)

The interaction between O{sub 2} and ZnO thin films prepared by atomic layer deposition has been investigated by time-dependent second-harmonic generation, by probing the electric field induced by adsorbed oxygen molecules on the surface. The second-harmonic generated signal decays upon laser exposure due to two-photon assisted desorption of O{sub 2}. Blocking and unblocking the laser beam for different time intervals reveals the adsorption rate of O{sub 2} onto ZnO. The results demonstrate that electric field induced second-harmonic generation provides a versatile non-contact probe of the adsorption kinetics of molecules on ZnO thin films.

Andersen, S. V., E-mail: sva@nano.aau.dk [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4A, DK-9220 Aalborg Øst (Denmark); Vandalon, V.; Bosch, R. H. E. C.; Loo, B. W. H. van de; Kessels, W. M. M., E-mail: w.m.m.kessels@tue.nl [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Pedersen, K. [Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4A, DK-9220 Aalborg Øst (Denmark)

2014-02-03T23:59:59.000Z

384

7 valence band symmetry related hole fine splitting of bound excitons in ZnO observed in magneto-optical studies  

E-Print Network [OSTI]

in other wurtzite II-VI materials such as ZnSe and CdS.1 Theoretical calculations explained the reversed lithium doped ZnO grown by chemical-vapor deposition CVD on Tokyo Denpa substrates and on the I4 and I8

Nabben, Reinhard

385

The effect of solution heat-treatment on grain boundary segregation and stress-corrosion cracking of Al-Zn-Mg alloys  

Science Journals Connector (OSTI)

The relationship between susceptibility to stress-corrosion cracking (SCC) and grain boundary (GB) chemistry was investigated to elucidate the SCC mechanism in two Al-Zn-Mg alloys (Al-6.92Zn-2.85Mg-0.13Zr, Al-...

J. R. Pickens; T. J. Langan

1987-10-01T23:59:59.000Z

386

FLEXIBLE CdTe SOLAR CELLS BY A LOW TEMPERATURE PROCESS ON ITO/ZnO COATED A. Salavei, I. Rimmaudo, F. Piccinelli1  

E-Print Network [OSTI]

FLEXIBLE CdTe SOLAR CELLS BY A LOW TEMPERATURE PROCESS ON ITO/ZnO COATED POLYMERS A. Salavei, I of a deposition process for flexible CdTe devices on ITO/ZnO coated polymers. Optimization of fabrication process will be discussed. Keywords: Flexible Substrate, CdTe, ITO, Laser Processing, Thin Film Solar Cell 1 INTRODUCTION

Romeo, Alessandro

387

ZnO-TiO2 Core-Shell Nanorod/P3HT Solar Cells Lori E. Greene, Matt Law, Benjamin D. Yuhas, and Peidong Yang*  

E-Print Network [OSTI]

diffusion bottleneck, has been addressed in organic and organic-inorganic hybrid solar cells by adoptingZnO-TiO2 Core-Shell Nanorod/P3HT Solar Cells Lori E. Greene, Matt Law, Benjamin D. Yuhas-inorganic solar cell architecture based on ZnO-TiO2 core-shell nanorod arrays encased in the hole

Yang, Peidong

388

CdS and CdS/CdSe sensitized ZnO nanorod array solar cells prepared by a solution ions exchange process  

SciTech Connect (OSTI)

Graphical abstract: - Highlights: • CdS and CdS/CdSe quantum dots are assembled on ZnO nanorods by ion exchange process. • The CdS/CdSe sensitization of ZnO effectively extends the absorption spectrum. • The performance of ZnO/CdS/CdSe cell is improved by extending absorption spectrum. - Abstract: In this paper, cadmium sulfide (CdS) and cadmium sulfide/cadmium selenide (CdS/CdSe) quantum dots (QDs) are assembled onto ZnO nanorod arrays by a solution ion exchange process for QD-sensitized solar cell application. The morphology, composition and absorption properties of different photoanodes were characterized with scanning electron microscope, transmission electron microscope, energy-dispersive X-ray spectrum and Raman spectrum in detail. It is shown that conformal and uniform CdS and CdS/CdSe shells can grow on ZnO nanorod cores. Quantum dot sensitized solar cells based on ZnO/CdS and ZnO/CdS/CdSe nanocable arrays were assembled with gold counter electrode and polysulfide electrolyte solution. The CdS/CdSe sensitization of ZnO can effectively extend the absorption spectrum up to 650 nm, which has a remarkable impact on the performance of a photovoltaic device by extending the absorption spectrum. Preliminary results show one fourth improvement in solar cell efficiency.

Chen, Ling; Gong, Haibo; Zheng, Xiaopeng; Zhu, Min; Zhang, Jun [Key Laboratory of Inorganic Functional Materials in Universities of Shandong, School of Materials Science and Engineering, University of Jinan, Jinan 250022, Shandong (China); Yang, Shikuan [Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802-6812 (United States); Cao, Bingqiang, E-mail: mse_caobq@ujn.edu.cn [Key Laboratory of Inorganic Functional Materials in Universities of Shandong, School of Materials Science and Engineering, University of Jinan, Jinan 250022, Shandong (China)

2013-10-15T23:59:59.000Z

389

The 3-stage evolution of the Angouran Zn "oxide"-sulfide deposit, Iran Fakultt Chemie, Technische Universitt Mnchen, Germany albert.gilg@geo.tum.de  

E-Print Network [OSTI]

The 3-stage evolution of the Angouran Zn "oxide"-sulfide deposit, Iran H.A. Gilg Fakultät Chemie@unina.it F. Moore Geological Department, University Shiraz, Iran moor@geology.susc.ac.ir Keywords: Angouran, Iran, sulfide, MVT, smithsonite, hypogene, supergene ABSTRACT: The giant Angouran Zn-Pb deposit (Zanjan

Boni, Maria

390

Intrinsic current-voltage properties of nanowires with four-probe scanning tunneling microscopy: A conductance transition of ZnO nanowire  

E-Print Network [OSTI]

strain. The ZnO-nanowire samples used in our experiments were synthesized via reduction and oxidation of ZnS powder13 and dispersed on a silicon wafer coated with a 500-nm-thick silicon dioxide layer as insulator. The STM tips were made from a tungsten or gold wire using the stan- dard preparation proce

Liu, Feng

391

Enhancement of surface phonon modes in the Raman spectrum of ZnSe nanoparticles on adsorption of 4-mercaptopyridine  

SciTech Connect (OSTI)

By chemically etching a thin film of crystalline ZnSe with acid, we observe a strong Raman enhancement of the surface phonon modes of ZnSe on adsorption of a molecule (4-mercaptopyridine). The surface is composed of oblate hemi-ellipsoids, which has a large surface-to-bulk ratio. The assignment of the observed modes (at 248 and 492 cm{sup ?1}) to a fundamental and first overtone of the surface optical mode is consistent with observations from high-resolution electron energy loss spectroscopy as well as calculations.

Islam, Syed K.; Lombardi, John R. [Department of Chemistry, The City College of New York, New York, New York 10031 (United States)] [Department of Chemistry, The City College of New York, New York, New York 10031 (United States)

2014-02-21T23:59:59.000Z

392

Controllable and Rapid Synthesis of Long ZnO Nanowire Arrays for Dye-Sensitized Solar Cells  

Science Journals Connector (OSTI)

In this paper, we report a controllable and rapid growth of long ZnO nanowire arrays by a microwave heating method with fresh precursor solution continuously injected into the reactor. ... In our work, along with the continuous injection of fresh solution into the reactor, part of the heated reactant is pumped out of the reactor, and the concentrations of the species in the solution gradually become stabilization and finally in equilibrium. ... Mahpeykar, S. M.; Koohsorkhi, J.; Ghafoori-fard, H.Ultra-Fast Microwave-Assisted Hydrothermal Synthesis of Long Vertically Aligned ZnO Nanowires for Dye-Sensitized Solar Cell Application Nanotechnology 2012, 23, 165602 ...

Liqing Liu; Kunquan Hong; Xing Ge; Dongmei Liu; Mingxiang Xu

2014-06-27T23:59:59.000Z

393

Formation behavior of Be{sub x}Zn{sub 1-x}O alloys grown by plasma-assisted molecular beam epitaxy  

SciTech Connect (OSTI)

We report the phase formation behavior of Be{sub x}Zn{sub 1-x}O alloys grown by plasma-assisted molecular beam epitaxy. We find the alloy with low- and high-Be contents could be obtained by alloying BeO into ZnO films. X-ray diffraction measurements shows the c lattice constant value shrinks, and room temperature absorption shows the energy band-gap widens after Be incorporated. However, the alloy with intermediate Be composition are unstable and segregated into low- and high-Be contents BeZnO alloys. We demonstrate the phase segregation of Be{sub x}Zn{sub 1-x}O alloys with intermediate Be composition resulted from large internal strain induced by large lattice mismatch between BeO and ZnO.

Chen, Mingming; Zhu, Yuan; Su, Longxing; Zhang, Quanlin; Chen, Anqi; Ji, Xu; Xiang, Rong; Gui, Xuchun; Wu, Tianzhun [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China)] [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Pan, Bicai [Department of Physics and Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China)] [Department of Physics and Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Tang, Zikang [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China) [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China)

2013-05-20T23:59:59.000Z

394

In Situ X-ray Absorption Near-Edge Structure Spectroscopy of ZnO Nanowire Growth During Chemical Bath Deposition  

SciTech Connect (OSTI)

Chemical bath deposition (CBD) offers a simple and inexpensive route to deposit semiconductor nanostructures, but lack of fundamental understanding and control of the underlying chemistry has limited its versatility. Here we report the first use of in situ X-ray absorption spectroscopy during CBD, enabling detailed investigation of both reaction mechanisms and kinetics of ZnO nanowire growth from zinc nitrate and hexamethylenetetramine (HMTA) precursors. Time-resolved X-ray absorption near-edge structure (XANES) spectra were used to quantify Zn(II) speciation in both solution and solid phases. ZnO crystallizes directly from [Zn(H{sub 2}O){sub 6}]{sup 2+} without long-lived intermediates. Using ZnO nanowire deposition as an example, this study establishes in situ XANES spectroscopy as an excellent quantitative tool to understand CBD of nanomaterials.

McPeak, Kevin M.; Becker, Matthew A.; Britton, Nathan G.; Majidi, Hasti; Bunker, Bruce A.; Baxter, Jason B. (Drexel); (Notre)

2010-12-03T23:59:59.000Z

395

Influence of in-situ annealing ambient on p-type conduction in dual ion beam sputtered Sb-doped ZnO thin films  

SciTech Connect (OSTI)

Sb-doped ZnO (SZO) films were deposited on c-plane sapphire substrates by dual ion beam sputtering deposition system and subsequently annealed in-situ in vacuum and in various proportions of O{sub 2}/(O{sub 2} + N{sub 2})% from 0% (N{sub 2}) to 100% (O{sub 2}). Hall measurements established all SZO films were p-type, as was also confirmed by typical diode-like rectifying current-voltage characteristics from p-ZnO/n-ZnO homojunction. SZO films annealed in O{sub 2} ambient exhibited higher hole concentration as compared with films annealed in vacuum or N{sub 2} ambient. X-ray photoelectron spectroscopic analysis confirmed that Sb{sup 5+} states were more preferable in comparison to Sb{sup 3+} states for acceptor-like Sb{sub Zn}-2V{sub Zn} complex formation in SZO films.

