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Note: This page contains sample records for the topic "bulk gallium nitride" 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
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1

Light-Emitting Diodes on Semipolar Bulk Gallium Nitride Substrate  

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

This project is producing high-efficiency semipolar light-emitting diodes (LEDs) on low-defect bulk gallium nitride (GaN) substrates.

2

High-Quality, Low-Cost Bulk Gallium Nitride Substrates  

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

To develop ESG into a viable bulk growth process for GaN that is more scalable to large-area wafer manufacturing and able to produce cost-effective, high-quality bulk GaN substrates.

3

Doping of gallium nitride using disilane  

Science Journals Connector (OSTI)

Keywords: disilane, gallium nitride, metalorganic chemical vapor deposition, organometallic vapor phase epitaxy, silicon doping

A. E. Wickenden; L. B. Rowland; K. Doverspike; D. K. Gaskill; J. A. Freitas, Jr.; D. S. Simons; P. H. Chi

1995-11-01T23:59:59.000Z

4

P-type gallium nitride  

DOE Patents (OSTI)

Several methods have been found to make p-type gallium nitride. P-type gallium nitride has long been sought for electronic devices. N-type gallium nitride is readily available. Discovery of p-type gallium nitride and the methods for making it will enable its use in ultraviolet and blue light-emitting diodes and lasers. pGaN will further enable blue photocathode elements to be made. Molecular beam epitaxy on substrates held at the proper temperatures, assisted by a nitrogen beam of the proper energy produced several types of p-type GaN with hole concentrations of about 5{times}10{sup 11} /cm{sup 3} and hole mobilities of about 500 cm{sup 2} /V-sec, measured at 250 K. P-type GaN can be formed of unintentionally-doped material or can be doped with magnesium by diffusion, ion implantation, or co-evaporation. When applicable, the nitrogen can be substituted with other group III elements such as Al. 9 figs.

Rubin, M.; Newman, N.; Fu, T.; Ross, J.; Chan, J.

1997-08-12T23:59:59.000Z

5

Gallium nitride junction field-effect transistor  

DOE Patents (OSTI)

An all-ion implanted gallium-nitride (GaN) junction field-effect transistor (JFET) and method of making the same. Also disclosed are various ion implants, both n- and p-type, together with or without phosphorous co-implantation, in selected III-V semiconductor materials.

Zolper, John C. (Albuquerque, NM); Shul, Randy J. (Albuquerque, NM)

1999-01-01T23:59:59.000Z

6

Gallium nitride junction field-effect transistor  

DOE Patents (OSTI)

An ion implanted gallium-nitride (GaN) junction field-effect transistor (JFET) and method of making the same are disclosed. Also disclosed are various ion implants, both n- and p-type, together with or without phosphorus co-implantation, in selected III-V semiconductor materials. 19 figs.

Zolper, J.C.; Shul, R.J.

1999-02-02T23:59:59.000Z

7

Temperature dependence of electrical properties of gallium-nitride bulk single crystals doped with Mg and their evolution with annealing  

Science Journals Connector (OSTI)

Comprehensive studies of the electrical properties of Mg-doped bulk GaN crystals grown by high-pressure synthesis were performed as a function of temperature up to 750?°C. Annealing of the samples in nitrogen ambient modifies qualitatively their resistivity values ? and the ?(T) variation. It was found that our material is characterized by a high concentration of oxygen-related donors and that the charge transport in the studied samples is determined by two types of states one of shallow character (Mg-related state E A ?0.15? eV ) and the second one much more deep E 2 ?0.95? eV (above the valence band). Depending on the effective concentration of either states different resistivities ? can be observed: lower resistivity (?10 6 ??? cm at ambient temperature) in samples with dominant E 2 states. For the first type of samples annealing at T ann <500?° C leads to a decrease of their resistivity and is associated with an increase of the effective concentration of the shallow Mg acceptors. Annealing of both types of samples at temperatures between 600 and 750?°C leads to an increase of the deep state concentration. The presence of hydrogen ambient during annealing of the low-resistivity samples strongly influences their properties. The increase of the sample resistivity and an appearance of a local vibrational mode of hydrogen at 3125 cm?1 were observed. These effects can be removed by annealing in hydrogen-free ambient.

E. Litwin-Staszewska; T. Suski; R. Piotrzkowski; I. Grzegory; M. Bockowski; J. L. Robert; L. Ko?czewicz; D. Wasik; E. Kami?ska; D. Cote; B. Clerjaud

2001-01-01T23:59:59.000Z

8

Gallium Nitride Synthesis Using Lithium Metal as a Nitrogen Fixant  

Science Journals Connector (OSTI)

This present work centers on the synthesis of white, microcrystalline gallium nitride from gallium and ammonia, using lithium to increase the solubility of nitrogen-containing species in the metal phase. ... After the acid was decanted and the product was rinsed repeatedly with water and then acetone, the resulting white powder was found to exhibit the powder X-ray diffractogram (PXRD) (Figure 2a) of crystalline gallium nitride (1). ...

Seán T. Barry; Stephen A. Ruoff; Arthur L. Ruoff

1998-08-13T23:59:59.000Z

9

Synthesis and characterization of visible emission from rare-earth doped aluminum nitride, gallium nitride and gallium aluminum nitride powders and thin films  

E-Print Network (OSTI)

of the Nitrides of Aluminum and Gallium," J. Electrochem.1) 24 (1962). G. Long and L. M. Foster, "Aluminum Nitride, aRefractory for Aluminum to 2000°C," J. Am. Ceram. Soc. ,

Tao, Jonathan Huai-Tse

2010-01-01T23:59:59.000Z

10

Formation of Hollow Gallium Nitride Spheres via Silica Sphere Templates  

Science Journals Connector (OSTI)

Formation of Hollow Gallium Nitride Spheres via Silica Sphere Templates ... To form reasonably uniform gallium oxide shells, the amounts of urea and water added to the reaction mixture were varied. ... Due to the low solubility of urea in 2-propanol, addition of a larger amount of urea than that used in this study is not desirable. ...

Chun-Neng Lin; Michael H. Huang

2008-12-30T23:59:59.000Z

11

Neutron detection using boron gallium nitride semiconductor material  

SciTech Connect

In this study, we developed a new neutron-detection device using a boron gallium nitride (BGaN) semiconductor in which the B atom acts as a neutron converter. BGaN and gallium nitride (GaN) samples were grown by metal organic vapor phase epitaxy, and their radiation detection properties were evaluated. GaN exhibited good sensitivity to ?-rays but poor sensitivity to ?-rays. Moreover, we confirmed that electrons were generated in the depletion layer under neutron irradiation. This resulted in a neutron-detection signal after ?-rays were generated by the capture of neutrons by the B atoms. These results prove that BGaN is useful as a neutron-detecting semiconductor material.

Atsumi, Katsuhiro [Department of Electrical and Electronic Engineering, Graduate School of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8561 (Japan); Inoue, Yoku; Nakano, Takayuki, E-mail: ttnakan@ipc.shizuoka.ac.jp [Department of Electrical and Materials Science, Graduate School of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8561 (Japan); Mimura, Hidenori; Aoki, Toru [Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011 (Japan)

2014-03-01T23:59:59.000Z

12

Polythiophene-based charge dissipation layer for electron beam lithography of zinc oxide and gallium nitride  

Science Journals Connector (OSTI)

The ability of thin polythiophene layers to dissipate accumulated charge in the electron beam lithography (EBL) of wide bandgap semiconductors such as zinc oxide and gallium nitride is demonstrated. A quick and inexpensive processing method is demonstrated for EBL exposure of dense and high-resolution patterns in a hydrogen silsesquioxane (HSQ) negative-tone resistdeposited on bulk ZnO samples and with GaN/AlN on sapphire substrates. For the former experimental results are given for three different cases: where no charge dissipation layer was used as well as cases where 40-nm-thick Al and 100-nm-thick conductive polymer layers were used on the top of the HSQ resist. For the latter material EBL exposure was investigated for pure HSQ and for HSQ with a thin conductive polymer layer on top. Based on the scanning electron microscope observations of the resulting photonic crystal(PhC) pattern conventional Al and the proposed polymer approach were compared. Good agreement between these results is reported while the new method considerably simplifies sample processing. Spin-coatable conducting polymer may be easily removed due to its solubility in water which makes it a perfect solution for the processing of amphoteric oxide samples i.e. zinc oxide. Gallium nitride processing also benefits from polymer dissipation layer usage due to extended exposure range and the avoidance of dense pattern overexposure in HSQ.

R. Dylewicz; S. Lis; R. M. De La Rue; F. Rahman

2010-01-01T23:59:59.000Z

13

Effect of the nitrogen ion energy on the MBE growth of thin gallium nitride films  

Science Journals Connector (OSTI)

The influence of the energy of bombarding nitrogen ions on the growth of thin gallium nitride (GaN) films under molecular beam epitaxy (MBE) conditions has been simulated using the method of balance kinetic eq...

D. V. Kulikov; Yu. V. Trushin; V. S. Kharlamov

2010-03-01T23:59:59.000Z

14

Wet Chemical Functionalization of III–V Semiconductor Surfaces: Alkylation of Gallium Arsenide and Gallium Nitride by a Grignard Reaction Sequence  

Science Journals Connector (OSTI)

Wet Chemical Functionalization of III–V Semiconductor Surfaces: Alkylation of Gallium Arsenide and Gallium Nitride by a Grignard Reaction Sequence ... These observations are consistent with the known solubility of oxidized As species in water. ... Remote H plasma exposure was effective for removing halogens and hydrocarbons from the surfaces of both nitrides at 450 °C, but was not efficient for oxide removal. ...

Sabrina L. Peczonczyk; Jhindan Mukherjee; Azhar I. Carim; Stephen Maldonado

2012-02-28T23:59:59.000Z

15

Simulation studies on the evolution of gallium nitride on a liquid gallium surface under plasma bombardmenta)  

Science Journals Connector (OSTI)

Monte Carlo simulations were conducted to study the formation of gallium-nitride (GaN) layer on liquid gallium (Ga) sputtering target immersed in nitrogen ( N 2 ) plasma. In the simulation model N ions were assumed to possess energy equal to the bias voltage applied to the sputtering target with respect to the plasma. The results showed the surface morphology of GaN changed from a relatively smooth GaN on Ga surface at 50 eV N ion energy to a rough surface with GaN dendrites on liquid Ga at 500 eV ion energy. Further increase in N ion energy up to 1 keV resulted in smaller density of GaN dendrites on surface. Increasing surface coverage of Ga by GaN substantially reduced the sputtering yield of Ga from the target. These simulation results were correlated with previously reported experimental observations on liquid Ga surface immersed in the nitrogen plasma of a plasma-sputter-type ion source.

M. R. Vasquez Jr.; R. E. Flauta; M. Wada

2008-01-01T23:59:59.000Z

16

Imaging the p-n junction in a gallium nitride nanowire with a scanning microwave microscope  

SciTech Connect

We used a broadband, atomic-force-microscope-based, scanning microwave microscope (SMM) to probe the axial dependence of the charge depletion in a p-n junction within a gallium nitride nanowire (NW). SMM enables the visualization of the p-n junction location without the need to make patterned electrical contacts to the NW. Spatially resolved measurements of S{sub 11}{sup ?}, which is the derivative of the RF reflection coefficient S{sub 11} with respect to voltage, varied strongly when probing axially along the NW and across the p-n junction. The axial variation in S{sub 11}{sup ?}? effectively mapped the asymmetric depletion arising from the doping concentrations on either side of the junction. Furthermore, variation of the probe tip voltage altered the apparent extent of features associated with the p-n junction in S{sub 11}{sup ?} images.

Imtiaz, Atif [Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, Colorado 80309 (United States); Wallis, Thomas M.; Brubaker, Matt D.; Blanchard, Paul T.; Bertness, Kris A.; Sanford, Norman A.; Kabos, Pavel, E-mail: kabos@boulder.nist.gov [Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); Weber, Joel C. [Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309 (United States); Coakley, Kevin J. [Information Technology Laboratory, National Institute of Standards and Technology, Boulder, Colorado 80305 (United States)

2014-06-30T23:59:59.000Z

17

Femtosecond laser-ultrasonic investigation of plasmonic fields on the metal/gallium nitride interface  

Science Journals Connector (OSTI)

By using femtosecond laser-ultrasonic we demonstrate an approach to study the surface plasmon field optically excited in the interface between metal and a semiconductor thin film. By femtosecond impulsive excitation on gallium–nitride (GaN) different optical probe signals were observed when the impulse-excited nanoacoustic pulse propagated through the metalfilm and metal nanoslits. By analyzing the shape and temporal response of thus induced acousto-optical signals our femtosecond laser-ultrasonic study not only reveals the plasmonic field distribution optically excited in the metal/substrate interface but also confirms that the penetration depth of surface plasmon field into the substrate agrees well with a simulation result.

Hung-Pin Chen; Yu-Chieh Wen; Yi-Hsin Chen; Cheng-Hua Tsai; Kuang-Li Lee; Pei-Kuen Wei; Jinn-Kong Sheu; Chi-Kuang Sun

2010-01-01T23:59:59.000Z

18

More Efficient Power Conversion for EVs: Gallium-Nitride Advanced Power Semiconductor and Packaging  

SciTech Connect

Broad Funding Opportunity Announcement Project: Delphi is developing power converters that are smaller and more energy efficient, reliable, and cost-effective than current power converters. Power converters rely on power transistors which act like a very precisely controlled on-off switch, controlling the electrical energy flowing through an electrical circuit. Most power transistors today use silicon (Si) semiconductors. However, Delphi is using semiconductors made with a thin layer of gallium-nitride (GaN) applied on top of the more conventional Si material. The GaN layer increases the energy efficiency of the power transistor and also enables the transistor to operate at much higher temperatures, voltages, and power-density levels compared to its Si counterpart. Delphi is packaging these high-performance GaN semiconductors with advanced electrical connections and a cooling system that extracts waste heat from both sides of the device to further increase the device’s efficiency and allow more electrical current to flow through it. When combined with other electronic components on a circuit board, Delphi’s GaN power transistor package will help improve the overall performance and cost-effectiveness of HEVs and EVs.

None

2010-02-01T23:59:59.000Z

19

Lewis Base Adduct Stabilized Organogallium Azides:? Synthesis and Dynamic NMR Spectroscopic Studies of Novel Precursors to Gallium Nitride and Role of Ammonia as Reactive Carrier Gas  

Science Journals Connector (OSTI)

Lewis Base Adduct Stabilized Organogallium Azides:? Synthesis and Dynamic NMR Spectroscopic Studies of Novel Precursors to Gallium Nitride and Role of Ammonia as Reactive Carrier Gas ... Solvents were dried under argon according to standard methods; n-pentane and toluene were stored over Na/K alloy, and diethyl ether and thf over potassium benzophenoate (residual water solubility in other solvents than thf. ...

Alexander Miehr; Mike R. Mattner; Roland A. Fischer

1996-04-16T23:59:59.000Z

20

Radiation tolerance of piezoelectric bulk single-crystal aluminum nitride  

SciTech Connect

For practical use in harsh radiation environments, we pose selection criteria for piezoelectric materials for nondestructive evaluation (NDE) and material characterization. Using these criteria, piezoelectric aluminum nitride is shown to be an excellent candidate. The results of tests on an aluminumnitride-based transducer operating in a nuclear reactor are also presented. We demonstrate the tolerance of single-crystal piezoelectric aluminum nitride after fast and thermal neutron fluences of 1.85 × 1018 neutron/cm2 and 5.8 × 1018 neutron/cm2, respectively, and a gamma dose of 26.8 MGy. The radiation hardness of AlN is most evident from the unaltered piezoelectric coefficient d33, which measured 5.5 pC/N after a fast and thermal neutron exposure in a nuclear reactor core for over 120 MWh, in agreement with the published literature value. The results offer potential for improving reactor safety and furthering the understanding of radiation effects on materials by enabling structural health monitoring and NDE in spite of the high levels of radiation and high temperatures, which are known to destroy typical commercial ultrasonic transducers.

David A. Parks; Bernhard R. Tittmann

2014-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "bulk gallium nitride" 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

E-Print Network 3.0 - arsenide gallium nitride Sample Search...  

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

An advanced diffusion model to identify emergent research issues: the case of optoelectronic devices Summary: instrumentation Absorption coefficients Aluminium Nitrides Aluminium...

22

The influence of prestrained metalorganic vapor phase epitaxial gallium-nitride templates on hydride vapor phase epitaxial growth  

Science Journals Connector (OSTI)

We have varied the strain situation in metalorganic vapor phase epitaxial (MOVPE) grown gallium-nitride (GaN) by exchanging the nucleation layer and by inserting a submono-Si x N y -interlayer in the first few hundred nanometers of growth on sapphire substrates. The influence on the MOVPE template and subsequent hydride vapor phase epitaxial (HVPE) growth could be shown by in-situ measurements of the sample curvature. Using the results of these investigations we have established a procedure to confine the curvature development in MOVPE and HVPE growth to a minimum. By increasing the layer thickness in HVPE we could create self-separated freestanding GaN layers with small remaining curvature.

2014-01-01T23:59:59.000Z

23

Effect of substrate temperature on crystal orientation and residual stress in radio frequency sputtered gallium–nitride films  

Science Journals Connector (OSTI)

The crystal orientation and residual stress in gallium nitride(GaN)filmsdeposited on a single-crystal (0001) sapphire substrate using a sputtering system are examined through x-ray diffraction measurements as part of a study of low-temperaturesputtering techniques for GaN. The rf sputtering system has an isolated deposition chamber to prevent contamination with impurities and is expected to produce high-purity nitride films.GaNfilms are deposited at various substrate temperatures and constant gas pressure and input power. This system is found to produce GaNfilms with good crystal orientation with the c axes of GaN crystals oriented normal to the substrate surface. The crystal size of filmsdeposited at high temperature is larger than that deposited at low T s . All films except that deposited at 973 K exhibit compressive residual stress and this residual stress is found to decrease with increasing temperature. Finally the filmdeposited at 973 K was tinged with white and the surface contained numerous microcracks.

Kazuya Kusaka; Takao Hanabusa; Kikuo Tominaga; Noriyoshi Yamauchi

2004-01-01T23:59:59.000Z

24

Structure and electronic properties of saturated and unsaturated gallium nitride nanotubes  

SciTech Connect

The atomic and electronic structures of saturated and unsaturated GaN nanotubes along the [001] direction with (100) lateral facets are studied using first-principles calculations. Atomic relaxation of nanotubes shows that appreciable distortion occurs in the unsaturated nanotubes. All the nanotubes considered, including saturated and unsaturated ones, exhibit semiconducting, with a direct band gap. Surface states arisen from the threefold-coordinated N and Ga atoms at the lateral facets exist inside the bulk-like band gap. When the nanotubes saturated with hydrogen, these dangling bond bands are removed from the band gap, but the band gap decreases with increasing the wall thickness of the nanotubes.

Wang, Zhiguo; Wang, Shengjie; Li, Jingbo; Gao, Fei; Weber, William J.

2009-11-05T23:59:59.000Z

25

Heat treatment of bulk gallium arsenide using a phosphosilicate glass cap  

SciTech Connect

n-type bulk GaAs crystals, capped with chemically vapor-deposited phosphosilicate glass, were heat treated at temperatures in the range of 600 to 950 /sup 0/C. Measurements on Schottky diodes and solar cells fabricated on the heat-treated material, after removal of a damaged surface layer, show an increase in free-carrier concentration, in minority-carrier-diffusion length, and in solar-cell short-circuit current. The observed changes are attributed to a removal of lifetime-reducing acceptorlike impurities, defects, or their complexes.

Mathur, G.; Wheaton, M.L.; Borrego, J.M.; Ghandhi, S.K.

1985-05-15T23:59:59.000Z

26

Synthesis and Structure of Sr3GaN3 and Sr6GaN5:? Strontium Gallium Nitrides with Isolated Planar [GaN3]6- Anions  

Science Journals Connector (OSTI)

Synthesis and Structure of Sr3GaN3 and Sr6GaN5:? Strontium Gallium Nitrides with Isolated Planar [GaN3]6- Anions ... 9-19 In most cases, an alkaline earth metal is introduced into a Na melt to enhance the solubility of nitrogen, and is incorporated in the nitride product. ... The container was sealed by welding its open end in an argon atmosphere with active water-cooling so that NaN3 did not decompose due to heating during the welding. ...

Dong Gon Park; Zoltán A. Gál; Francis J. DiSalvo

2003-02-13T23:59:59.000Z

27

E-Print Network 3.0 - adaptive nitride-based coatings Sample...  

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

DELAUSANNE Summary: AND ELECTRONICS PROF. N. GRANDJEAN 33 III-NITRIDE BASED OPTOELECTRONIC DEVICES 34 GALLIUM NITRIDE-BASED 2D... FOR DIVERSE APPLICATIONS 84 HOLE ARRAY...

28

IIl-nitride nanowires and heterostructures : growth and optical properties on nanoscale  

E-Print Network (OSTI)

Gallium nitride (GaN) and indium gallium nitride (InGaN) nanowires promise potential for further improving the electricity-to-light energy conversion efficiencies in light emitting diodes due to strain relaxation, reduced ...

Zhou, Xiang, Ph. D. Massachusetts Institute of Technology

2014-01-01T23:59:59.000Z

29

Carrier localization in gallium nitride  

SciTech Connect

In wide bandgap GaN, a large number of interesting and important scientific questions remain to be answered. For example, the large free electron concentration reaching 10{sup 19} to 10{sup 20} cm{sup - 3} in nominally undoped material are ascribed to intrinsic defects because no chemical impurity has been found at such high concentrations. According to theoretical models, a nitrogen vacancy acts as a donor but its formation energy is very large in n-type materials, making this suggestion controversial. We have investigated the nature of this yet unidentified donor at large hydrostatic pressure. Results from infrared reflection and Raman scattering indicate strong evidence for localization of free carriers by large pressures. The carrier density is drastically decreased by two orders of magnitude between 20 and 30 GPa. Several techniques provide independent evidence for results in earlier reports and present the first quantitative analysis. A possible interpretation of this effect in terms of the resonant donor level is presented.

Wetzel, C. [Lawrence Berkeley National Lab., CA (United States)][California Univ., Berkeley, CA (United States); Walukiewicz, W. [Lawrence Berkeley National Lab., CA (United States); Haller, E.E. [Lawrence Berkeley National Lab., CA (United States)][California Univ., Berkeley, CA (United States)] [and others

1996-09-01T23:59:59.000Z

30

Superconducting structure with layers of niobium nitride and aluminum nitride  

DOE Patents (OSTI)

A superconducting structure is formed by depositing alternate layers of aluminum nitride and niobium nitride on a substrate. Deposition methods include dc magnetron reactive sputtering, rf magnetron reactive sputtering, thin-film diffusion, chemical vapor deposition, and ion-beam deposition. Structures have been built with layers of niobium nitride and aluminum nitride having thicknesses in a range of 20 to 350 Angstroms. Best results have been achieved with films of niobium nitride deposited to a thickness of approximately 70 Angstroms and aluminum nitride deposited to a thickness of approximately 20 Angstroms. Such films of niobium nitride separated by a single layer of aluminum nitride are useful in forming Josephson junctions. Structures of 30 or more alternating layers of niobium nitride and aluminum nitride are useful when deposited on fixed substrates or flexible strips to form bulk superconductors for carrying electric current. They are also adaptable as voltage-controlled microwave energy sources.

Murduck, James M. (Lisle, IL); Lepetre, Yves J. (Lauris, FR); Schuller, Ivan K. (Woodridge, IL); Ketterson, John B. (Evanston, IL)

1989-01-01T23:59:59.000Z

31

Superconducting structure with layers of niobium nitride and aluminum nitride  

DOE Patents (OSTI)

A superconducting structure is formed by depositing alternate layers of aluminum nitride and niobium nitride on a substrate. Deposition methods include dc magnetron reactive sputtering, rf magnetron reactive sputtering, thin-film diffusion, chemical vapor deposition, and ion-beam deposition. Structures have been built with layers of niobium nitride and aluminum nitride having thicknesses in a range of 20 to 350 Angstroms. Best results have been achieved with films of niobium nitride deposited to a thickness of approximately 70 Angstroms and aluminum nitride deposited to a thickness of approximately 20 Angstroms. Such films of niobium nitride separated by a single layer of aluminum nitride are useful in forming Josephson junctions. Structures of 30 or more alternating layers of niobium nitride and aluminum nitride are useful when deposited on fixed substrates or flexible strips to form bulk superconductors for carrying electric current. They are also adaptable as voltage-controlled microwave energy sources. 8 figs.

Murduck, J.M.; Lepetre, Y.J.; Schuller, I.K.; Ketterson, J.B.

1989-07-04T23:59:59.000Z

32

Electronic properties of gallium nitride nanowires  

E-Print Network (OSTI)

This thesis presents a systematic study of the electrical transport in GaN nanowires. Particularly, the effect of the surrounding dielectric on the conductivity of GaN nanowires is experimentally shown for the first time. ...

Yoon, Joonah

2008-01-01T23:59:59.000Z

33

Development of a Bulk GaN Growth Technique for Low Defect Density, Large-Area Native Substrates  

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

Next-Generation Power Electronics: Next-Generation Power Electronics: Electrochemical Solution Growth (ESG) Technique for Bulk Gallium Nitride Substrates Karen Waldrip Dept. 2546, Advanced Power Sources R&D Sandia National Labs, Albuquerque, NM knwaldr@sandia.gov, (505) 844-1619 Acknowledgements: Mike Soboroff, Stan Atcitty, Nancy Clark, and John Boyes David Ingersoll, Frank Delnick, and Travis Anderson 2010 DOE Peer Review, Nov. 2-4, Washington, DC Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. Funded by the Energy Storage Systems Program of the U.S. Department Of Energy through Sandia National Laboratories Project Objective

34

Group III-nitride thin films grown using MBE and bismuth  

DOE Patents (OSTI)

The present invention comprises growing gallium nitride films in the presence of bismuth using MBE at temperatures of about 1000 K or less. The present invention further comprises the gallium nitride films fabricated using the inventive fabrication method. The inventive films may be doped with magnesium or other dopants. The gallium nitride films were grown on sapphire substrates using a hollow anode Constricted Glow Discharge nitrogen plasma source. When bismuth was used as a surfactant, two-dimensional gallium nitride crystal sizes ranging between 10 .mu.m and 20 .mu.m were observed. This is 20 to 40 times larger than crystal sizes observed when GaN films were grown under similar circumstances but without bismuth. It is thought that the observed increase in crystal size is due bismuth inducing an increased surface diffusion coefficient for gallium. The calculated value of 4.7.times.10.sup.-7 cm.sup.2 /sec. reveals a virtual substrate temperature of 1258 K which is 260 degrees higher than the actual one.

Kisielowski, Christian K. (Peidmont, CA); Rubin, Michael (Berkeley, CA)

2000-01-01T23:59:59.000Z

35

Group III-nitride thin films grown using MBE and bismuth  

DOE Patents (OSTI)

The present invention comprises growing gallium nitride films in the presence of bismuth using MBE at temperatures of about 1000 K or less. The present invention further comprises the gallium nitride films fabricated using the inventive fabrication method. The inventive films may be doped with magnesium or other dopants. The gallium nitride films were grown on sapphire substrates using a hollow anode Constricted Glow Discharge nitrogen plasma source. When bismuth was used as a surfactant, two-dimensional gallium nitride crystal sizes ranging between 10 .mu.m and 20 .mu.m were observed. This is 20 to 40 times larger than crystal sizes observed when GaN films were grown under similar circumstances but without bismuth. It is thought that the observed increase in crystal size is due bismuth inducing an increased surface diffusion coefficient for gallium. The calculated value of 4.7.times.10.sup.-7 cm.sup.2 /sec. reveals a virtual substrate temperature of 1258 K which is 260 degrees higher than the actual one.

Kisielowski, Christian K. (Piedmont, CA); Rubin, Michael (Berkeley, CA)

2002-01-01T23:59:59.000Z

36

Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers  

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

Vacancy-Induced Nanoscale Wire Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers Print Wednesday, 21 December 2005 00:00 Low-dimensional materials have gained much attention not only because of the nonstop march toward miniaturization in the electronics industry but also for the exotic properties that are inherent in their small size. One approach for creating low-dimensional structures is to exploit the nanoscale or atomic-scale features that exist naturally in the three-dimensional (bulk) form of materials. By this means, a group from the University of Washington has demonstrated a new way of creating one-dimensional nanoscale structures (nanowires) in the compound gallium selenide. In short, ordered lines of structural vacancies in the material stimulate the growth of "one-dimensional" structures less than 1 nanometer in width.

37

Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers  

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

Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers Print Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers Print Low-dimensional materials have gained much attention not only because of the nonstop march toward miniaturization in the electronics industry but also for the exotic properties that are inherent in their small size. One approach for creating low-dimensional structures is to exploit the nanoscale or atomic-scale features that exist naturally in the three-dimensional (bulk) form of materials. By this means, a group from the University of Washington has demonstrated a new way of creating one-dimensional nanoscale structures (nanowires) in the compound gallium selenide. In short, ordered lines of structural vacancies in the material stimulate the growth of "one-dimensional" structures less than 1 nanometer in width.

38

Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers  

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

Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers Print Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers Print Low-dimensional materials have gained much attention not only because of the nonstop march toward miniaturization in the electronics industry but also for the exotic properties that are inherent in their small size. One approach for creating low-dimensional structures is to exploit the nanoscale or atomic-scale features that exist naturally in the three-dimensional (bulk) form of materials. By this means, a group from the University of Washington has demonstrated a new way of creating one-dimensional nanoscale structures (nanowires) in the compound gallium selenide. In short, ordered lines of structural vacancies in the material stimulate the growth of "one-dimensional" structures less than 1 nanometer in width.