Pandey, Sushil Kumar; Kumar Pandey, Saurabh; Awasthi, Vishnu; Mukherjee, Shaibal [Hybrid Nanodevice Research Group (HNRG), Discipline of Electrical Engineering, Indian Institute of Technology, Indore 453441 (India)] [Hybrid Nanodevice Research Group (HNRG), Discipline of Electrical Engineering, Indian Institute of Technology, Indore 453441 (India); Gupta, M.; Deshpande, U. P. [University Grants Commission Department of Atomic Energy (UGC DAE) Consortium for Scientific Research, Indore (India)] [University Grants Commission Department of Atomic Energy (UGC DAE) Consortium for Scientific Research, Indore (India)

2013-08-12T23:59:59.000Z

396

Preparation of Cu/ZnO/Al2O3 catalyst for a micro methanol reformer  

Science Journals Connector (OSTI)

A Cu/ZnO/Al2O3 catalyst suitable for low-temperature methanol reforming is proposed. The catalyst achieved by optimization of the temperature and pH of preparation and the addition of boehmite has superior catalytic activity to commercial catalysts. The catalytic activity is found to depend on the Cu surface area, which is related to the amount of Cu dispersed within ZnO. Dispersion of Cu is promoted by precipitation at low temperature, which results in the formation of small crystallites of the precursor. Enlarged BET surface area by the addition of boehmite as the third component derives high catalytic activity. Under optimized pH, it is predicted that the excess of Cu species existing as amorphous-like malachite in the precursor, in addition to aurichalcite, facilitates the dispersion of Cu. The proposed catalyst system can achieve methanol reforming at temperatures 20–25 °C lower than conventional catalysts, representing an improved source of H2 for small proton exchange membrane fuel cell systems.

Yoshihiro Kawamura; Kazuto Yamamoto; Naotsugu Ogura; Takashi Katsumata; Akira Igarashi

2005-01-01T23:59:59.000Z

397

SeZnSb alloy and its nano tubes, graphene composites properties  

SciTech Connect (OSTI)

Composite can alter the individual element physical property, could be useful to define the specific use of the material. Therefore, work demonstrates the synthesis of a new composition Se{sub 96}-Zn{sub 2}-Sb{sub 2} and its composites with 0.05% multi-walled carbon nano tubes and 0.05% bilayer graphene, in the glassy form. The diffused amorphous structure of the multi walled carbon nano tubes and bilayer gaphene in the Se{sub 96}-Zn{sub 2}-Sb{sub 2} alloy have been analyzed by using the Raman, X-ray photoluminescence spectroscopy, Furrier transmission infrared spectra, photoluminescence, UV/visible absorption spectroscopic measurements. The diffused prime Raman bands (G and D) have been appeared for the multi walled carbon nano tubes and graphene composites, while the X-ray photoluminescence core energy levels peak shifts have been observed for the composite materials. Subsequently the photoluminescence property at room temperature and a drastic enhancement (upto 80%) in infrared transmission percentage has been obtained for the bilayer graphene composite, along with optical energy band gaps for these materials have been evaluated 1.37, 1.39 and 1.41 eV.

Singh, Abhay Kumar [Department of Physics, Indian Institute of Physics, Bangalore-560012 (India)

2013-04-15T23:59:59.000Z

398

Experimental and theoretical study of the energy loss of C and O in Zn  

SciTech Connect (OSTI)

We present a combined experimental-theoretical study of the energy loss of C and O ions in Zn in the energy range 50-1000 keV/amu. This contribution has a double purpose, experimental and theoretical. On the experimental side, we present stopping power measurements that fill a gap in the literature for these projectile-target combinations and cover an extended energy range, including the stopping maximum. On the theoretical side, we make a quantitative test on the applicability of various theoretical approaches to calculate the energy loss of heavy swift ions in solids. The description is performed using different models for valence and inner-shell electrons: a nonperturbative scattering calculation based on the transport cross section formalism to describe the Zn valence electron contribution, and two different models for the inner-shell contribution: the shellwise local plasma approximation (SLPA) and the convolution approximation for swift particles (CasP). The experimental results indicate that C is the limit for the applicability of the SLPA approach, which previously was successfully applied to projectiles from H to B. We find that this model clearly overestimates the stopping data for O ions. The origin of these discrepancies is related to the perturbative approximation involved in the SLPA. This shortcoming has been solved by using the nonperturbative CasP results to describe the inner-shell contribution, which yields a very good agreement with the experiments for both C and O ions.

Cantero, E. D.; Lantschner, G. H.; Arista, N. R. [Centro Atomico Bariloche and Instituto Balseiro, Comision Nacional de Energia Atomica, 8400 San Carlos de Bariloche (Argentina); Montanari, C. C.; Miraglia, J. E. [Instituto de Astronomia y Fisica del Espacio (CONICET-UBA), Buenos Aires (Argentina); Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires (Argentina); Behar, M.; Fadanelli, R. C. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Avenida Bento Goncalves 9500, Porto Alegre-RS (Brazil)

2011-07-15T23:59:59.000Z

399

Magnetoresistance in Mn ion-implanted GaAs:Zn nanowires  

SciTech Connect (OSTI)

We have investigated the magnetoresistance (MR) in a series of Zn doped (p-type) GaAs nanowires implanted with different Mn concentrations. The nanowires with the lowest Mn concentration (?0.0001%) exhibit a low resistance of a few k? at 300?K and a 4% positive MR at 1.6?K, which can be well described by invoking a spin-split subband model. In contrast, nanowires with the highest Mn concentration (4%) display a large resistance of several M? at 300?K and a large negative MR of 85% at 1.6?K. The large negative MR is interpreted in terms of spin-dependent hopping in a complex magnetic nanowire landscape of magnetic polarons, separated by intermediate regions of Mn impurity spins. Sweeping the magnetic field back and forth for the 4% sample reveals a hysteresis that indicates the presence of a weak ferromagnetic phase. We propose co-doping with Zn to be a promising way to reach the goal of realizing ferromagnetic Ga{sub 1?x}Mn{sub x}As nanowires for future nanospintronics.

Paschoal, W.; Kumar, Sandeep; Jain, V.; Pettersson, H., E-mail: hakan.pettersson@hh.se [Solid State Physics/The Nanometer Structure Consortium, Lund University, Box 118, SE-221 00 Lund (Sweden); Department of Mathematics, Physics and Electrical Engineering, Halmstad University, Box 823, SE-301 18, Halmstad (Sweden); Jacobsson, D.; Samuelson, L. [Solid State Physics/The Nanometer Structure Consortium, Lund University, Box 118, SE-221 00 Lund (Sweden); Johannes, A.; Ronning, C. [Institute for Solid State Physics, Friedrich-Schiller-University Jena, Max-Wien-Platz 1, D-07743 Jena (Germany); Canali, C. M.; Pertsova, A. [Department of Physics and Electrical Engineering, Linneaus University, SE-39233 Kalmar (Sweden); Dick, K. A. [Solid State Physics/The Nanometer Structure Consortium, Lund University, Box 118, SE-221 00 Lund (Sweden); Center for Analysis and Synthesis, Lund University, Box 124, S-221 00 Lund (Sweden)

2014-04-14T23:59:59.000Z

400

Temperature dependence of photoconductivity in Zn-doped GaN  

SciTech Connect (OSTI)

In agreement with predictions from a model that explained an abrupt thermal quenching of the blue luminescence (BL) band in high-resistivity Zn-doped GaN [Reshchikov et al., Phys. Rev. B 84, 075212 (2011) and Phys. Rev. B 85, 245203 (2012)], we observed the stepwise decrease of photoconductivity in this material with increasing temperature. For the sample studied in this work, the decrease in photoconductivity occurred in two steps at characteristic temperatures T{sub 1} and T{sub 2}. The characteristic temperatures increased with increasing excitation intensity, very similar to the photoluminescence (PL) behavior. The steps in photoconductivity at about 100 K and 200 K are attributed to drop in the concentration of free electrons due to the thermal emission of holes from a shallow acceptor and the Zn{sub Ga} acceptor, respectively, to the valence band and their recombination with electrons via nonradiative centers. This finding supports the model suggested previously and helps to explain other examples of tunable photoconductivity reported in literature.

Reshchikov, Michael A. [Department of Physics, Virginia Commonwealth University, Richmond, VA 23284 (United States)

2014-02-21T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" 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

Nanoassembly control and optical absorption in CdTe-ZnO nanocomposite thin films  

SciTech Connect (OSTI)

The spatial distribution of CdTe nanoparticles within a ZnO thin-film matrix was manipulated using a dual-source, sequential radio-frequency (RF)-sputter deposition technique to produce nanocomposite materials with tuned spectral absorption characteristics. The relative substrate exposure time to each sputtering source was used to control the semiconductor phase connectivity, both within the film plane and along the film growth direction, to influence the degree of photocarrier confinement and the resulting optical transition energies exhibited by the CdTe phase. Significant changes (up to {Delta}E {approx_equal} 0.3 eV) in the absorption onset energy for the CdTe nanoparticle ensemble were produced through modification in the extended structure of the semiconductor phase. Raman spectroscopy, cross-sectional transmission electron microscopy, and x-ray diffraction were used to confirm the phase identity of the CdTe and ZnO and to characterize the nanostructures produced in these composite films. Isochronal annealing for 5 min at temperatures up to 800 deg. C further indicated the potential to improve film crystallinity as well as to establish the post-deposition thermal processing limits of stability for the semiconductor phase. The study highlights the significance of ensemble behavior as a means to influence quantum-scale semiconductor optical characteristics of import to the use of such materials as the basis for a variety of optoelectronic devices, including photosensitized heterojunction components in thin film photovoltaics.

Potter, B. G. Jr. [Materials Science and Engineering Department, University of Arizona, Tucson, Arizona 85721 (United States); College of Optical Sciences, University of Arizona, Tucson, Arizona 85721 (United States); Beal, R. J.; Allen, C. G. [Materials Science and Engineering Department, University of Arizona, Tucson, Arizona 85721 (United States)

2012-02-01T23:59:59.000Z

402

Rejection of randomly coinciding events in ZnMoO$_4$ scintillating bolometers  

E-Print Network [OSTI]

Random coincidence of events (particularly from two neutrino double beta decay) could be one of the main sources of background in the search for neutrinoless double beta decay with cryogenic bolometers due to their poor time resolution. Pulse-shape discrimination by using front edge analysis, mean-time and $\\chi^2$ methods was applied to discriminate randomly coinciding events in ZnMoO$_4$ cryogenic scintillating bolometers. These events can be effectively rejected at the level of 99% by the analysis of the heat signals with rise-time of about 14 ms and signal-to-noise ratio of 900, and at the level of 92% by the analysis of the light signals with rise-time of about 3 ms and signal-to-noise ratio of 30, under the requirement to detect 95% of single events. These rejection efficiencies are compatible with extremely low background levels in the region of interest of neutrinoless double beta decay of $^{100}$Mo for enriched ZnMoO$_4$ detectors, of the order of $10^{-4}$ counts/(y keV kg). Pulse-shape parameters ...

Chernyak, D M; Giuliani, A; Mancuso, M; Nones, C; Olivieri, E; Tenconi, M; Tretyak, V I

2014-01-01T23:59:59.000Z

403

Cu2ZnSnS x O4 x and Cu2ZnSnS x Se4 x : First principles simulations of optimal alloy configurations and their energies  

E-Print Network [OSTI]

is the development of thin film photovoltaic devices with high effi- ciency and low cost. As an absorber layer) photovoltaic absorber layer material J. Appl. Phys. 112, 124508 (2012); 10.1063/1.4769738 Analysis of lattice and selenization of the photovoltaic material Cu2ZnSnS4, we used first principles methods to study the structure

Holzwarth, Natalie

404

Heavy-ion fusion cross sections of weakly bound $^{9}$Be on $^{27}$Al, $^{64}$Zn and tightly bound $^{16}$O on $^{64}$Zn target using Coulomb and proximity potential  

E-Print Network [OSTI]

The total fusion cross sections for the fusion of weakly bound $^{9}$Be on $^{27}$Al and $^{64}$Zn targets at near and above the barrier have been calculated using one dimensional barrier penetration model, taking scattering potential as the sum of Coulomb and proximity potential and the calculated values are compared with experimental data. For the purpose of comparison of the fusion of weakly bound projectiles and strongly bound projectiles, the total fusion cross sections for the reaction of tightly bound nucleus $^{16}$O on $^{64}$Zn have also been computed using a similar procedure. The calculated values of total fusion cross sections in all cases are compared with coupled channel calculations using the code CCFULL. The computed cross sections using Coulomb and proximity potential explain the fusion reactions well in both cases of weakly bound and strongly bound projectiles. Reduced reaction cross sections for the systems $^{9}$Be + $^{27}$Al, $^{9}$Be+ $^{64}$Zn and $^{16}$O + $^{64}$Zn have also been described.