39

Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers  

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

Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers Print Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide Layers Print Low-dimensional materials have gained much attention not only because of the nonstop march toward miniaturization in the electronics industry but also for the exotic properties that are inherent in their small size. One approach for creating low-dimensional structures is to exploit the nanoscale or atomic-scale features that exist naturally in the three-dimensional (bulk) form of materials. By this means, a group from the University of Washington has demonstrated a new way of creating one-dimensional nanoscale structures (nanowires) in the compound gallium selenide. In short, ordered lines of structural vacancies in the material stimulate the growth of "one-dimensional" structures less than 1 nanometer in width.

40

Gallium interactions with Zircaloy  

SciTech Connect

This study focuses on the effects of gallium ion implantation into zircaloy cladding material to investigate the effects that gallium may have in a reactor. High fluence ion implantation of Ga ions was conducted on heated Zircaloy-4 in the range of 10{sup 16}--10{sup 18} Ga ions/cm2. Surface effects were studied using SEM and electron microprobe analysis. The depth profile of Ga in the Zircaloy was characterized with Rutherford backscattering and SIMS techniques. Results indicate that the Zirc-4 is little affected up to a fluence of 10{sup 17} Ga ions/cm{sup 2}. After implantation of 10{sup 18} Ga ions/cm{sup 2}, sub-grain features on the order of 2 {micro}m were observed which may be due to intermetallic compound formation between Ga and Zr. For the highest fluence implant, Ga content in the Zirc-4 reached a saturation value of between 30 and 40 atomic %; significant enhanced diffusion was observed but gallium was not seen to concentrate at grain boundaries.

Woods, A.L. [ed.; West, M.K. [Texas A and M Univ., College Station, TX (United States). Dept. of Nuclear Engineering

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "bulk gallium nitride" 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

Gain analysis of blue nitride-based lasers by small signal modulation  

Science Journals Connector (OSTI)

With a small signal frequency-modulation of the driving current the resonance frequency and the damping factor of the optical output power response of blue nitride-based ridge lasers grown on [0001]-plane gallium-nitride substrates were investigated with a network analyzer setup. From the linear dependence of the squared resonance frequency on the driving current the gain coefficients of the logarithmic gain model could be extracted being 7680 ? cm ? 1 for blue nitride-based lasers. For this purpose additional parameters such as the carrier density and the confinement factor were assigned by carrier lifetime and quantum efficiencymeasurements and one dimensional transfer matrix simulations respectively.

J. Müller; M. Scheubeck; M. Sabathil; G. Brüderl; D. Dini; S. Tautz; T. Lermer; A. Breidenassel; S. Lutgen

2010-01-01T23:59:59.000Z

42

Cyclotron Resonance in Gallium  

Science Journals Connector (OSTI)

Azbel'-Kaner cyclotron resonance has been studied at 36 and 9 Gc/sec at 1.2°K in the three principal symmetry planes of gallium with the microwave currents both parallel and perpendicular to the applied magnetic field. The resonance signals were characterized by extreme complexity and high resolution (long relaxation times). Mass values are determined as a function of orientation of the magnetic field in the sample surfaces. No interpretation of the mass branches on a model Fermi surface is attempted, but some correlations with previous de Haas-van Alphen data are presented.

T. W. Moore

1968-01-15T23:59:59.000Z

43

Gallium interactions with Zircaloy  

E-Print Network (OSTI)

of weapons-grade plutonium (WGPu) in the United States is the conversion of weapons-grade plutonium into mixed-oxide (MOX) reactor fuel. MOX fuel fabricated in this way must be compatible with currently used nuclear fuel components. Since US WGPu contains... that gallium may have on zircaloy cladding during reactor operation. As a result of the reprocessing of spent fuel used in European nuclear programs, many studies have been conducted on the production and behavior of MOX fuel in traditional reactors [5...

West, Michael Keith

2012-06-07T23:59:59.000Z

44

Neutron irradiation effects on gallium nitride-based Schottky diodes  

SciTech Connect

Depth-resolved cathodoluminescence spectroscopy (DRCLS), time-resolved surface photovoltage spectroscopy, X-ray photoemission spectroscopy (XPS), and current-voltage measurements together show that fast versus thermal neutrons differ strongly in their electronic and morphological effects on metal-GaN Schottky diodes. Fast and thermal neutrons introduce GaN displacement damage and native point defects, while thermal neutrons also drive metallurgical reactions at metal/GaN interfaces. Defect densities exhibit a threshold neutron fluence below which thermal neutrons preferentially heal versus create new native point defects. Scanning XPS and DRCLS reveal strong fluence- and metal-dependent electronic and chemical changes near the free surface and metal interfaces that impact diode properties.

Lin, Chung-Han; Katz, Evan J.; Zhang, Zhichun [Department of Electrical and Computer Engineering, The Ohio State University, Columbus Ohio 43210 (United States)] [Department of Electrical and Computer Engineering, The Ohio State University, Columbus Ohio 43210 (United States); Qiu, Jie; Cao, Lei [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)] [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Mishra, Umesh K. [Departments of Electrical and Computer Engineering and Materials Science and Engineering, University of California, Santa Barbara, California 93106 (United States)] [Departments of Electrical and Computer Engineering and Materials Science and Engineering, University of California, Santa Barbara, California 93106 (United States); Brillson, Leonard J. [Department of Electrical and Computer Engineering, The Ohio State University, Columbus Ohio 43210 (United States) [Department of Electrical and Computer Engineering, The Ohio State University, Columbus Ohio 43210 (United States); Department of Physics and Center for Materials Research, The Ohio State University, Columbus, Ohio 43210 (United States)

2013-10-14T23:59:59.000Z

45

Au-free Ohmic Contacts to Gallium Nitride and Graphene  

E-Print Network (OSTI)

. ................................................................................................. 43 Figure 28 Specific contact resistivity of co-sputtered Ti-Ta contact calculated after RTA at different temperatures ......................................................... 43 Figure 29 PMMA transfer method for transferring CVD grown...

Ravikirthi, Pradhyumna

2014-08-10T23:59:59.000Z

46

Effect of Gallium Nitride Template Layer Strain on the Growth...  

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

5µm layer experienced tensile strain. Dynamic Secondary Ion Mass Spectrometry (SIMS) depth profiles show that the 15µm template layer device had an average indium...

47

Corrosion behavior of mesoporous transition metal nitrides  

SciTech Connect

Transition metal nitrides (TMN) have many desirable characteristics such as high hardness and good thermal stability under reducing conditions. This work reports an initial survey of the chemical stability of mesoporous TMNs (TM=Nb, V, Cr and Ti) in water at 80 °C at neutral, acidic and alkaline pH. The mesoporous TMNs had specific surface areas of 25–60 m{sup 2}/g with average pore sizes ranging from 10 to 50 nm. The high surface areas of these materials enhance the rate of corrosion per unit mass over that of a bulk material, making detection of corrosion much easier. The products were characterized by Rietveld refinement of powder X-ray diffraction (PXRD) patterns and by scanning electron microscopy (SEM). Several nitrides have corrosion rates that are, within error, not distinguishable from zero (±1 Ĺ/day). Of the nitrides examined, CrN appears to be the most corrosion resistant under acidic conditions. None of the nitrides studied are corrosion resistant under alkaline conditions. - Graphical abstract: Corrosion behavior of mesoporous transition metal nitrides (TM=Nb, V, Cr and Ti) in acidic and alkaline solutions at 80 °C for 2 weeks. Display Omitted - highlights: • Corrosion rates of mesoporous transition metal nitrides in aqueous solution is reported. • The mesoporous TMNs had surface areas of 25–60 m{sup 2}/g. • CrN is the most corrosion resistant under the conditions studied.

Yang, Minghui, E-mail: m.yang@cornell.edu [Department of Chemistry, Cornell University, Ithaca 14853-1301, NY (United States); Allen, Amy J.; Nguyen, Minh T. [Department of Chemistry, Cornell University, Ithaca 14853-1301, NY (United States); Ralston, Walter T. [College of Chemistry, University of California, Berkeley 94720-1460, CA (United States); MacLeod, Michelle J. [Department of Chemistry, Massachusetts Institute of Technology, Cambridge 02139-4307, MA (United States); DiSalvo, Francis J., E-mail: fjd3@cornell.edu [Department of Chemistry, Cornell University, Ithaca 14853-1301, NY (United States)

2013-09-15T23:59:59.000Z

48

Suppression of bulk conductivity in InAs/GaSb broken gap composite quantum wells  

SciTech Connect

The two-dimensional topological insulator state in InAs/GaSb quantum wells manifests itself by topologically protected helical edge channel transport relying on an insulating bulk. This work investigates a way of suppressing bulk conductivity by using gallium source materials of different degrees of impurity concentrations. While highest-purity gallium is accompanied by clear conduction through the sample bulk, intentional impurity incorporation leads to a bulk resistance over 1 M?, independent of applied magnetic fields. In addition, ultra high electron mobilities for GaAs/AlGaAs structures fabricated in a molecular beam epitaxy system used for the growth of Sb-based samples are reported.

Charpentier, Christophe; Fält, Stefan; Reichl, Christian; Nichele, Fabrizio; Nath Pal, Atindra; Pietsch, Patrick; Ihn, Thomas; Ensslin, Klaus; Wegscheider, Werner [Laboratory for Solid State Physics, ETH Zürich, 8093 Zürich (Switzerland)] [Laboratory for Solid State Physics, ETH Zürich, 8093 Zürich (Switzerland)

2013-09-09T23:59:59.000Z

49

Photopolymerization of Self-Assembled Monolayers of Diacetylenic Alkylphosphonic Acids on Group-III Nitride Substrates  

Science Journals Connector (OSTI)

(1, 4-7) In addition, the selectivity and sensitivity of a nitrides-based sensor can be tailored by modifying the nitride’s surface with a thin layer that selectively recognizes chemical species of interest. ... However, ODPA SAMs desorbed from GaN substrates upon immersion in aqueous solution, especially in basic solution, probably reflecting the high solubility of deprotonated ODPA in the solution,(18) electrostatic repulsion between the negatively charged ODPA and substrate surface,(18) and/or the dissolution of the gallium oxide layer. ... Water contact angles on group-III nitride samples were measured using a PG-1 pocket contact angle goniometer by reading contact angle values of the two sides of a drop (2 ?L) within 30 s after deposition of the drop. ...

Feng Li; Evgeniy Shishkin; Michael A. Mastro; Jennifer K. Hite; Charles R. Eddy, Jr.; J. H. Edgar; Takashi Ito

2010-06-04T23:59:59.000Z

50

Metal Nitride and Metal Carbide Nanoparticles by a Soft Urea Pathway  

Science Journals Connector (OSTI)

It also worth noting that in the presence of the metal precursors, the solubility of urea (or similar compounds) is significantly higher than in pure ethanol (4.877 g/100 g at 18.2 °C), which already indicates the formation of soluble complexes and coordination polymers. ... HRTEM shown well-developed lattice fringes, with d = 2.43 Ĺ as interplanar distance, corresponding to the plane 101 of the hexagonal structures of gallium nitride (dcalcd = 2.43765 Ĺ, ref ICDD-PDF4+ 01?089?7522). ... (Oxy)nitrides as new photocatalysts for water splitting under visible light irradiation ...

Cristina Giordano; Christian Erpen; Weitang Yao; Bettina Milke; Markus Antonietti

2009-10-07T23:59:59.000Z

51

16 - Applications of Refractory Carbides and Nitrides  

Science Journals Connector (OSTI)

Publisher Summary This chapter reviews the applications of refractory carbides and nitrides in each of the following industrial categories: (1) automotive and aerospace, (2) industrial machinery and equipment, (3) cutting and grinding tools, (4) armor, (5) nuclear, (6) semiconductor, and (6) optical. Many of the automotive and aerospace applications of refractory carbides and nitrides are of a structural and chemical nature, especially in applications involving high temperature and/or corrosive environments where most metals are no longer suitable. These applications are usually in the bulk form and are made possible by recent advances in processing technology. Relatively large parts can now be produced to near-net shape with little machining required. Applications of refractory carbides and nitrides are found extensively in machinery and equipment for protection against wear, erosion, and chemical attack. Both bulk materials and coatings are used. The most important bulk material is tungsten carbide sintered with a metallic binder that is usually cobalt. Cutting and grinding tools are a special case of wear and corrosion applications. Cutting tools have a sharp edge for the purpose of shaving and generating a material chip. This edge must remain sharp for the tool to perform properly. Grinding tools are different in that they have an abrasive-coated surface that generates a powder as opposed to the chip of a cutting tool.

Hugh O. Pierson

1996-01-01T23:59:59.000Z

52

Local environment and composition of magnesium gallium layered...  

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

Local environment and composition of magnesium gallium layered double hydroxides determined from solid-state 1H and 71Ga NMR Local environment and composition of magnesium gallium...

53

Synthesis and characterization of visible emission from rare-earth doped aluminum nitride, gallium nitride and gallium aluminum nitride powders and thin films  

E-Print Network (OSTI)

74 (19) 2821 (1999). F. H. Spedding, Rare-earth Elements, inby the use of rare- earth elements as color emitters inpowders activated with rare-earth elements Eu 3+ , Tb 3+ ,

Tao, Jonathan Huai-Tse

2010-01-01T23:59:59.000Z

54

Synthesis and characterization of visible emission from rare-earth doped aluminum nitride, gallium nitride and gallium aluminum nitride powders and thin films  

E-Print Network (OSTI)

residential lighting using incandescent lights [2], as shownenergy used for the incandescent lamp is wasted as infraredlight source to replace incandescent lighting [1]. Figure

Tao, Jonathan Huai-Tse

2010-01-01T23:59:59.000Z

55

Catalytic hydrodesulfurization by molybdenum nitride  

SciTech Connect

High surface area molybdenum nitride (up to 108 m{sup 2}/g) was synthesized, characterized, and tested for thiophene desulfurization activity. The surface area was found to depend on synthesis temperature profile, mass transfer, and passivation procedure. Passivated and sulfided catalysts retained the bulk structure of face-centered-cubic Mo{sub 2}N. X-ray diffraction and Raman spectroscopy showed no evidence for MoO{sub 3} or MoS{sub 2} formation in fresh catalysts or catalysts sulfided at 673 K. Thiophene desulfurization activity was measured over a broad range Mo{sub 2}N surface areas and reactor condition. Small amounts of tetrahydrothiophene were formed during desulfurization and low-conversion data at 673 K indicate that butane is one of the initial products of the thiophene desulfurization reaction, in addition to butadiene and the butenes.

Markel, E.J.; Van Zee, J.W. (Univ. of South Carolina, Columbia (USA))

1990-12-01T23:59:59.000Z

56

Nitrided Metallic Bipolar Plates  

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

to meet 5000 h automotive durability goal at cost < 5kW Year 1 Goals: Single-cell fuel cell test performance for 25 cm 2 stamped and nitrided metallic bipolar plates...

57

Boron nitride nanotubes  

DOE Patents (OSTI)

Boron nitride nanotubes are prepared by a process which includes: (a) creating a source of boron vapor; (b) mixing the boron vapor with nitrogen gas so that a mixture of boron vapor and nitrogen gas is present at a nucleation site, which is a surface, the nitrogen gas being provided at a pressure elevated above atmospheric, e.g., from greater than about 2 atmospheres up to about 250 atmospheres; and (c) harvesting boron nitride nanotubes, which are formed at the nucleation site.

Smith, Michael W. (Newport News, VA); Jordan, Kevin (Newport News, VA); Park, Cheol (Yorktown, VA)

2012-06-06T23:59:59.000Z

58

Cryogenic gallium phosphide acousto-optic deflectors  

Science Journals Connector (OSTI)

We present measurements of the acoustic intensity in a gallium phosphide acousto-optic deflector for the 0.6–1.3-GHz frequency range and the 8–295-K temperature range. The data show a...

Fuss, Ian; Smart, Darryn

1991-01-01T23:59:59.000Z

59

Die Bestimmung von Kupfer- und Nickelspuren in Gallium  

Science Journals Connector (OSTI)

Nickel- und Kupferkontaminierungen in Gallium im ppm-Bereich und darunter stören empfindlich bei der Verwendung in der Halbleiterphysik. Der Chloridkomplex des Galliums in 6-n HC1 wird von einem stark basische...

H. Titze

1977-01-01T23:59:59.000Z

60

High Efficiency m-plane LEDs on Low Defect Density Bulk GaN Substrates  

SciTech Connect

Solid-state lighting is a key technology for reduction of energy consumption in the US and worldwide. In principle, by replacing standard incandescent bulbs and other light sources with sources based on light-emitting diodes (LEDs), ultimate energy efficiency can be achieved. The efficiency of LEDs has improved tremendously over the past two decades, however further progress is required for solid- state lighting to reach its full potential. The ability of an LED at converting electricity to light is quantified by its internal quantum efficiency (IQE). The material of choice for visible LEDs is Gallium Nitride (GaN), which is at the basis of blue-emitting LEDs. A key factor limiting the performance of GaN LEDs is the so-called efficiency droop, whereby the IQE of the LED decreases significantly at high current density. Despite decades of research, efficiency droop remains a major issue. Since high-current operation is necessary for practical lighting applications, reducing droop is a major challenge for the scientific community and the LED industry. Our approach to solving the droop issue is the use of newly available low-defect-density bulk GaN non-polar substrates. In contrast to the standard foreign substrates (sapphire, silicon carbide, silicon) used in the industry, we have employed native bulk GaN substrates with very low defect density, thus ensuring exquisite material quality and high IQE. Whereas all commercial LEDs are grown along the c-plane crystal direction of GaN, we have used m-plane non-polar substrates; these drastically modify the physical properties of the LED and enable a reduction of droop. With this approach, we have demonstrated very high IQE performance and low droop. Our results focused on violet and blue LEDs. For these, we have demonstrated very high peak IQEs and current droops of 6% and 10% respectively (up to a high current density of 200A.cm-2). All these results were obtained under electrical operation. These high IQE and low droop values are in line with the program’s milestones. They demonstrate that bulk non-polar GaN substrates represent a disruptive technology for LED performance. Application of this technology to real-world products is feasible, provided that the cost of GaN substrates is compatible with the market’s requirement.

David, Aurelien

2012-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "bulk gallium nitride" 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

GALLIUM--2000 30.1 By Deborah A. Kramer  

E-Print Network (OSTI)

the largest application for gallium, with optoelectronic devices [mostly laser diodes and light-use application for gallium, with 63% of total consumption. Optoelectronic devices accounted for 32% of domestic% of the gallium consumed in the United States was in the form of GaAs. GaAs was manufactured into optoelectronic

62

GALLIUM--1998 29.1 By Deborah A. Kramer  

E-Print Network (OSTI)

's) were the largest application for gallium, with optoelectronic devices [mostly laser diodes and light-use application for gallium, with 52% of total consumption. Optoelectronic devices accounted for 45% of domestic% of the gallium consumed in the United States was in the form of GaAs. GaAs was manufactured into optoelectronic

63

GALLIUM--1999 29.1 By Deborah A. Kramer  

E-Print Network (OSTI)

circuits (IC's) were the largest application for gallium, with optoelectronic devices [mostly laser diodes-use application for gallium, with 52% of total consumption. Optoelectronic devices accounted for 42% of domestic% of the gallium consumed in the United States was in the form of GaAs. GaAs was manufactured into optoelectronic

64

High-Efficiency Nitride-Based Photonic Crystal Light Sources  

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

The University of California Santa Barbara (UCSB) is maximizing the efficiency of a white LED by enhancing the external quantum efficiency using photonic crystals to extract light that would normally be confined in a conventional structure. Ultimate efficiency can only be achieved by looking at the internal structure of light. To do this, UCSB is focusing on maximizing the light extraction efficiency and total light output from light engines driven by Gallium Nitride (GaN)-based LEDs. The challenge is to engineer large overlap (interaction) between modes and photonic crystals. The project is focused on achieving high extraction efficiency in LEDs, controlled directionality of emitted light, integrated design of vertical device structure, and nanoscale patterning of lateral structure.

65

Helical nanotubes of hexagonal boron nitride  

Science Journals Connector (OSTI)

......Physical: Full-length Papers Helical nanotubes of hexagonal boron nitride Masami Terauchi...Hongo, Bunkyo-ku, Tokyo 113, Japan Nanotubes of hexagonal boron nitride (h-BN...discovered. hexagonal boron nitride,|nanotube,|nanoball,|amorphous boron| C......

Masami Terauchi; Michiyoshi Tanaka; Hirofumi Matsuda; Masatoshi Takeda; Kaoru Kimura

1997-01-01T23:59:59.000Z

66

Superplastic forging nitride ceramics  

DOE Patents (OSTI)

The invention relates to producing relatively flaw free silicon nitride ceramic shapes requiring little or no machining by superplastic forging This invention herein was made in part under Department of Energy Grant DE-AC01-84ER80167, creating certain rights in the United States Government. The invention was also made in part under New York State Science and Technology Grant SB1R 1985-10.

Panda, Prakash C. (Ithaca, NY); Seydel, Edgar R. (Ithaca, NY); Raj, Rishi (Ithaca, NY)

1988-03-22T23:59:59.000Z

67

Method for Plutonium-Gallium Separation by Anodic Dissolution of a Solid Plutonium-Gallium Alloy  

SciTech Connect

Purified plutonium and gallium are efficiently recovered from a solid plutonium-gallium (Pu-Ga) alloy by using an electrorefining process. The solid Pu-Ga alloy is the cell anode, preferably placed in a moving basket within the electrolyte. As the surface of the Pu-Ga anode is depleted in plutonium by the electrotransport of the plutonium to a cathode, the temperature of the electrolyte is sufficient to liquify the surface, preferably at about 500 C, resulting in a liquid anode layer substantially comprised of gallium. The gallium drips from the liquified surface and is collected below the anode within the electrochemical cell. The transported plutonium is collected on the cathode surface and is recovered.

Miller, William E.; Tomczuk, Zygmunt

1998-12-08T23:59:59.000Z

68

Hafnium nitride for hot carrier solar cells  

Science Journals Connector (OSTI)

Abstract Hot carrier solar cells is an attractive technology with the potential of reaching high energy conversion efficiencies approaching the thermodynamic limit of infinitely stacked multi-junction solar cells: 65% under one sun and 86% under maximally concentrated. The hot carrier solar cell is conceptually simple consisting of two key components: absorber and energy selective contacts. High efficiencies are achieved by minimising the energy lost to thermalisaton of hot photo-generated carriers while absorbing majority of the solar spectrum. For this to be achieved, energy selective contacts are required to allow the extraction of carriers fast enough at an energy level above the electronic band edge. It is critical for the absorber to be able to maintain a hot carrier population for a sufficiently long time period for the extraction of carriers while they are ‘hot’. Bulk materials with a large gap between acoustic and optical branches in the phonon dispersion are predicted to exhibit slow hot carrier thermalisation rates. Hafnium nitride is such a material with a large gap in its phonon dispersion and is identified as a potential material to be used as a hot carrier absorber. Hafnium nitride has been deposited using reactive sputtering and characterised to investigate material properties and carrier cooling rates.

Simon Chung; Santosh Shrestha; Xiaoming Wen; Yu Feng; Neeti Gupta; Hongze Xia; Pyng Yu; Jau Tang; Gavin Conibeer

2014-01-01T23:59:59.000Z

69

Functionalized boron nitride nanotubes  

DOE Patents (OSTI)

A plasma treatment has been used to modify the surface of BNNTs. In one example, the surface of the BNNT has been modified using ammonia plasma to include amine functional groups. Amine functionalization allows BNNTs to be soluble in chloroform, which had not been possible previously. Further functionalization of amine-functionalized BNNTs with thiol-terminated organic molecules has also been demonstrated. Gold nanoparticles have been self-assembled at the surface of both amine- and thiol-functionalized boron nitride Nanotubes (BNNTs) in solution. This approach constitutes a basis for the preparation of highly functionalized BNNTs and for their utilization as nanoscale templates for assembly and integration with other nanoscale materials.

Sainsbury, Toby; Ikuno, Takashi; Zettl, Alexander K

2014-04-22T23:59:59.000Z

70

Interactions of zircaloy cladding with gallium -- 1997 status  

SciTech Connect

A four phase program has been implemented to evaluate the effect of gallium in mixed oxide (MOX) fuel derived from weapons grade (WG) plutonium on Zircaloy cladding performance. The objective is to demonstrate that low levels of gallium will not compromise the performance of the MOX fuel system in LWR. This graded, four phase experimental program will evaluate the performance of prototypic Zircaloy cladding materials against: (1) liquid gallium (Phase 1), (2) various concentrations of Ga{sub 2}O{sub 3} (Phase 2), (3) centrally heated surrogate fuel pellets with expected levels of gallium (Phase 3), and (4) centrally heated prototypic MOX fuel pellets (Phase 4). This status report describes the results of an initial series of tests for phases 1 and 2. Three types of tests are being performed: (1) corrosion, (2) liquid metal embrittlement (LME), and (3) corrosion mechanical. These tests are designed to determine the corrosion mechanisms, thresholds for temperature and concentration of gallium that may delineate behavioral regimes, and changes in mechanical properties of Zircaloy. Initial results have generally been favorable for the use of WG-MOX fuel. The MOX fuel cladding, Zircaloy, does react with gallium to form intermetallic compounds at {ge} 300 C; however, this reaction is limited by the mass of gallium and is therefore not expected to be significant with a low level (in parts per million) of gallium in the MOX fuel. While continued migration of gallium into the initially formed intermetallic compound results in large stresses that can lead to distortion, this is also highly unlikely because of the low mass of gallium or gallium oxide present and expected clad temperatures below 400 C. Furthermore, no evidence for grain boundary penetration by gallium has been observed.

Wilson, D.F.; DiStefano, J.R.; King, J.F.; Manneschmidt, E.T.; Strizak, J.P.

1997-11-01T23:59:59.000Z

71

Interactions of Zircaloy cladding with gallium: 1998 midyear status  

SciTech Connect

A program has been implemented to evaluate the effect of gallium in mixed-oxide (MOX) fuel derived from weapons-grade (WG) plutonium on Zircaloy cladding performance. The objective is to demonstrate that low levels of gallium will not compromise the performance of the MOX fuel system in a light-water reactor. The graded, four-phase experimental program was designed to evaluate the performance of prototypic Zircaloy cladding materials against (1) liquid gallium (Phase 1), (2) various concentrations of Ga{sub 2}O{sub 3} (Phase 2), (3) centrally heated surrogate fuel pellets with expected levels of gallium (Phase 3), and (4) centrally heated prototypic MOX fuel pellets (Phase 4). This status report describes the results of a series of tests for Phases 1 and 2. Three types of tests are being performed: (1) corrosion, (2) liquid metal embrittlement, and (3) corrosion-mechanical. These tests will determine corrosion mechanisms, thresholds for temperature and concentration of gallium that may delineate behavioral regimes, and changes in the mechanical properties of Zircaloy. Initial results have generally been favorable for the use of WG-MOX fuel. The MOX fuel cladding, Zircaloy, does react with gallium to form intermetallic compounds at {ge}300 C; however, this reaction is limited by the mass of gallium and is therefore not expected to be significant with a low level (parts per million) of gallium in the MOX fuel. Although continued migration of gallium into the initially formed intermetallic compound can result in large stresses that may lead to distortion, this was shown to be extremely unlikely because of the low mass of gallium or gallium oxide present and expected clad temperatures below 400 C. Furthermore, no evidence for grain boundary penetration by gallium has been observed.

Wilson, D.F.; DiStefano, J.R.; Strizak, J.P.; King, J.F.; Manneschmidt, E.T.

1998-06-01T23:59:59.000Z

72

Cordierite silicon nitride filters  

SciTech Connect

The objective of this project was to develop a silicon nitride based crossflow filter. This report summarizes the findings and results of the project. The project was phased with Phase I consisting of filter material development and crossflow filter design. Phase II involved filter manufacturing, filter testing under simulated conditions and reporting the results. In Phase I, Cordierite Silicon Nitride (CSN) was developed and tested for permeability and strength. Target values for each of these parameters were established early in the program. The values were met by the material development effort in Phase I. The crossflow filter design effort proceeded by developing a macroscopic design based on required surface area and estimated stresses. Then the thermal and pressure stresses were estimated using finite element analysis. In Phase II of this program, the filter manufacturing technique was developed, and the manufactured filters were tested. The technique developed involved press-bonding extruded tiles to form a filter, producing a monolithic filter after sintering. Filters manufactured using this technique were tested at Acurex and at the Westinghouse Science and Technology Center. The filters did not delaminate during testing and operated and high collection efficiency and good cleanability. Further development in areas of sintering and filter design is recommended.

Sawyer, J.; Buchan, B. (Acurex Environmental Corp., Mountain View, CA (United States)); Duiven, R.; Berger, M. (Aerotherm Corp., Mountain View, CA (United States)); Cleveland, J.; Ferri, J. (GTE Products Corp., Towanda, PA (United States))

1992-02-01T23:59:59.000Z

73

High intensity x-ray source using liquid gallium target  

DOE Patents (OSTI)

A high intensity x-ray source that uses a flowing stream of liquid gallium as a target with the electron beam impinging directly on the liquid metal.

Smither, Robert K. (Hinsdale, IL); Knapp, Gordon S. (Cupertino, CA); Westbrook, Edwin M. (Chicago, IL); Forster, George A. (Westmont, IL)

1990-01-01T23:59:59.000Z

74

Vacancy-Induced Nanoscale Wire Structure in Gallium Selenide...  

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

(nanowires) in the compound gallium selenide. In short, ordered lines of structural vacancies in the material stimulate the growth of "one-dimensional" structures less than 1...

75

Study of nitrogen-rich titanium and zirconium nitride films  

SciTech Connect

Thin titanium nitride (TiN) and zirconium nitride (ZrN) films containing excess nitrogen up to 59 and 63 at. % N, respectively, were deposited on austenitic stainless-steel substrates by reactive triode ion plating at about 823 K. The film structure and surface chemistry were studied using x-ray diffraction, scanning Auger spectroscopy, and electron energy-loss spectroscopy (EELS). In TiN films only the face-centered-cubic mononitride phase was detected. The lattice parameter of the stoichiometric TiN film was larger than the corresponding bulk value and it increased with increasing nitrogen content. The lattice parameter of overstoichiometric ZrN films showed abnormal behavior when calculated from different diffracting planes. This behavior together with the EELS and other measurements indicate that a dielectric Zr/sub 3/N/sub 4/ phase was formed at overstoichiometric compositions.

Ristolainen, E.O.; Molarius, J.M.; Korhonen, A.S.; Lindroos, V.K.

1987-07-01T23:59:59.000Z

76

Analytic bond-order potential for the gallium arsenide system  

Science Journals Connector (OSTI)

An analytic, bond-order potential (BOP) is proposed and parametrized for the gallium arsenide system. The potential addresses primary (?) and secondary (?) bonding and the valence-dependent character of heteroatomic bonding, and it can be combined with an electron counting potential to address the distribution of electrons on the GaAs surface. The potential was derived from a tight-binding description of covalent bonding by retaining the first two levels of an expanded Green’s function for the ? and ? bond-order terms. Predictions using the potential were compared with independent estimates for the structures and binding energy of small clusters (dimers, trimers, and tetramers) and for various bulk lattices with coordinations varying from 4 to 12. The structure and energies of simple point defects and melting transitions were also investigated. The relative stabilities of the (001) surface reconstructions of GaAs were well predicted, especially under high-arsenic-overpressure conditions. The structural and binding energy trends of this GaAs BOP generally match experimental observations and ab initio calculations.

D. A. Murdick; X. W. Zhou; H. N. G. Wadley; D. Nguyen-Manh; R. Drautz; D. G. Pettifor

2006-01-20T23:59:59.000Z

77

Nitrides Race Beyond the Light  

Science Journals Connector (OSTI)

...are far from the limit,” Palacios says. Nitride transistors might also prove essential for a variety of future “smart grid” applications. First, however, they must be able to withstand transmitting large amounts of power, something silicon-based...

Robert F. Service

2010-03-26T23:59:59.000Z

78

Superplastic forging nitride ceramics  

DOE Patents (OSTI)

A process is disclosed for preparing silicon nitride ceramic parts which are relatively flaw free and which need little or no machining, said process comprising the steps of: (a) preparing a starting powder by wet or dry mixing ingredients comprising by weight from about 70% to about 99% silicon nitride, from about 1% to about 30% of liquid phase forming additive and from 1% to about 7% free silicon; (b) cold pressing to obtain a preform of green density ranging from about 30% to about 75% of theoretical density; (c) sintering at atmospheric pressure in a nitrogen atmosphere at a temperature ranging from about 1,400 C to about 2,200 C to obtain a density which ranges from about 50% to about 100% of theoretical density and which is higher than said preform green density, and (d) press forging workpiece resulting from step (c) by isothermally uniaxially pressing said workpiece in an open die without initial contact between said workpiece and die wall perpendicular to the direction of pressing and so that pressed workpiece does not contact die wall perpendicular to the direction of pressing, to substantially final shape in a nitrogen atmosphere utilizing a temperature within the range of from about 1,400 C to essentially 1,750 C and strain rate within the range of about 10[sup [minus]7] to about 10[sup [minus]1] seconds[sup [minus]1], the temperature and strain rate being such that surface cracks do not occur, said pressing being carried out to obtain a shear deformation greater than 30% whereby superplastic forging is effected.

Panda, P.C.; Seydel, E.R.; Raj, R.

1988-03-22T23:59:59.000Z

79

Inhibition of Protein Tyrosine Phosphatase by the Antitumor Agent Gallium Nitrate  

Science Journals Connector (OSTI)

...Gallium is known to bind to the iron transport protein transferrin...NSC 166828. gallium, tris(acetylacetonate). The gallium nitrate:transferrin...the binding of gallium to the iron transport protein transferrin...and incorporation into the iron storage protein ferritin...

Margareta M. Berggren; Leigh Ann Burns; Robert T. Abraham; and Garth Powis

1993-04-15T23:59:59.000Z

80

Boron Nitride Porous Microbelts for Hydrogen Storage  

Science Journals Connector (OSTI)

Boron Nitride Porous Microbelts for Hydrogen Storage ... However, the attention paid to their potential applications in gas sorption, especially in case of hydrogen, has obviously been insufficient. ... boron nitride; porous; microbelts; specific surface area; hydrogen storage ...

Qunhong Weng; Xuebin Wang; Chunyi Zhi; Yoshio Bando; Dmitri Golberg

2013-01-09T23:59:59.000Z

Note: This page contains sample records for the topic "bulk gallium nitride" 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

Growth Kinetics and Doping of Gallium Nitride Grown by rf-Plasma Assisted Molecular Beam Epitaxy  

E-Print Network (OSTI)

Thomas H. Myers, Ph.D., Chair Larry E. Halliburton, Ph.D. Nancy C. Giles, Ph.D. Charter D. Stinespring Giles, Dr. Charter Stinespring, Dr. Larry Halliburton, and Dr. Mohindar Seehra. In addition, I would

Myers, Tom

82

Unusual strategies for using indium gallium nitride grown on silicon (111) for solid-state lighting  

Science Journals Connector (OSTI)

...lighting research and development: Multi-year program plan) ( US DoE , Washington, DC ) Available from http://www1.eere.energy.gov/buildings/ssl/techroadmaps.html . 6 Karlicek RF Jr ( 2005 ) Conference on Lasers and Electro-optics...

Hoon-sik Kim; Eric Brueckner; Jizhou Song; Yuhang Li; Seok Kim; Chaofeng Lu; Joshua Sulkin; Kent Choquette; Yonggang Huang; Ralph G. Nuzzo; John A. Rogers

2011-01-01T23:59:59.000Z

83

Unusual strategies for using indium gallium nitride grown on silicon (111) for solid-state lighting  

Science Journals Connector (OSTI)

...of Materials Science and Engineering...Mechanical and Aerospace Engineering...energy. Further advances in this technology...that extend our recent work in flexible electronics...of Materials Sciences under Award...funded by National Science Foundation...energy. Further advances in this technology...

Hoon-sik Kim; Eric Brueckner; Jizhou Song; Yuhang Li; Seok Kim; Chaofeng Lu; Joshua Sulkin; Kent Choquette; Yonggang Huang; Ralph G. Nuzzo; John A. Rogers

2011-01-01T23:59:59.000Z

84

Radiation-Hardened Gallium Nitride Detector and Arrays for Fusion Diagnostics  

SciTech Connect

This poster reports testing to confirm that GaN devices exhibit the extreme radiation hardness needed for use at the NIF, functioning properly after 1x10{sup 12} protons/cm{sup 2} proton irradiation in one year.

Sun, K. X., and MacNeil, L.

2011-09-08T23:59:59.000Z

85

Professor Mathias Schubert explains his study of indium gallium nitride semiconductor systems, which  

E-Print Network (OSTI)

generation of multiple-junction solar energy conversion devices with improved ease of manufacture, cost within a sample. Conversely, the blue light-emitting diodes (LEDs) intended for transferring from energy free charge carrier properties in contact- based electrical measurements, in the extreme case

Farritor, Shane

86

Temperature dependence of plasmonic terahertz absorption in grating-gate gallium-nitride transistor structures  

Science Journals Connector (OSTI)

Strong plasmon resonances have been observed in the terahertz transmission spectra (1–5 THz) of large-area slit-grating-gate AlGaN/GaN-based high-electron-mobility transistor(HEMT) structures at temperatures from 10 to 170 K. The resonance frequencies correspond to the excitation of plasmons with wave vectors equal to the reciprocal lattice vectors of the metal grating which serves both as a gate electrode for the HEMT and a coupler between plasmons and incident terahertz radiation. Wide tunability of the resonances by the applied gate voltage demonstrates potential of these devices for terahertz applications.

A. V. Muravjov; D. B. Veksler; V. V. Popov; O. V. Polischuk; N. Pala; X. Hu; R. Gaska; H. Saxena; R. E. Peale; M. S. Shur

2010-01-01T23:59:59.000Z

87

Picosecond response of gallium-nitride metal–semiconductor–metal photodetectors  

Science Journals Connector (OSTI)

Metal–semiconductor–metal ultraviolet photodiodes fabricated on GaN were tested in the picosecond regime with an electro-optic sampling system. A device with a feature size of 1 ?m showed a response with 1.4 ps rise time and 3.5 ps full width at half maximum. The derived electron velocity 1.43×10 7 ? cm/s is in good agreement with independent photoexcitation measurements. A slower impulse response was observed in a device with smaller feature size of 0.5?? m .

Jianliang Li; Ying Xu; T. Y. Hsiang; W. R. Donaldson

2004-01-01T23:59:59.000Z

88

Control of the emission wavelength of gallium nitride-based nanowire light-emitting diodes.  

E-Print Network (OSTI)

??Halbleiter-Nanosäulen (auch -Nanodrähte) werden als Baustein für Leuchtdioden (LEDs) untersucht. Herkömmliche LEDs aus Galliumnitrid (GaN) bestehen aus mehreren Kristallschichten auf einkristallinen Substraten. Ihr Leistungsvermögen wird… (more)

Wölz, Martin

2013-01-01T23:59:59.000Z

89

Process for making transition metal nitride whiskers  

DOE Patents (OSTI)

A process for making metal nitrides, particularly titanium nitride whiskers, using a cyanide salt as a reducing agent for a metal compound in the presence of an alkali metal oxide. Sodium cyanide, various titanates and titanium oxide mixed with sodium oxide react to provide titanium nitride whiskers that can be used as reinforcement to ceramic composites. 1 fig., 1 tab.

Bamberger, C.E.

1988-04-12T23:59:59.000Z

90

15 - Processing of Refractory Carbides and Nitrides (Coatings)  

Science Journals Connector (OSTI)

Publisher Summary This chapter reviews the coating processes of refractory carbides and nitrides. Coatings of refractory carbides and nitrides have great industrial importance with a wide range of applications in semiconductors and other electronic components, in cutting tools, gas-turbine vanes and blades, precision bearings, punch sets, extruders, prostheses, and many other products. The surface of a material may be exposed to wear, corrosion, radiation, electrical or magnetic fields, and other phenomena and hence, it must have the ability to withstand these environments. This can be accomplished by coating the base material to obtain a composite in which the surface properties may be considerably different from those of the substrate. Chemical vapor deposition (CVD) and physical vapor deposition (PVD) belong to the class of vapor-transfer processes, which are atomistic in nature—that is, the deposition species are atoms or molecules or a combination of these. The coatings are also commonly known as thin-films when their thickness is less than 10 ?m. CVD is a versatile process that is well adapted to the production of all the refractory carbides and nitrides, not only as coatings but also as powders, bulk/monolithic components, and fibers. It may be defined as the deposition of a solid on a heated surface from a chemical reaction in the vapor phase.

Hugh O. Pierson

1996-01-01T23:59:59.000Z

91

Compatibility of ITER candidate structural materials with static gallium  

SciTech Connect

Tests were conducted on the compatibility of gallium with candidate structural materials for the International Thermonuclear Experimental Reactor, e.g., Type 316 SS, Inconel 625, and Nb-5 Mo-1 Zr alloy, as well as Armco iron, Nickel 270, and pure chromium. Type 316 stainless steel is least resistant to corrosion in static gallium and Nb-5 Mo-1 Zr alloy is most resistant. At 400{degrees}C, corrosion rates are {approx}4.0, 0.5, and 0.03 mm/yr for type 316 SS, Inconel 625, and Nb-5 Mo- 1 Zr alloy, respectively. The pure metals react rapidly with gallium. In contrast to findings in earlier studies, pure iron shows greater corrosion than nickel. The corrosion rates at 400{degrees}C are {ge}88 and 18 mm/yr, respectively, for Armco iron and Nickel 270. The results indicate that at temperatures up to 400{degrees}C, corrosion occurs primarily by dissolution and is accompanied by formation of metal/gallium intermetallic compounds. The solubility data for pure metals and oxygen in gallium are reviewed. The physical, chemical, and radioactive properties of gallium are also presented. The supply and availability of gallium, as well as price predictions through the year 2020, are summarized.

Luebbers, P.R.; Michaud, W.F.; Chopra, O.K.

1993-12-01T23:59:59.000Z

92

Behavior of Zircaloy Cladding in the Presence of Gallium  

SciTech Connect

The U.S. Department of Energy has established a dual-track approach to the disposition of plutonium arising from the dismantling of nuclear weapons. Both immobilization and reactor-based mixed-oxide (MOX) fuel technologies are being evaluated. The reactor-based MOX fuel option requires assessment of the potential impact of concentrations of gallium (on the order of 1 to 10 ppm), not present in conventional MOX fuel, on cladding material performance. An experimental program was designed to evaluate the performance of prototypic Zircaloy cladding materials against (1) liquid gallium, and (2) various concentrations of G~03. Three types of tests were performed: (1) corrosion, (2) liquid metal embrittlement, and (3) corrosion-mechanical. These tests were to determine corrosion mechanisms, thresholds for temperature and concentration of gallium that delineate behavioral regimes, and changes in the mechanical properties of Zircaloy. Results have generally been favorable for the use of weapons-grade (WG) MOX fhel. The Zircaloy cladding does react with gallium to form intermetallic compounds at >3000 C; however, this reaction is limited by the mass of gallium and is therefore not expected to be significant with a low level (parts per million) of gallium in the MOX fuel. Furthermore, no evidence for grain boundary penetration by gallium or liquid metal embrittlement was observed.

DiStefano, J.R.; King, J.F.; Manneschmidt, E.T.; Strizak, J.P.; Wilson, D.F.

1998-09-28T23:59:59.000Z

93

(Data in kilograms of gallium content unless otherwise noted) Domestic Production and Use: No domestic primary (crude, unrefined) gallium was recovered in 2013. Globally,  

E-Print Network (OSTI)

% of the gallium consumed was used in integrated circuits (ICs). Optoelectronic devices, which include laser diodes of the remaining gallium consumption. Optoelectronic devices were used in aerospace applications, consumer goods

94

CX-010873: Categorical Exclusion Determination  

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

Ammonothermal Bulk Gallium Nitride Crystal Growth for Energy Efficient Lightning and Power Electronics CX(s) Applied: B3.6 Date: 05/22/2013 Location(s): California Offices(s): Advanced Research Projects Agency-Energy

95

Role of gallium-67 in the clinical evaluation of cancer  

SciTech Connect

This review is based primarily on historic data, and it examines the indications for and limitations of gallium-67 scanning in the evaluation of patients with neoplasms. The use of gallium-67 scans is discussed according to tumor type, and data from the most representative and comprehensive studies are included. The results described, some of which were obtained primarily with older imaging techniques, should be regarded as representing the minimum that can be expected from application of this imaging procedure.

Bekerman, C.; Hoffer, P.B.; Bitran, J.D.

1984-10-01T23:59:59.000Z

96

Self-aligned submicron gate length gallium arsenide MESFET  

E-Print Network (OSTI)

SELF-ALIGNED SUBMICRON GATE LENGTH GALLIUM ARSENIDE MESFET A Thesis by HSIEN-CHING HUANG Submitted to the Graduate College of Texas ASSAM University in partial fulfillment of the requirement for the degree ol' MASTER OF SCIENCE May 1987... Major Subject: Electrical Engineering SELF-ALIGNED SUBMICRON GATE LENGTH GALLIUM ARSENIDE MESFET A Thesis by HSIEN-CHING HUANG Approved as to style and content by: Mark. H. Weichold (Chairman of Committee) Donald L. Parker (Member) dali L...

Huang, Hsien-Ching

2012-06-07T23:59:59.000Z

97

It's Elemental - Isotopes of the Element Gallium  

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

Zinc Zinc Previous Element (Zinc) The Periodic Table of Elements Next Element (Germanium) Germanium Isotopes of the Element Gallium [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 69 60.108% STABLE 71 39.892% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 56 No Data Available Proton Emission (suspected) No Data Available 57 No Data Available Proton Emission (suspected) No Data Available 58 No Data Available Proton Emission (suspected) No Data Available 59 No Data Available Proton Emission (suspected) No Data Available 60 70 milliseconds Electron Capture 98.40%

98

Cavity optomechanics in gallium phosphide microdisks  

SciTech Connect

We demonstrate gallium phosphide (GaP) microdisk optical cavities with intrinsic quality factors >2.8?×?10{sup 5} and mode volumes <10(?/n){sup 3}, and study their nonlinear and optomechanical properties. For optical intensities up to 8.0?×?10{sup 4} intracavity photons, we observe optical loss in the microcavity to decrease with increasing intensity, indicating that saturable absorption sites are present in the GaP material, and that two-photon absorption is not significant. We observe optomechanical coupling between optical modes of the microdisk around 1.5??m and several mechanical resonances, and measure an optical spring effect consistent with a theoretically predicted optomechanical coupling rate g{sub 0}/2??30?kHz for the fundamental mechanical radial breathing mode at 488?MHz.

Mitchell, Matthew; Barclay, Paul E., E-mail: pbarclay@ucalgary.ca [Institute for Quantum Science and Technology, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); National Institute for Nanotechnology, 11421 Saskatchewan Dr. NW, Edmonton, Alberta T6G 2M9 (Canada); Hryciw, Aaron C. [National Institute for Nanotechnology, 11421 Saskatchewan Dr. NW, Edmonton, Alberta T6G 2M9 (Canada)

2014-04-07T23:59:59.000Z

99

Hanford ETR Bulk Vitrification System - Demonstration Bulk Vitrification  

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

Bulk Vitrification System - Demonstration Bulk Bulk Vitrification System - Demonstration Bulk Vitrification System (DBVS) Review Report Hanford ETR Bulk Vitrification System - Demonstration Bulk Vitrification System (DBVS) Review Report Full Document and Summary Versions are available for download Hanford ETR Bulk Vitrification System - Demonstration Bulk Vitrification System (DBVS) Review Report Summary - Demonstration Bulk Vitrification System (DBVS) for Low-Actvity Waste at Hanford More Documents & Publications Independent Oversight Activity Report, Hanford Waste Treatment and Immobilization Plant - November 2013 SRS Tank 48H Waste Treatment Project Technology Readiness Assessment External Technical Review for Evaluation of System Level Modeling and Simulation Tools in Support of Hanford Site Liquid Waste Process

100

Nitrided Metallic Bipolar Plates | Department of Energy  

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

Nitrided Metallic Bipolar Plates Mass Production Cost Estimation for Direct H2 PEM Fuel Cell Systems for Automotive Applications: 2010 Update Mass Production Cost Estimation...

Note: This page contains sample records for the topic "bulk gallium nitride" 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

Nanostructure, Chemistry and Crystallography of Iron Nitride...  

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

Nanostructure, Chemistry and Crystallography of Iron Nitride Magnetic Materials by Ultra-High-Resolution Electron Microscopy and Related Methods Nanostructure, Chemistry and...

102

Multifunctional bulk plasma source based on discharge with electron injection  

SciTech Connect

A bulk plasma source, based on a high-current dc glow discharge with electron injection, is described. Electron injection and some special design features of the plasma arc emitter provide a plasma source with very long periods between maintenance down-times and a long overall lifetime. The source uses a sectioned sputter-electrode array with six individual sputter targets, each of which can be independently biased. This discharge assembly configuration provides multifunctional operation, including plasma generation from different gases (argon, nitrogen, oxygen, acetylene) and deposition of composite metal nitride and oxide coatings.

Klimov, A. S.; Medovnik, A. V. [Tomsk State University of Control Systems and Radioelectronics, Tomsk 634050 (Russian Federation); Tyunkov, A. V. [Tomsk State University of Control Systems and Radioelectronics, Tomsk 634050 (Russian Federation); Institute of High Current Electronics, Tomsk 634055 (Russian Federation); Savkin, K. P.; Shandrikov, M. V.; Vizir, A. V. [Institute of High Current Electronics, Tomsk 634055 (Russian Federation)

2013-01-15T23:59:59.000Z

103

Process for forming pure silver ohmic contacts to N- and P-type gallium arsenide materials  

DOE Patents (OSTI)

Disclosed is an improved process for manufacturing gallium arsenide semiconductor devices having as its components a n-type gallium arsenide substrate layer and a p-type gallium arsenide diffused layer. The improved process comprises forming a pure silver ohmic contact to both the diffuse layer and the substrate layer wherein the n-type layer comprises a substantially low doping carrier concentration.

Hogan, S.J.

1983-03-13T23:59:59.000Z

104

Gallium based low-interaction anions  

DOE Patents (OSTI)

The present invention provides: a composition of the formula M.sup.+x (Ga(Y).sub.4.sup.-).sub.x where M is a metal selected from the group consisting of lithium, sodium, potassium, cesium, calcium, strontium, thallium, and silver, x is an integer selected from the group consisting of 1 or 2, each Y is a ligand selected from the group consisting of aryl, alkyl, hydride and halide with the proviso that at least one Y is a ligand selected from the group consisting of aryl, alkyl and halide; a composition of the formula (R).sub.x Q.sup.+ Ga(Y).sub.4.sup.- where Q is selected from the group consisting of carbon, nitrogen, sulfur, phosphorus and oxygen, each R is a ligand selected from the group consisting of alkyl, aryl, and hydrogen, x is an integer selected from the group consisting of 3 and 4 depending upon Q, and each Y is a ligand selected from the group consisting of aryl, alkyl, hydride and halide with the proviso that at least one Y is a ligand selected from the group consisting of aryl, alkyl and halide; an ionic polymerization catalyst composition including an active cationic portion and a gallium based weakly coordinating anion; and bridged anion species of the formula M.sup.+x.sub.y [X(Ga(Y.sub.3).sub.z ].sup.-y.sub.x where M is a metal selected from the group consisting of lithium, sodium, potassium, magnesium, cesium, calcium, strontium, thallium, and silver, x is an integer selected from the group consisting of 1 or 2, X is a bridging group between two gallium atoms, y is an integer selected from the group consisting 1 and 2, z is an integer of at least 2, each Y is a ligand selected from the group consisting of aryl, alkyl, hydride and halide with the proviso that at least one Y is a ligand selected from the group consisting of aryl, alkyl and halide.

King, Wayne A. (Santa Fe, NM); Kubas, Gregory J. (Santa Fe, NM)

2000-01-01T23:59:59.000Z

105

Bamboo-like boron nitride nanotubes  

Science Journals Connector (OSTI)

......Full-length paper Bamboo-like boron nitride nanotubes Renzhi Ma Yoshio Bando Tadao Sato To...305-0044, Japan Bamboo-like boron nitride nanotubes (BN-NTs), synthesized from melamine...the temperature gradient applied in the nanotube growth process was considered as the......

Renzhi Ma; Yoshio Bando; Tadao Sato

2002-03-01T23:59:59.000Z

106

Molten-Salt-Based Growth of Group III Nitrides  

DOE Patents (OSTI)

A method for growing Group III nitride materials using a molten halide salt as a solvent to solubilize the Group-III ions and nitride ions that react to form the Group III nitride material. The concentration of at least one of the nitride ion or Group III cation is determined by electrochemical generation of the ions.

Waldrip, Karen E. (Albuquerque, NM); Tsao, Jeffrey Y. (Albuquerque, NM); Kerley, Thomas M. (Albuquerque, NM)

2008-10-14T23:59:59.000Z

107

E-Print Network 3.0 - amorphous silicon nitride Sample Search...  

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

nitride, aluminium oxide, titanium nitride are promising materials for the high... of powder analysis made by the following processes: - Preparation of silicon nitride by...

108

Aluminum Nitride Micro-Channels Grown via Metal Organic Vapor Phase Epitaxy for MEMs Applications  

SciTech Connect

Aluminum nitride (AlN) is a promising material for a number of applications due to its temperature and chemical stability. Furthermore, AlN maintains its piezoelectric properties at higher temperatures than more commonly used materials, such as Lead Zirconate Titanate (PZT) [1, 2], making AlN attractive for high temperature micro and nanoelectromechanical (MEMs and NEMs) applications including, but not limited to, high temperature sensors and actuators, micro-channels for fuel cell applications, and micromechanical resonators. This work presents a novel AlN micro-channel fabrication technique using Metal Organic Vapor Phase Epitaxy (MOVPE). AlN easily nucleates on dielectric surfaces due to the large sticking coefficient and short diffusion length of the aluminum species resulting in a high quality polycrystalline growth on typical mask materials, such as silicon dioxide and silicon nitride [3,4]. The fabrication process introduced involves partially masking a substrate with a silicon dioxide striped pattern and then growing AlN via MOVPE simultaneously on the dielectric mask and exposed substrate. A buffered oxide etch is then used to remove the underlying silicon dioxide and leave a free standing AlN micro-channel. The width of the channel has been varied from 5 ěm to 110 ěm and the height of the air gap from 130 nm to 800 nm indicating the stability of the structure. Furthermore, this versatile process has been performed on (111) silicon, c-plane sapphire, and gallium nitride epilayers on sapphire substrates. Reflection High Energy Electron Diffraction (RHEED), Atomic Force Microscopy (AFM), and Raman measurements have been taken on channels grown on each substrate and indicate that the substrate is influencing the growth of the AlN micro-channels on the SiO2 sacrificial layer.

Rodak, L.E.; Kuchibhatla, S.; Famouri, P.; Ting, L.; Korakakis, D.

2008-01-01T23:59:59.000Z

109

Bulk Hydrogen Strategic Directions for  

E-Print Network (OSTI)

Bulk Hydrogen Storage Strategic Directions for Hydrogen Delivery Workshop May 7-8, 2003 Crystal City, Virginia #12;Breakout Session - Bulk Hydrogen Storage Main Themes/Caveats Bulk Storage = Anything storage is an economic solution to address supply/demand imbalance #12;Breakout Session - Bulk Hydrogen

110

Synthesis of transition metal nitride by nitridation of metastable oxide precursor  

SciTech Connect

Metastable transition metal oxides were used as precursors to synthesize transition metal nitrides at low temperature. Amorphous MoO{sub 2} was prepared by reduction of (NH{sub 4}){sub 6}Mo{sub 7}O{sub 24} solution with hydrazine. As-synthesized amorphous MoO{sub 2} was transformed into fcc {gamma}-Mo{sub 2}N at 400 Degree-Sign C and then into hexagonal {delta}-MoN by further increasing the temperature to 600 Degree-Sign C under a NH{sub 3} flow. The nitridation temperature employed here is much lower than that employed in nitridation of crystalline materials, and the amorphous materials underwent a unique nitridation process. Besides this, the bimetallic nitride Ni{sub 2}Mo{sub 3}N was also synthesized by nitridating amorphous bimetallic precursor. These results suggested that the nitridation of amorphous precursor possessed potential to be a general method for synthesizing many interstitial metallic compounds, such as nitrides and carbides at low temperature. - graphical abstract: Amorphous oxide was used as new precursor to prepare nitride at low temperature. Pure {gamma}-Mo{sub 2}N and {delta}-MoN were obtained at 400 Degree-Sign C and at 600 Degree-Sign C, respectively. Highlights: Black-Right-Pointing-Pointer We bring out a new method to synthesize transition metal nitrides at low temperature. Black-Right-Pointing-Pointer Both mono- and bimetallic molybdenum nitrides were synthesized at a mild condition. Black-Right-Pointing-Pointer The formation of two different molybdenum nitrides {gamma}-Mo{sub 2}N and {delta}-MoN can be controlled from the same metastable precursor. Black-Right-Pointing-Pointer The nitridation temperature was much lower than that reported from crystalline precursors. Black-Right-Pointing-Pointer The metastable precursor had different reaction process in comparison with crystalline precursor.

Wang, Huamin; Wu, Zijie; Kong, Jing [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China)] [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China); Wang, Zhiqiang, E-mail: zqwang@mail.nankai.edu.cn [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China) [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China); Tianjin Key Laboratory of Water Environment and Resources, Tianjin Normal University, No. 393 Binshui Road, Xiqing Dist., Tianjin 300387 (China); Zhang, Minghui, E-mail: zhangmh@nankai.edu.cn [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China)] [Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071 (China)

2012-10-15T23:59:59.000Z

111

Compressibilities and phonon spectra of high-hardness transition metal-nitride materials  

SciTech Connect

We report compressibilities measured by synchrotron X-ray diffraction and phonon spectra from Raman scattering at high pressure in the diamond anvil cell (DAC) for cubic transition metal nitrides TiN{sub 1-x}, {gamma}-Mo{sub 2}N and VN{sub x}. The high-hardness metal nitride compounds have large values of the bulk modulus. B1-structured nitrides normally have no allowed first-order Raman spectra. However, they exhibit broad bands that reflect the vibrational density of states g({omega}) associated with breakdown of q=0 selection rules because of the presence of N{sup 3-} vacancies on anion sites. Peaks in g({omega}) at low frequency are identified with the longitudinal and transverse acoustic (TA) branches. The maximum in the TA band is correlated with the superconducting transition temperature in these materials (T{sub c}). In situ Raman scattering measurements in the DAC thus permit predictions of the T{sub c} variation with pressure for cubic nitrides and isostructural carbide materials.

Shebanova, O.; Soignard, E.; Mcmillan, P.F. (ASU); (UCL)

2010-01-20T23:59:59.000Z

112

Auctioning Bulk Mobile Messages  

Science Journals Connector (OSTI)

The search for enablers of continued growth of SMS traffic, as well as the take-off of the more diversified MMS message contents, open up for enterprises the potential of bulk use of mobile messaging, instead of essentially one-by-one use. In parallel, ... Keywords: EMS, MMS, SMS, auctions, mobile commerce, mobile operators, multi-attribute auctions

S. Meij; L. -F. Pau

2006-05-01T23:59:59.000Z

113

GALLIUM--1997 29.1 By Deborah A. Kramer  

E-Print Network (OSTI)

As is manufactured into optoelectronic devices (LED's, laser diodes, photodetectors, and solar cells) and integrated consumption. Optoelectronic devices accounted for 44% of domestic consumption, and the remaining 7% was used by imports, primarily high-purity gallium from France and low-purity material from Russia. Optoelectronic

114

Sputtering of tin and gallium-tin clusters  

SciTech Connect

Tin and gallium-tin clusters have been produced by 4 keV Ar{sup +} ion bombardment of polycrystalline tin and the gallium-tin eutectic alloy and analyzed by time-of-flight mass spectrometry. The sputtered neutral species were photoionized with 193 nm (6.4 eV) excimer laser light. Neutral tin clusters containing up to 10 atoms and mixed gallium-tin clusters Ga{sub (n-m)}Sn{sub m} with n {<=} 4 for the neutrals and N {<=} 3 for the sputtered ionic species have been detected. Laser power density dependent intensity measurements, relative yields, and kinetic energy distributions have been measured. The abundance distributions of the mixed clusters have been found to be nonstatistical due to significant differences in the ionization efficiencies for clusters with equal nuclearity but different number of tin atoms. The results indicate that Ga{sub 2}Sn and Ga{sub 3}Sn like the all-gallium clusters have ionization potentials below 6.4 eV. In the case of Sn{sub 5}, Sn{sub 6}, GaSn and Ga{sub (n-m)}Sn{sub m} clusters with n=2 to 4 and m>1, the authors detect species that have sufficient internal energy to be one photon ionized despite ionization potentials that are higher 6.4 eV. The tin atom signal that is detected can be attributed to photofragmentation of dimers for both sputtering from polycrystalline tin and from the gallium-tin eutectic alloy.