K. P. Santhosh; V. Bobby Jose

2013-12-19T23:59:59.000Z

405

Hydrogenolysis of Glycerol over Cu/ZnO-Based Catalysts: Influence of Transport Phenomena Using the Madon–Boudart Criterion  

Science Journals Connector (OSTI)

Batch hydrogenolysis of concentrated glycerol has been conducted over different Cu/ZnO-based catalysts prepared by the coprecipitation method. The catalysts were characterized by X-ray diffraction, H2 temperature-programmed reduction, and the N2O ...

Dominique Jean; Bendaoud Nohair; Jean-Yves Bergeron; Serge Kaliaguine

2014-05-27T23:59:59.000Z

406

Influence of Cobalt Doping on the Physical Properties of Zn0.9Cd0.1S Nanoparticles  

Science Journals Connector (OSTI)

Zn0.9Cd0.1S nanoparticles doped with 0.005–0.24 M cobalt have been prepared by co-precipitation technique in ice bath at 280 K. For the cobalt concentration >0.18 M, XRD pattern shows unidentified phases along wi...

Sonal Singhal; Amit Kumar Chawla; Hari Om Gupta…

2010-02-01T23:59:59.000Z

407

Mechanochemical synthesis of tungsten carbide nano particles by using WO{sub 3}/Zn/C powder mixture  

SciTech Connect (OSTI)

Graphical abstract: Display Omitted Highlights: ? Nano particles of WC are synthesized by mechanochemical process. ? Zn was used to reduce WO{sub 3}. ? By removing ZnO from the milling products with an acid leaching, WC will be the final products. ? XRD results showed that the reduction reactions were completed after 36 h. ? TEM and SEM images showed that the morphology of produced powder is nearly spherical like. -- Abstract: In this research we introduce a new, facile, and economical system for fabrication of tungsten carbide (WC) nano particle powder. In this system WO{sub 3}, Zn, and C have been ball-milled for several hours, which led to the synthesis of tungsten carbide nano particles. The synthesized WC can successfully be separated from the ball-milled product by subjecting the product powder to diluted HCl for removing ZnO and obtaining WC. X-ray diffraction (XRD) analysis indicates that the reduction of WO{sub 3} will be completed gradually by increasing milling time up to 36 h. Scanning electron microscope (SEM), and transmission electron microscope (TEM) images show that after 36 h of milling the particle size of the fabricated powder is nano metric (about 20 nm). Results have shown that this system can surmount some main problems occurred in previous similar WC synthesizing systems. For example carbothermic reduction reactions, which lead to the synthesis of W{sub 2}C instead of WC, would not be activated because in this system reactions take place gradually.

Hoseinpur, Arman, E-mail: arman.hoseinpur@stu-mail.um.ac.ir [Department of Materials and Metallurgical Engineering, Ferdowsi University of Mashhad, Mashhad 91775-1111, Islamic Republic of Iran (Iran, Islamic Republic of)] [Department of Materials and Metallurgical Engineering, Ferdowsi University of Mashhad, Mashhad 91775-1111, Islamic Republic of Iran (Iran, Islamic Republic of); Vahdati Khaki, Jalil; Marashi, Maryam Sadat [Department of Materials and Metallurgical Engineering, Ferdowsi University of Mashhad, Mashhad 91775-1111, Islamic Republic of Iran (Iran, Islamic Republic of)] [Department of Materials and Metallurgical Engineering, Ferdowsi University of Mashhad, Mashhad 91775-1111, Islamic Republic of Iran (Iran, Islamic Republic of)

2013-02-15T23:59:59.000Z

408

Measuring charge trap occupation and energy level in CdSe/ZnS quantum dots using a scanning tunneling microscope  

E-Print Network [OSTI]

We use a scanning tunneling microscope to probe single-electron charging phenomena in individual CdSe/ZnS (core/shell) quantum dots (QDs) at room temperature. The QDs are deposited on top of a bare Au thin film and form a ...

Bulovic, Vladimir

409

Thermal ionization induced metal-semiconductor transition and room temperature ferromagnetism in trivalent doped ZnO codoped with lithium  

SciTech Connect (OSTI)

Thermal ionization induced metallic to semiconductor (MST) transition occurring at 460?K for Zn{sub 0.97}Al{sub 0.03}O, 463?K for Zn{sub 0.94}Al{sub 0.03}Li{sub 0.03}O, and 503?K for Zn{sub 0.91}Al{sub 0.03}Li{sub 0.03}Mn{sub 0.03}O has been found in the sol-gel synthesized (using hexamethylenetetramine), trivalent doped (Al, Mn) ZnO codoped with lithium. Increase in the thermally ionized carrier concentration due to Al doping is responsible for near band edge (NBE) peak shift causing Fermi level to move into conduction band making it metallic consistent with resistivity results. Free carrier (thermally activated) neutralization with ionized donor is responsible for semiconducting nature, which is supported from the free carrier screening produced energy shift in the NBE of photoluminescence peak. Furthermore, independently band gap shrinkage is also obtained from UV-Visible studies confirming localization induced MST. An anti-correlation is found between defect density (DLE) and room temperature ferromagnetism (RTFM) indicating intrinsic defects are not directly responsible for RTFM.

Sivagamasundari, A.; Chandrasekar, S.; Pugaze, R.; Kannan, R., E-mail: kannan@pec.edu [Department of Physics, Pondicherry Engineering College, Puducherry 605 014 (India); Rajagopan, S. [Department of Chemistry, Pondicherry Engineering College, Puducherry 605 014 (India)

2014-03-07T23:59:59.000Z

410

Highly efficient flexible inverted organic solar cells using atomic layer deposited ZnO as electron selective layer  

E-Print Network [OSTI]

advancements, the power conversion efficiency (PCE) of organic solar cells (OSCs) has been improved with PCE more than 4% was demonstrated.7 However,Cs2CO3 exhibitsdeliquescencewhichaffects severely a PCE of 3.09%.14 Hau et al. adopted spin-coated ZnO nanoparticles as the electron selective layer

411

Effect of temperature and time on properties of Spark Plasma Sintered NiCuZn: Co ferrite  

E-Print Network [OSTI]

behavior and their applications in power electronics devices for from the radio frequency (300 kHz to 3 MHzEffect of temperature and time on properties of Spark Plasma Sintered NiCuZn: Co ferrite K. Zehani Plasma Sintering is a powerfal method to produce fine grain dense ferrite at low temperature. However

412

Laser irradiation effects on the CdTe/ZnTe quantum dot structure studied by Raman and AFM spectroscopy  

SciTech Connect (OSTI)

Micro-Raman spectroscopy has been applied to investigate the impact of laser irradiation on semiconducting CdTe/ZnTe quantum dots (QDs) structures. A reference sample (without dots) was also studied for comparison. Both samples were grown by molecular beam epitaxy technique on the p-type GaAs substrate. The Raman spectra have been recorded for different time of a laser exposure and for various laser powers. The spectra for both samples exhibit peak related to the localized longitudinal (LO) ZnTe phonon of a wavenumber equal to 210 cm{sup -1}. For the QD sample, a broad band corresponding to the LO CdTe phonon related to the QD-layer appears at a wavenumber of 160 cm{sup -1}. With increasing time of a laser beam exposure and laser power, the spectra get dominated by tellurium-related peaks appearing at wavenumbers around 120 cm{sup -1} and 140 cm{sup -1}. Simultaneously, the ZnTe surface undergoes rising damage, with the formation of Te aggregates at the pinhole edge as reveal atomic force microscopy observations. Local temperature of irradiated region has been estimated from the anti-Stokes/Stokes ratio of the Te modes intensity and it was found to be close or exceeding ZnTe melting point. Thus, the laser damage can be explained by the ablation process.

Zielony, E.; Placzek-Popko, E.; Henrykowski, A.; Gumienny, Z.; Kamyczek, P.; Jacak, J. [Institute of Physics, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Nowakowski, P.; Karczewski, G. [Institute of Physics, Polish Academy of Sciences, al. Lotnikow 32/46, 02-668 Warsaw (Poland)

2012-09-15T23:59:59.000Z

413

InAs(ZnCdS) Quantum Dots Optimized for Biological Imaging in the Near-Infrared  

E-Print Network [OSTI]

We present the synthesis of InAs quantum dots (QDs) with a ZnCdS shell with bright and stable emission in the near-infrared (NIR, 700?900 nm) region for biological imaging applications. We demonstrate how NIR QDs can image ...

Allen, Peter M.

414

Emergent Honeycomb Lattice in LiZn[subscript 2]Mo[subscript 3]O[subscript 8  

E-Print Network [OSTI]

We introduce the idea of emergent lattices, where a simple lattice decouples into two weakly coupled lattices as a way to stabilize spin liquids. In LiZn[subscript 2]Mo[subscript 3]O[subscript 8], the disappearance of 2/3 ...

Flint, Rebecca

415

UV-blocking ZnO nanostructure anti-reflective coatings Qing Guo Du a,b  

E-Print Network [OSTI]

layer for solar energy applications. According to these two properties, ZnO nanostructures can be used are essential parts for high ef- ficiency and low cost solar cell devices especially for thin film solar cell some problems such as ma- terial selection, thermal mismatch, sensitivity to thickness variation

Demir, Hilmi Volkan

416

Zn Sorption Mechanisms onto Sheathed Leptothrix Discophora and the Impact of the Nanoparticulate Biogenic Mn Oxide Coating  

SciTech Connect (OSTI)

Zinc sorption on sheathed Leptothrix discophora bacterium, the isolated extracellular polymeric substances (EPS) sheath, and Mn oxide-coated bacteria was investigated with macroscopic and spectroscopic techniques. Complexation with L. discophora was dominated by the outer membrane phosphoryl groups of the phospholipid bilayer while sorption to isolated EPS was dominated by carboxyl groups. Precipitation of nanoparticulate Mn oxide coatings on the cell surface increased site capacity by over twenty times with significant increase in metal sorption. XAS analysis of Zn sorption in the coated system showed Mn oxide phase contributions of 18 to 43% through mononuclear inner-sphere complexes. The coordination environments in coprecipitation samples were identical to those of sorption samples, indicating that, even in coprecipitation, Zn is not incorporated into the Mn oxide structure. Rather, through enzymatic oxidation by L. discophora, Mn(II) is oxidized and precipitated onto the biofilm providing a large surface for metal sequestration. The nanoparticulate Mn oxide coating exhibited significant microporosity (75%) suggesting contributions from intraparticle diffusion. Transient studies conducted over 7 months revealed a 170% increase in Zn loading. However, the intraparticle diffusivity of 10{sup -19} cm{sup 2} s{sup -1} is two orders of magnitude smaller than that for abiotic Mn oxide which we attribute to morphological changes such as reduced pore sizes in the nanoparticulate oxide. Our results demonstrate that the cell-bound Mn oxide particles can sorb significant amounts of Zn over long periods of time representing an important surface for sequestration of metal contaminants.

Boonfueng, T.; Axe, L; Yee, N; Hahn, D; Ndiba, P

2009-01-01T23:59:59.000Z

417

Bioaccumulation of essential metals (Co, Mn and Zn) in the king scallop Pecten maximus: seawater, food and sediment exposures  

E-Print Network [OSTI]

, food and sediment exposures Marc Metiana,b , Michel Warnaua* , Laetitia Hédouina,b , Paco Bustamanteb-feeding mollusks living in soft sediments, the uptake and depuration kinetics of three elements (Co, Mn and Zn) were investigated in the king scallop Pecten maximus exposed via seawater, food, or sediment, using

Boyer, Edmond

418

Raman spectroscopic study of carbon nanotubes prepared using Fe/ZnO-palm olein-chemical vapour deposition  

Science Journals Connector (OSTI)

Multiwalled carbon nanotubes (MWCNTs) were synthesized using Fe/ZnO catalyst by a dual-furnace thermal chemical vapor deposition (CVD) method at 800-1000°C using nitrogen gas with a constant flow rate of 150 sccm/min as a gas carrier. Palm olein ...

Syazwan Afif Mohd Zobir; Suriani Abu Bakar; Saifollah Abdullah; Zulkarnain Zainal; Siti Halimah Sarijo; Mohamad Rusop

2012-01-01T23:59:59.000Z

419

Patterned Growth of Vertically Aligned ZnO Nanowire Arrays on Inorganic Substrates at Low Temperature without Catalyst  

E-Print Network [OSTI]

as optoelectronic and electromechanical nanodevices, such as solar cells,1 field emission devices,2,3 UV lasers,4 with many other materials. Metal-organic vapor-phase epitaxial growth12 and template-assisted growth13 have). The nonepitaxial growth of ZnO NW arrays on Si wafers (or any other inorganic substrates) was assisted by a thin

Wang, Zhong L.

420

Density-functional study of organicinorganic hybrid single crystal ZnSe,,C2H8N2...12  

E-Print Network [OSTI]

January 2004 Unusual properties i.e., strong band dispersion, high carrier mobility, wide absorption-energy electric energy conversion are predicted to exist in the organic­inorganic chalcogenide single crystal Zn structures and exhibiting high carrier mobilities, as well as for possessing a variety of doping

Li, Jing

Note: This page contains sample records for the topic "zn zurn ot" 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.


421

Photoelectrochemical Study of the Band Structure of Zn2SnO4 Prepared by the Hydrothermal Method  

Science Journals Connector (OSTI)

In this paper, we study the band gap (Eg) and energetics of the conduction band (CB) and valence band (VB) for films of zinc stannate (Zn2SnO4) nanoparticles (ca. 25 nm) of the inverse-spinel structure prepared by the hydrothermal method. ...

Mario A. Alpuche-Aviles; Yiying Wu

2009-02-16T23:59:59.000Z

422

Absorption spectra of CdSe-ZnS core-shell quantum dots at high photon energies : experiment and modeling  

E-Print Network [OSTI]

Absorption spectra of CdSe-ZnS core-shell quantum dots at high photon energies : experiment Tata Institute of Fundamental Research Homi Bhabha Road, Mumbai 400005, India Abstract Absorption. In agreement with previous reports, the absorption coefficient at energies 1 eV above the effective bandgap

Ghosh, Sandip

423

Quantifying oxygen diffusion in ZnO nanobelt Jin Liu, Puxian Gao, Wenjie Mai, Changshi Lao, and Zhong L. Wanga  

E-Print Network [OSTI]

Quantifying oxygen diffusion in ZnO nanobelt Jin Liu, Puxian Gao, Wenjie Mai, Changshi Lao A method is presented for quantifying oxygen diffusion behavior in a nanodevice fabricated using individual for several days, oxygen in air diffused into the nanobelt and significantly changed the conductivity

Wang, Zhong L.

424

Monolithic multichannel ultraviolet detector arrays and continuous phase evolution in MgxZn1xO composition spreads  

E-Print Network [OSTI]

American Institute of Physics. DOI: 10.1063/1.1623923 I. INTRODUCTION ZnO is a wide band gap semiconductor whose potential device applications include UV lasers,1,2 transparent con- ducting films for solar cells simultaneously is central in today's photonics tech- nology. In order to detect signals at discrete wavelengths

Rubloff, Gary W.

425

Phase change behaviors of Zn-doped Ge{sub 2}Sb{sub 2}Te{sub 5} films  

SciTech Connect (OSTI)

Zn-doped Ge{sub 2}Sb{sub 2}Te{sub 5} phase-change materials have been investigated for phase change memory applications. Zn{sub 15.16}(Ge{sub 2}Sb{sub 2}Te{sub 5}){sub 84.84} phase change film exhibits a higher crystallization temperature ({approx}258 Degree-Sign C), wider band gap ({approx}0.78 eV), better data retention of 10 years at 167.5 Degree-Sign C, higher crystalline resistance, and faster crystallization speed compared with the conventional Ge{sub 2}Sb{sub 2}Te{sub 5}. The proper Zn atom added into Ge{sub 2}Sb{sub 2}Te{sub 5} serves as a center for suppression of the face-centered-cubic (fcc) phase to hexagonal close-packed (hcp) phase transition, and fcc phase has high thermal stability partially due to the bond recombination among Zn, Sb, and Te atoms.

Wang Guoxiang; Nie Qiuhua [Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Faculty of Information Science and Engineering, Ningbo University, Ningbo 315211 (China); Shen Xiang; Fu Jing; Xu Tiefeng; Dai Shixun [Faculty of Information Science and Engineering, Ningbo University, Ningbo 315211 (China); Wang, R. P. [Laser Physics Centre, Australian National University, Canberra, ACT 0200 (Australia); Wu Liangcai [Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China)

2012-07-30T23:59:59.000Z

426

Factors Affecting the Hydrogen Environment Assisted Cracking Resistance of an Al-Zn-Mg-(Cu) Alloy  

SciTech Connect (OSTI)

It is well established that Al-Zn-Mg-(Cu) aluminum alloys are susceptible to hydrogen environment assisted cracking (HEAC) when exposed to aqueous environments. In Al-Zn-Mg-Cu alloys, overaged tempers are commonly used to increase HEAC resistance at the expense of strength. Overaging has little benefit in low copper alloys. However, the mechanism or mechanisms by which overaging imparts HEAC resistance is poorly understood. The present research investigated hydrogen uptake, diffusion, and crack growth rate in 90% relative humidity (RH) air for both a commercial copper bearing Al-Zn-Mg-Cu alloy (AA 7050) and a low copper variant of this alloy in order to better understand the factors which affect HEAC resistance. Experimental methods used to evaluate hydrogen concentrations local to a surface and near a crack tip include nuclear reaction analysis (NRA), focused ion beam, secondary ion mass spectroscopy (FIB/SIMS) and thermal desorption spectroscopy (TDS). When freshly bared coupons of AA 7050 are exposed to 90 C, 90% RH air, hydrogen ingress follows inverse-logarithmic-type kinetics and is equivalent for underaged (HEAC susceptible) and overaged (HEAC resistant) tempers. However, when the native oxide is allowed to form (24 hrs in 25 C, 40% RH lab air) prior to exposure to 90 C, 90% RH air, underaged alloy shows significantly greater hydrogen ingress than the overaged alloy. Humid air is a very aggressive environment producing local ({approx}1{micro}m) hydrogen concentrations in excess of 10,000 wt. ppm at 90 C. In the copper bearing alloy, overaging also effects the apparent diffusivity of hydrogen. As AA 7050 is aged from underaged {yields} peak aged {yields} overaged, the activation energy for hydrogen diffusion increases and the apparent diffusivity for hydrogen decreases, In the low copper alloy, overaging has little effect on hydrogen diffusion. Comparison of the apparent activation energies for hydrogen diffusion and for K independent (stage II) crack growth rate in 90% RH air between 25 and 90 C indicates that hydrogen transport kinetics are responsible for the decreased crack growth rate of overaged AA 7050 relative to the peak aged temper.

G.A. Young; J.R. Scully

2001-09-12T23:59:59.000Z

427

Roughness-based monitoring of transparency and conductivity in boron-doped ZnO thin films prepared by spray pyrolysis  

SciTech Connect (OSTI)

Graphical abstract: Display Omitted Highlights: ? We report surface roughness dependent transparency and conductivity in ZnO films. ? The surface roughness with respected to boron doping concentrations is studied. ? Boron doped and pristine Zinc oxide thin films have showed ?95% transmittance. ? Increased carrier concentration of 9.21 × 10{sup 21} cm{sup ?3} revealed from Hall measurement. -- Abstract: Sprayed polycrystalline ZnO and boron-doped ZnO thin films composed of spherical grains of 25–32 nm in diameters are used in roughness measurement and further correlated with the transparency and the conductivity characteristics. The surface roughness is increased up to Zn{sub 0.98}B{sub 0.02}O and then declined at higher boron concentrations. The sprayed ZnO films revealed ?95% transmittance in the visible wavelength range, 1.956 × 10{sup ?4} ? cm electrical resistivity, 46 cm{sup 2}/V s Hall mobility and 9.21 × 10{sup 21} cm{sup ?3} charge carrier concentration. The X-ray photoelectron spectroscopy study has confirmed 0.15 eV binding energy change for Zn 2p{sub 3/2} when 2 at% boron content is mixed without altering electro-optical properties substantially. Finally, using soft modeling importance of these textured ZnO over non-textured films for enhancing the solar cells performance is explored.

Gaikwad, Rajendra S. [Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of) [Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of); Department of Physics, Yashwantrao Mohite College, Bharati Vidyapeeth Deemed University, Pune 411038, Maharashtra (India); Bhande, Sambhaji S. [Centre for Nanomaterials and Energy Devices, School of Physical Sciences, Swami Ramand Teerth Marathwada University, Nanded (India)] [Centre for Nanomaterials and Energy Devices, School of Physical Sciences, Swami Ramand Teerth Marathwada University, Nanded (India); Mane, Rajaram S., E-mail: rsmane_2000@yahoo.com [Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of); Inorganic Nanomaterials Laboratory, Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of); Centre for Nanomaterials and Energy Devices, School of Physical Sciences, Swami Ramand Teerth Marathwada University, Nanded (India); Pawar, Bhagwat N. [Department of Physics, Yashwantrao Mohite College, Bharati Vidyapeeth Deemed University, Pune 411038, Maharashtra (India)] [Department of Physics, Yashwantrao Mohite College, Bharati Vidyapeeth Deemed University, Pune 411038, Maharashtra (India); Gaikwad, Sanjay L. [Centre for Nanomaterials and Energy Devices, School of Physical Sciences, Swami Ramand Teerth Marathwada University, Nanded (India)] [Centre for Nanomaterials and Energy Devices, School of Physical Sciences, Swami Ramand Teerth Marathwada University, Nanded (India); Han, Sung-Hwan [Inorganic Nanomaterials Laboratory, Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of)] [Inorganic Nanomaterials Laboratory, Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of); Joo, Oh-Shim, E-mail: jookat@kist.ac.kr [Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of)] [Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of)

2012-12-15T23:59:59.000Z

428

Surface strain engineering through Tb doping to study the pressure dependence of exciton-phonon coupling in ZnO nanoparticles  

SciTech Connect (OSTI)

A compressive hydrostatic strain has been found to develop in the ZnO lattice as a result of accumulation of Tb ions on the surface of the nanoparticles for Tb mole-fraction less than 0.04. This hydrostatic strain can be controlled up to ?14?GPa by varying the Tb mole-fraction. Here, we have utilized this novel technique of surface strain engineering through Tb doping for introducing hydrostatic compressive strain in the lattice to study the pressure dependent electronic and vibrational properties of ZnO nanoparticles. Our study reveals that when subjected to pressure, nanoparticles of ZnO behave quite differently than bulk in many aspects. Unlike bulk ZnO, which is reported to go through a wurtzite to rock-salt structural phase transition at ?8?GPa, ZnO nanoparticles do not show such transition and remain in wurtzite phase even at 14?GPa of pressure. Furthermore, the Grüneisen parameters for the optical phonon modes are found to be order of magnitude smaller in ZnO nanoparticles as compared to bulk. Our study also suggests an increase of the dielectric constant with pressure, which is opposite to what has been reported for bulk ZnO. Interestingly, it has also been found that the exciton-phonon interaction depends strongly upon pressure in this system. The exciton-phonon coupling has been found to decrease as pressure increases. A variational technique has been adopted to theoretically calculate the exciton-LO phonon coupling coefficient in ZnO nanoparticles as a function of pressure, which shows a good agreement with the experimental results. These findings imply that surface engineering of ZnO nanoparticles with Tb could indeed be an efficient tool to enhance and control the optical performance of this material.