Lill, T.; Calaway, W.F.; Ma, Z.; Pellin, M.J.

1994-08-01T23:59:59.000Z

115

Self- and zinc diffusion in gallium antimonide  

SciTech Connect

The technological age has in large part been driven by the applications of semiconductors, and most notably by silicon. Our lives have been thoroughly changed by devices using the broad range of semiconductor technology developed over the past forty years. Much of the technological development has its foundation in research carried out on the different semiconductors whose properties can be exploited to make transistors, lasers, and many other devices. While the technological focus has largely been on silicon, many other semiconductor systems have applications in industry and offer formidable academic challenges. Diffusion studies belong to the most basic studies in semiconductors, important from both an application as well as research standpoint. Diffusion processes govern the junctions formed for device applications. As the device dimensions are decreased and the dopant concentrations increased, keeping pace with Moore's Law, a deeper understanding of diffusion is necessary to establish and maintain the sharp dopant profiles engineered for optimal device performance. From an academic viewpoint, diffusion in semiconductors allows for the study of point defects. Very few techniques exist which allow for the extraction of as much information of their properties. This study focuses on diffusion in the semiconductor gallium antimonide (GaSb). As will become clear, this compound semiconductor proves to be a powerful one for investigating both self- and foreign atom diffusion. While the results have direct applications for work on GaSb devices, the results should also be taken in the broader context of III-V semiconductors. Results here can be compared and contrasted to results in systems such as GaAs and even GaN, indicating trends within this common group of semiconductors. The results also have direct importance for ternary and quaternary semiconductor systems used in devices such as high speed InP/GaAsSb/InP double heterojunction bipolar transistors (DHBT) [Dvorak, (2001)]. Many of the findings which will be reported here were previously published in three journal articles. Hartmut Bracht was the lead author on two articles on self-diffusion studies in GaSb [Bracht, (2001), (2000)], while this report's author was the lead author on Zn diffusion results [Nicols, (2001)]. Much of the information contained herein can be found in those articles, but a more detailed treatment is presented here.

Nicols, Samuel Piers

2002-03-26T23:59:59.000Z

116

Method of nitriding refractory metal articles  

DOE Patents (OSTI)

A method of nitriding a refractory-nitride forming metal or metalloid articles and composite articles. A consolidated metal or metalloid article or composite is placed inside a microwave oven and nitrogen containing gas is introduced into the microwave oven. The metal or metalloid article or composite is heated to a temperature sufficient to react the metal or metalloid with the nitrogen by applying a microwave energy within the microwave oven. The metal or metalloid article or composite is maintained at that temperature for a period of time sufficient to convert the article of metal or metalloid or composite to an article or composite of refractory nitride. In addition, a method of applying a coating, such as a coating of an oxide, a carbide, or a carbo-nitride, to an article of metal or metalloid by microwave heating.

Tiegs, Terry N. (Lenoir City, TN); Holcombe, Cressie E. (Knoxville, TN); Dykes, Norman L. (Oak Ridge, TN); Omatete, Ogbemi O. (Lagos, NG); Young, Albert C. (Flushing, NY)

1994-01-01T23:59:59.000Z

117

Method of nitriding refractory metal articles  

DOE Patents (OSTI)

A method of nitriding a refractory-nitride forming metal or metalloid articles and composite articles. A consolidated metal or metalloid article or composite is placed inside a microwave oven and nitrogen containing gas is introduced into the microwave oven. The metal or metalloid article or composite is heated to a temperature sufficient to react the metal or metalloid with the nitrogen by applying a microwave energy within the microwave oven. The metal or metalloid article or composite is maintained at that temperature for a period of time sufficient to convert the article of metal or metalloid or composite to an article or composite of refractory nitride. In addition, a method of applying a coating, such as a coating of an oxide, a carbide, or a carbo-nitride, to an article of metal or metalloid by microwave heating.

Tiegs, T.N.; Holcombe, C.E.; Dykes, N.L.; Omatete, O.O.; Young, A.C.

1994-03-15T23:59:59.000Z

118

Silicon nitride having a high tensile strength  

DOE Patents (OSTI)

A ceramic body is disclosed comprising at least about 80 w/o silicon nitride and having a mean tensile strength of at least about 800 MPa. 4 figs.

Pujari, V.K.; Tracey, D.M.; Foley, M.R.; Paille, N.I.; Pelletier, P.J.; Sales, L.C.; Willkens, C.A.; Yeckley, R.L.

1998-06-02T23:59:59.000Z

119

Low temperature route to uranium nitride  

DOE Patents (OSTI)

A method of preparing an actinide nitride fuel for nuclear reactors is provided. The method comprises the steps of a) providing at least one actinide oxide and optionally zirconium oxide; b) mixing the oxide with a source of hydrogen fluoride for a period of time and at a temperature sufficient to convert the oxide to a fluoride salt; c) heating the fluoride salt to remove water; d) heating the fluoride salt in a nitrogen atmosphere for a period of time and at a temperature sufficient to convert the fluorides to nitrides; and e) heating the nitrides under vacuum and/or inert atmosphere for a period of time sufficient to convert the nitrides to mononitrides.

Burrell, Anthony K. (Los Alamos, NM); Sattelberger, Alfred P. (Darien, IL); Yeamans, Charles (Berkeley, CA); Hartmann, Thomas (Idaho Falls, ID); Silva, G. W. Chinthaka (Las Vegas, NV); Cerefice, Gary (Henderson, NV); Czerwinski, Kenneth R. (Henderson, NV)

2009-09-01T23:59:59.000Z

120

The Nitrogen-Nitride Anode.  

SciTech Connect

Nitrogen gas N 2 can be reduced to nitride N -3 in molten LiCl-KCl eutectic salt electrolyte. However, the direct oxidation of N -3 back to N 2 is kinetically slow and only occurs at high overvoltage. The overvoltage for N -3 oxidation can be eliminated by coordinating the N -3 with BN to form the dinitridoborate (BN 2 -3 ) anion which forms a 1-D conjugated linear inorganic polymer with -Li-N-B-N- repeating units. This polymer precipitates out of solution as Li 3 BN 2 which becomes a metallic conductor upon delithiation. Li 3 BN 2 is oxidized to Li + + N 2 + BN at about the N 2 /N -3 redox potential with very little overvoltage. In this report we evaluate the N 2 /N -3 redox couple as a battery anode for energy storage.

Delnick, Frank M.

2014-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "bulk gallium nitride" 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.


121

Surface reactivity and oxygen migration in amorphous indium-gallium-zinc oxide films annealed in humid atmosphere  

SciTech Connect

An isotope tracer study, i.e., {sup 18}O/{sup 16}O exchange using {sup 18}O{sub 2} and H{sub 2}{sup 18}O, was performed to determine how post-deposition annealing (PDA) affected surface reactivity and oxygen diffusivity of amorphous indium–gallium–zinc oxide (a-IGZO) films. The oxygen tracer diffusivity was very high in the bulk even at low temperatures, e.g., 200?°C, regardless of PDA and exchange conditions. In contrast, the isotope exchange rate, dominated by surface reactivity, was much lower for {sup 18}O{sub 2} than for H{sub 2}{sup 18}O. PDA in a humid atmosphere at 400?°C further suppressed the reactivity of O{sub 2} at the a-IGZO film surface, which is attributable to –OH-terminated surface formation.

Watanabe, Ken, E-mail: Watanabe.Ken@nims.go.jp [International Center for Young Scientists (ICYS-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba 305-0044 (Japan)] [International Center for Young Scientists (ICYS-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba 305-0044 (Japan); Lee, Dong-Hee [Optical and Electronic Materials Unit, NIMS, 1-1 Namiki, Tsukuba 305-0044 (Japan) [Optical and Electronic Materials Unit, NIMS, 1-1 Namiki, Tsukuba 305-0044 (Japan); Materials and Structures Laboratory (MSL), Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan); Sakaguchi, Isao; Haneda, Hajime [Optical and Electronic Materials Unit, NIMS, 1-1 Namiki, Tsukuba 305-0044 (Japan)] [Optical and Electronic Materials Unit, NIMS, 1-1 Namiki, Tsukuba 305-0044 (Japan); Nomura, Kenji [Frontier Research Center, Tokyo Institute of Technology, Mailbox S2-13, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan)] [Frontier Research Center, Tokyo Institute of Technology, Mailbox S2-13, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan); Kamiya, Toshio [Materials and Structures Laboratory (MSL), Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan) [Materials and Structures Laboratory (MSL), Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan); Materials Research Center for Element Strategy (MCES), Mailbox S2-13, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan); Hosono, Hideo [Materials and Structures Laboratory (MSL), Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan) [Materials and Structures Laboratory (MSL), Tokyo Institute of Technology, Mailbox R3-4, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan); Frontier Research Center, Tokyo Institute of Technology, Mailbox S2-13, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan); Materials Research Center for Element Strategy (MCES), Mailbox S2-13, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan); Ohashi, Naoki, E-mail: Ohashi.Naoki@nims.go.jp [Optical and Electronic Materials Unit, NIMS, 1-1 Namiki, Tsukuba 305-0044 (Japan) [Optical and Electronic Materials Unit, NIMS, 1-1 Namiki, Tsukuba 305-0044 (Japan); Materials Research Center for Element Strategy (MCES), Mailbox S2-13, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan)

2013-11-11T23:59:59.000Z

122

E-Print Network 3.0 - arsenide- gallium instrument Sample Search...  

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

Summary: of gallium arsenide, a semiconductor, which is used in advanced optoelectronics, lasers, microwave circuits... , and solar cells. To determine material...

123

Boron-Nitride Nanotubes Show Potential in Cancer Treatment |...  

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

Boron-Nitride Nanotubes Show Potential in Cancer Treatment NEWPORT NEWS, VA, April 26 - A new study has shown that adding boron-nitride nanotubes to the surface of cancer cells can...

124

Superconductive silicon nanowires using gallium beam lithography.  

SciTech Connect

This work was an early career LDRD investigating the idea of using a focused ion beam (FIB) to implant Ga into silicon to create embedded nanowires and/or fully suspended nanowires. The embedded Ga nanowires demonstrated electrical resistivity of 5 m-cm, conductivity down to 4 K, and acts as an Ohmic silicon contact. The suspended nanowires achieved dimensions down to 20 nm x 30 nm x 10 m with large sensitivity to pressure. These structures then performed well as Pirani gauges. Sputtered niobium was also developed in this research for use as a superconductive coating on the nanowire. Oxidation characteristics of Nb were detailed and a technique to place the Nb under tensile stress resulted in the Nb resisting bulk atmospheric oxidation for up to years.

Henry, Michael David; Jarecki, Robert Leo,

2014-01-01T23:59:59.000Z

125

Preparation Of Copper Indium Gallium Diselenide Films For Solar Cells  

DOE Patents (OSTI)

High quality thin films of copper-indium-gallium-diselenide useful in the production of solar cells are prepared by electrodepositing at least one of the constituent metals onto a glass/Mo substrate, followed by physical vapor deposition of copper and selenium or indium and selenium to adjust the final stoichiometry of the thin film to approximately Cu(In,Ga)Se.sub.2. Using an AC voltage of 1-100 KHz in combination with a DC voltage for electrodeposition improves the morphology and growth rate of the deposited thin film. An electrodeposition solution comprising at least in part an organic solvent may be used in conjunction with an increased cathodic potential to increase the gallium content of the electrodeposited thin film.

Bhattacharya, Raghu N. (Littleton, CO); Contreras, Miguel A. (Golden, CO); Keane, James (Lakewood, CO); Tennant, Andrew L. (Denver, CO), Tuttle, John R. (Denver, CO); Ramanathan, Kannan (Lakewood, CO); Noufi, Rommel (Golden, CO)

1998-08-08T23:59:59.000Z

126

The Russian-American Gallium solar neutrino Experiment  

SciTech Connect

The Russian-American Gallium solar neutrino Experiment (SAGE) is described. The solar neutrino flux measured by 31 extractions through October, 1993 is presented. The result of 69 {+-} 10{sub {minus}7}{sup +5} SNU is to be compared with a standard solar model prediction of 132 SNU. The status of a {sup 51}Cr neutrino source irradiation to test the overall operation of the experiment is also presented.

Elliott, S.R. [Univ. of Washington, Seattle, WA (United States); Abdurashitov, J.N. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. for Nuclear Research; Bowles, T.J. [Los Alamos National Lab., NM (United States)] [and others

1995-12-31T23:59:59.000Z

127

The Russian-American gallium solar neutrino experiment  

SciTech Connect

The Russian-American Gallium solar neutrino Experiment (SAGE) is described. The solar neutrino flux measured by 31 extractions through October, 1993 is presented. The result of 69 {+-} 10{sub {minus}7}{sup +5} SNU is to be compared with a standard solar model prediction of 132 SNU. The status of a {sup 51}Cr neutrino source irradiation to test the overall operation of the experiment is also presented.

Elliott, S.R.; Wilkerson, J.F. [Univ. of Washington, Seattle, WA (United States); Abdurashitov, J.N. [Russian Academy of Sciences, Moscow (Russian Federation). Institute of Nuclear Research] [and others

1995-08-01T23:59:59.000Z

128

Electrodeposition of Crystalline GaAs on Liquid Gallium Electrodes in Aqueous Electrolytes  

Science Journals Connector (OSTI)

Crystalline gallium arsenide (c-GaAs) possesses many desirable optoelectronic properties suited for solar energy conversion,(1) light and radiation detection,(2) chemical sensing,(3) lighting,(4) and high speed electronics. ... In contrast to conflicting previous reports on the electrodeposition of GaAs,(17, 18) we posit that c-GaAs(s) can be synthesized predictably through the electrodeposition of As from dissolved As2O3 specifically on a Ga(l) electrode at modest temperatures in water. ... Specifically, for any binary system composed of a solid dissolving into a liquid, the rate of dissolution of the solid into the liquid phase is given by eq 5:(60)(5)where kdiss is the dissolution rate constant, s is the surface area of the solid in contact with the liquid, V is the volume of the liquid, Csat is the solubility of the solid in the liquid, and Cdiss is the concentration of the dissolved solid in the bulk of the liquid phase. ...

Eli Fahrenkrug; Junsi Gu; Stephen Maldonado

2012-12-24T23:59:59.000Z

129

Creating bulk nanocrystalline metal.  

SciTech Connect

Nanocrystalline and nanostructured materials offer unique microstructure-dependent properties that are superior to coarse-grained materials. These materials have been shown to have very high hardness, strength, and wear resistance. However, most current methods of producing nanostructured materials in weapons-relevant materials create powdered metal that must be consolidated into bulk form to be useful. Conventional consolidation methods are not appropriate due to the need to maintain the nanocrystalline structure. This research investigated new ways of creating nanocrystalline material, new methods of consolidating nanocrystalline material, and an analysis of these different methods of creation and consolidation to evaluate their applicability to mesoscale weapons applications where part features are often under 100 {micro}m wide and the material's microstructure must be very small to give homogeneous properties across the feature.

Fredenburg, D. Anthony (Georgia Institute of Technology, Atlanta, GA); Saldana, Christopher J. (Purdue University, West Lafayette, IN); Gill, David D.; Hall, Aaron Christopher; Roemer, Timothy John (Ktech Corporation, Albuquerque, NM); Vogler, Tracy John; Yang, Pin

2008-10-01T23:59:59.000Z

130

Bulk Heterojunction Polymer Solar Cells  

Science Journals Connector (OSTI)

Recent developments on bulk-heterojunction polymer photovoltaic diodes will be presented, focusing on the mechanism of charge generation, low bandgap polymers for increased photon...

Janssen, René

131

Evaluation of silicon-nitride ceramic valves.  

SciTech Connect

Silicon-nitride ceramic valves can improve the performance of both light- and heavy-duty automotive engines because of the superior material properties of silicon nitrides over current metal alloys. However, ceramics are brittle materials that may introduce uncertainties in the reliability and durability of ceramic valves. As a result, the lifetime of ceramic valves are difficult to predict theoretically due to wide variations in the type and distribution of microstructural flaws in the material. Nondestructive evaluation (NDE) methods are therefore required to assess the quality and reliability of these valves. Because ceramic materials are optically translucent and the strength-limiting flaws are normally located near the valve surface, a laser-scatter method can be used for NDE evaluation of ceramic valves. This paper reviews the progress in the development of this NDE method and its application to inspect silicon-nitride ceramic valves at various stages of manufacturing and bench and engine tests.

Sun, J. G.; Zhang, J. M.; Andrews, M. J.; Tretheway, J. S.; Phillips, N. S .L.; Jensen, J. A.; Nuclear Engineering Division; Univ. of Texas; Caterpillar, Inc.

2008-01-01T23:59:59.000Z

132

Physics based analytical modelling of Gallium Nitride(GaN) MESFET considering different ion implantation energy with high temperature annealing.  

E-Print Network (OSTI)

??A physics based analytical model of ion implanted GaN MESFET has been presented considering high temperature annealing effects. Choosing appropriate activation energy of impurity atoms,… (more)

Raghavan, Vinay

2015-01-01T23:59:59.000Z

133

Comparative band alignment of plasma-enhanced atomic layer deposited high-k dielectrics on gallium nitride  

SciTech Connect

Al{sub 2}O{sub 3} films, HfO{sub 2} films, and HfO{sub 2}/Al{sub 2}O{sub 3} stacked structures were deposited on n-type, Ga-face, GaN wafers using plasma-enhanced atomic layer deposition (PEALD). The wafers were first treated with a wet-chemical clean to remove organics and an in-situ combined H{sub 2}/N{sub 2} plasma at 650 Degree-Sign C to remove residual carbon contamination, resulting in a clean, oxygen-terminated surface. This cleaning process produced slightly upward band bending of 0.1 eV. Additional 650 Degree-Sign C annealing after plasma cleaning increased the upward band bending by 0.2 eV. After the initial clean, high-k oxide films were deposited using oxygen PEALD at 140 Degree-Sign C. The valence band and conduction band offsets (VBOs and CBOs) of the Al{sub 2}O{sub 3}/GaN and HfO{sub 2}/GaN structures were deduced from in-situ x-ray and ultraviolet photoemission spectroscopy (XPS and UPS). The valence band offsets were determined to be 1.8 and 1.4 eV, while the deduced conduction band offsets were 1.3 and 1.0 eV, respectively. These values are compared with the theoretical calculations based on the electron affinity model and charge neutrality level model. Moreover, subsequent annealing had little effect on these offsets; however, the GaN band bending did change depending on the annealing and processing. An Al{sub 2}O{sub 3} layer was investigated as an interfacial passivation layer (IPL), which, as results suggest, may lead to improved stability, performance, and reliability of HfO{sub 2}/IPL/GaN structures. The VBOs were {approx}0.1 and 1.3 eV, while the deduced CBOs were 0.6 and 1.1 eV for HfO{sub 2} with respect to Al{sub 2}O{sub 3} and GaN, respectively.

Yang Jialing; Eller, Brianna S.; Zhu Chiyu; England, Chris; Nemanich, Robert J. [Department of Physics, Arizona State University, Tempe, Arizona 85287-1504 (United States)

2012-09-01T23:59:59.000Z

134

GALLIUM NITRIDE INTEGRATED GAS/TEMPERATURE SENSORS FOR FUEL CELL SYSTEM MONITORING FOR HYDROGEN AND CARBON MONOXIDE  

E-Print Network (OSTI)

on field effect devices using catalytic metal gates on silicon carbide substrates has been reviewed (Spetz-10%) of transition metals such as copper, silver, and chromium (Feinstein et al 1997 and Pyke 1993). High temperature. Introduction Gas sensing and analysis based on gas adsorption on a catalytic metal surface has been extensively

135

The influence of framework-gallium in zeolites: Electronegativity and infrared spectroscopic study  

SciTech Connect

Based on the influence of the composition (Si/Al and Si/Ga ratio) on the framework vibrations of zeolites with different structure types (FAU, LTL, BETA, MOR, MEL, MFI, TON, and MTW), an electronegativity value for gallium substituted into zeolite frameworks is proposed (Sanderson electronegativity scale). The present electronegativity value agrees with the known physicochemical properties of gallium substituted zeolites.

Dompas, D.H.; Mortier, W.J. (Katholieke Univ. Leuven (Belgium)); Kenter, O.C.H. (Delft Univ. of Technology (The Netherlands)); Janssen, M.J.G.; Verduijn, J.P. (Exxon Chemical Holland, Rotterdam (The Netherlands))

1991-05-01T23:59:59.000Z

136

Two-photon photovoltaic effect in gallium arsenide Jeff Chiles,1  

E-Print Network (OSTI)

Two-photon photovoltaic effect in gallium arsenide Jichi Ma,1 Jeff Chiles,1 Yagya D. Sharma,2 214669); published September 4, 2014 The two-photon photovoltaic effect is demonstrated in gallium; (230.0250) Optoelectronics; (040.5350) Photovoltaic; (130.4310) Nonlinear. http://dx.doi.org/10.1364/OL

Fathpour, Sasan

137

IEEE JOURNAL OF PHOTOVOLTAICS, VOL. 2, NO. 2, APRIL 2012 123 Gallium Arsenide Solar Cell Absorption  

E-Print Network (OSTI)

IEEE JOURNAL OF PHOTOVOLTAICS, VOL. 2, NO. 2, APRIL 2012 123 Gallium Arsenide Solar Cell Absorption flat gallium arsenide solar cell, we show that it is possible to modify the flow of light and enhance above the solar cell. The incoupling element is lossless and, thus, has the advantage that no energy

Grandidier, Jonathan

138

Diffusion of indium and gallium in Cu(In,Ga)Se2 thin film solar cells  

E-Print Network (OSTI)

Diffusion of indium and gallium in Cu(In,Ga)Se2 thin film solar cells O. Lundberga,*, J. Lua , A. Rockettb , M. Edoffa , L. Stolta a A°ngstro¨m Solar Center, Uppsala University, P.O. Box 534, SE-751 21 Abstract The diffusion of indium and gallium in polycrystalline thin film Cu(In,Ga)Se2 layers has been

Rockett, Angus

139

Gallium/aluminum nanocomposite material for nonlinear optics and nonlinear plasmonics  

E-Print Network (OSTI)

Gallium/aluminum nanocomposite material for nonlinear optics and nonlinear plasmonics A. V penetration of gallium into an aluminum film. These composite films form mirrorlike interfaces with silica optics and active plasmonics. The material is a polycrystalline aluminum film on a silica sub- strate

Zheludev, Nikolay

140

Synthesis and use of (polyfluoroaryl)fluoroanions of aluminum, gallium and indium  

DOE Patents (OSTI)

Salts of (polyfluoroaryl)fluoroanions of aluminum, gallium, and indium are described. The (polyfluoroaryl)fluoroanions have the formula [ER'R"R'"F].sup..crclbar. wherein E is aluminum, gallium, or indium, wherein F is fluorine, and wherein R', R", and R'" is each a fluorinated phenyl, fluorinated biphenyl, or fluorinated polycyclic group.

Marks, Tobin J. (Evanston, IL); Chen, You-Xian (Midland, MI)

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "bulk gallium nitride" 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

Anisotropic Hexagonal Boron Nitride Nanomaterials - Synthesis and Applications  

SciTech Connect

Boron nitride (BN) is a synthetic binary compound located between III and V group elements in the Periodic Table. However, its properties, in terms of polymorphism and mechanical characteristics, are rather close to those of carbon compared with other III-V compounds, such as gallium nitride. BN crystallizes into a layered or a tetrahedrally linked structure, like those of graphite and diamond, respectively, depending on the conditions of its preparation, especially the pressure applied. Such correspondence between BN and carbon readily can be understood from their isoelectronic structures [1, 2]. On the other hand, in contrast to graphite, layered BN is transparent and is an insulator. This material has attracted great interest because, similar to carbon, it exists in various polymorphic forms exhibiting very different properties; however, these forms do not correspond strictly to those of carbon. Crystallographically, BN is classified into four polymorphic forms: Hexagonal BN (h-BN) (Figure 1(b)); rhombohedral BN (r-BN); cubic BN (c-BN); and wurtzite BN (w-BN). BN does not occur in nature. In 1842, Balmain [3] obtained BN as a reaction product between molten boric oxide and potassium cyanide under atmospheric pressure. Thereafter, many methods for its synthesis were reported. h-BN and r-BN are formed under ambient pressure. c-BN is synthesized from h-BN under high pressure at high temperature while w-BN is prepared from h-BN under high pressure at room temperature [1]. Each BN layer consists of stacks of hexagonal plate-like units of boron and nitrogen atoms linked by SP{sup 2} hybridized orbits and held together mainly by Van der Waals force (Fig 1(b)). The hexagonal polymorph has two-layered repeating units: AA'AA'... that differ from those in graphite: ABAB... (Figure 1(a)). Within the layers of h-BN there is coincidence between the same phases of the hexagons, although the boron atoms and nitrogen atoms are alternatively located along the c-axis. The rhombohedral system consists of three-layered units: ABCABC..., whose honeycomb layers are arranged in a shifted phase, like as those of graphite. Reflecting its weak interlayer bond, the h-BN can be cleaved easily along its layers, and hence, is widely used as a lubricant material. The material is stable up to a high temperature of 2300 C before decomposition sets in [2] does not fuse a nitrogen atmosphere of 1 atm, and thus, is applicable as a refractory material. Besides having such properties, similar to those of graphite, the material is transparent, and acts as a good electric insulator, especially at high temperatures (10{sup 6} {Omega}m at 1000 C) [1]. c-BN and w-BN are tetrahedrally linked BN. The former has a cubic sphalerite-type structure, and the latter has a hexagonal wurtzite-type structure. c-BN is the second hardest known material (the hardest is diamond), the so-called white diamond. It is used mainly for grinding and cutting industrial ferrous materials because it does not react with molten iron, nickel, and related alloys at high temperatures whereas diamond does [1]. It displays the second highest thermal conductivity (6-9 W/cm.deg) after diamond. This chapter focuses principally upon information about h-BN nanomaterials, mainly BN nanotubes (BNNTs), porous BN, mono- and few-layer-BN sheets. There are good reviews book chapters about c-BN in [1, 4-6].

Han,W.Q.

2008-08-01T23:59:59.000Z

142

Hort-Range Wetting at Liquid Gallium-Bismuth Alloy Surfaces: X-ray Measurements and Square-Gradient Theory  

SciTech Connect

We present an x-ray reflectivity study of wetting at the free surface of the binary liquid metal alloy gallium-bismuth (Ga-Bi) in the region where the bulk phase separates into Bi-rich and Ga-rich liquid phases. The measurements reveal the evolution of the microscopic structure of the wetting films of the Bi-rich, low-surface-tension phase along several paths in the bulk phase diagram. The wetting of the Ga-rich bulk's surface by a Bi-rich wetting film, the thickness of which is limited by gravity to only 50 Angstroms, creates a Ga-rich/Bi-rich liquid/liquid interface close enough to the free surface to allow its detailed study by x rays. The structure of the interface is determined with Angstromsngstrem resolution, which allows the application of a mean-field square gradient model extended by the inclusion of capillary waves as the dominant thermal fluctuations. The sole free parameter of the gradient model, the influence parameter K, that characterizes the influence of concentration gradients on the interfacial excess energy, is determined from our measurements. This, in turn, allows a calculation of the liquid/liquid interfacial tension, and a separation of the intrinsic and capillary wave contributions to the interfacial structure. In spite of expected deviations from MF behavior, based on the upper critical dimensionality (Du = 3 ) of the bulk, we find that the capillary wave excitations only marginally affect the short-range complete wetting behavior. A critical wetting transition that is sensitive to thermal fluctuations appears to be absent in this binary liquid-metal alloy.

Huber, P.; Shpyrko, O; Pershan, P; Ocko, B; DiMasi, E; Deutsch, M

2009-01-01T23:59:59.000Z

143

Effect of strain on low-loss electron energy loss spectra of group-III nitrides  

Science Journals Connector (OSTI)

Thin films of AlN experiencing different strain states were investigated with a scanning transmission electron microscope (STEM) by low-loss electron energy loss spectroscopy (EELS). The results conclude that the low-loss properties and in particular, the plasmon peak position is shifted as a direct consequence of the inherent strain of the sample. The results reveal that strain, even minor levels, can be measured by STEM-EELS. These results were further corroborated by full potential calculations and expanded to include the similar III nitrides GaN and InN. It is found that a unit-cell volume change of 1% results in a bulk plasmon peak shift of 0.159, 0.168, and 0.079 eV for AlN, GaN, and InN, respectively, according to simulations. The AlN peak shift was experimentally corroborated with a corresponding peak shift of 0.156 eV. The unit-cell volume is used here since it is found that regardless of in- and out-of-plane lattice augmentation, the low-loss properties appear near identical for constant volume. These results have an impact on the interpretation of the plasmon energy and its applicability for determining and separating stress and composition. It is found that while the bulk plasmon energy can be used as a measure of the composition in a group-III nitride alloy for relaxed structures, the presence of strain significantly affects such a measurement. The strain is found to have a lower impact on the peak shift for Al1-xInxN (?3% compositional error per 1% volume change) and In1-xGaxN alloys compared to significant variations for Al1-xGaxN (16% compositional error for 1% volume change). Hence a key understanding in low-loss studies of III nitrides is that strain and composition are coupled and affect one another.