Sharma, A.; Dhar, S., E-mail: dhar@phy.iitb.ac.in; Singh, B. P. [Physics Department, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India); Nayak, C.; Bhattacharyya, D. [Applied Spectroscopy Division, Bhabha Atomic Research Centre, Mumbai-400085 (India); Jha, S. N. [Raja Ramanna Centre for Advanced Technology (RRCAT), Indore (India)

2013-12-07T23:59:59.000Z

429

The use of novel biodegradable, optically active and nanostructured poly(amide-ester-imide) as a polymer matrix for preparation of modified ZnO based bionanocomposites  

SciTech Connect (OSTI)

Highlights: Black-Right-Pointing-Pointer A novel biodegradable and nanostructured PAEI based on two amino acids, was synthesized. Black-Right-Pointing-Pointer ZnO nanoparticles were modified via two different silane coupling agents. Black-Right-Pointing-Pointer PAEI/modified ZnO BNCs were synthesized through ultrasound irradiation. Black-Right-Pointing-Pointer ZnO particles were dispersed homogeneously in PAEI matrix on nanoscale. Black-Right-Pointing-Pointer The effect of ZnO nanoparticles on the properties of synthesized polymer was examined. -- Abstract: A novel biodegradable and nanostructured poly(amide-ester-imide) (PAEI) based on two different amino acids, was synthesized via direct polycondensation of biodegradable N,N Prime -bis[2-(methyl-3-(4-hydroxyphenyl)propanoate)]isophthaldiamide and N,N Prime -(pyromellitoyl)-bis-L-phenylalanine diacid. The resulting polymer was characterized by FT-IR, {sup 1}H NMR, specific rotation, elemental analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) analysis. The synthesized polymer showed good thermal stability with nano and sphere structure. Then PAEI/ZnO bionanocomposites (BNCs) were fabricated via interaction of pure PAEI and ZnO nanoparticles. The surface of ZnO was modified with two different silane coupling agents. PAEI/ZnO BNCs were studied and characterized by FT-IR, XRD, UV/vis, FE-SEM and TEM. The TEM and FE-SEM results indicated that the nanoparticles were dispersed homogeneously in PAEI matrix on nanoscale. Furthermore the effect of ZnO nanoparticle on the thermal stability of the polymer was investigated with TGA and DSC technique.

Abdolmaleki, Amir, E-mail: abdolmaleki@cc.iut.ac.ir [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of) [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of); Nanotechnology and Advanced Materials Institute, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of); Mallakpour, Shadpour, E-mail: mallak@cc.iut.ac.ir [Organic Polymer Chemistry Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of) [Organic Polymer Chemistry Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of); Nanotechnology and Advanced Materials Institute, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of); Borandeh, Sedigheh [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of)] [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of)

2012-05-15T23:59:59.000Z

430

Generation and recombination rates at ZnTe:O intermediate band states  

SciTech Connect (OSTI)

Carrier generation and recombination processes of ZnTeO thin films are studied by time-resolved photoluminescence, where carrier lifetimes at oxygen states and the conduction band are inferred to be >1??s and <100?ps, respectively. The radiative recombination coefficient for optical transitions from oxygen states to the valence band is extracted to be 1.2×10{sup ?10}?cm{sup 3}?sec{sup ?1} based on the excitation dependence of decay time constants. Rate equation analysis further suggests an increase in electron lifetime at the conduction band as oxygen states occupation is critical in achieving high conversion efficiency for solar cells based on multiphoton processes in these materials.

Wang, Weiming; Lin, Albert S.; Phillips, Jamie D.; Metzger, Wyatt K.

2009-01-01T23:59:59.000Z

431

Composite system based on CdSe/ZnS quantum dots and GaAs nanowires  

SciTech Connect (OSTI)

The possibility of fabricating a composite system based on colloidal CdSe/ZnS quantum dots and GaAs nanowires is demonstrated and the structural and emission properties of this system are investigated by electron microscopy and photoluminescence spectroscopy techniques. The good wettability and developed surface of the nanowire array lead to an increase in the surface density of quantum dots and, as a consequence, in the luminosity of the system in the 600-nm wavelength region. The photoluminescence spectrum of the quantum dots exhibits good temperature stability in the entire range 10-295 K. The impact of surface states on energy relaxation and the role of exciton states in radiative recombination in the quantum dots are discussed.

Khrebtov, A. I. [St. Petersburg Academic University-Nanotechnology Research and Education Center, Russian Academy of Sciences (Russian Federation)] [St. Petersburg Academic University-Nanotechnology Research and Education Center, Russian Academy of Sciences (Russian Federation); Talalaev, V. G. [St. Petersburg State University, Fock Institute of Physics (Russian Federation)] [St. Petersburg State University, Fock Institute of Physics (Russian Federation); Werner, P. [Max-Planck-Institut fuer Mikrostukturphysik (Germany)] [Max-Planck-Institut fuer Mikrostukturphysik (Germany); Danilov, V. V. [Vavilov State Optical Institute (Russian Federation)] [Vavilov State Optical Institute (Russian Federation); Artemyev, M. V. [Belarussian State University, Institute for Physicochemical Problems (Belarus)] [Belarussian State University, Institute for Physicochemical Problems (Belarus); Novikov, B. V. [St. Petersburg State University, Fock Institute of Physics (Russian Federation)] [St. Petersburg State University, Fock Institute of Physics (Russian Federation); Shtrom, I. V. [St. Petersburg Academic University-Nanotechnology Research and Education Center, Russian Academy of Sciences (Russian Federation)] [St. Petersburg Academic University-Nanotechnology Research and Education Center, Russian Academy of Sciences (Russian Federation); Panfutova, A. S. [Vavilov State Optical Institute (Russian Federation)] [Vavilov State Optical Institute (Russian Federation); Cirlin, G. E. [St. Petersburg Academic University-Nanotechnology Research and Education Center, Russian Academy of Sciences (Russian Federation)] [St. Petersburg Academic University-Nanotechnology Research and Education Center, Russian Academy of Sciences (Russian Federation)

2013-10-15T23:59:59.000Z

432

Photo-instability of CdSe/ZnS quantum dots in poly(methylmethacrylate) film  

SciTech Connect (OSTI)

The photo-instability of CdSe/ZnS quantum dots (QDs) has been studied under varied conditions. We discussed the main features of the evolution of photoluminescence (PL) intensity and energy at different laser powers, which showed critical dependences on the environment. The PL red shift in a vacuum showed strong temperature dependence, from which we concluded that the thermal activation energy for trapping states of the charge carriers was about 14.7 meV. Furthermore, the PL spectra showed asymmetric evolution during the laser irradiation, for which two possible explanations were discussed. Those results provided a comprehensive picture for the photo-instability of the colloidal QDs under different conditions.

Zhang, Hongyi; Liu, Yu; Ye, Xiaoling; Chen, Yonghai [Key Laboratory of Semiconductor Materials Science and Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China)] [Key Laboratory of Semiconductor Materials Science and Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China)

2013-12-28T23:59:59.000Z

433

Co-Evaporated Cu2ZnSnSe4 Films and Devices  

SciTech Connect (OSTI)

The use of vacuum co-evaporation to produce Cu2ZnSnSe4 photovoltaic devices with 9.15% total-area efficiency is described. These new results suggest that the early success of the atmospheric techniques for kesterite photovoltaics may be related to the ease with which one can control film composition and volatile phases, rather than a fundamental benefit of atmospheric conditions for film properties. The co-evaporation growth recipe is documented, as is the motivation for various features of the recipe. Characteristics of the resulting kesterite films and devices are shown in scanning electron micrographs, including photoluminescence, current-voltage, and quantum efficiency. Current-voltage curves demonstrate low series resistance without the light-dark cross-over seen in many devices in the literature. Band gap indicated by quantum efficiency and photoluminescence is roughly consistent with that expected from first principles calculation.

Repins, I.; Beall, C.; Vora, N.; DeHart, C.; Kuciauskas, D.; Dippo, P.; To, B.; Mann, J.; Hsu, W. C.; Goodrich, A.; Noufi, R.

2012-06-01T23:59:59.000Z

434

Measurement of the $^{58}$Ni($?$,$?$)$^{62}$Zn reaction and its astrophysical impact  

E-Print Network [OSTI]

Cross section measurements of the $^{58}$Ni($\\alpha$,$\\gamma$)$^{62}$Zn reaction were performed in the energy range $E_{\\alpha}=5.5-9.5$ MeV at the Nuclear Science Laboratory of the University of Notre Dame, using the NSCL Summing NaI(Tl) detector and the $\\gamma$-summing technique. The measurements are compared to predictions in the statistical Hauser-Feshbach model of nuclear reactions using the SMARAGD code. It is found that the energy dependence of the cross section is reproduced well but the absolute value is overestimated by the prediction. This can be remedied by rescaling the $\\alpha$ width by a factor of 0.45. Stellar reactivities were calculated with the rescaled $\\alpha$ width and their impact on nucleosynthesis in type Ia supernovae has been studied. It is found that the resulting abundances change by up to 5\\% when using the new reactivities.

S. J. Quinn; A. Spyrou; E. Bravo; T. Rauscher; A. Simon; A. Battaglia; M. Bowers; B. Bucher; C. Casarella; M. Couder; P. A. DeYoung; A. C. Dombos; J. Görres; A. Kontos; Q. Li; A. Long; M. Moran; N. Paul; J. Pereira; D. Robertson; K. Smith; M. K. Smith; E. Stech; R. Talwar; W. P. Tan; M. Wiescher

2014-05-23T23:59:59.000Z

435

Amorphous Zn?GeO? Nanoparticles as Anodes with High Reversible Capacity and Long Cycling Life for Li-ion Batteries  

SciTech Connect (OSTI)

Amorphous and crystalline Zn?GeO? nanoparticles were prepared and characterized as anode materials for Li-ion batteries. A higher reversible specific capacity of 1250 mAh/g after 500 cycles and excellent rate capability were obtained for amorphous Zn?GeO? nanoparticles, compared to that of crystalline Zn?GeO? nanoparticles. Small particle size, amorphous phase and incorporation of zinc and oxygen contribute synergetically to the improved performance by effectively mitigating the huge volume variations during lithiation and delithiation process.

Yi, Ran; Feng, Jinkui; Lv, Dongping; Gordin, Mikhail; Chen, Shuru; Choi, Daiwon; Wang, Donghai

2013-07-30T23:59:59.000Z

436

Development of cryogenic phonon detectors based on CaMoO4 and ZnWO4 scintillating crystals for direct dark matter search experiments  

E-Print Network [OSTI]

This work reports on the development of the first phonon detectors based on CaMoO4 and ZnWO4 scintillating crystals for the CRESST-II experiment. In particular, a novel technique for the production of the ZnWO4 phonon detector with a separate thermometer carrier was investigated. The influence of the thermal and mechanical treatment on the scintillation light output of CaMoO4 and ZnWO4 crystals at room temperature is discussed.

I. Bavykina; G. Angloher; D. Hauff; M. Kiefer; F. Petricca; F. Proebst

2008-11-12T23:59:59.000Z

437

Study of the interface of undoped and p?doped ZnSe with GaAs and AlAs  

Science Journals Connector (OSTI)

We have used electrolyte electroreflectance (EER) to characterize ZnSe/GaAs and ZnSe/AlAs interfaces. The great sensitivity of EER to interface space?charge regions enabled us to detect both interface crossover transitions and transitions to triangular?well interface states. The observation of these transitions provides the first unambiguous proof that the ZnSe/GaAs interface is type I and allowed us to determine the band offsets and band bendings the diffusion lengths across each interface and the amount of interdiffusion.

L. Kassel; H. Abad; J. W. Garland; P. M. Raccah; J. E. Potts; M. A. Haase; H. Cheng

1990-01-01T23:59:59.000Z

438

Crystal structure and magnetic properties and Zn substitution effects on the spin-chain compound Sr{sub 3}Co{sub 2}O{sub 6}  

SciTech Connect (OSTI)

The effects of substituting Co on the spin-chain compound Sr{sub 3}Co{sub 2}O{sub 6} with Zn were investigated by synchrotron X-ray diffraction, magnetic susceptibility, isothermal magnetization, and specific heat measurements. To the best of our knowledge, this is the first report to describe the successful substitution of Co in Sr{sub 3}Co{sub 2}O{sub 6} with Zn. The substitution was carried out by a method involving high pressures and temperatures to obtain Sr{sub 3}CoZnO{sub 6}, which crystalized into a K{sub 4}CdCl{sub 6}-derived rhombohedral structure with a space group of R-3c, similar to the host compound. With the Zn substitution, the Ising-type magnetic anisotropy of the host compound remarkably reduced; the newly formed Sr{sub 3}CoZnO{sub 6} became magnetically isotropic with Heisenberg-type characteristics. This could probably be ascribed to the establishment of a different interaction pathway, –Co{sup 4+}(S=1/2)–O–Zn{sup 2+}(S=0)–O–Co{sup 4+}(S=1/2)–. Details of the magnetic properties of Zn substituted Sr{sub 3}Co{sub 2}O{sub 6} were reported. - Graphical abstract: Crystal structure of the spin-chain compound Sr{sub 3}CoZnO{sub 6} synthesized at 6 GPa. Zn atoms preferably occupy the trigonal prism sites rather than the octahedral sites. As a result, the compound is much magnetically isotropic. Highlights: • Effects of substituting Co with Zn on spin-chain magnetism of Sr{sub 3}Co{sub 2}O{sub 6} were studied. • High-pressure synthesis resulted in a solid solution of Sr{sub 3}CoZnO{sub 6}. • Sr{sub 3}CoZnO{sub 6} showed more isotropic magnetism than the host Sr{sub 3}Co{sub 2}O{sub 6}.

Wang, Xia [Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba Ibaraki 305-0044 (Japan); Department of Chemistry, Graduate School of Science, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan); Guo, Yanfeng, E-mail: Yangfeng.Guo@physics.ox.ac.uk [Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba Ibaraki 305-0044 (Japan); Sun, Ying [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba Ibaraki 305-0044 (Japan); Tsujimoto, Yoshihiro [Materials Processing Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba Ibaraki 305-0047 (Japan); Matsushita, Yoshitaka [Materials Analysis Station, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba Ibaraki 305-0047 (Japan); Yamaura, Kazunari, E-mail: yamaura.kazunari@nims.go.jp [Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba Ibaraki 305-0044 (Japan); Department of Chemistry, Graduate School of Science, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan)

2013-08-15T23:59:59.000Z

439

Taheri-Saramad x-ray detector (TSXD): A novel high spatial resolution x-ray imager based on ZnO nano scintillator wires in polycarbonate membrane  

SciTech Connect (OSTI)

A novel x-ray imager based on ZnO nanowires is designed and fabricated. The proposed architecture is based on scintillation properties of ZnO nanostructures in a polycarbonate track-etched membrane. Because of higher refractive index of ZnO nanowire compared to the membrane, the nanowire acts as an optical fiber that prevents the generated optical photons to spread inside the detector. This effect improves the spatial resolution of the imager. The detection quantum efficiency and spatial resolution of the fabricated imager are 11% and <6.8 ?m, respectively.

Taheri, A., E-mail: at1361@aut.ac.ir; Saramad, S.; Ghalenoei, S.; Setayeshi, S. [Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran 15875-4413 (Iran, Islamic Republic of)] [Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran 15875-4413 (Iran, Islamic Republic of)

2014-01-15T23:59:59.000Z

440

Polarimetric performance of a Laue lens gamma-ray CdZnTe focal plane prototype  

SciTech Connect (OSTI)

A gamma-ray telescope mission concept [gamma ray imager (GRI)] based on Laue focusing techniques has been proposed in reply to the European Space Agency call for mission ideas within the framework of the next decade planning (Cosmic Vision 2015-2025). In order to optimize the design of a focal plane for this satellite mission, a CdZnTe detector prototype has been tested at the European Synchrotron Radiation Facility under an {approx}100% polarized gamma-ray beam. The spectroscopic, imaging, and timing performances were studied and in particular its potential as a polarimeter was evaluated. Polarization has been recognized as being a very important observational parameter in high energy astrophysics (>100 keV) and therefore this capability has been specifically included as part of the GRI mission proposal. The prototype detector tested was a 5 mm thick CdZnTe array with an 11x11 active pixel matrix (pixel area of 2.5x2.5 mm{sup 2}). The detector was irradiated by a monochromatic linearly polarized beam with a spot diameter of about 0.5 mm over the energy range between 150 and 750 keV. Polarimetric Q factors of 0.35 and double event relative detection efficiency of 20% were obtained. Further measurements were performed with a copper Laue monochromator crystal placed between the beam and the detector prototype. In this configuration we have demonstrated that a polarized beam does not change its polarization level and direction after undergoing a small angle (<1 deg.) Laue diffraction inside a crystal.

Curado da Silva, R. M. [Departmento de Fisica, Universidade de Coimbra, P-3000 Coimbra (Portugal); Center for Space Radiations, Univesite Catholique de Louvain (Belgium); Caroli, E.; Stephen, J. B.; Schiavone, F.; Donati, A.; Ventura, G. [Istituto di Astrofisica Spaziale e Fisica Cosmica-Bologna, Via Gobetti 101, I-40129 Bologna (Italy); Pisa, A.; Auricchio, N.; Frontera, F. [Dipartimento di Fisica, Universita di Ferrara, Ferrara (Italy); Del Sordo, S. [Istituto di Astrofisica Spaziale e Fisica Cosmica-Palermo, Via Ugo La Malfa 153, 90146 Palermo (Italy); Honkimaeki, V. [European Synchrotron Radiation Facility, Grenoble (France); Trindade, A. M. F. [Departmento de Fisica, Universidade de Coimbra, P-3000 Coimbra (Portugal)

2008-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "zn zurn ot" 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

Thermoelectric properties of ( Zn 1?y Mg y ) 1?x Al x O ceramics prepared by the polymerized complex method  

Science Journals Connector (OSTI)

( Zn 1?y Mg y ) 1?x Al x O powders were synthesized by the polymerized complex method and then consolidated by spark plasma sintering apparatus. The microscopic structure and thermoelectric properties were examined comparing with the experimental results of the samples prepared by the conventional solid-state reaction method. A small amount of ZnAl 2 O 4 spinel phase as the second phase was observed in the sintered samples with x?0.02 by x-ray diffraction and a scanning electron microscope. The grain size of the samples prepared by the polymerized complex method is much smaller than that of the samples prepared by the conventional solid-state reaction method. The absolute values of the Seebeck coefficient and electrical resistivity decrease with increasing x up to about x=0.01 but above x=0.01 they are almost independent of x. This result indicates that the solubility limit of Al in Zn 1?x Al x O is about x=0.01 which is also confirmed by 27 Al nuclear magnetic resonance spectroscopy. At a fixed composition of x the absolute values of the Seebeck coefficient and electrical resistivity for the samples prepared by the polymerized complex method are smaller than those for the samples prepared by the solid-state reaction method which indicates that the doping of the carrier into the material can be more easily realized in the samples prepared by the polymerized complex method. The thermal conductivity decreases with increasing x but the further suppression of the thermal conductivity was attained by the additional substitution on the Zn site by Mg. The Seebeck coefficient of ( Zn 1?y Mg y ) 1?x Al x O is almost independent of Mg content y but the electrical resistivity increases with increasing y. As a result ( Zn 0.90 Mg 0.10 ) 0.9975 Al 0.0025 O shows a maximum dimensionless figure of merit of 0.10 at 1073 K.

S. Katsuyama; Y. Takagi; M. Ito; K. Majima; H. Nagai; H. Sakai; K. Yoshimura; K. Kosuge

2002-01-01T23:59:59.000Z

442

Hard x-ray photoelectron spectroscopy study on band alignment at poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/ZnO interface  

SciTech Connect (OSTI)

We used hard x-ray photoelectron spectroscopy to investigate the interfacial electronic states of a poly(styrenesulfonate) doped poly(3,4-ethylenedioxythiophene) (PEDOT:PSS) contact on a ZnO single crystal. An understanding of the interfacial band structure is useful for putting the organic contact to practical use. We observed upward band bending of the ZnO layer a few nanometers from the interface. The detected ZnO bulk region exhibited a flat band structure, meaning that the PEDOT:PSS does not greatly deplete the ZnO layer. The band bending caused the charge injection barrier formation with the result that the contact exhibited the Schottky property.

Nagata, T.; Hayakawa, R.; Chikyow, T. [International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); Oh, S.; Wakayama, Y. [International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); Department of Chemistry and Biochemistry, Faculty of Engineering, Kyushu University, 1-1 Namiki, Tsukuba 305-0044 (Japan); Yamashita, Y. [International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); NIMS Beamline Station at SPring-8, National Institute for Materials Science, 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Yoshikawa, H.; Kobayashi, K. [NIMS Beamline Station at SPring-8, National Institute for Materials Science, 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

2012-10-22T23:59:59.000Z

443

Enhanced photocatalytic hydrogen evolution under visible light irradiation over Cd0.5Zn0.5S solid solution by magnesium-doping  

Science Journals Connector (OSTI)

A series of Mg doped Cd0.5Zn0.5S solid solution photocatalysts were prepared by a hydrothermal method and characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscope, BE...

Shaoqin Peng; Caihong Chen; Xiaoyan Liu…

2013-10-01T23:59:59.000Z

444

Photocurrent Spectroscopy of CdS/Plastic, CdS/Glass, and ZnTe/GaAs Hetero-pairs Formed with Pulsed-laser Deposition.  

E-Print Network [OSTI]

?? This dissertation presents photocurrent (PC) spectroscopy of thin-film cadmium sulfide (CdS) on plastic, CdS on glass, and zinc telluride (ZnTe) on gallium arsenide (GaAs)… (more)

Acharya, Krishna Prasad

2009-01-01T23:59:59.000Z

445

The effect of oxygen flow rate and radio frequency plasma power on cubic ZnMgO ultraviolet sensors grown by plasma-enhanced molecular beam epitaxy  

SciTech Connect (OSTI)

Cubic Zn{sub 1-x}Mg{sub x}O thin films were produced by Plasma-Enhanced Molecular Beam Epitaxy. Oxygen flow rate and applied Radio-Frequency (RF) plasma power were varied to investigate the impact on film growth and optoelectronic device performance. Solar-blind and visible-blind detectors were fabricated with metal-semiconductor-metal interdigitated Ni/Mg/Au contacts and responsivity is compared under different growth conditions. Increasing oxygen flow rate and RF plasma power increased Zn incorporation in the film, which leads to phase segregation at relatively high Zn/Mg ratio. Responsivity as high as 61 A/W was measured in phase-segregated ZnMgO visible-blind detectors.