J. Palisaitis; C.-L. Hsiao; M. Junaid; J. Birch; L. Hultman; P. O. Ĺ. Persson

2011-12-07T23:59:59.000Z

144

Titanium nitride electrodes for thermoelectric generators  

DOE Patents (OSTI)

The invention is directed to a composite article suitable for use in thermoelectric generators. The article comprises a thin film of titanium nitride as an electrode deposited onto solid electrolyte. The invention is also directed to the method of making same.

Novak, Robert F. (Farmington Hills, MI); Schmatz, Duane J. (Dearborn Heights, MI); Hunt, Thomas K. (Ann Arbor, MI)

1987-12-22T23:59:59.000Z

145

bulk power | OpenEI  

Open Energy Info (EERE)

bulk power bulk power Dataset Summary Description The Form EIA-411, "Coordinated Bulk Power Supply Program Report," collects information from the Nation's power system planners about the electricity supply, both capacity and energy, that is needed to serve current demand and for future growth. Source Energy Information Administration (EIA) Date Released December 03rd, 2010 (3 years ago) Date Updated December 03rd, 2010 (3 years ago) Keywords bulk power EIA Electricity Generation Data application/vnd.ms-excel icon Net Energy for Load - Historic, Actual and Projected Five-Years (xls, 26.1 KiB) application/vnd.ms-excel icon Noncoincident Peak Load - Historic, Actual and Projected Five-Years (xls, 25.6 KiB) application/vnd.ms-excel icon Noncoincident Peak Load - Historic, Actual and Projected Five-Years (xls, 0 bytes)

146

Bulk Hauling Equipment for CHG  

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

load of CHG Semitrailer Mass Trailer or ModuleChassis Module Mass Hydrogen Gas Mass CAPITAL EXPENDITURE FOR BULK HAULING EQUIPMENT For large consumption, total CapEx for...

147

Microsoft PowerPoint - Gallium Oxide_Ramana  

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

Gallium Oxide Nanostructures Gallium Oxide Nanostructures for High Temperature Sensors C.V. Ramana (PI) Evgeny Shafirovich (Co-PI) Mechanical Engineering, University of Texas at El Paso Students: Ernesto Rubio (PhD); S.K. Samala (MS) A.K. Narayana Swamy (PhD); K. Abhilash (MS) Program Manager: Richard Dunst, NETL, DOE Project: DE-FE0007225 Project Period: 10/01/2011 to 09/31/2014 1 06/12/2013 DOE UCR/HBCU Conference, June 11-13, 2013 2 ď‚· Introduction ď‚· Research Objectives ď‚· Experiments â–ş Synthesis â–ş Characterization ď‚· Results and Discussion â–ş Pure Ga 2 O 3 Thin Films â–ş W-doped Ga 2 O 3 Thin Films (Physical Methods) ď‚· Summary & Future Work 06/12/2013 DOE UCR/HBCU Conference, June 11-13, 2013 3 06/12/2013 DOE UCR/HBCU Conference, June 11-13, 2013 4 Energy Systems High-T High-T High-P High-P

148

E-Print Network 3.0 - aligned carbon nitride Sample Search Results  

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

nitride-coated electroless nickelaluminum masters. The sub- strate material... replica removal through differential contraction in liquid nitrogen. Carbon nitride is a...

149

E-Print Network 3.0 - americium nitrides Sample Search Results  

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

carbides and nitrides for the inert matrix fuel by spark plasma sintering Summary: in carbide or nitride matrix to fabricate oxide-dispersed IMF pellets. Further study using...

150

All-optical Wavelength Conversion in Aluminum Gallium Arsenide at Telecommunications Wavelengths.  

E-Print Network (OSTI)

??This thesis aims at both developing highly nonlinear Aluminum Gallium Arsenide waveguides(AlGaAs) and demonstrating all-optical wavelength conversion via cross-phase modulation in AlGaAs waveguides at telecommunications… (more)

Ng, Wing-Chau

2011-01-01T23:59:59.000Z

151

E-Print Network 3.0 - aluminum gallium indium Sample Search Results  

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

4F84E-A98D-4D11-B923-779B4467077F Unexpected Discovery Could Yield Full Spectrum Solar Cell Summary: elements from group III of the periodic table, like aluminum, gallium, and...

152

GALLIUM--2002 29.1 References that include a section mark () are found in the Internet  

E-Print Network (OSTI)

consumed in the United States was in the form of GaAs. GaAs was manufactured into optoelectronic devices application for gallium, with 46% of total consumption. Optoelectronic devices accounted for 42% of domestic

153

Polycrystalline Thin-Film Research: Copper Indium Gallium Diselenide (Fact Sheet)  

SciTech Connect

Capabilities fact sheet for the National Center for Photovoltaics: Polycrystalline Thin-Film Research: Copper Indium Gallium Diselenide that includes scope, core competencies and capabilities, and contact/web information.

Not Available

2011-06-01T23:59:59.000Z

154

Fabrication of optoelectronic microwave linear and ring resonators on a gallium arsenide substrate  

E-Print Network (OSTI)

FABRICATION OF OPTOELECTRONIC MICROWAVE LINEAR AND RING RESONATORS ON A GALLIUM ARSENIDE SUBSTRATE A Thesis by CHUN-LIANG YEH Submitted to the Office of Graduate Studies of Texas ASM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August 1993 Major Subject: Electrical Engineering FABRICATION OF OPTOELECTRONIC MICROWAVE LINEAR AND RING RESONATORS ON A GALLIUM ARSENIDE SUBSTRATE A Thesis by CHUN-LIANG YEH Approved as to style and content by: Mark...

Yeh, Chun-Liang

1993-01-01T23:59:59.000Z

155

Bulk Viscosity of Interacting Hadrons  

E-Print Network (OSTI)

We show that first approximations to the bulk viscosity $\\eta_v$ are expressible in terms of factors that depend on the sound speed $v_s$, the enthalpy, and the interaction (elastic and inelastic) cross section. The explicit dependence of $\\eta_v$ on the factor $(\\frac 13 - v_s^2)$ is demonstrated in the Chapman-Enskog approximation as well as the variational and relaxation time approaches. The interesting feature of bulk viscosity is that the dominant contributions at a given temperature arise from particles which are neither extremely nonrelativistic nor extremely relativistic. Numerical results for a model binary mixture are reported.

A. Wiranata; M. Prakash

2009-06-30T23:59:59.000Z

156

Charm contribution to bulk viscosity  

E-Print Network (OSTI)

In the range of temperatures reached in future heavy ion collision experiments, hadronic pair annihilations and creations of charm quarks may take place within the lifetime of the plasma. As a result, charm quarks may increase the bulk viscosity affecting the early stages of hydrodynamic expansion. Assuming thermalization, we estimate the charm contribution to bulk viscosity within the same effective kinetic theory framework in which the light parton contribution has been computed previously. The time scale at which this physics becomes relevant is related to the width of the transport peak associated with the trace anomaly correlator, and is found to be 600 MeV.

Laine, M

2014-01-01T23:59:59.000Z

157

Charm contribution to bulk viscosity  

E-Print Network (OSTI)

In the range of temperatures reached in future heavy ion collision experiments, hadronic pair annihilations and creations of charm quarks may take place within the lifetime of the plasma. As a result, charm quarks may increase the bulk viscosity affecting the early stages of hydrodynamic expansion. Assuming thermalization, we estimate the charm contribution to bulk viscosity within the same effective kinetic theory framework in which the light parton contribution has been computed previously. The time scale at which this physics becomes relevant is related to the width of the transport peak associated with the trace anomaly correlator, and is found to be 600 MeV.

M. Laine; Kiyoumars A. Sohrabi

2014-10-24T23:59:59.000Z

158

Study of Magnetohydrodynamic Surface Waves on Liquid Gallium  

SciTech Connect

Magnetohydrodynamic (MHD) surface waves on liquid gallium are studied theoretically and experimentally in the small magnetic Reynolds number limit. A linear dispersion relation is derived when a horizontal magnetic field and a horizontal electric current is imposed. No wave damping is found in the shallow liquid limit while waves always damp in the deep liquid limit with a magnetic field parallel to the propagation direction. When the magnetic field is weak, waves are weakly damped and the real part of the dispersion is unaffected, while in the opposite limit waves are strongly damped with shortened wavelengths. In a table-top experiment, planar MHD surface waves on liquid gallium are studied in detail in the regime of weak magnetic field and deep liquid. A non-invasive diagnostic accurately measures surface waves at multiple locations by reflecting an array of lasers off the surface onto a screen, which is recorded by an Intensified-CCD camera. The measured dispersion relation is consistent with the linear theory with a reduced surface tension likely due to surface oxidation. In excellent agreement with linear theory, it is observed that surface waves are damped only when a horizontal magnetic field is imposed parallel to the propagation direction. No damping is observed under a perpendicular magnetic field. The existence of strong wave damping even without magnetic field suggests the importance of the surface oxide layer. Implications to the liquid metal wall concept in fusion reactors, especially on the wave damping and a Rayleigh-Taylor instability when the Lorentz force is used to support liquid metal layer against gravity, are discussed.

Hantao Ji; William Fox; David Pace; H.L. Rappaport

2004-05-13T23:59:59.000Z

159

Process for producing ceramic nitrides anc carbonitrides and their precursors  

DOE Patents (OSTI)

A process for preparing ceramic nitrides and carbon nitrides in the form of very pure, fine particulate powder. Appropriate precursors is prepared by reaching a transition metal alkylamide with ammonia to produce a mixture of metal amide and metal imide in the form of an easily pyrolyzable precipitate.

Brown, G.M.; Maya, L.

1987-02-25T23:59:59.000Z

160

Process for making boron nitride using sodium cyanide and boron  

DOE Patents (OSTI)

This a very simple process for making boron nitride by mixing sodium cyanide and boron phosphate and heating the mixture in an inert atmosphere until a reaction takes place. The product is a white powder of boron nitride that can be used in applications that require compounds that are stable at high temperatures and that exhibit high electrical resistance.

Bamberger, Carlos E. (Oak Ridge, TN)

1990-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "bulk gallium nitride" 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

Oxidation Protection of Uranium Nitride Fuel using Liquid Phase Sintering  

SciTech Connect

Two methods are proposed to increase the oxidation resistance of uranium nitride (UN) nuclear fuel. These paths are: (1) Addition of USi{sub x} (e.g. U3Si2) to UN nitride powder, followed by liquid phase sintering, and (2) 'alloying' UN nitride with various compounds (followed by densification via Spark Plasma Sintering or Liquid Phase Sintering) that will greatly increase oxidation resistance. The advantages (high thermal conductivity, very high melting point, and high density) of nitride fuel have long been recognized. The sodium cooled BR-10 reactor in Russia operated for 18 years on uranium nitride fuel (UN was used as the driver fuel for two core loads). However, the potential advantages (large power up-grade, increased cycle lengths, possible high burn-ups) as a Light Water Reactor (LWR) fuel are offset by uranium nitride's extremely low oxidation resistance (UN powders oxidize in air and UN pellets decompose in hot water). Innovative research is proposed to solve this problem and thereby provide an accident tolerant LWR fuel that would resist water leaks and high temperature steam oxidation/spalling during an accident. It is proposed that we investigate two methods to increase the oxidation resistance of UN: (1) Addition of USi{sub x} (e.g. U{sub 3}Si{sub 2}) to UN nitride powder, followed by liquid phase sintering, and (2) 'alloying' UN nitride with compounds (followed by densification via Spark Plasma Sintering) that will greatly increase oxidation resistance.

Dr. Paul A. Lessing

2012-03-01T23:59:59.000Z

162

Atomic Layer Deposition of Insulating Hafnium and Zirconium Nitrides  

E-Print Network (OSTI)

author. E-mail: gordon@chemistry.harvard.edu. (1) Toth, L. E. Transition Metal Carbides and Nitrides homoleptic tetrakis(dialkylamido)- metal(IV) complexes and ammonia at low substrate temperatures (150-250 °C). The precursor vapors were alternately pulsed into a heated reactor, yielding 1.15-1.20 � of metal nitride film

163

Bulk viscosity and deflationary universes  

E-Print Network (OSTI)

We analyze the conditions that make possible the description of entropy generation in the new inflationary model by means of a nearequilibrium process. We show that there are situations in which the bulk viscosity cannot describe particle production during the coherent field oscillations phase.

J. A. S. Lima; R. Portugal; I. Waga

2007-08-24T23:59:59.000Z

164

JOURNAL OF MATERIALS SCIENCE 40 (2005) 2101 2103 LETTERS Pressureless sintering of silicon nitride/boron nitride  

E-Print Network (OSTI)

, West Lafayette, Indiana 47907-2044, USA Silicon nitride (Si3N4) and boron nitride (BN) are ma- terials2O3 (Alcoa A- 16SG, 0.4 µm in diameter) and 4 wt% Y2O3 (Alfa Aesar REacton, 10 µm in diameter

Trice, Rodney W.

165

A final report for Gallium arsenide P-I-N detectors for high-sensitivity imaging of thermal neutrons  

E-Print Network (OSTI)

This SBIR Phase I developed neutron detectors made FR-om gallium arsenide (GaAs) p-type/ intrinsic/n-type (P-I-N) diodes grown by metalorganic chemical vapor deposition (MOCVD) onto semi-insulating (S1) bulk GaAs wafers. A layer of isotonically enriched boron-10 evaporated onto the FR-ont surface serves to convert incoming neutrons into lithium ions and a 1.47 MeV alpha particle which creates electron-hole pairs that are detected by the GaAs diode. Various thicknesses of ''intrinsic'' (I) undoped GaAs were tested, as was use of a back-surface field (BSF) formed FR-om a layer of Al sub x Ga sub 1 sub - sub x As. Schottky-barrier diodes formed FR-om the same structures without the p+ GaAs top layer were tested as a comparison. After mesa etching and application of contacts, devices were tested in visible light before application of the boron coating. Internal quantum efficiency (IQE) of the best diode near the GaAs bandedge is over 90%. The lowest dark current measured is 1 x 10 sup - sup 1 sup 2 amps at -1 V o...

Vernon, S M

1999-01-01T23:59:59.000Z

166

By Deborah A. Kramer No gallium production was reported in the McDonnell Douglas Corp. reportedly will world producers were Australia, Germany, and  

E-Print Network (OSTI)

facility in optoelectronic devices [light-emitting diodes France from stockpiled crude gallium produced, and in 1994. Although the total quantity of gallium used in optoelectronic devices increased, its percentage

167

Nanowire-templated lateral epitaxial growth of non-polar group III nitrides  

DOE Patents (OSTI)

A method for growing high quality, nonpolar Group III nitrides using lateral growth from Group III nitride nanowires. The method of nanowire-templated lateral epitaxial growth (NTLEG) employs crystallographically aligned, substantially vertical Group III nitride nanowire arrays grown by metal-catalyzed metal-organic chemical vapor deposition (MOCVD) as templates for the lateral growth and coalescence of virtually crack-free Group III nitride films. This method requires no patterning or separate nitride growth step.

Wang, George T. (Albuquerque, NM); Li, Qiming (Albuquerque, NM); Creighton, J. Randall (Albuquerque, NM)

2010-03-02T23:59:59.000Z

168

Bulk Hauling Equipment for CHG  

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

BULK HAULING EQUIPMENT FOR CHG BULK HAULING EQUIPMENT FOR CHG Don Baldwin Director of Product Development - Hexagon Lincoln HEXAGON LINCOLN TITAN(tm) Module System Compressed Hydrogen Gas * Capacity 250 bar - 616 kg 350 bar - 809 kg 540 bar - 1155 kg * Gross Vehicle Weight (with prime mover) 250 bar - 28 450 kg 350 bar - 30 820 kg 540 bar - 39 440 kg * Purchase Cost 250 bar - $510,000 350 bar - $633,750 540 bar - $1,100,000 Compressed Natural Gas * Capacity (250 bar at 15 C) - 7412 kg * GVW (With prime mover) - 35 250 kg * Purchase Cost (+/- 5%) - $510,000 HEXAGON LINCOLN TITAN(tm) V Magnum Trailer System Compressed Hydrogen Gas * Capacity 250 bar - 800 kg 350 bar - 1050 kg 540 bar - 1500 kg * Gross Vehicle Weight (with prime mover) 250 bar - 31 000 kg 350 bar - 34 200 kg 540 bar - 45 700 kg * Purchase Cost (+/-

169

Bulk viscosity in hybrid stars  

Science Journals Connector (OSTI)

We compute the bulk viscosity of a mixed quark-hadron phase. In the first scenario to be discussed, the mixed phase occurs at large densities and we assume that it is composed of a mixing of hyperonic matter and quarks in the Color Flavor Locked phase. In a second scenario, the mixed phase occurs at lower densities and it is composed of a mixing of nucleons and unpaired quark matter. We have also investigated the effect of a nonvanishing surface tension at the interface between hadronic and quark matter. In both scenarios, the bulk viscosity is large when the surface tension is absent, while the value of the viscosity reduces in the second scenario when a finite value for the surface tension is taken into account. In all cases, the r-mode instabilities of the corresponding hybrid star are suppressed.

A. Drago; A. Lavagno; G. Pagliara

2005-05-16T23:59:59.000Z

170

Cordierite silicon nitride filters. Final report  

SciTech Connect

The objective of this project was to develop a silicon nitride based crossflow filter. This report summarizes the findings and results of the project. The project was phased with Phase I consisting of filter material development and crossflow filter design. Phase II involved filter manufacturing, filter testing under simulated conditions and reporting the results. In Phase I, Cordierite Silicon Nitride (CSN) was developed and tested for permeability and strength. Target values for each of these parameters were established early in the program. The values were met by the material development effort in Phase I. The crossflow filter design effort proceeded by developing a macroscopic design based on required surface area and estimated stresses. Then the thermal and pressure stresses were estimated using finite element analysis. In Phase II of this program, the filter manufacturing technique was developed, and the manufactured filters were tested. The technique developed involved press-bonding extruded tiles to form a filter, producing a monolithic filter after sintering. Filters manufactured using this technique were tested at Acurex and at the Westinghouse Science and Technology Center. The filters did not delaminate during testing and operated and high collection efficiency and good cleanability. Further development in areas of sintering and filter design is recommended.

Sawyer, J.; Buchan, B. [Acurex Environmental Corp., Mountain View, CA (United States); Duiven, R.; Berger, M. [Aerotherm Corp., Mountain View, CA (United States); Cleveland, J.; Ferri, J. [GTE Products Corp., Towanda, PA (United States)

1992-02-01T23:59:59.000Z

171

Vacancy Hardening and Softening in Transition Metal Carbides and Nitrides  

SciTech Connect

The effects of vacancies on mechanical properties of the transition metal carbides and nitrides are studied using the ab initio pseudopotential approach. Calculated shear elastic stiffness and electronic structures show that the vacancy produces entirely different effects on the mechanical strength of groups IVb nitrides and Vb carbides. It is found that the occupation of shear-unstable metallic dd bonding states changes essentially in an opposite way for the carbides and nitrides in the presence of vacancies, resulting in different responses to shear stress. Our study provides an atomistic understanding of the anomaly in hardness for these substoichiometric materials.

Jhi, Seung-Hoon; Louie, Steven G.; Cohen, Marvin L.; Ihm, Jisoon

2001-04-09T23:59:59.000Z

172

Diffusive shielding stabilizes bulk nanobubble clusters  

E-Print Network (OSTI)

Using molecular dynamics, we study the nucleation and stability of bulk nanobubble clusters. We study the formation, growth, and final size of bulk nanobubbles. We find that, as long as the bubble-bubble interspacing is small enough, bulk nanobubbles are stable against dissolution. Simple diffusion calculations provide an excellent match with the simulation results, giving insight into the reason for the stability: nanobubbles in a cluster of bulk nanobubbles "protect" each other from diffusion by a shielding effect.

Weijs, Joost H; Lohse, D

2011-01-01T23:59:59.000Z

173

Iron-Nitride Alloy Magnets: Transformation Enabled Nitride Magnets Absent Rare Earths (TEN Mare)  

SciTech Connect

REACT Project: Case Western is developing a highly magnetic iron-nitride alloy to use in the magnets that power electric motors found in EVs and renewable power generators. This would reduce the overall price of the motor by eliminating the expensive imported rare earth minerals typically found in today’s best commercial magnets. The iron-nitride powder is sourced from abundant and inexpensive materials found in the U.S. The ultimate goal of this project is to demonstrate this new magnet system, which contains no rare earths, in a prototype electric motor. This could significantly reduce the amount of greenhouse gases emitted in the U.S. each year by encouraging the use of clean alternatives to oil and coal.

None

2012-01-01T23:59:59.000Z

174

Deprotecting Thioacetyl-Terminated Terphenyldithiol for Assembly on Gallium Arsenide  

SciTech Connect

We characterize the assembly of terphenyldithiol (TPDT) on gallium arsenide (GaAs) from ethanol (EtOH) and tetrahydrofuran (THF) as a function of ammonium hydroxide (NH4OH) concentration. NH4OH facilitates the conversion of thioacetyl end groups of the TPDT precursor to thiolates in the assembly solution. The final structure of TPDT assembled on GaAs is sensitive not only to the assembly solvent but also to NH4OH concentration. In the presence of low concentrations of NH4OH (1 mM), TPDT assemblies from EtOH are oriented upright. The same assemblies are less upright when adsorption is carried out at higher NH4OH concentrations. In THF, TPDT does not adsorb significantly on GaAs at low NH4OH concentrations. The surface coverage and structural organization of these assemblies improve with increasing NH4OH concentrations, although these assemblies are never as organized as those from EtOH. The difference in the final structure of TPDT assemblies is attributed to differences in the thiolate fraction in the assembly solution at the point of substrate immersion.

Krapchetov,D.; Ma, H.; Jen, A.; Fischer, D.; Loo, Y.

2008-01-01T23:59:59.000Z

175

Change in the current-carrier concentration upon doping PbTe with gallium  

SciTech Connect

Upon doping PbTe with gallium, both high-resistivity samples with intrinsic conductivity and low-resistivity samples with electronic conductivity (n/sub e/ = 10/sup 18/ cm/sup -3/) are produced on the PbTe-GaTe section. A thorough investigation of the dependence of the thermo-emf of Pb/sub 1-x/Ga/sub x/Te on the excess Pb and Te side showed the presence of a wide region with intrinsic conductivity. The experimental data can be explained by the fact that impure gallium in PbTe has negative Hubbard energy and stabilizes the Fermi level almost at the center of the forbidden band. At high gallium concentrations, Ga/sub 2/Te/sub 3/ precipitates at first, and then GaTe precipitates as well. The lead forming in excess transforms Ga/sup 3 +/ to Ga/sup +/, which produces the electronic conductivity in the material.

Bushmarina, G.S.; Gruzinov, B.F.; Drabkin, I.A.; Lev, E.Ya.; Moizhes, B.Ya; Suprun, S.G.

1987-07-01T23:59:59.000Z

176

Sandia National Laboratories: III-Nitride core-shell nanowire...  

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

Sector III-Nitride core-shell nanowire arrayed solar cells On April 27, 2012, in Energy, Energy Efficiency, News, News & Events, Solid-State Lighting In a new EFRC-supported...

177

Molybdenum enhanced low-temperature deposition of crystalline silicon nitride  

DOE Patents (OSTI)

A process for chemical vapor deposition of crystalline silicon nitride is described which comprises the steps of: introducing a mixture of a silicon source, a molybdenum source, a nitrogen source, and a hydrogen source into a vessel containing a suitable substrate; and thermally decomposing the mixture to deposit onto the substrate a coating comprising crystalline silicon nitride containing a dispersion of molybdenum silicide. 5 figures.

Lowden, R.A.

1994-04-05T23:59:59.000Z

178

Gallium diffusion into self-assembled InAs quantum dots grown on indium phosphide substrates  

SciTech Connect

The photoluminescence spectrum of small self-assembled In(Ga)As quantum dots grown on InP substrates is composed of distinct spectral lines. These lines correspond to monolayer variations in the dots smallest dimension: their heights. We use this phenomenon in order to study the diffusion of gallium atoms into the self-assembled quantum dots. We demonstrate that substantial amounts of gallium atoms diffuse from a strained GaInP layer underneath the quantum dots into the quantum dots.

Raz, T.; Shuall, N.; Bahir, G.; Ritter, D.; Gershoni, D.; Chu, S.N.G. [Department of Electrical Engineering, Technion - Israel Institute of Technology, Technion City, Haifa 32000 (Israel); Physics Department and The Solid State Institute, Technion - Israel Institute of Technology, Technion City, Haifa 32000 (Israel); Multiplex, Inc., 5000 Hadley Rd., South Plainfield, New Jersey 07080 (United States)

2004-10-18T23:59:59.000Z

179

A boron nitride nanotube peapod thermal rectifier  

SciTech Connect

The precise guidance of heat from one specific location to another is paramount in many industrial and commercial applications, including thermal management and thermoelectric generation. One of the cardinal requirements is a preferential conduction of thermal energy, also known as thermal rectification, in the materials. This study introduces a novel nanomaterial for rectifying heat—the boron nitride nanotube peapod thermal rectifier. Classical non-equilibrium molecular dynamics simulations are performed on this nanomaterial, and interestingly, the strength of the rectification phenomenon is dissimilar at different operating temperatures. This is due to the contingence of the thermal flux on the conductance at the localized region around the scatterer, which varies with temperature. The rectification performance of the peapod rectifier is inherently dependent on its asymmetry. Last but not least, the favourable rectifying direction in the nanomaterial is established.

Loh, G. C., E-mail: jgloh@mtu.edu [Department of Physics, Michigan Technological University, Houghton, Michigan 49931 (United States); Institute of High Performance Computing, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632 (Singapore); Baillargeat, D. [CNRS-International-NTU-Thales Research Alliance (CINTRA), 50 Nanyang Drive, Singapore 637553 (Singapore)

2014-06-28T23:59:59.000Z

180

RAPID/BulkTransmission/Siting/California | Open Energy Information  

Open Energy Info (EERE)

Information Desktop Toolkit BETA RAPID Toolkit About Bulk Transmission Geothermal Solar Resources Contribute Contact Us RAPID Bulk Transmission Siting California Bulk...

Note: This page contains sample records for the topic "bulk gallium nitride" 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

Bulk Hydrogen Storage - Strategic Directions for Hydrogen Delivery...  

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

Bulk Hydrogen Storage Strategic Directions for Hydrogen Delivery Workshop May 7-8, 2003 Crystal City, Virginia Breakout Session - Bulk Hydrogen Storage Main ThemesCaveats Bulk...

182

RAPID/BulkTransmission/Power Plant | Open Energy Information  

Open Energy Info (EERE)

BulkTransmissionPower Plant < RAPID | BulkTransmission Jump to: navigation, search RAPID Regulatory and Permitting Information Desktop Toolkit BETA RAPID Toolkit About Bulk...

183

Millimeter wave ferromagnetic resonance in gallium-substituted ?-iron oxide  

SciTech Connect

In millimeter wave frequency range, hexagonal ferrites with high uniaxial anisotropic magnetic fields are used as absorbers. These ferrites include M-type barium ferrite (BaFe{sub 12}O{sub 19}) and strontium ferrite (SrFe{sub 12}O{sub 19}), which have natural ferromagnetic resonant frequency range from 40 GHz to 60?GHz. However, the higher frequency range lacks suitable materials that support the higher frequency ferromagnetic resonance. A new series of gallium-substituted ?-iron oxides (?-Ga{sub x}Fe{sub 2?x}O{sub 3}) are synthesized which have ferromagnetic resonant frequencies appearing over the frequency range 30 GHz–150 GHz. The ?-Ga{sub x}Fe{sub 2?x}O{sub 3} is synthesized by the combination of reverse micelle and sol-gel techniques or the sol-gel method only. The particle sizes are observed to be smaller than 100 nm. In this paper, the free space magneto-optical approach has been employed to study these newly developed ?-Ga{sub x}Fe{sub 2?x}O{sub 3} particles in millimeter waves. This technique enables to obtain precise transmission spectra to determine the dielectric and magnetic properties of both isotropic and anisotropic ferrites in the millimeter wave frequency range from a single set of direct measurements. The transmittance and absorbance spectra of ?-Ga{sub x}Fe{sub 2?x}O{sub 3} are shown in this paper. Strong ferromagnetic resonances at different frequencies determined by the x parameter are found.

Chao, Liu, E-mail: liu.chao@tufts.edu; Afsar, Mohammed N. [Department of Electrical and Computer Engineering, Tufts University, Medford, Massachusetts 02155 (United States); Ohkoshi, Shin-ichi [Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

2014-05-07T23:59:59.000Z

184

Protective nitride formation on stainless steel alloys for proton exchange membrane fuel cell bipolar plates  

SciTech Connect

Gas nitridation has shown excellent promise to form dense, electrically conductive and corrosion-resistant Cr-nitride surface layers on Ni-Cr base alloys for use as proton exchange membrane fuel cell (PEMFC) bipolar plates. Due to the high cost of nickel, Fe-base bipolar plate alloys are needed to meet the cost targets for many PEMFC applications. Unfortunately, nitridation of Fe-base stainless steel alloys typically leads to internal Cr-nitride precipitation rather than the desired protective surface nitride layer formation, due to the high permeability of nitrogen in these alloys. This paper reports the finding that it is possible to form a continuous, protective Cr-nitride (CrN and Cr{sub 2}N) surface layer through nitridation of Fe-base stainless steel alloys. The key to form a protective Cr-nitride surface layer was found to be the initial formation of oxide during nitridation, which prevented the internal nitridation typically observed for these alloys, and resulted in external Cr-nitride layer formation. The addition of V to the alloy, which resulted in the initial formation of V{sub 2}O{sub 3}-Cr{sub 2}O{sub 3}, was found to enhance this effect, by making the initially formed oxide more amenable to subsequent nitridation. The Cr-nitride surface layer formed on model V-modified Fe-27Cr alloys exhibited excellent corrosion resistance and low interfacial contact resistance under simulated PEMFC bipolar plate conditions.

Yang, Bing [ORNL; Brady, Michael P [ORNL; Wang, Heli [National Renewable Energy Laboratory (NREL); Turner, John [National Renewable Energy Laboratory (NREL); More, Karren Leslie [ORNL; Young, David J [ORNL; Tortorelli, Peter F [ORNL; Payzant, E Andrew [ORNL; Walker, Larry R [ORNL

2007-01-01T23:59:59.000Z

185

Nanofluidics, from bulk to interfaces  

E-Print Network (OSTI)

Nanofluidics has emerged recently in the footsteps of microfluidics, following the quest of scale reduction inherent to nanotechnologies. By definition, nanofluidics explores transport phenomena of fluids at the nanometer scales. Why is the nanometer scale specific ? What fluid properties are probed at nanometric scales ? In other words, why 'nanofluidics' deserves its own brand name ? In this critical review, we will explore the vast manifold of length scales emerging for the fluid behavior at the nanoscales, as well as the associated mechanisms and corresponding applications. We will in particular explore the interplay between bulk and interface phenomena. The limit of validity of the continuum approaches will be discussed, as well as the numerous surface induced effects occuring at these scales, from hydrodynamic slippage to the various electro-kinetic phenomena originating from the couplings between hydrodynamics and electrostatics. An enlightening analogy between ion transport in nanochannels and transport in doped semi-conductors will be discussed.

Lyderic Bocquet; Elisabeth Charlaix

2009-09-03T23:59:59.000Z

186

E-Print Network 3.0 - amorphous carbon nitride Sample Search...  

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

-8984(99)96581-5 Structural and magnetic properties of ammonia-nitrided Y2Fe17 N X Shen, J I Budnick, W A Hines, Y D Zhang, D... and magnetic properties of ammonia-nitrided...

187

Synthesis of III-V nitride nanowires with controlled structure, morphology, and composition  

E-Print Network (OSTI)

The III-V nitride materials system offers tunable electronic and optical properties that can be tailored for specific electronic and optoelectronic applications by varying the (In,Ga,Al)N alloy composition. While nitride ...

Crawford, Samuel Curtis

2014-01-01T23:59:59.000Z

188

Surface engineering and chemical characterization in ion-nitrided titanium and titanium alloys  

Science Journals Connector (OSTI)

The chemical and physical characteristics of ion-nitrided surface layers, obtained on ?-? titanium alloys, are examined and correlated both with the working conditions adopted in the ion-nitriding process and wit...

T. Bacci; G. Pradelli; B. Tesi; C. Gianoglio; C. Badini

1990-10-01T23:59:59.000Z

189

Investigation of Gallium Partitioning Behavior in Aqueous Two-Phase Systems Containing Polyethylene Glycol and Ammonium Sulfate  

Science Journals Connector (OSTI)

Gallium is assumed to be an indispensable rare metal mainly because of its fast growing demand as gallium arsenide (GaAs) in integrated circuits. ... Traditional extraction methods for gallium usually are organic?water two-phase systems, which involve volatile, flammable, and explosive organic solvents, such as n-hexane, toluene, xylene, benzene, nitrobenzene and kerosene. ... (17) A temperature increase reduces the mutual solubility of the two phases and results in an increase of PEG concentration in the upper phase and of volume in the lower phase, which all make ?w1 increase. ...

Yuhuan Chen; Xiaoli Liu; Yan Lu; Xiuying Zhang

2009-04-22T23:59:59.000Z

190

Optical, electrical, and solar energy-conversion properties of gallium arsenide nanowire-array  

E-Print Network (OSTI)

Optical, electrical, and solar energy-conversion properties of gallium arsenide nanowire, and will aid in the design and optimization of nanowire-based systems for solar energy-conversion applications, and the photoelectrochemical energy-conversion properties of GaAs nanowire arrays were evaluated in contact with one

Zhou, Chongwu

191

Molten Gallium as a Catalyst for the Large-Scale Growth of Highly Aligned Silica Nanowires  

E-Print Network (OSTI)

Molten Gallium as a Catalyst for the Large-Scale Growth of Highly Aligned Silica Nanowires Zheng a small size (5-100 nm in diameter), high melting point metal (such as gold and iron) catalyst particle as an effective catalyst for the large-scale growth of highly aligned, closely packed silica nanowire bunches

Wang, Zhong L.

192

GALLIUM--2003 28.1 References that include a section mark () are found in the Internet  

E-Print Network (OSTI)

in the United States was in the form of GaAs. GaAs was manufactured into optoelectronic devices (LEDs, laser diodes, photodetectors, and solar cells) and ICs. ICs and optoelectronic devices each accounted for 41) and optoelectronic devices [mostly laser diodes and light- emitting diodes (LEDs)]. Estimated crude gallium

193

Synthesis and Characterization of Bulk Vitreous Cadmium Germanium...  

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

Bulk Vitreous Cadmium Germanium Arsenide. Synthesis and Characterization of Bulk Vitreous Cadmium Germanium Arsenide. Abstract: Abstract Cadmium-germanium-diarsenide...

194

Bulk viscosity of a pion gas  

Science Journals Connector (OSTI)

We compute the bulk viscosity of a gas of pions at temperatures below the QCD crossover temperature, for the physical value of m?, to lowest order in chiral perturbation theory. Bulk viscosity is controlled by number-changing processes which become exponentially slow at low temperatures when the pions become exponentially dilute, leading to an exponentially large bulk viscosity ?~(F08/m?5)exp(2m?/T), where F0?93?MeV is the pion decay constant.

Egang Lu and Guy D. Moore

2011-04-07T23:59:59.000Z

195

Hyperon bulk viscosity in strong magnetic fields  

SciTech Connect

We study the bulk viscosity of neutron star matter including {lambda} hyperons in the presence of quantizing magnetic fields. Relaxation time and bulk viscosity due to both the nonleptonic weak process involving {lambda} hyperons and direct Urca processes are calculated here. In the presence of a strong magnetic field of 10{sup 17} G, the hyperon bulk viscosity coefficient is reduced, whereas bulk viscosity coefficients due to direct Urca processes are enhanced compared with their field free cases when many Landau levels are populated by protons, electrons, and muons.

Sinha, Monika; Bandyopadhyay, Debades [Theory Division and Centre for Astroparticle Physics, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064 (India)

2009-06-15T23:59:59.000Z

196

Bulk viscosity in kaon condensed matter  

E-Print Network (OSTI)

We investigate the effect of $K^-$ condensed matter on bulk viscosity and r-mode instability in neutron stars. The bulk viscosity coefficient due to the non-leptonic process $n \\rightleftharpoons p + K^-$ is studied here. In this connection, equations of state are constructed within the framework of relativistic field theoretical models where nucleon-nucleon and kaon-nucleon interactions are mediated by the exchange of scalar and vector mesons. We find that the bulk viscosity coefficient due to the non-leptonic weak process in the condensate is suppressed by several orders of magnitude. Consequently, kaon bulk viscosity may not damp the r-mode instability in neutron stars.

Debarati Chatterjee; Debades Bandyopadhyay

2007-02-09T23:59:59.000Z

197

Oxygen penetration into the bulk of palladium  

Science Journals Connector (OSTI)

Oxygen penetration into the bulk of palladium ... During heating, the reaction rate exhibited an activity maximum at 650 K, whereas no activity maximum was found during the ... ...

C. T. Campbell; D. C. Foyt; J. M. White

1977-01-01T23:59:59.000Z

198

Commercialization of Bulk Thermoelectric Materials for Power...  

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

& Publications Commercialization of Bulk Thermoelectric Materials for Power Generation Hydrogen Embrittlement of Pipeline Steels: Causes and Remediation Distributed Bio-Oil...

199

Nanostructured High Temperature Bulk Thermoelectric Energy Conversion...  

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

Efficient Automotive Waste Heat Recovery Multi-physics modeling of thermoelectric generators for waste heat recovery applications Nanostructured High-Temperature Bulk...

200

Applications of bulk high-temperature superconductors  

SciTech Connect

The development of high-temperature superconductors (HTSs) can be broadly generalized into thin-film electronics, wire applications, and bulk applications. We consider bulk HTSs to include sintered or crystallized forms that do not take the geometry of filaments or tapes, and we discuss major applications for these materials. For the most part applications may be realized with the HTSs cooled to 77 K, and the properties of the bulk HTSs are often already sufficient for commercial use. A non-exhaustive list of applications for bulk HTSs includes trapped field magnets, hysteresis motors, magnetic shielding, current leads, and magnetic bearings. These applications are briefly discussed in this paper.

Hull, J.R.

1995-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "bulk gallium nitride" 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

Recent Device Developments with Advanced Bulk Thermoelectric...  

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

at RTI Reviews work in engineered thin-film nanoscale thermoelectric materials and nano-bulk materials with high ZT undertaken by RTI in collaboration with its research...

202

Thermodynamic stability of oxide, nitride, and carbide coating materials in liquid Sn25Li  

E-Print Network (OSTI)

Thermodynamic stability of oxide, nitride, and carbide coating materials in liquid Sn­25Li S of various oxides, carbides, and nitrides in Sn­Li is estimated as a function of lithium composition K most of the studied nitrides, carbides, and some oxides were found to be stable (DrG > 0). However

Ghoniem, Nasr M.

203

Trends in elasticity and electronic structure of transition-metal nitrides and carbides from first principles  

E-Print Network (OSTI)

Trends in elasticity and electronic structure of transition-metal nitrides and carbides from first 2005 The elastic properties of selected transition-metal TM nitrides and carbides in B1 structure the transition-metal nitrides and carbides remain unclear and a challenge for engineering hard materials

Wu, Zhigang

204

Extreme nitriding limits in aluminium extrusion  

Science Journals Connector (OSTI)

Extrusion of aluminium is an efficient manufacturing process which allows long continuous production. The heated billet (aluminium material) is squeezed through the opening of a metal die in order to shape the desired aluminium profile. A long continuous production increases aging of the die and hampers its capability to yield homogeneously shaped profiles. Hence the dies are usually removed from production lines before their breaking point and only go back into production after receiving a layer coat for protection of the metal. This paper consists of a preliminary analysis of the extrusion amounts between consecutive maintenance procedures of the dies. A maintenance procedure in its whole encompasses an immersion bath of the die in caustic soda, a polishing operation and possibly a subsequent coat layering process in a nitriding chamber. The main goal here is to find the optimal life cycle for a die, in the sense that we are looking for a risk level (an extrusion amount) above which die-damage occurs with a certain high probability. We shall rely on extreme value statistics to answer the question of how long can we go on at each continuous operation of aluminium extrusion.

Claudia Neves; M. Ivette Gomes; Isabel Fraga Alves

2011-01-01T23:59:59.000Z

205

Active Control of Nitride Plasmonic Dispersion in the Far Infrared.  

SciTech Connect

We investigate plasmonic structures in nitride-based materials for far-infrared (IR) applications. The two dimensional electron gas (2DEG) in the GaN/AlGaN material system, much like metal- dielectric structures, is a patternable plasmonic medium. However, it also permits for direct tunability via an applied voltage. While there have been proof-of-principle demonstrations of plasma excitations in nitride 2DEGs, exploration of the potential of this material system has thus far been limited. We recently demonstrated coherent phenomena such as the formation of plasmonic crystals, strong coupling of tunable crystal defects to a plasmonic crystal, and electromagnetically induced transparency in GaAs/AlGaAs 2DEGs at sub-THz frequencies. In this project, we explore whether these effects can be realized in nitride 2DEG materials above 1 THz and at temperatures exceeding 77 K.

Shaner, Eric A.; Dyer, Gregory Conrad; Seng, William Francis; Bethke, Donald Thomas; Grine, Albert Dario,; Baca, Albert G.; Allerman, Andrew A.

2014-11-01T23:59:59.000Z

206

Low temperature thermal transport in partially perforated silicon nitride membranes.  

SciTech Connect

The thermal transport in partially trenched silicon nitride membranes has been studied in the temperature range from 0.3 to 0.6 K, with the transition edge sensor (TES), the sole source of membrane heating. The test configuration consisted of Mo/Au TESs lithographically defined on silicon nitride membranes 1 {micro}m thick and 6 mm{sup 2} in size. Trenches with variable depth were incorporated between the TES and the silicon frame in order to manage the thermal transport. It was shown that sharp features in the membrane surface, such as trenches, significantly impede the modes of phonon transport. A nonlinear dependence of thermal resistance on trench depth was observed. Partial perforation of silicon nitride membranes to control thermal transport could be useful in fabricating mechanically robust detector devices.

Yefremenko, V.; Wang, G.; Novosad, V.; Datesman, A.; Pearson, J.; Divan, R.; Chang, C. L.; Downes, T. P.; Mcmahon, J. J.; Bleem, L. E.; Crites, A. T.; Meyer, S. S.; Carlstrom, J. E.; Univ. of Chicago

2009-05-04T23:59:59.000Z

207

Structural studies of magnesium nitride fluorides by powder neutron diffraction  

SciTech Connect

Samples of ternary nitride fluorides, Mg{sub 3}NF{sub 3} and Mg{sub 2}NF have been prepared by solid state reaction of Mg{sub 3}N{sub 2} and MgF{sub 2} at 1323-1423 K and investigated by powder X-ray and powder neutron diffraction techniques. Mg{sub 3}NF{sub 3} is cubic (space group: Pm3m) and has a structure related to rock-salt MgO, but with one cation site vacant. Mg{sub 2}NF is tetragonal (space group: I4{sub 1}/amd) and has an anti-LiFeO{sub 2} related structure. Both compounds are essentially ionic and form structures in which nitride and fluoride anions are crystallographically ordered. The nitride fluorides show temperature independent paramagnetic behaviour between 5 and 300 K. - Graphical abstract: Definitive structures of the ternary magnesium nitride fluorides Mg{sub 3}NF{sub 3} and the lower temperature polymorph of Mg{sub 2}NF have been determined from powder neutron diffraction data. The nitride halides are essentially ionic and exhibit weak temperature independent paramagnetic behaviour. Highlights: Black-Right-Pointing-Pointer Definitive structures of Mg{sub 3}NF{sub 3} and Mg{sub 2}NF were determined by neutron diffraction. Black-Right-Pointing-Pointer Nitride and fluoride anions are crystallographically ordered in both structures. Black-Right-Pointing-Pointer Both compounds exhibit weak, temperature independent paramagnetic behaviour. Black-Right-Pointing-Pointer The compounds are essentially ionic with ionicity increasing with F{sup -} content.

Brogan, Michael A. [School of Chemistry, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Hughes, Robert W. [WestCHEM, School of Chemistry, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Smith, Ronald I. [ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX (United Kingdom); Gregory, Duncan H., E-mail: Duncan.Gregory@glasgow.ac.uk [WestCHEM, School of Chemistry, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

2012-01-15T23:59:59.000Z

208

Synthesis of uranium nitride and uranium carbide powder by carbothermic reduction  

SciTech Connect

Uranium nitride and uranium carbide are being considered as high burnup fuels in next generation nuclear reactors and accelerated driven systems for the transmutation of nuclear waste. The same characteristics that make nitrides and carbides candidates for these applications (i.e. favorable thermal properties, mutual solubility of nitrides, etc.), also make these compositions candidate fuels for space nuclear reactors. In this paper, we discuss the synthesis and characterization of depleted uranium nitride and carbide for a space nuclear reactor program. Importantly, this project emphasized that to synthesize high quality uranium nitride and carbide, it is necessary to understand the exact stoichiometry of the oxide feedstock. (authors)

Dunwoody, J.T.; Stanek, C.R.; McClellan, K.J.; Voit, S.L.; Volz, H.M. [Los Alamos National Laboratory, Los Alamos, New Mexico (United States); Hickman, R.R. [NASA Marshall Space Flight Center, Huntsville, Alabama (United States)

2007-07-01T23:59:59.000Z

209

Process for synthesizing titanium carbide, titanium nitride and titanium carbonitride  

DOE Patents (OSTI)

A process for synthesizing titanium carbide, titanium nitride or titanium carbonitride. The process comprises placing particles of titanium, a titanium salt or titanium dioxide within a vessel and providing a carbon-containing atmosphere within the vessel. The vessel is heated to a pyrolysis temperature sufficient to pyrolyze the carbon to thereby coat the particles with a carbon coating. Thereafter, the carbon-coated particles are heated in an inert atmosphere to produce titanium carbide, or in a nitrogen atmosphere to produce titanium nitride or titanium carbonitride, with the heating being of a temperature and time sufficient to produce a substantially complete solid solution.

Koc, Rasit (Lakewood, CO); Glatzmaier, Gregory C. (Boulder, CO)

1995-01-01T23:59:59.000Z

210

Process for synthesizing titanium carbide, titanium nitride and titanium carbonitride  

DOE Patents (OSTI)

A process is disclosed for synthesizing titanium carbide, titanium nitride or titanium carbonitride. The process comprises placing particles of titanium, a titanium salt or titanium dioxide within a vessel and providing a carbon-containing atmosphere within the vessel. The vessel is heated to a pyrolysis temperature sufficient to pyrolyze the carbon to thereby coat the particles with a carbon coating. Thereafter, the carbon-coated particles are heated in an inert atmosphere to produce titanium carbide, or in a nitrogen atmosphere to produce titanium nitride or titanium carbonitride, with the heating being of a temperature and time sufficient to produce a substantially complete solid solution.

Koc, R.; Glatzmaier, G.C.

1995-05-23T23:59:59.000Z

211

Process for producing amorphous and crystalline silicon nitride  

DOE Patents (OSTI)

A process for producing amorphous or crystalline silicon nitride is disclosed which comprises reacting silicon disulfide ammonia gas at elevated temperature. In a preferred embodiment silicon disulfide in the form of "whiskers" or needles is heated at temperature ranging from about 900.degree. C. to about 1200.degree. C. to produce silicon nitride which retains the whisker or needle morphological characteristics of the silicon disulfide. Silicon carbide, e.g. in the form of whiskers, also can be prepared by reacting substituted ammonia, e.g. methylamine, or a hydrocarbon containing active hydrogen-containing groups, such as ethylene, with silicon disulfide, at elevated temperature, e.g. 900.degree. C.

Morgan, Peter E. D. (Thousand Oaks, CA); Pugar, Eloise A. (Newbury Park, CA)

1985-01-01T23:59:59.000Z

212

Process for producing wurtzitic or cubic boron nitride  

DOE Patents (OSTI)

Disclosed is a process for producing wurtzitic or cubic boron nitride comprising the steps of: [A] preparing an intimate mixture of powdered boron oxide, a powdered metal selected from the group consisting of magnesium or aluminum, and a powdered metal azide; [B] igniting the mixture and bringing it to a temperature at which self-sustaining combustion occurs; [C] shocking the mixture at the end of the combustion thereof with a high pressure wave, thereby forming as a reaction product, wurtzitic or cubic boron nitride and occluded metal oxide; and, optionally [D] removing the occluded metal oxide from the reaction product. Also disclosed are reaction products made by the process described.

Holt, J.B.; Kingman, D.D.; Bianchini, G.M.

1992-04-28T23:59:59.000Z

213

Process for producing wurtzitic or cubic boron nitride  

DOE Patents (OSTI)

Disclosed is a process for producing wurtzitic or cubic boron nitride comprising the steps of: [A] preparing an intimate mixture of powdered boron oxide, a powdered metal selected from the group consisting of magnesium or aluminum, and a powdered metal azide; [B] igniting the mixture and bringing it to a temperature at which self-sustaining combustion occurs; [C] shocking the mixture at the end of the combustion thereof with a high pressure wave, thereby forming as a reaction product, wurtzitic or cubic boron nitride and occluded metal oxide; and, optionally [D] removing the occluded metal oxide from the reaction product. Also disclosed are reaction products made by the process described.

Holt, J. Birch (San Jose, CA); Kingman, deceased, Donald D. (late of Danville, CA); Bianchini, Gregory M. (Livermore, CA)

1992-01-01T23:59:59.000Z

214

Bulk viscosity of a pion gas  

SciTech Connect

We compute the bulk viscosity of a gas of pions at temperatures below the QCD crossover temperature, for the physical value of m{sub {pi}}, to lowest order in chiral perturbation theory. Bulk viscosity is controlled by number-changing processes which become exponentially slow at low temperatures when the pions become exponentially dilute, leading to an exponentially large bulk viscosity {zeta}{approx}(F{sub 0}{sup 8}/m{sub {pi}}{sup 5})exp(2m{sub {pi}}/T), where F{sub 0}{approx_equal}93 MeV is the pion decay constant.

Lu Egang; Moore, Guy D. [Department of Physics, McGill University, 3600 rue University, Montreal, Quebec, H3A 2T8 (Canada)

2011-04-15T23:59:59.000Z

215

The Bulk Viscosity of a Pion Gas  

E-Print Network (OSTI)

We compute the bulk viscosity of a gas of pions at temperatures below the QCD crossover temperature, for the physical value of pion mass, to lowest order in chiral perturbation theory. Bulk viscosity is controlled by number-changing processes which become exponentially slow at low temperatures when the pions become exponentially dilute, leading to an exponentially large bulk viscosity zeta ~ (F_0^8/m_\\pi^5) exp(2m_\\pi/T), where F_0 = 93 MeV is the pion decay constant.

Egang Lu; Guy D. Moore

2011-01-31T23:59:59.000Z

216

OXIDE / LPCVD NITRIDE STACKS ON SILICON: THE EFFECTS OF HIGH TEMPERATURE TREATMENTS ON BULK LIFETIME AND ON SURFACE PASSIVATION.  

E-Print Network (OSTI)

phosphorous diffusion (830°C for 30 minutes R[ ~800-1000/[#12; D WKHUPDOO\\ JURZQ R[LGH °C or 1100°C

217

Preliminary results from the Russian-American gallium experiment Cr-neutrino source measurement  

SciTech Connect

The Russian-American Gallium Experiment has been collecting solar neutrino data since early 1990. The flux measurement of solar neutrinos is well below that expected from solar models. We discuss the initial results of a measurement of experimental efficiencies by exposing the gallium target to neutrinos from an artificial source. The capture rate of neutrinos from this source is very close to that which is expected. The result can be expressed as a ratio of the measured capture rate to the anticipated rate from the source activity. This ratio is 0.93 + 0.15, {minus}0.17 where the systematic and statistical errors have been combined. To first order the experimental efficiencies are in agreement with those determined during solar neutrino measurements and in previous auxiliary measurements. One must conclude that the discrepancy between the measured solar neutrino flux and that predicted by the solar models can not arise from an experimental artifact. 17 refs., 3 figs., 1 tab.

Elliott, S.R. [Washington Univ., Seattle, WA (United States); Abdurashitov, J.N. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. for Nuclear Research; Bowles, T.J. [Los Alamos National Lab., NM (United States)] [and others

1995-12-31T23:59:59.000Z

218

Fast neutron scattering on Gallium target at 14.8 MeV  

E-Print Network (OSTI)

Benchmarking of evaluated nuclear data libraries was performed for $\\sim 14.8$ MeV neutrons on Gallium targets. The experiments were performed at China Institute of Atomic Energy(CIAE). Solid samples of natural Gallium (3.2 cm and 6.4 cm thick) were bombarded by $\\sim 14.8$ MeV neutrons and leakage neutron energy spectra were measured at 60$^{\\circ}$ and 120$^{\\circ}$. The measured spectra are rather well reproduced by MCNP-4C simulations with the CENDL-3.1, ENDF/B-VII and JENDL-4.0 evaluated nuclear data libraries, except for the inelastic contributions around $E_{n} = 10-13$ MeV. All three libraries significantly underestimate the inelastic contributions. The inelastic contributions are further studied, using the Talys simulation code and the experimental spectra are reproduced reasonably well in the whole energy range by the Talys calculation, including the inelastic contributions.

Han, R; Chen, Z; Nie, Y; Liu, X; Zhang, S; Ren, P; Jia, B; Tian, G; Luo, F; Lin, W; Liu, J; Shi, F; Huang, M; Ruan, X; Ren, J; Zhou, Z; Huang, H; Bao, J; Zhang, K; Hu, B

2014-01-01T23:59:59.000Z

219

Fast neutron scattering on Gallium target at 14.8 MeV  

E-Print Network (OSTI)

Benchmarking of evaluated nuclear data libraries was performed for $\\sim 14.8$ MeV neutrons on Gallium targets. The experiments were performed at China Institute of Atomic Energy(CIAE). Solid samples of natural Gallium (3.2 cm and 6.4 cm thick) were bombarded by $\\sim 14.8$ MeV neutrons and leakage neutron energy spectra were measured at 60$^{\\circ}$ and 120$^{\\circ}$. The measured spectra are rather well reproduced by MCNP-4C simulations with the CENDL-3.1, ENDF/B-VII and JENDL-4.0 evaluated nuclear data libraries, except for the inelastic contributions around $E_{n} = 10-13$ MeV. All three libraries significantly underestimate the inelastic contributions. The inelastic contributions are further studied, using the Talys simulation code and the experimental spectra are reproduced reasonably well in the whole energy range by the Talys calculation, including the inelastic contributions.

R. Han; R. Wada; Z. Chen; Y. Nie; X. Liu; S. Zhang; P. Ren; B. Jia; G. Tian; F. Luo; W. Lin; J. Liu; F. Shi; M. Huang; X. Ruan; J. Ren; Z. Zhou; H. Huang; J. Bao; K. Zhang; B. Hu

2014-11-03T23:59:59.000Z

220

Thermodynamic property evaluation and magnetic refrigeration cycle analysis for gadolinium gallium garnet  

SciTech Connect

Based on relevant material property data and previous model formulations, a magnetothermodynamic property map for gadolinium gallium garnet (Gd{sub 3}Ga{sub 5}O{sub 12}) was adapted for refrigeration cycle analysis in the temperature range 4-40 K and the magnetic field range 0-6 T. Employing methods similar to those previously developed for other materials and temperature ranges, assessments of limitations and relative performance were made for Carnot, ideal regenerative, and pseudo-constant field regenerative cycles. It was found that although Carnot cycle limitations on available temperature lift for gadolinium gallium garnet are not as severe as the limitations for materials previously examined, considerable improvement in cooling capacity and temperature lift combinations can be achieved by using regenerative cycles if serious loss mechanisms are avoided.

Murphy, R.W.

1994-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "bulk gallium nitride" 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

Continuous Fiber Ceramic Composite (CFCC) Program: Gaseous Nitridation  

SciTech Connect

Textron has developed a mature process for the fabrication of continuous fiber ceramic composite (CFCC) tubes for application in the aluminum processing and casting industry. The major milestones in this project are System Composition; Matrix Formulation; Preform Fabrication; Nitridation; Material Characterization; Component Evaluation

R. Suplinskas G. DiBona; W. Grant

2001-10-29T23:59:59.000Z

222

BORON NITRIDE CAPACITORS FOR ADVANCED POWER ELECTRONIC DEVICES  

SciTech Connect

This project fabricates long-life boron nitride/boron oxynitride thin film -based capacitors for advanced SiC power electronics with a broad operating temperature range using a physical vapor deposition (PVD) technique. The use of vapor deposition provides for precise control and quality material formation.

N. Badi; D. Starikov; C. Boney; A. Bensaoula; D. Johnstone

2010-11-01T23:59:59.000Z

223

Methods for improved growth of group III nitride buffer layers  

DOE Patents (OSTI)

Methods are disclosed for growing high crystal quality group III-nitride epitaxial layers with advanced multiple buffer layer techniques. In an embodiment, a method includes forming group III-nitride buffer layers that contain aluminum on suitable substrate in a processing chamber of a hydride vapor phase epitaxy processing system. A hydrogen halide or halogen gas is flowing into the growth zone during deposition of buffer layers to suppress homogeneous particle formation. Some combinations of low temperature buffers that contain aluminum (e.g., AlN, AlGaN) and high temperature buffers that contain aluminum (e.g., AlN, AlGaN) may be used to improve crystal quality and morphology of subsequently grown group III-nitride epitaxial layers. The buffer may be deposited on the substrate, or on the surface of another buffer. The additional buffer layers may be added as interlayers in group III-nitride layers (e.g., GaN, AlGaN, AlN).

Melnik, Yurity; Chen, Lu; Kojiri, Hidehiro

2014-07-15T23:59:59.000Z

224

Novel compound semiconductor devices based on III-V nitrides  

SciTech Connect

New developments in dry and wet etching, ohmic contacts and epitaxial growth of Ill-V nitrides are reported. These make possible devices such as microdisk laser structures and GaAs/AlGaAs heterojunction bipolar transistors with improved InN ohmic contacts.

Pearton, S.J.; Abernathy, C.R. [Florida Univ., Gainesville, FL (United States); Ren, F. [AT & T Bell Laboratories, Murray Hill, NJ (United States)] [and others

1995-10-01T23:59:59.000Z

225

Nitridation of zirconium using energetic ions from plasma focus device  

Science Journals Connector (OSTI)

The nitridation of zirconium disks is achieved by irradiating energetic nitrogen ions from 2.3 kJ plasma focus device using multiple focus deposition shots (10, 20, 30 and 40) at different angular positions with respect to the anode axis. The X-ray diffraction analysis reveals the evolution of ZrN, Zr2N and Zr3N4 phases of zirconium nitride depending upon the ion energy flux and angular positions. The crystallite size of ZrN and Zr2N phases increases by increasing the number of focus deposition shots. The residual stresses estimated for Zr (101), ZrN (111) and ZrN (200) phases are maximum in the nitrided surfaces at lower nitrogen ion dose, decreases as the nitrogen ion dose increases. The field emission scanning electron microscopy results exhibit the uniform and smooth film of zirconium nitride with granular surface morphology at 10° angular position. The energy dispersive X-rays spectroscopy data indicate that nitrogen content in the film is improved for higher nitrogen ion dose while reduced at larger angular positions. The Vickers microhardness of the film is enhanced up to 400%. The microhardness increases by increasing the nitrogen ion dose and decreases rapidly by increasing the angular position.