Casey Boutwell, R.; Wei Ming; Schoenfeld, Winston V. [CREOL, College of Optics and Photonics, University of Central Florida, Orlando, Florida 32816-2700 (United States)

2013-07-15T23:59:59.000Z

446

Single phase synthesis of ?-brass (Cu5Zn8) nanoparticles by electric arc discharge method and investigation of their order–disorder transition temperature  

Science Journals Connector (OSTI)

Abstract Single phase ?-brass (Cu5Zn8) nanoparticles were synthesized using the electric arc discharge method. The effect of various arc currents and pressures on the size and phase purity of the Cu–Zn alloy was studied. The arc currents of 200, 300 and 400 A and chamber pressures of 1, 2 and 3 atm of Ar were examined. The samples were characterized using XRD and SEM measurements. The results showed that the spherical nanoparticles of Cu5Zn8 with a mean particle size of 21 nm were produced at a pressure of 1 atm and an arc current of 300 A. Post annealing and quenching of the samples were used to investigate the order disorder phase transformation temperature of Cu5Zn8 in the nanosized form. The XRD analyses showed that the disorder phase starts at 400 °C and completes at 480 °C which is different from the bulk brasses.

Mansoor Farbod; Alireza Mohammadian

2014-01-01T23:59:59.000Z

447

Structure and magnetic properties of three-dimensional (La,Sr)MnO{sub 3} nanofilms on ZnO nanorod arrays  

SciTech Connect (OSTI)

Three-dimensional (3D) cubic perovskite (La,Sr)MnO{sub 3} (LSMO) nanofilms have been deposited on ZnO nanorod arrays with controlled dimensionality and crystallinity by radio frequency (rf) magnetron sputtering and post thermal annealing. Compared to the two-dimensional (2D) LSMO nanofilm on flat Si, the structure and magnetic properties of 3D LSMO nanofilms on ZnO nanorod arrays have a strong anisotropic morphology and thickness dependence. Ferromagnetic property has been observed in both 2D and 3D LSMO nanofilms while a ferromagnetic-superparamagnetic transition was revaled in 3D LSMO nanofilms on ZnO nanorod array with decreasing nanofilm thickness, due to a large surface dispersion effect. The LSMO/ZnO nanofilm/nanorod structures could open up new avenues for intriguing magnetic properties studies and applications of nanoscale perovskites.

Gao Haiyong; Gao Puxian; Shimpi, Paresh; Guo Yanbing; Cai Wenjie; Lin Huijan [Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269-3136 (United States); Department of Chemical, Materials, and Biomolecular Engineering, University of Connecticut, Storrs, Connecticut 06269-3136 (United States); Staruch, M. [Department of Physics, University of Connecticut, Storrs, Connecticut 06269-3046 (United States); Jain, Menka [Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269-3136 (United States); Department of Physics, University of Connecticut, Storrs, Connecticut 06269-3046 (United States)

2011-03-21T23:59:59.000Z

448

Characterization and performance of Cu/ZnO/Al2O3 catalysts prepared via decomposition of M(Cu, Zn)-ammonia complexes under sub-atmospheric pressure for methanol synthesis from H2 and CO2  

Science Journals Connector (OSTI)

Methanol synthesis from hydrogénation of CO2 is investigated over Cu/ZnO/Al2O3 catalysts prepared by decomposition of M(Cu, Zn)-ammonia complexes (DMAC) at various temperatures. The catalysts were characterized in detail, including X-ray diffraction, N2 adsorption-desorption, N2O chemisorption, temperature-programmed reduction and evolved gas analyses. The influences of DMAC temperature, reaction temperature and specific Cu surface area on catalytic performance are investigated. It is considered that the aurichalcite phase in the precursor plays a key role in improving the physiochemical properties and activities of the final catalysts. The catalyst from rich-aurichalcite precursor exhibits large specific Cu surface area and high space time yield of methanol (212 g/(Lcat · h); T = 513 K, p = 3 MPa, SV = 12000 h?1).

Danjun Wang; Jun Zhao; Huanling Song; Lingjun Chou

2011-01-01T23:59:59.000Z

449

Solution-Derived ZnO Homojunction Nanowire Films on Wearable Substrates for Energy Conversion and Self-Powered Gesture Recognition  

Science Journals Connector (OSTI)

Solution-Derived ZnO Homojunction Nanowire Films on Wearable Substrates for Energy Conversion and Self-Powered Gesture Recognition ... As more donor sources are produced, the depletion of free holes makes the material more insulating (green curve in Figure 2b). ... As the concn. of intrinsic defects becomes sufficiently high in O-deficient ZnO, interactions between defects lead to a significant redn. in their formation energies. ...

Ken C. Pradel; Wenzhuo Wu; Yong Ding; Zhong Lin Wang

2014-11-25T23:59:59.000Z

450

Structural and Energetic Analysis of MgxM1?x(OH)2 (M = Zn, Cu or Ca) Brucite-Like Compounds by DFT Calculations  

Science Journals Connector (OSTI)

Structural and Energetic Analysis of MgxM1?x(OH)2 (M = Zn, Cu or Ca) Brucite-Like Compounds by DFT Calculations ... Brucite-like mixed hydroxides of the general formula MgxM1?x(OH)2 for M = Zn, Cu or Ca were studied by density functional theory within pseudopotential approximation, plane waves basis set, and periodic boundary conditions. ... Brucite, which is the mineral form of magnesium hydroxide, is a commonly occurring material. ...

Deyse G. Costa; Alexandre B. Rocha; Wladmir F. Souza; Sandra Shirley X. Chiaro; Alexandre A. Leitão

2008-06-28T23:59:59.000Z

451

Performance and Loss Analyses of High-Efficiency CBD-ZnS/Cu(In1-xGax)Se2 Thin-Film Solar Cells  

E-Print Network [OSTI]

1 Performance and Loss Analyses of High-Efficiency CBD-ZnS/Cu(In1-xGax)Se2 Thin-Film Solar Cells, Setagaya-ku, Tokyo 157-8572, Japan (Received ) KEYWORDS: ZnS buffer, Cu(In,Ga)Se2, thin-film solar cells alternative to CdS in polycrystalline thin-film Cu(In1-xGax)Se2 (CIGS) solar cells. Cells with efficiency

Sites, James R.

452

Polyacrylamide/Ni0.02Zn0.98O Nanocomposite with High Solar Light Photocatalytic Activity and Efficient Adsorption Capacity for Toxic Dye Removal  

Science Journals Connector (OSTI)

Polyacrylamide/Ni0.02Zn0.98O Nanocomposite with High Solar Light Photocatalytic Activity and Efficient Adsorption Capacity for Toxic Dye Removal ... The effect of adsorption capacity of cross-linked polyacrylamide on photocatalytic activity of Ni0.02Zn0.98O was also studied. ... A significant removal efficiency of 99.17% for RB and 96.55% for MG was achieved in 2 h of solar illumination in the presence of the nanocomposite. ...

Amit Kumar; Gaurav Sharma; Mu Naushad; Pardeep Singh; Susheel Kalia

2014-09-13T23:59:59.000Z

453

Methanol Synthesis over Cu/ZnO/Al2O3: The Active Site in Industrial Catalysis  

SciTech Connect (OSTI)

Unlike homogeneous catalysts, heterogeneous catalysts that have been optimized through decades are typically so complex and hard to characterize that the nature of the catalytically active site is not known. This is one of the main stumbling blocks in developing rational catalyst design strategies in heterogeneous catalysis. We show here how to identify the crucial atomic structure motif for the industrial Cu/ZnO/Al{sub 2}O{sub 3} methanol synthesis catalyst. Using a combination of experimental evidence from bulk-, surface-sensitive and imaging methods collected on real high-performance catalytic systems in combination with DFT calculations. We show that the active site consists of Cu steps peppered with Zn atoms, all stabilized by a series of well defined bulk defects and surface species that need jointly to be present for the system to work.

Behrens, Malte

2012-03-28T23:59:59.000Z

454

Schottky barrier source-gated ZnO thin film transistors by low temperature atomic layer deposition  

SciTech Connect (OSTI)

We have fabricated ZnO source-gated thin film transistors (SGTFTs) with a buried TiW source Schottky barrier and a top gate contact. The ZnO active channel and thin high-? HfO{sub 2} dielectric utilized are both grown by atomic layer deposition at temperatures less than 130?°C, and their material and electronic properties are characterized. These SGTFTs demonstrate enhancement-mode operation with a threshold voltage of 0.91?V, electron mobility of 3.9 cm{sup 2} V{sup ?1} s{sup ?1}, and low subthreshold swing of 192?mV/decade. The devices also exhibit a unique combination of high breakdown voltages (>20?V) with low output conductances.

Ma, Alex M.; Gupta, Manisha; Shoute, Gem; Tsui, Ying Y.; Barlage, Douglas W., E-mail: barlage@ualberta.ca [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada); Afshar, Amir; Cadien, Kenneth C. [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada)] [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada)

2013-12-16T23:59:59.000Z

455

Magneto-optical studies of ensembles of semimagnetic self-organized Cd(Mn)Se/Zn(Mn)Se Quantum Dots  

SciTech Connect (OSTI)

Ensembles of Cd(Mn)Se/ZnSe and CdSe/Zn(Mn)Se semimagnetic self-organized quantum dots with different Mn content have been studied by photoluminescence and resonant Raman scattering under strong magnetic fields in Faraday and Voigt geometries and with spectral and polarization selective excitation. Electron spin-flip Raman scattering has been observed in Voigt geometry in the structures with large Mn content. Narrow exciton peaks completely ?{sup ?}?{sup +} polarized have been observed under selective excitation in Faraday geometry in the structures with medium and small Mn content. A number of specific effects manifested themselves in the structures with a smallest Mn content where no Zeeman shift of the photoluminescence bands was observed.

Reshina, I. I.; Ivanov, S. V.; Toropov, A. A. [Ioffe Physical Technical Institute of RAS, Polytechnicheskaya 26, 194021 St. Petersburg (Russian Federation)

2013-12-04T23:59:59.000Z

456

Origins of low resistivity and Ge donor level in Ge ion-implanted ZnO bulk single crystals  

SciTech Connect (OSTI)

The energy level of Ge in Ge-ion implanted ZnO single crystals is studied by Hall-effect and photoluminescence (PL) methods. The variations in resistivity from ?10{sup 3} ?cm for un-implanted samples to ?10{sup ?2} ?cm for as-implanted ones are observed. The resistivity is further decreased to ?10{sup ?3} ?cm by annealing. The origins of the low resistivity are attributed to both the zinc interstitial (Zn{sub i}) related defects and the electrical activated Ge donor. An activation energy of Ge donors estimated from the temperature dependence of carrier concentration is 102 meV. In PL studies, the new peak at 372 nm (3.33 eV) related to the Ge donor is observed in 1000 °C annealed samples.

Kamioka, K.; Oga, T.; Izawa, Y.; Kuriyama, K. [College of Engineering and Research Center of Ion Beam Technology, Hosei University Koganei, Tokyo 184-8584 (Japan); Kushida, K. [Departments of Arts and Sciences, Osaka Kyoiku University Kashiwara, Osaka 582-8582 (Japan)

2013-12-04T23:59:59.000Z

457

Effect of the thickness and hydrogen treatment on the properties of Ga-doped ZnO transparent conductive films  

Science Journals Connector (OSTI)

Combined effects of the thickness and hydrogen post-annealing treatment on the structural, electrical, and optical properties of Ga-doped ZnO (GZO) films were investigated as a potential substitute for indium tin oxide transparent conductive oxide. In the as-deposited films, microstructural evolution initially improved the crystallinity up to the thickness of 160 nm accompanying enhanced electrical and optical properties, but further thickness increase resulted in the deterioration of these properties attributable to the development of ZnGa2O4 and Ga2O3 phases originating from the excessive amount of the Ga dopant. Post-annealing treatment of the GZO films in a hydrogen atmosphere improved the electrical and optical properties substantially through possible reduction of the oxide phases and passivation of the surfaces and grain boundaries. In this case, electrical and optical properties remained almost similar for the thickness above 160 nm indicating that there exists a certain optimal film thickness.