I.A. Khan; M. Hassan; R. Ahmad; A. Qayyum; G. Murtaza; M. Zakaullah; R.S. Rawat

2008-01-01T23:59:59.000Z

226

Definition: Bulk Electric System | Open Energy Information  

Open Energy Info (EERE)

Bulk Electric System Bulk Electric System Jump to: navigation, search Dictionary.png Bulk Electric System As defined by the Regional Reliability Organization, the electrical generation resources, transmission lines, interconnections with neighboring systems, and associated equipment, generally operated at voltages of 100 kV or higher. Radial transmission facilities serving only load with one transmission source are generally not included in this definition.[1] Related Terms Regional Reliability Organization, transmission lines, transmission line References ↑ Glossary of Terms Used in Reliability Standards An in LikeLike UnlikeLike You like this.Sign Up to see what your friends like. line Glossary Definition Retrieved from "http://en.openei.org/w/index.php?title=Definition:Bulk_Electric_System&oldid=48030

227

Bulk Viscosity of a Pion Gas  

SciTech Connect

We calculate the bulk viscosity of a pion gas at low energies within the kinetic theory approach and show the importance of dealing properly with the zero modes of this transport coefficient.

Dobado, Antonio; Torres-Rincon, Juan M. [Dpto. Fisica Teorica I, Universidad Complutense de Madrid, 28040 Madrid (Spain)

2011-05-23T23:59:59.000Z

228

Effects of bulk viscosity at freezeout  

SciTech Connect

We investigate particle spectra and elliptic flow coefficients in relativistic heavy-ion collisions by taking into account the distortion of phase space distributions by bulk viscosity at freezeout. We first calculate the distortion of phase space distributions in a multicomponent system with Grad's 14-moment method. We find some subtle issues when macroscopic variables are matched with microscopic momentum distributions in a multicomponent system, and we develop a consistent procedure to uniquely determine the corrections to the phase space distributions. Next, we calculate particle spectra by using the Cooper-Frye formula to see the effect of the bulk viscosity. Despite the relative smallness of the bulk viscosity, we find that it is likely to have a visible effect on particle spectra and elliptic flow coefficients. This indicates the importance of taking into account bulk viscosity together with shear viscosity to constrain the transport coefficients with better accuracy from comparison with experimental data.

Monnai, Akihiko; Hirano, Tetsufumi [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan)

2009-11-15T23:59:59.000Z

229

Inorganic Nanocrystal Bulk Heterojunctions - Energy Innovation...  

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

This Technology

Schematic illustration of a nanocrystal bulk heterojunction solar cell with an active layer in which the concentration of n-type and p-type nanocrystals is...

230

Texas Bulk Power Study-- An Overview  

E-Print Network (OSTI)

TEXAS BULK POWER STUDY -- AN OVERVIEW BIll MOORE Economist Publ ic Utility Commission of Texas Austin, Texas ABSTRACT In the 1980' s, several signi ficant changes have evolved in markets for electric power in Texas. Cogeneration, fuel... of bulk power transactions may reduce some uncertainty and result in cost savings to the util ities involved. However, both the transactions potential and any corresponding changes in operating costs are quite sensitive to assumptions about the price...

Moore, B.

231

Layered insulator hexagonal boron nitride for surface passivation in quantum dot solar cell  

SciTech Connect

Single crystalline, two dimensional (2D) layered insulator hexagonal boron nitride (h-BN), is demonstrated as an emerging material candidate for surface passivation on mesoporous TiO{sub 2}. Cadmium selenide (CdSe) quantum dot based bulk heterojunction (BHJ) solar cell employed h-BN passivated TiO{sub 2} as an electron acceptor exhibits photoconversion efficiency ?46% more than BHJ employed unpassivated TiO{sub 2}. Dominant interfacial recombination pathways such as electron capture by TiO{sub 2} surface states and recombination with hole at valence band of CdSe are efficiently controlled by h-BN enabled surface passivation, leading to improved photovoltaic performance. Highly crystalline, confirmed by transmission electron microscopy, dangling bond-free 2D layered h-BN with self-terminated atomic planes, achieved by chemical exfoliation, enables efficient passivation on TiO{sub 2}, allowing electronic transport at TiO{sub 2}/h-BN/CdSe interface with much lower recombination rate compared to an unpassivated TiO{sub 2}/CdSe interface.

Shanmugam, Mariyappan; Jain, Nikhil; Jacobs-Gedrim, Robin; Yu, Bin, E-mail: byu@albany.edu [College of Nanoscale Science and Engineering, State University of New York, Albany, New York 12203 (United States)] [College of Nanoscale Science and Engineering, State University of New York, Albany, New York 12203 (United States); Xu, Yang [Institute of Microelectronics and Optoelectronics, Zhejiang University, Hangzhou 310027 (China)] [Institute of Microelectronics and Optoelectronics, Zhejiang University, Hangzhou 310027 (China)

2013-12-09T23:59:59.000Z

232

RAPID/BulkTransmission/Land Access | Open Energy Information  

Open Energy Info (EERE)

Information Desktop Toolkit BETA RAPID Toolkit About Bulk Transmission Geothermal Solar Tools Contribute Contact Us RAPID Bulk Transmission Land Access Regulatory...

233

RAPID/BulkTransmission/Siting/New Mexico | Open Energy Information  

Open Energy Info (EERE)

Solar Resources Contribute Contact Us RAPID Bulk Transmission Siting New Mexico Bulk Transmission Siting in New Mexico Regulatory Information Overviews Search for...

234

High Heat Flux Thermoelectric Module Using Standard Bulk Material...  

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

Heat Flux Thermoelectric Module Using Standard Bulk Material High Heat Flux Thermoelectric Module Using Standard Bulk Material Presents high heat flux thermoelectric module design...

235

RAPID/Overview/BulkTransmission/Siting/Colorado | Open Energy...  

Open Energy Info (EERE)

Colorado < RAPID | Overview | BulkTransmission | Siting(Redirected from RAPIDAtlasBulkTransmissionSitingColorado) Redirect page Jump to: navigation, search REDIRECT...

236

Bulk Hydrogen Storage - Strategic Directions for Hydrogen Delivery...  

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

Bulk Hydrogen Storage - Strategic Directions for Hydrogen Delivery Workshop Bulk Hydrogen Storage - Strategic Directions for Hydrogen Delivery Workshop Targets, barriers and...

237

Nanostructured High-Temperature Bulk Thermoelectric Energy Conversion...  

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

Nanostructured High-Temperature Bulk Thermoelectric Energy Conversion for Efficient Automotive Waste Heat Recovery Nanostructured High-Temperature Bulk Thermoelectric Energy...

238

The influence of molecular orientation on organic bulk heterojunction...  

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

The influence of molecular orientation on organic bulk heterojunction solar cells The influence of molecular orientation on organic bulk heterojunction solar cells Print Monday, 28...

239

RAPID/BulkTransmission/Water Use | Open Energy Information  

Open Energy Info (EERE)

RAPIDBulkTransmissionWater Use < RAPID | BulkTransmission Jump to: navigation, search RAPID Regulatory and Permitting Information Desktop Toolkit BETA RAPID Toolkit About Bulk...

240

Sandia National Laboratories: Energy Efficiency  

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

Single-mode gallium nitride nanowire lasers On January 28, 2013, in EC, Energy Efficiency, Solid-State Lighting A new top-down method for fabricating gallium nitride...

Note: This page contains sample records for the topic "bulk gallium nitride" 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

E-Print Network 3.0 - aluminum oxide selectively Sample Search...  

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

between GaN and AlGaN has been observed up to an aluminum mole fraction... oxides.1-3 For gallium nitride and aluminum gallium nitride this effect has been seldom reported.4... ,...

242

Sandia National Laboratories: BES Web Highlight: Single-mode...  

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

ClimateECEnergyEnergy EfficiencyBES Web Highlight: Single-mode gallium nitride nanowire lasers BES Web Highlight: Single-mode gallium nitride nanowire lasers "Solid-state Lighting:...

243

4 - Bulk high temperature superconductor (HTS) materials  

Science Journals Connector (OSTI)

Abstract: This chapter concentrates on bulk materials. A bulk superconductor is one in which the superconductor has been formed into a lump, usually cylindrically shaped, but can also be hexagonal, rectangular or even square. Bulk superconductors are typically 3–5 cm across and 1 cm thick. They have many uses but the principal one is as extremely compact high-field permanent magnets in superconducting machines. A 2.6 cm (RE)BCO puck has been magnetised to 17.24 T: this is an order of magnitude greater than the flux density available from a conventional permanent magnet. This chapter describes the materials, manufacturing process, magnetisation process and some examples of machines.

T. Coombs

2012-01-01T23:59:59.000Z

244

Ion implantation of silicon nitride ball bearings  

SciTech Connect

Hypothesis for ion implantation effect was that stress concentrations reflected into the bulk due to topography such as polishing imperfections, texture in the race, or transferred material, might be reduced due to surface amorphization. 42 control samples were tested to an intended runout period of 60 h. Six ion implanted balls were tested to an extended period of 150 h. Accelerated testing was done in a V groove so that wear was on two narrow wear tracks. Rutherford backscattering, XRPS, profilometry, optical microscopy, nanoindentation hardness, and white light interferometry were used. The balls were implanted with 150-keV C ions at fluence 1.1x10{sup 17}/cm{sup 2}. The samples had preexisting surface defects (C-cracks), so the failure rate of the control group was unacceptable. None of the ion-implanted samples failed in 150 h of testing. Probability of randomly selecting 6 samples from the control group that would perform this well is about 5%, so there is good probability that ion implantation improved performance. Possible reasons are discussed. Wear tracks, microstructure, and impurity content were studied in possible relation to C-cracks.

Williams, J.M. [Oak Ridge National Lab., TN (United States); Miner, J.R. [United Technologies, Pratt and Whitney, West Palm Beach, FL (United States)

1996-09-01T23:59:59.000Z

245

E-Print Network 3.0 - alkali-resistant silicon nitride Sample...  

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

Computer Science Collection: Engineering ; Materials Science 4 Published in 'Silicon Carbide, III-Nitrides and Related Materials', Year: 1998, pp: 1149-1152 Periodical: Materials...

246

David Niedzwiecki 3/2/2012 2:37:42 PM Protocol for Ultrathin Nitride Membranes  

E-Print Network (OSTI)

necessary to remove the nitride layer. -Use the CHF3/CF4/Ar oxide removal protocol to remove the oxide. Do 8

Movileanu, Liviu

247

Method and apparatus for use of III-nitride wide bandgap semiconductors in optical communications  

DOE Patents (OSTI)

The present disclosure relates to the use of III-nitride wide bandgap semiconductor materials for optical communications. In one embodiment, an optical device includes an optical waveguide device fabricated using a III-nitride semiconductor material. The III-nitride semiconductor material provides for an electrically controllable refractive index. The optical waveguide device provides for high speed optical communications in an infrared wavelength region. In one embodiment, an optical amplifier is provided using optical coatings at the facet ends of a waveguide formed of erbium-doped III-nitride semiconductor materials.

Hui, Rongqing (Lenexa, KS); Jiang,Hong-Xing (Manhattan, KS); Lin, Jing-Yu (Manhattan, KS)

2008-03-18T23:59:59.000Z

248

E-Print Network 3.0 - aluminum nitride ceramics Sample Search...  

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

Emily Parker, Vanni Lughi, Noel C. MacDonald Summary: , biocompatibility, and high fracture toughness. As a piezoelectric ceramic, aluminum nitride is compatible... Aluminum...

249

Metal clusters with exposed and low-coordinate nitride nitrogen atoms  

SciTech Connect

The synthesis and structural characterization of a prototypic series of iron nitride clusters in which the nitrogen atoms are exposed and of low coordination number, namely four and five are described. The term nitride denotes species in which a nitrogen atom is only within bonding distance of metal atoms. The clusters prepared were (Fe/sub 4/N(CO)/sub 12//sup -/), (Fe/sub 5/N(CO)/sub 14//sup -/). The 62-electron four-iron nitrides should have butterfly structures and the 74-electron five-iron nitrides should have square-pyramidal structures. 1 figure.

Tachikawa, M. (Univ. of California, Berkeley); Stein, J.; Muetterties, E.L.; Teller, R.G.; Beno, M.A.; Gebert, E.; Williams, J.M.

1980-10-08T23:59:59.000Z

250

Chemical preparation and shock wave compression of carbon nitride precursors  

SciTech Connect

Two synthetic routes have been developed to produce high-molecular-weight organic precursors containing a high weight fraction of nitrogen. One of the precursors is a pyrolysis residue of melamine-formaldehyde resin. The second precursor is the byproduct of an unusual low-temperature combustion reaction of tetrazole and its sodium salt. These precursors have been shock compressed under typical conditions for diamond and wurtzite boron nitride synthesis in an attempt to recover a new ultrahard carbon nitride. The recovered material has been analyzed by X-ray diffraction, FTIR, and Raman microprobe analysis. Diamond is present in the recovered material. This diamond is well ordered relative to diamond shock synthesized from carbonaceous starting materials.

Wixon, M.R. (KMS Fusion, Inc., Ann Arbor, MI (USA))

1990-07-01T23:59:59.000Z

251

Electrically dependent bandgaps in graphene on hexagonal boron nitride  

SciTech Connect

We present first-principles calculations on the bandgap of graphene on a layer of hexagonal boron nitride in three different stacking configurations. Relative stability of the configurations is identified and bandgap tunability is demonstrated through the application of an external, perpendicularly applied electric field. We carefully examine the bandgap's sensitivity to both magnitude of the applied field as well as separation between the graphene and hexagonal boron nitride layers. Features of the band structure are examined and configuration-dependent relationships between the field and bandgap are revealed and elucidated through the atom-projected density of states. These findings suggest the potential for opening and modulating a bandgap in graphene as high as several hundred meV.

Kaplan, D., E-mail: daniel.b.kaplan.civ@mail.mil; Swaminathan, V. [U.S. Army RDECOM-ARDEC, Fuze Precision Armaments and Technology Directorate, Picatinny Arsenal, New Jersey 07806 (United States); Recine, G. [Department of Applied Physics, Polytechnic Institute of New York University, Brooklyn, New York 11201 (United States); Department of Physics and Engineering Physics, Fordham University, Bronx, New York 10458 (United States)

2014-03-31T23:59:59.000Z

252

2009 Minerals Yearbook U.S. Department of the Interior  

E-Print Network (OSTI)

As and gallium nitride (GaN) and was used in integrated circuits (ICs) and optoelectronic devices [laser diodes

253
254

Transistor-Based Miniature Microwave-Drill Applicator Yehuda Meir and Eli Jerby*  

E-Print Network (OSTI)

. Recent developments of gallium-nitride (GaN) and silicon- carbide (SiC) transistors have increased

Jerby, Eli

255

314 IEEE MICROWAVE AND GUIDED WAVE LETTERS, VOL. 9, NO. 8, AUGUST 1999 39-GHz GaN-Based Microwave Power  

E-Print Network (OSTI)

As-based counterparts of the same sizes. Index Terms--Amplifier, field-effect transistors, gallium-nitride (Ga

York, Robert A.

256

THERMAL STUDY OF A GaN-BASED HEMT A Dissertation  

E-Print Network (OSTI)

of gallium-nitride (GaN) high-electron-mobility transistors (HEMTs) under bias conditions. An experimental

Sen, Mihir

257

Employment after UC Graduation: 2005 2007: Assistant Professor, Department of Electrical Engineering, California Polytechnic State  

E-Print Network (OSTI)

and Educational Activity on Gallium-Nitride (GaN) Lasers and Light Emitting Diodes (LEDs)" International Journal

Boolchand, Punit

258

3-D view of 1-D nanostructures January 6th, 2012 Filed under Nano Science Tagged cormick-school, engineering,  

E-Print Network (OSTI)

cormick-school, engineering, esearchers-at-the, gallium-nitride, great-promise, have-found, mccormick

Espinosa, Horacio D.

259

Dual operation characteristics of resistance random access memory in indium-gallium-zinc-oxide thin film transistors  

SciTech Connect

In this study, indium-gallium-zinc-oxide thin film transistors can be operated either as transistors or resistance random access memory devices. Before the forming process, current-voltage curve transfer characteristics are observed, and resistance switching characteristics are measured after a forming process. These resistance switching characteristics exhibit two behaviors, and are dominated by different mechanisms. The mode 1 resistance switching behavior is due to oxygen vacancies, while mode 2 is dominated by the formation of an oxygen-rich layer. Furthermore, an easy approach is proposed to reduce power consumption when using these resistance random access memory devices with the amorphous indium-gallium-zinc-oxide thin film transistor.

Yang, Jyun-Bao; Chen, Yu-Ting; Chu, Ann-Kuo [Department of Photonics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Chang, Ting-Chang, E-mail: tcchang@mail.phys.nsysu.edu.tw [Department of Photonics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Department of Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Advanced Optoelectronics Technology Center, National Cheng Kung University, Taiwan (China); Huang, Jheng-Jie; Chen, Yu-Chun; Tseng, Hsueh-Chih [Department of Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Sze, Simon M. [Department of Physics, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Department of Electronics Engineering, National Chiao Tung University, Hsinchu, Taiwan (China)

2014-04-14T23:59:59.000Z

260

Bulk viscosity in a cold CFL superfluid  

E-Print Network (OSTI)

We compute one of the bulk viscosity coefficients of cold CFL quark matter in the temperature regime where the contribution of mesons, quarks and gluons to transport phenomena is Boltzmann suppressed. In that regime dissipation occurs due to collisions of superfluid phonons, the Goldstone modes associated to the spontaneous breaking of baryon symmetry. We first review the hydrodynamics of relativistic superfluids, and remind that there are at least three bulk viscosity coefficients in these systems. We then compute the bulk viscosity coefficient associated to the normal fluid component of the superfluid. In our analysis we use Son's effective field theory for the superfluid phonon, amended to include scale breaking effects proportional to the square of the strange quark mass m_s. We compute the bulk viscosity at leading order in the scale breaking parameter, and find that it is dominated by collinear splitting and joining processes. The resulting transport coefficient is zeta=0.011 m_s^4/T, growing at low temperature T until the phonon fluid description stops making sense. Our results are relevant to study the rotational properties of a compact star formed by CFL quark matter.

Cristina Manuel; Felipe Llanes-Estrada

2007-05-26T23:59:59.000Z

Note: This page contains sample records for the topic "bulk gallium nitride" 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

Synthesis of graphene nanoribbons from amyloid templates by gallium vapor-assisted solid-phase graphitization  

SciTech Connect

Single- and double-layer graphene nanoribbons (GNRs) with widths of around 10?nm were synthesized directly onto an insulating substrate by solid-phase graphitization using a gallium vapor catalyst and carbon templates made of amyloid fibrils. Subsequent investigation revealed that the crystallinity, conductivity, and carrier mobility were all improved by increasing the temperature of synthesis. The carrier mobility of the GNR synthesized at 1050?°C was 0.83 cm{sup 2}/V?s, which is lower than that of mechanically exfoliated graphene. This is considered to be most likely due to electron scattering by the defects and edges of the GNRs.

Murakami, Katsuhisa, E-mail: k.murakami@bk.tsukuba.ac.jp; Dong, Tianchen; Kajiwara, Yuya; Takahashi, Teppei; Fujita, Jun-ichi [Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Tsukuba Research Center for Interdisciplinary Materials Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Hiyama, Takaki; Takai, Eisuke; Ohashi, Gai; Shiraki, Kentaro [Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan)

2014-06-16T23:59:59.000Z

262

Excitons in Boron Nitride Nanotubes: Dimensionality Effects Ludger Wirtz,1,2  

E-Print Network (OSTI)

Excitons in Boron Nitride Nanotubes: Dimensionality Effects Ludger Wirtz,1,2 Andrea Marini,3; published 30 March 2006) We show that the optical absorption spectra of boron nitride (BN) nanotubes are dominated by strongly bound excitons. Our first-principles calculations indicate that the binding energy

Marini, Andrea

263

Ultra-thin ohmic contacts for p-type nitride light emitting devices  

DOE Patents (OSTI)

A semiconductor based Light Emitting Device (LED) can include a p-type nitride layer and a metal ohmic contact, on the p-type nitride layer. The metal ohmic contact can have an average thickness of less than about 25 .ANG. and a specific contact resistivity less than about 10.sup.-3 ohm-cm.sup.2.

Raffetto, Mark (Raleigh, NC); Bharathan, Jayesh (Cary, NC); Haberern, Kevin (Cary, NC); Bergmann, Michael (Chapel Hill, NC); Emerson, David (Chapel Hill, NC); Ibbetson, James (Santa Barbara, CA); Li, Ting (Ventura, CA)

2012-01-03T23:59:59.000Z

264

Tunneling characteristics in chemical vapor deposited graphene hexagonal boron nitride graphene junctions  

E-Print Network (OSTI)

1 Tunneling characteristics in chemical vapor deposited graphene ­ hexagonal boron nitride ­ graphene junctions T. Roy1 , L. Liu2 , S. de la Barrera,3 B. Chakrabarti1,4 , Z. R. Hesabi1 , C. A. Joiner1 Abstract: Large area chemical vapor deposited graphene and hexagonal boron nitride was used to fabricate

Feenstra, Randall

265

One step process for producing dense aluminum nitride and composites thereof  

DOE Patents (OSTI)

A one step combustion process for the synthesis of dense aluminum nitride compositions is disclosed. The process comprises igniting pure aluminum powder in a nitrogen atmosphere at a pressure of about 1000 atmospheres or higher. The process enables the production of aluminum nitride bodies to be formed directly in a mold of any desired shape.

Holt, J. Birch (San Jose, CA); Kingman, Donald D. (Danville, CA); Bianchini, Gregory M. (Livermore, CA)

1989-01-01T23:59:59.000Z

266

carbides. The multiphase/polytypic region can be expected to occur also in the nitrides because  

E-Print Network (OSTI)

in valence electron concentration where sev- eral phases of the 3d, 4d, and 5d transition metal carbides have, Transition Metal Carbides and Nitrides (Academic Press, New York, 1971). 6. C. Maerky, M.-O. Guillou, J. L is predicted to be substantially enhanced over that of traditional transition metal car- bide/nitride coatings

Shen, Guoyin

267

Single-Crystalline Mesoporous Molybdenum Nitride Nanowires with Improved Electrochemical Properties  

E-Print Network (OSTI)

process. I. Introduction TRANSITION -metal oxides, carbides, sulfides, and nitrides are extensively, and catalytic properties.1­4 Among the transition-metal com- pounds, transition-metal nitrides are regarded using transition-metal complex materials.16 However, the transi- tion-metal complex materials are lower

Cao, Guozhong

268

Hard superconducting nitrides Xiao-Jia Chen*, Viktor V. Struzhkin*, Zhigang Wu*, Maddury Somayazulu  

E-Print Network (OSTI)

(4). The refractory characteristics of these transition- metal nitrides and carbides have been, and hardness of selected superconducting transition-metal nitrides reveals inter- esting correlations among transition temperature (Tc) near 4 K when doped with boron (3). However, the transition-metal compounds

Wu, Zhigang

269

Large-scale well aligned carbon nitride nanotube films: Low temperature growth and electron field emission  

E-Print Network (OSTI)

Large-scale well aligned carbon nitride nanotube films: Low temperature growth and electron field emission Dingyong Zhong, Shuang Liu, Guangyu Zhang, and E. G. Wanga) State Key Laboratory for Surface Received 2 January 2001; accepted for publication 13 March 2001 Large-scale well aligned carbon nitride

Zhang, Guangyu

270

Identification of the gallium vacancy-oxygen pair defect in GaN  

SciTech Connect

Cation vacancies like V{sub Ga}, V{sub Al} and their complexes with oxygen are predicted to be abundant in III-nitrides and to play an important role in nonradiative recombination. Appearing in triple or double negatively charged states, they are not paramagnetic and have not so far been detected by magnetic resonance even under illumination. In this Brief Report, we demonstrate an efficient way to make cation vacancy defects in GaN detectable by electron paramagnetic resonance and present our identification of the V{sub Ga}O{sub N} pair in GaN which is the model material for the III-nitrides and their alloys.

Son, N. T.; Hemmingsson, C. G.; Janzen, E. [Department of Physics, Chemistry and Biology, Linkoeping University, SE-581 83 Linkoeping (Sweden); Paskova, T.; Evans, K. R. [Kyma Technologies Inc., 8829 Midway West Road, Raleigh, North Carolina 27617 (United States); Usui, A. [R and D Division, Furukawa Co., Ltd., Tsukuba, Ibaraki 305-0856 (Japan); Morishita, N.; Ohshima, T. [Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Isoya, J. [Graduate School of Library, Information and Media Studies, University of Tsukuba, Tsukuba, Ibaraki 305-8550 (Japan); Monemar, B. [Department of Physics, Chemistry and Biology, Linkoeping University, SE-581 83 Linkoeping (Sweden); Nanometer Structure Consortium, Lund University, P.O. Box 118, S-221 00 Lund (Sweden)

2009-10-15T23:59:59.000Z

271

Characterization of gallium-doped CdS thin films grown by chemical bath Hani Khallaf a  

E-Print Network (OSTI)

Characterization of gallium-doped CdS thin films grown by chemical bath deposition Hani Khallaf In-situ doping with group III elements has been widely used to decrease the dark resistivity of CdS technique for aluminum in-situ doping of CdS. We have also shown that due to extremely low solubility

Chow, Lee

272

Synthesis of Gallium Oxide Hydroxide Crystals in Aqueous Solutions with or without Urea and Their Calcination Behavior  

E-Print Network (OSTI)

solution of gallium(III) nitrate and stirring at 90°C for 10 h, followed by calcination of the recovered of solid electro- lytes of superior (as compared with Y-stabilized zirconia) ionic conductivity, i.e., La0-chemical synthesis of powders of doped LaGaO3 fuel cell ceramics.24,25 The first experimental study

Tas, A. Cuneyt

273

An assessment of the validity of cerium oxide as a surrogate for plutonium oxide gallium removal studies  

SciTech Connect

Methods for purifying plutonium metal have long been established. These methods use acid solutions to dissolve and concentrate the metal. However, these methods can produce significant mixed waste, that is, waste containing both radioactive and chemical hazards. The volume of waste produced from the aqueous purification of thousands of weapons would be expensive to treat and dispose. Therefore, a dry method of purification is highly desirable. Recently, a dry gallium removal research program commenced. Based on initial calculations, it appeared that a particular form of gallium (gallium suboxide, Ga{sub 2}O) could be evaporated from plutonium oxide in the presence of a reducing agent, such as small amounts of hydrogen dry gas within an inert environment. Initial tests using ceria-based material (as a surrogate for PuO{sub 2}) showed that thermally-induced gallium removal (TIGR) from small samples (on the order of one gram) was indeed viable. Because of the expense and difficulty of optimizing TIGR from plutonium dioxide, TIGR optimization tests using ceria have continued. This document details the relationship between the ceria surrogate tests and those conducted using plutonia.

Kolman, D.G.; Park, Y.; Stan, M.; Hanrahan, R.J. Jr.; Butt, D.P.

1999-03-01T23:59:59.000Z

274

Formation of etch pits during carbon doping of gallium arsenide with carbon tetrachloride by metalorganic vapor-phase epitaxy  

E-Print Network (OSTI)

Formation of etch pits during carbon doping of gallium arsenide with carbon tetrachloride to examine the effects of carbon tetrachloride concentration and temperature on the morphology of carbon with increasing carbon tetrachloride concentration. Step bunching and pinning was observed at a IV/III ratio

Li, Lian

275

Bulk viscosity in heavy ion collision  

E-Print Network (OSTI)

The effect of a temperature dependent bulk viscosity to entropy density ratio~($\\zeta/s$) along with a constant shear viscosity to entropy density ratio~($\\eta/s$) on the space time evolution of the fluid produced in high energy heavy ion collisions have been studied in a relativistic viscous hydrodynamics model. The boost invariant Israel-Stewart theory of causal relativistic viscous hydrodynamics is used to simulate the evolution of the fluid in 2 spatial and 1 temporal dimension. The dissipative correction to the freezeout distribution for bulk viscosity is calculated using Grad's fourteen moment method. From our simulation we show that the method is applicable only for $\\zeta/s<0.004$.

Victor Roy; A. K. Chaudhuri

2012-01-20T23:59:59.000Z

276

Formation of Nickel Silicide from Direct-liquid-injection Chemical-vapor-deposited Nickel Nitride Films  

SciTech Connect

Smooth, continuous, and highly conformal nickel nitride (NiN{sub x}) films were deposited by direct liquid injection (DLI)-chemical vapor deposition (CVD) using a solution of bis(N,N{prime}-di-tert-butylacetamidinato)nickel(II) in tetrahydronaphthalene as the nickel (Ni) source and ammonia (NH{sub 3}) as the coreactant gas. The DLI-CVD NiNx films grown on HF-last (100) silicon and on highly doped polysilicon substrates served as the intermediate for subsequent conversion into nickel silicide (NiSi), which is a key material for source, drain, and gate contacts in microelectronic devices. Rapid thermal annealing in the forming gas of DLI-CVD NiNx films formed continuous NiSi films at temperatures above 400 C. The resistivity of the NiSi films was 15{mu}{Omega} cm, close to the value for bulk crystals. The NiSi films have remarkably smooth and sharp interfaces with underlying Si substrates, thereby producing contacts for transistors with a higher drive current and a lower junction leakage. Resistivity and synchrotron X-ray diffraction in real-time during annealing of NiNx films showed the formation of a NiSi film at about 440 C, which is morphologically stable up to about 650 C. These NiSi films could find applications in future nanoscale complementary metal oxide semiconductor devices or three-dimensional metal-oxide-semiconductor devices such as Fin-type field effect transistors for the 22 nm technology node and beyond.