Min-Jung Lee; Jinhyong Lim; Jungsik Bang; Woong Lee; Jae-Min Myoung

2008-01-01T23:59:59.000Z

458

Tailoring the coercivity in ferromagnetic ZnO thin films by 3d and 4f elements codoping  

SciTech Connect (OSTI)

Cluster free, Co (3d) and Eu (4f) doped ZnO thin films were prepared using ion implantation technique accompanied by post annealing treatments. Compared with the mono-doped ZnO thin films, the samples codoped with Co and Eu exhibit a stronger magnetization with a giant coercivity of 1200?Oe at ambient temperature. This was further verified through x-ray magnetic circular dichroism analysis, revealing the exchange interaction between the Co 3d electrons and the localized carriers induced by Eu{sup 3+} ions codoping. The insight gained with modulating coercivity in magnetic oxides opens up an avenue for applications requiring non-volatility in spintronic devices.

Lee, J. J.; Xing, G. Z., E-mail: guozhong.xing@unsw.edu.au; Yi, J. B.; Li, S. [School of Materials Science and Engineering, The University of New South Wales, Sydney, New South Wales 2052 (Australia)] [School of Materials Science and Engineering, The University of New South Wales, Sydney, New South Wales 2052 (Australia); Chen, T. [Department of Physics, The Chinese University of Hong Kong, Shatin (Hong Kong)] [Department of Physics, The Chinese University of Hong Kong, Shatin (Hong Kong); Ionescu, M. [Australian Nuclear Science and Technology Organization, Sydney, New South Wales 2234 (Australia)] [Australian Nuclear Science and Technology Organization, Sydney, New South Wales 2234 (Australia)

2014-01-06T23:59:59.000Z

459

Chlorine doping of cubic CdS and ZnS grown by compound source molecular-beam epitaxy  

Science Journals Connector (OSTI)

We report on the chlorine doping of ZnS and CdS grown by compound source molecular-beam epitaxy. The maximum free electron concentrations achieved were 1×1018 and 8×1019 cm?3, respectively. The conductivity of the cubic CdS epilayers turned out to be anisotropic with respect to the ?1 1 0? crystallographic directions due to an anisotropic lattice defect structure.

M Grün; A Storzum; M Hetterich; A Kamilli; W Send; Th Walter; C Klingshirn

1999-01-01T23:59:59.000Z

460

Three-photon absorption in water-soluble ZnS nanocrystals Jun He, Wei Ji,a  

E-Print Network [OSTI]

:sapphire femtosecond lasers. This value is nearly one order of magnitude greater than that of CdS NCs, and four to five,4 research effort on their three-photon absorption 3PA is limited.5 Although high-quality CdS NCs show strong and fluorescence8 of doped ZnS NCs have been investigated. Furthermore, Nikesh et al. have re- ported large 2PA

Wei, Ji

Note: This page contains sample records for the topic "zn zurn ot" from the National Library of EnergyBeta (NLEBeta).
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461

Chemical composition and temperature dependent performance of ZnO-thin film transistors deposited by pulsed and continuous spray pyrolysis  

SciTech Connect (OSTI)

Zinc oxide thin film transistors (TFTs) deposited by continuous and pulsed spray pyrolysis were investigated to analyze process kinetics which make reduction of process temperature possible. Thus, fluid mechanics, chemical composition, electrical performance, and deposition and annealing temperature were systematically analyzed. It was found that ZnO layers continuously deposited at 360?°C contained zinc oxynitrides, CO{sub 3}, and hydro carbonate groups from pyrolysis of basic zinc acetate. Statistically, every second wurtzite ZnO unit cell contained an impurity atom. The purity and performance of the ZnO-TFTs increased systematically with increasing deposition temperature due to an improved oxidation processes. At 500?°C the zinc to oxygen ratio exceeded a high value of 0.96. Additionally, the ZnO film was not found to be in a stabilized state after deposition even at high temperatures. Introducing additional subsequent annealing steps stabilizes the film and allows the reduction of the overall thermal stress to the substrate. Further improvement of device characteristics was obtained by pulsed deposition which allowed a more effective transport of the by-products and oxygen. A significant reduction of the deposition temperature by 140?°C was achieved compared to the same performance as in continuous deposition mode. The trap density close to the Fermi energy could be reduced by a factor of two to 4?×?10{sup 17}?eV{sup ?1}?cm{sup ?3} due to the optimized combustion process on the surface. The optimization of the deposition processes made the fabrication of TFTs with excellent performance possible. The mobility was high and exceeded 12 cm{sup 2}/V s, the subthreshold slope was 0.3 V dec{sup ?1}, and an on-set close to the ideal value of 0?V was achieved.

Ortel, Marlis; Balster, Torsten; Wagner, Veit [School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen (Germany)

2013-12-21T23:59:59.000Z

462

Electrochemical Impedance Spectroscopy Characterization of Electron Transport and Recombination in ZnO Nanorod Dye-Sensitized Solar Cells  

Science Journals Connector (OSTI)

In this work we carried out electrochemical impedance spectroscopic (EIS) characterizations on a ZnO nanorod dye-sensitized solar cell to investigate its electron transport and recombination properties and how these properties influence the cell performance. ... Supplemental figures for impedance spectra under illumination, the transmission line model, comparison of the measured capacitance to the depletion model, charge transfer resistance at open-circuit conditions, and total resistances of the cell. ...

Chuan He; Zhi Zheng; Huili Tang; Linan Zhao; Fang Lu

2009-05-26T23:59:59.000Z

463

Retaining the 3D Framework of Zinc Sponge Anodes upon Deep Discharge in Zn–Air Cells  

Science Journals Connector (OSTI)

zinc; zinc?air; batteries; morphology; energy; three-dimensional architecture ... Zinc-based batteries offer many appealing characteristics, including low-cost components, water-based electrolytes, and high energy density, yet their broader applicability has been limited by suboptimal performance of the Zn anode, which undergoes complex chemical and electrochemical reactions during operation. ... discharge depth-of-discharge specific capacityaverage dischargespecific energy Rcell,initialc Rcell,post?dischargec ...

Joseph F. Parker; Eric S. Nelson; Matthew D. Wattendorf; Christopher N. Chervin; Jeffrey W. Long; Debra R. Rolison

2014-10-28T23:59:59.000Z

464

Visible-light photoconductivity of Zn1-xCoxO and its dependence on Co2+ concentration  

Science Journals Connector (OSTI)

Many metal oxides investigated for solar photocatalysis or photoelectrochemistry have band gaps that are too wide to absorb a sufficient portion of the solar spectrum. Doping with impurity ions has been extensively explored as a strategy to sensitize such oxides to visible light, but the electronic structures of the resulting materials are frequently complex and poorly understood. Here, we report a detailed photoconductivity investigation of the wide-gap II-VI semiconductor ZnO doped with Co2+ (Zn1-xCoxO), which responds to visible light in photoelectrochemical and photoconductivity experiments and thus represents a well-defined model system for understanding dopant-sensitized oxides. Variable-temperature scanning photoconductivity measurements have been performed on Zn1-xCoxO epitaxial films to examine the relationship between dopant concentration (x) and visible-light photoconductivity, with particular focus on mid-gap intra-d-shell (d-d) photoactivity. Excitation into the intense 4T1(P) d-d band at ?2.0 eV (620 nm) leads to Co2+/3+ ionization with a quantum efficiency that increases with decreasing cobalt concentration and increasing sample temperature. Both spontaneous and thermally assisted ionization from the Co2+ d-d excited state are found to become less effective as x is increased, attributed to an increasing conduction-band-edge potential. These trends counter the increasing light absorption with increasing x, explaining the experimental maximum in external photon-to-current conversion efficiencies at values well below the solid solubility of Co2+ in ZnO.

Claire A. Johnson; Alicia Cohn; Tiffany Kaspar; Scott A. Chambers; G. Mackay Salley; Daniel R. Gamelin

2011-09-06T23:59:59.000Z

465

Hydrothermal synthesis and structure of an open framework Co0.7Zn1.3(PO4)2(NH3–CH2CH2NH3) and Co6.2(OH)4(PO4)4Zn1.80, a new adamite type phase  

Science Journals Connector (OSTI)

The hydrothermal reaction of cobalt(II)oxalate di-hydrate, zinc oxide, and triethyl-orthophosphate, using 1,2-diaminoethane as structure directing template in water, produced two major crystal phases in almost equal amount: the purple crystals of [NH3–CH2CH2NH3][Co0.7Zn1.3(PO4)2] (1) and the red burgundy crystals of Co6.2(OH)4(PO4)4Zn1.80 (2), a new adamite type phase. The structure of [NH3–CH2CH2NH3] [Co0.7Zn1.3(PO4)2] (1) exhibits a 3D open framework built from PO4 and (Co/Zn)O4 tetrahedra, and (Co/Zn)O5 trigonal bipyramids, forming two major channels, an 8-membered ring channel and a 16-membered ring channel, that host the ethanediammonium ions. The Co6.2(OH)4(PO4)4Zn1.80 (2) is isomorphous with adamite-type M2(OH)XO4 structure, with a condensed vertex and edge sharing network of (Co/Zn)O5, and distorted CoO6, and PO4 subunits. The cobalt preference for higher coordination numbers is displayed in this structure, where the octahedral sites are wholly occupied by cobalt. Thermal analysis confirmed that these compounds display high thermal stability.

Aderemi Oki; Matthias Zeller; Yaneth Coranza; Jose Luevano; Allen D. Hunter

2007-01-01T23:59:59.000Z

466

Temperature-dependent electrical characterization of nitrogen-doped ZnO thin film: vacuum annealing effect  

Science Journals Connector (OSTI)

Temperature-dependent Hall effect measurements were carried out at an N-doped ZnO thin film grown by the reactive sputtering method onto (001) Si substrate before and after being vacuum annealed at 900?°C. p-Type ZnO thin film was obtained with a relatively high mobility of ~60?cm2?V?1?s?1, a high carrier concentration of 2.5?1017?cm?3 and a low resistivity of 0.4???cm. After vacuum annealing, the temperature dependence of electrical parameters such as mobility and carrier concentration showed highly different characteristics. Time-resolved photoluminescence (TRPL), PL and x-ray diffraction measurements (XRD) were performed after the annealing process to check whether the high-temperature annealing can remove the ZnO film on Si or not. The PL measurement shows band-to-band recombination at 360?nm and TRPL shows the exciton recombination lifetime to be 571.7?ps. The XRD measurement reveals highly preferred c-axis (0002) orientation. Activation energies were calculated using the ln ? versus 1000?T?1 plot to be 20?meV for the as-grown and 24 and 6.8?meV after the vacuum annealing process.

Emre Gür; S Tüzemen; S Do?an

2009-01-01T23:59:59.000Z

467

Magnetic resonance investigation of Zn{sub 1?x}Fe{sub x}O properties influenced by annealing atmosphere  

SciTech Connect (OSTI)

ZnO is an attractive system for a wide variety of practical applications, being a chemically stable oxide semiconductor. It has been shown that Fe doping produces ferromagnetic semiconductor at room temperature. This material, therefore, has the potential for use in spintronic devices such as spin transistors, spin light emitting diodes, very high density nonvolatile semiconductor memory and optical emitters. It is believed that oxygen vacancies and substitutional incorporation are important to produce ferromagnetism in semiconductor oxide doped with transition metal ions. The present paper reports detailed electron paramagnetic resonance investigations (EPR) of the samples in order to investigate how annealing atmosphere (Air and Argon) influenced the magnetic behavior of the samples. X-band electron paramagnetic resonance (EPR) studies of Fe{sup 3+} ions in Zn{sub 1?x}Fe{sub x}O powders with x = 1%, 3% is reported. These samples are interesting to investigate as Fe doping produce ferromagnetism in ZnO, making a promising ferromagnetic semiconductor at room temperature.

Raita, O.; Popa, A.; Toloman, D.; Stan, M.; Giurgiu, L. M. [National Institute for Research and Development of Isotopic and Molecular Technologies Donath 65-103, 400293, Cluj-Napoca (Romania)] [National Institute for Research and Development of Isotopic and Molecular Technologies Donath 65-103, 400293, Cluj-Napoca (Romania)

2013-11-13T23:59:59.000Z

468