Li, Z.; Gordon, R; Li, H; Shenai, D; Lavoie, C

2010-01-01T23:59:59.000Z

277

Boron nitride nanosheets as oxygen-atom corrosion protective coatings  

SciTech Connect

The research of two-dimensional nanomaterials for anticorrosion applications is just recently burgeoning. Herein, we demonstrate the boron nitride nanosheets (BNNSs) coatings for protecting polymer from oxygen-atom corrosion. High-quality BNNSs, which are produced by an effective fluid dynamics method with multiple exfoliation mechanisms, can be assembled into coatings with controlled thickness by vacuum filtration. After exposed in atom oxygen, the naked polymer is severely corroded with remarkable mass loss, while the BNNSs-coated polymer remains intact. Barrier and bonding effects of the BNNSs are responsible for the coating's protective performance. These preliminary yet reproducible results pave a way for resisting oxygen-atom corrosion.

Yi, Min [Beijing Key Laboratory for Powder Technology Research and Development, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Plasma Laboratory, Ministry-of-Education Key Laboratory of Fluid Mechanics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Shen, Zhigang, E-mail: shenzhg@buaa.edu.cn [Beijing Key Laboratory for Powder Technology Research and Development, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Plasma Laboratory, Ministry-of-Education Key Laboratory of Fluid Mechanics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); School of Material Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Zhao, Xiaohu [Plasma Laboratory, Ministry-of-Education Key Laboratory of Fluid Mechanics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Liang, Shuaishuai [Beijing Key Laboratory for Powder Technology Research and Development, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Liu, Lei [Beijing Key Laboratory for Powder Technology Research and Development, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); School of Material Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China)

2014-04-07T23:59:59.000Z

278

Excellent oxidation endurance of boron nitride nanotube field electron emitters  

SciTech Connect

Boron nitride nanotubes (BNNTs) are considered as a promising cold electron emission material owing to their negative electron affinity. BNNT field emitters show excellent oxidation endurance after high temperature thermal annealing of 600?°C in air ambient. There is no damage to the BNNTs after thermal annealing at a temperature of 600?°C and also no degradation of field emission properties. The thermally annealed BNNTs exhibit a high maximum emission current density of 8.39?mA/cm{sup 2} and show very robust emission stability. The BNNTs can be a promising emitter material for field emission devices under harsh oxygen environments.

Song, Yenan [Department of Micro/Nano Systems, Korea University, Seoul 136-713 (Korea, Republic of); Sun, Yuning; Hoon Shin, Dong; Nam Yun, Ki [School of Electrical Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Song, Yoon-Ho [Nano Electron-Source Creative Research Center, Creative and Challenging Research Division, ETRI, Daejeon 305-700 (Korea, Republic of); Milne, William I. [Electrical Engineering Division, Engineering Department, Cambridge University, Cambridge CB3 0FA (United Kingdom); Jin Lee, Cheol, E-mail: cjlee@korea.ac.kr [Department of Micro/Nano Systems, Korea University, Seoul 136-713 (Korea, Republic of); School of Electrical Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

2014-04-21T23:59:59.000Z

279

Method of nitriding niobium to form a superconducting surface  

DOE Patents (OSTI)

A method of forming a delta niobium nitride .delta.-NbN layer on the surface of a niobium object including cleaning the surface of the niobium object; providing a treatment chamber; placing the niobium object in the treatment chamber; evacuating the chamber; passing pure nitrogen into the treatment chamber; focusing a laser spot on the niobium object; delivering laser fluences at the laser spot until the surface of the niobium object reaches above its boiling temperature; and rastering the laser spot over the surface of the niobium object.

Kelley, Michael J.; Klopf, John Michael; Singaravelu, Senthilaraja

2014-08-19T23:59:59.000Z

280

Field emission characteristics from graphene on hexagonal boron nitride  

SciTech Connect

An attempt has been made to utilize uniquely high electron mobility of graphene on hexagonal boron nitride (h-BN) to electron emitter. The field emission property of graphene/h-BN/Si structure has shown enhanced threshold voltage and emission current, both of which are key to develop novel vacuum nanoelectronics devices. The field emission property was discussed along with the electronic structure of graphene investigated by Fowler-Nordheim plot and ultraviolet photoelectron spectroscopy. The result suggested that transferring graphene on h-BN modified its work function, which changed field emission mechanism. Our report opens up a possibility of graphene-based vacuum nanoelectronics devices with tuned work function.

Yamada, Takatoshi, E-mail: takatoshi-yamada@aist.go.jp [National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565 (Japan); Masuzawa, Tomoaki; Ebisudani, Taishi; Okano, Ken [International Christian University, 3-10-2 Osawa, Mitaka, Tokyo 181-8585 (Japan); Taniguchi, Takashi [National Institute for Material Science (NIMS), 1-1-1 Namiki, Tsukuba 305-0044 (Japan)

2014-06-02T23:59:59.000Z

Note: This page contains sample records for the topic "bulk gallium nitride" 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

Fast reverse osmosis using boron nitride and carbon nanotubes  

Science Journals Connector (OSTI)

We investigate reverse osmosis through commonly used polymeric and advanced inorganic nanotube based semipermeable membranes by performing nonequilibrium molecular dynamics simulations. Simulations indicate that there is a significantly higher water flux through boron-nitride nanotube (BNNT) and carbon nanotube(CNT) compared to a polymethyl methacrylate (PMMA) pore and a slightly higher water flux through BNNT as compared to CNT. The calculated permeation coefficient is in reasonable agreement with the theoretical single-file “hopping” model. Potential of mean force analysis indicates that the irregular nature of PMMA pore surface can cause significant localized energy barriers inside the pore thereby reducing the water flux.

M. E. Suk; A. V. Raghunathan; N. R. Aluru

2008-01-01T23:59:59.000Z

282

Aluminum nitride nanophotonic circuits operating at ultraviolet wavelengths  

SciTech Connect

Aluminum nitride (AlN) has recently emerged as a promising material for integrated photonics due to a large bandgap and attractive optical properties. Exploiting the wideband transparency, we demonstrate waveguiding in AlN-on-Insulator circuits from near-infrared to ultraviolet wavelengths using nanophotonic components with dimensions down to 40?nm. By measuring the propagation loss over a wide spectral range, we conclude that both scattering and absorption of AlN-intrinsic defects contribute to strong attenuation at short wavelengths, thus providing guidelines for future improvements in thin-film deposition and circuit fabrication.

Stegmaier, M.; Ebert, J.; Pernice, W. H. P., E-mail: wolfram.pernice@kit.edu [Institute of Nanotechnology, Karlsruhe Institute of Technology, 76133 Karlsruhe (Germany); Meckbach, J. M.; Ilin, K.; Siegel, M. [Institute of Micro- und Nanoelectronic Systems, Karlsruhe Institute of Technology, 76187 Karlsruhe (Germany)

2014-03-03T23:59:59.000Z

283

Local environment of silicon in cubic boron nitride  

SciTech Connect

Si-doped cubic boron nitride (c-BN) is synthesized at high pressure and high temperature, and the local environment of Si is investigated using X-ray absorption near edge structure (XANES) and first-principles calculations. Si-K XANES indicates that Si in c-BN is surrounded by four nitrogen atoms. According to first-principles calculations, the model for substitutional Si at the B site well reproduces experimental Si-K XANES, and it is energetically more favorable than substitutional Si at the N site. Both the present experimental and theoretical results indicate that Si in c-BN prefers the B site to the N site.

Murata, Hidenobu, E-mail: MURATA.Hidenobu@nims.go.jp; Taniguchi, Takashi [Advanced Key Technologies Division, National Institute for Materials Science, 1-1 Namiki Tsukuba, Ibaraki 305–0044 (Japan); Hishita, Shunichi [Environment and Energy Materials Division, National Institute for Materials Science, 1-1 Namiki Tsukuba, Ibaraki 305–0044 (Japan); Yamamoto, Tomoyuki [Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169–8555 (Japan); Oba, Fumiyasu [Department of Materials Science and Engineering, Kyoto University, Yoshida-Honmachi, Sakyo, Kyoto 606–8501 (Japan); Tanaka, Isao [Department of Materials Science and Engineering, Kyoto University, Yoshida-Honmachi, Sakyo, Kyoto 606–8501 (Japan); Nanostructures Research Laboratory, Japan Fine Ceramics Center, 2-4-1 Mutsuno, Atsuta, Nagoya 456–8587 (Japan)

2013-12-21T23:59:59.000Z

284

Nanostructured High-Temperature Bulk Thermoelectric Energy Conversion...  

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

More Documents & Publications Nanostructured High-Temperature Bulk Thermoelectric Energy Conversion for Efficient Automotive Waste Heat Recovery Vehicle Technologies Office...

285

The Economic Case for Bulk Energy Storage in Transmission Systems  

E-Print Network (OSTI)

The Economic Case for Bulk Energy Storage in Transmission Systems with High Percentages to Engineer the Future Electric Energy System #12;#12;The Economic Case for Bulk Energy Storage Economic Case for Bulk Energy Storage in Transmission Sys- tems with High Percentages of Renewable

286

Bulk viscosity and r-modes of neutron stars  

E-Print Network (OSTI)

The bulk viscosity due to the non-leptonic process involving hyperons in $K^-$ condensed matter is discussed here. We find that the bulk viscosity is modified in a superconducting phase. Further, we demonstrate how the exotic bulk viscosity coefficient influences $r$-modes of neutron stars which might be sources of detectable gravitational waves.

Debarati Chatterjee; Debades Bandyopadhyay

2008-08-08T23:59:59.000Z

287

Bulk viscosity of gauge theory plasma at strong coupling  

E-Print Network (OSTI)

We propose a lower bound on bulk viscosity of strongly coupled gauge theory plasmas. Using explicit example of the N=2^* gauge theory plasma we show that the bulk viscosity remains finite at a critical point with a divergent specific heat. We present an estimate for the bulk viscosity of QGP plasma at RHIC.

Alex Buchel

2007-08-27T23:59:59.000Z

288

Rescheduling Bulk Gas Production and Distribution Wasu Glankwamdee  

E-Print Network (OSTI)

customer demand at minimum cost? #12;Bulk Gas Wrinkles Production Most sites operate in two modes: RegularRescheduling Bulk Gas Production and Distribution Wasu Glankwamdee Jackie Griffin Jeff Linderoth March 15, 2006 #12;Liquid Bulk Gas Production-Distribution Sites S Products P = {LOX, LNI} Customers C

Grossmann, Ignacio E.

289

Local environment and composition of magnesium gallium layered double hydroxides determined from solid-state 1H and 71Ga NMR spectroscopy  

SciTech Connect

Ordering of gallium(III) in a series of magnesium gallium layered double hydroxides (LDH’s), [Mg1-xGax(OH)2(NO3)x yH2O], was determined using solid-state 1H and 71Ga NMR spectroscopy. Depletion of Ga in these LDH’s is demonstrated to be the result of soluble [Ga(OH)4]-complexes formed during synthesis.

Petersen, Line B.; Lipton, Andrew S.; Zorin, Vadim; Nielsen, Ulla Gro

2014-11-01T23:59:59.000Z

290

Hanford ETR Bulk Vitrification System - Demonstration Bulk Vitrification System (DBVS) Review Report  

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

A Comprehensive Technical A Comprehensive Technical Review of the Demonstration Bulk Vitrification System Technical Assessment Conducted by an Independent and External Team of Experts Volume 1 September 28, 2006 Chartered by CH2M HILL Hanford Group, Inc. Richland, Washington 99352 RPP-31314 Executive Summary In May 2006, CH2M HILL Hanford Group, Inc. chartered an Expert Review Panel (ERP) to review the current status of the Demonstration Bulk Vitrification System (DBVS). It is the consensus of the ERP that bulk vitrification is a technology that requires further development and evaluation to determine its potential for meeting the Hanford waste stabilization mission. No fatal flaws (issues that would jeopardize the overall DBVS mission that cannot be mitigated) were found, given the current state of the project.

291

Bulk viscosity effects on elliptic flow  

E-Print Network (OSTI)

The effects of bulk viscosity on the elliptic flow $v_{2}$ are studied using realistic equation of state and realistic transport coefficients. We find that thebulk viscosity acts in a non trivial manner on $v_{2}$. At low $p_{T}$, the reduction of $v_{2}$ is even more effective compared to the case of shear viscosity, whereas at high $p_{T}$, an enhancement of $v_{2}$ compared to the ideal case is observed. We argue that this is caused by the competition of the critical behavior of the equation of state and the transport coefficients.

G. S. Denicol; T. Kodama; T. Koide; Ph. Mota

2009-07-24T23:59:59.000Z

292

A New Approach to Cosmological Bulk Viscosity  

E-Print Network (OSTI)

We examine the cosmological consequences of an alternative to the standard expression for bulk viscosity, one which was proposed to avoid the propagation of superluminal signals without the necessity of extending the space of variables of the theory. The Friedmann equation is derived for this case, along with an expression for the effective pressure. We find solutions for the evolution of the density of a viscous component, which differs markedly from the case of conventional Eckart theory; our model evolves toward late-time phantom-like behavior with a future singularity. Entropy production is addressed, and some similarities and differences to approaches based on the Mueller-Israel-Stewart theory are discussed.

Disconzi, Marcelo M; Scherrer, Robert J

2014-01-01T23:59:59.000Z

293

Magnetic structures of hcp bulk gadolinium  

Science Journals Connector (OSTI)

We present results of self-consistent linear-muffin-tin-orbital calculations with the atomic-sphere approximation for hcp bulk Gd, using the local spin-density approximation (LSDA) and gradient correction (GC) for the description of exchange and correlation. In the LSDA calculation antiferromagnetic order is favored over the ferromagnetic, and experimentally observed, structure. The GC weakens the bonding, leading to a higher equilibrium lattice parameter. At the new equilibrium volume the ground state is ferromagnetic. Our results point towards a magnetic phase transition under pressure.

Martina Heinemann and Walter M. Temmerman

1994-02-01T23:59:59.000Z

294

Nitride and Oxynitride Based Phosphors for Solid State Lighting  

SciTech Connect

The objective of the project is to advance the technology of the Lightscape Materials Inc. (Lightscape) proprietary nitride and oxynitride phosphors for solid state lighting (SSL) from the current level of maturity of applied research to advanced engineering development. This objective will be accomplished by optimizing the novel nitride and oxynitride phosphors, whose formulations are listed in Table 1, and establishing cost-effective preparation processes for the phosphors. The target performances of the phosphors are: • High luminescence efficiency: Quantum Yield = 90%. • Superior thermal stability of luminescence: Thermal Quenching Loss <10% at 150 °C. • Superior environmental stability: Luminescence Maintenance >90% after 5,000 hours at 85 °C and 85% relative humidity. • Scattering loss <10%. • Cost-effective preparation processes. The resulting phosphor materials and their preparation processes are anticipated to be a drop-in component for product development paths undertaken by LED lamp makers in the SSL industry. Upon program completion, Lightscape will target market insertion that enables high efficacy, high color rendering index (CRI), high thermal stability and long lifetime LED-based lighting products for general illumination that realizes substantial energy savings.

Tian, Yongchi

2011-10-15T23:59:59.000Z

295

Origin of deep subgap states in amorphous indium gallium zinc oxide: Chemically disordered coordination of oxygen  

SciTech Connect

The origin of the deep subgap states in amorphous indium gallium zinc oxide (a-IGZO), whether intrinsic to the amorphous structure or not, has serious implications for the development of p-type transparent amorphous oxide semiconductors. We report that the deep subgap feature in a-IGZO originates from local variations in the oxygen coordination and not from oxygen vacancies. This is shown by the positive correlation between oxygen composition and subgap intensity as observed with X-ray photoelectron spectroscopy. We also demonstrate that the subgap feature is not intrinsic to the amorphous phase because the deep subgap feature can be removed by low-temperature annealing in a reducing environment. Atomistic calculations of a-IGZO reveal that the subgap state originates from certain oxygen environments associated with the disorder. Specifically, the subgap states originate from oxygen environments with a lower coordination number and/or a larger metal-oxygen separation.

Sallis, S.; Williams, D. S. [Materials Science and Engineering, Binghamton University, Binghamton, New York 13902 (United States); Butler, K. T.; Walsh, A. [Center for Sustainable Technologies and Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Quackenbush, N. F. [Department of Physics, Applied Physics, and Astronomy, Binghamton University, Binghamton, New York 13902 (United States); Junda, M.; Podraza, N. J. [Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606 (United States); Fischer, D. A.; Woicik, J. C. [Materials Science and Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); White, B. E.; Piper, L. F. J., E-mail: lpiper@binghamton.edu [Department of Physics, Applied Physics, and Astronomy, Binghamton University, Binghamton, New York 13902 (United States); Materials Science and Engineering, Binghamton University, Binghamton, New York 13902 (United States)

2014-06-09T23:59:59.000Z

296

Catalytic and physicochemical properties of aluminoplatinum catalysts modified with indium and gallium  

SciTech Connect

Aluminoplatinum catalysts (APC) are widely used in transformations of hydrocarbons, particularly in reforming of gasoline fractions and dehydrogenation of higher normal paraffins. Promotion of APC with indium and gallium increases their activity and stability in the dehydrogenation of paraffins. Introduction of group III elements in APC inhibits coke formation during dehydrogenation and prevents blocking of the surface of the Pt. The change in the catalytic properties of APC modified with In is due to the partial transfer of the electron density from Pt to In. Both APC with In and Ga additives and monometallic catalysts were studied in the present article by the methods of IR spectroscopy and adsorption. In addition to traditional transmission IR spectroscopy, IR spectroscopy in diffusely scattered light was used, which permits conducting both spectral and adsorption measurements on the same samples.

Zaitsev, A.V.; Tyupaev, A.P.; Borovkov, V.Yu.; Timofeeva, E.A.; Isatulyants, G.V.; Kazanskii, B.B.

1986-10-10T23:59:59.000Z

297

Plasma Sputter-type Ion Source with Wire Electrodes for Low-energy Gallium Ion Extraction  

SciTech Connect

Low-energy ions of gallium (Ga) and argon (Ar) were extracted from a plasma sputter-type ion source system that utilized a tungsten (W) wire extractor geometry. The 90% transparent W wire extractor configuration had shown that the system was capable of producing an ion beam with the energy as low as 10 eV in a dc filament discharge and 50 eV in a radio frequency (rf) excited system. In the present investigation, Ar plasma was sustained in an ion source chamber through an inductively coupled 13.56 MHz rf power source. Negatively biased liquid Ga target suspended on a W reservoir was sputtered and postionized prior to extraction. Mass spectral analyses revealed a strong dependence of the Ga{sup +} current on the induced target bias.

Vasquez, M. Jr.; Kasuya, T.; Wada, M. [Graduate School of Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan); Maeno, S. [Novelion Systems Co. Ltd., Kyotanabe, Kyoto 610-0332 (Japan); Miyamoto, N. [Nissin Ion Equipment Co. Ltd., Minami-ku, Kyoto 601-8205 (Japan)

2011-01-07T23:59:59.000Z

298

The status of the solar neutrino problem and the Russian-American gallium experiment (SAGE)  

SciTech Connect

Perhaps the most outstanding discrepancy between prediction and measurements in current particle physics comes from the solar neutrino problem, in which a large deficit of high-energy solar neutrinos is observed. Many Nonstandard Solar Models have been invoked to try to reduce the predicted flux, but all have run into problems in trying to reproduce other measured parameters (e.g., the luminosity) of the Sun. Other explanations involving new physics such as neutrino decay and neutrino oscillations, etc. have also been proffered. Again, most of these explanations have been ruled out by either laboratory or astrophysical measurements. It appears that perhaps the most likely particle physics solution is that of matter enhanced neutrino oscillation, the Mikheyev-Smirnov-Wolfenstein (MSW) oscillations. Two new radiochemical gallium experiments, which have a low enough threshold to be sensitive to the dominant flux of low-energy p-p neutrinos, now also report a deficit and also favor a particle physics solution.

Bowles, T.J.

1994-04-01T23:59:59.000Z

299

Outdoor Performance of a Thin-Film Gallium-Arsenide Photovoltaic Module  

SciTech Connect

We deployed a 855 cm2 thin-film, single-junction gallium arsenide (GaAs) photovoltaic (PV) module outdoors. Due to its fundamentally different cell technology compared to silicon (Si), the module responds differently to outdoor conditions. On average during the test, the GaAs module produced more power when its temperature was higher. We show that its maximum-power temperature coefficient, while actually negative, is several times smaller in magnitude than that of a Si module used for comparison. The positive correlation of power with temperature in GaAs is due to temperature-correlated changes in the incident spectrum. We show that a simple correction based on precipitable water vapor (PWV) brings the photocurrent temperature coefficient into agreement with that measured by other methods and predicted by theory. The low operating temperature and small temperature coefficient of GaAs give it an energy production advantage in warm weather.

Silverman, T. J.; Deceglie, M. G.; Marion, B.; Cowley, S.; Kayes, B.; Kurtz, S.

2013-06-01T23:59:59.000Z

300

Solvent-Dependent Assembly of Terphenyl- and Quaterphenyldithiol on Gold and Gallium Arsenide  

Science Journals Connector (OSTI)

Solvent-Dependent Assembly of Terphenyl- and Quaterphenyldithiol on Gold and Gallium Arsenide ... This solvent pair was chosen because of an apparent solubility conflict:? while EtOH is the most common solvent for assembling alkylthiol and conjugated monothiol molecules,43-45 the longer n-phenyldithiols (n = 3, 4), in their thioacetyl forms (compounds 3 and 4 in Scheme 1), are poorly soluble in EtOH. ... The precipitate was filtered, washed with water, hexane, and methylene chloride, and dried overnight at 40 °C under vacuum to afford a light-yellow solid (5.90 g, 92%). 1H NMR (200 MHz, CDCl3) ? 7.65 (s, 4H), 7.55 (d, J = 8.0 Hz, 4H), 7.32 (d, J = 8.0 Hz, 4H), 2.55 (s, 6H). ...

Dmitry A. Krapchetov; Hong Ma; Alex K. Y. Jen; Daniel A. Fischer; Yueh-Lin Loo

2005-05-17T23:59:59.000Z

Note: This page contains sample records for the topic "bulk gallium nitride" 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

Tunneling characteristics in chemical vapor deposited graphene–hexagonal boron nitride–graphene junctions  

SciTech Connect

Large area chemical vapor deposited graphene and hexagonal boron nitride was used to fabricate graphene–hexagonal boron nitride–graphene symmetric field effect transistors. Gate control of the tunneling characteristics is observed similar to previously reported results for exfoliated graphene–hexagonal boron nitride–graphene devices. Density-of-states features are observed in the tunneling characteristics of the devices, although without large resonant peaks that would arise from lateral momentum conservation. The lack of distinct resonant behavior is attributed to disorder in the devices, and a possible source of the disorder is discussed.

Roy, T.; Hesabi, Z. R.; Joiner, C. A.; Vogel, E. M. [School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332 (United States); Liu, L.; Gu, G. [Department of Electrical Engineering and Computer Science, University of Tennessee, 1520 Middle Drive, Knoxville, Tennessee 37996 (United States); Barrera, S. de la; Feenstra, R. M. [Department of Physics, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, Pennsylvania 15213 (United States); Chakrabarti, B. [School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332 (United States); Department of Materials Science and Engineering, University of Texas at Dallas, 800 West Campbell Rd., Richardson, Texas 75080 (United States)

2014-03-24T23:59:59.000Z

302

The Bulk Channel in Thermal Gauge Theories  

E-Print Network (OSTI)

We investigate the thermal correlator of the trace of the energy-momentum tensor in the SU(3) Yang-Mills theory. Our goal is to constrain the spectral function in that channel, whose low-frequency part determines the bulk viscosity. We focus on the thermal modification of the spectral function, $\\rho(\\omega,T)-\\rho(\\omega,0)$. Using the operator-product expansion we give the high-frequency behavior of this difference in terms of thermodynamic potentials. We take into account the presence of an exact delta function located at the origin, which had been missed in previous analyses. We then combine the bulk sum rule and a Monte-Carlo evaluation of the Euclidean correlator to determine the intervals of frequency where the spectral density is enhanced or depleted by thermal effects. We find evidence that the thermal spectral density is non-zero for frequencies below the scalar glueball mass $m$ and is significantly depleted for $m\\lesssim\\omega\\lesssim 3m$.

Harvey B. Meyer

2010-02-17T23:59:59.000Z

303

Boron-Nitride (BN) Nanotubes (BNNT) at TJNAF| U.S. DOE Office of Science  

Office of Science (SC) Website

Boron-Nitride (BN) Nanotubes (BNNT) at Boron-Nitride (BN) Nanotubes (BNNT) at TJNAF Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff Archives SBIR/STTR Applications of Nuclear Science and Technology Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » Spinoff Archives Boron-Nitride (BN) Nanotubes (BNNT) at TJNAF Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: Boron-Nitride (BN) Nanotubes (BNNT) Developed at: Jefferson Lab Free Electron Facility Developed in: 2008-2011

304

Friction and wear behavior of in-situ reinforced silicon nitride. Final report  

SciTech Connect

Specimens of in-situ-reinforced silicon nitride (ISRSH) have been wear tested in lubricated, reciprocating, sliding motion against a silicon nitride counterface. Only mild wear of the ISRSN was observed at contact pressures up to 4.8 GPa at an average sliding velocity of 0.3 m/s. At 0.6 m/s, a wear mode transition was observed in ISRSN at 4.2 - 4.4 GPa. In comparison, the wear mode transition in silicon carbide whisker reinforced silicon nitride at both velocities was evident at about 2.2 - 2.4 GPa. Scanning electron microscopy of the ISRSN wear surfaces revealed the presence of a 40 pm thick debris layer on the mild wear tracks. The ISRSN wear mode transition response indicated a potential for an improved wear resistance in this material as compared to whisker reinforced silicon nitride.

Yust, C.S.

1995-10-01T23:59:59.000Z

305

Method of nitriding, carburizing, or oxidizing refractory metal articles using microwaves  

DOE Patents (OSTI)

A method of nitriding an article of refractory-nitride-forming metal or metalloids. A consolidated metal or metalloid article is placed inside a microwave oven and nitrogen containing gas is introduced into the microwave oven. The metal or metalloid article is heated to a temperature sufficient to react the metal or metalloid with the nitrogen by applying a microwave energy within the microwave oven. The metal or metalloid article is maintained at that temperature for a period of time sufficient to convert the article of metal or metalloid to an article of refractory nitride. in addition, a method of applying a coating, such as a coating of an oxide, a carbide, or a carbo-nitride, to an article of metal or metalloid by microwave heating.

Holcombe, C.E.; Dykes, N.L.; Tiegs, T.N.

1992-10-13T23:59:59.000Z

306

Method of nitriding, carburizing, or oxidizing refractory metal articles using microwaves  

DOE Patents (OSTI)

A method of nitriding an article of refractory-nitride-forming metal or metalloids. A consolidated metal or metalloid article is placed inside a microwave oven and nitrogen containing gas is introduced into the microwave oven. The metal or metalloid article is heated to a temperature sufficient to react the metal or metalloid with the nitrogen by applying a microwave energy within the microwave oven. The metal or metalloid article is maintained at that temperature for a period of time sufficient to convert the article of metal or metalloid to an article of refractory nitride. in addition, a method of applying a coating, such as a coating of an oxide, a carbide, or a carbo-nitride, to an article of metal or metalloid by microwave heating.

Holcombe, Cressie E. (Knoxville, TN); Dykes, Norman L. (Oak Ridge, TN); Tiegs, Terry N. (Lenoir City, TN)

1992-01-01T23:59:59.000Z

307

E-Print Network 3.0 - argon nitrides Sample Search Results  

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

I?MAYR Sti+ng Institutfur Werkstofiechnik... ,Badgasteiner Str: 3, 2800Bremen 33, Germany Abstract Aluminium nitride (AlN) is a ve interestin ceramic because... the use %of...

308

Lasers Used to Make First Boron-Nitride Nanotube Yarn | Jefferson...  

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

Yarn Visualization of helium-4 and beryllium nuclei. A yarn spun of boron-nitride nanotubes suspends a quarter. NEWPORT NEWS, VA, Dec. 2 -Researchers have used lasers to create...

309

High-Temperature Oxidation Resistance of Refractory Silicon Nitride—Silicon Carbide Materials  

Science Journals Connector (OSTI)

Silicon nitride and carbide are promising materials for use as refractories; they are highly resistant to mineral acids and alkalis, have a high melting point, and are thermally very stable [1].

I. N. Godovannaya; O. I. Popova

1972-01-01T23:59:59.000Z

310

Optoelectronic Properties in Monolayers of Hybridized Graphene and Hexagonal Boron Nitride  

E-Print Network (OSTI)

We explain the nature of the electronic energy gap and optical absorption spectrum of carbon–boron-nitride (CBN) monolayers using density functional theory, GW and Bethe-Salpeter calculations. The band structure and the ...

Bernardi, Marco

311

Hydrogen adsorption on boron nitride nanotubes: A path to room-temperature hydrogen storage  

Science Journals Connector (OSTI)

The adsorption of molecular hydrogen on boron nitride nanotubes is studied with the use of the pseudopotential density functional method. The binding energy and distance of adsorbed hydrogen is particularly calculated. It is found that the binding energy of hydrogen on boron nitride nanotubes is increased by as much as 40% compared to that on carbon nanotubes, which is attributed to heteropolar bonding in boron nitride. The effect of substitutional doping and structural defects on hydrogen adsorption is also studied and we find a substantial enhancement of the binding energy from that on perfect boron nitride. The current study demonstrates a pathway to the finding of proper media that can hold hydrogen at ambient conditions through physisorption.

Seung-Hoon Jhi and Young-Kyun Kwon

2004-06-22T23:59:59.000Z

312

Fluorination of a depleted uranium-plutonium-nitride fuel with elemental fluorine  

Science Journals Connector (OSTI)

A physical and a mathematical model have been developed to describe the physicochemical process of torch fluorination of an uranium-plutonium-nitride fuel. An algorithm for calculating the velocity, temperatur...

V. A. Karelin; V. N. Brendakov; M. V. Popadeikin

313

Method of enhancing the wettability of boron nitride for use as an electrochemical cell separator  

DOE Patents (OSTI)

A felt or other fabric of boron nitride suitable for use as an interelecte separator within an electrochemical cell is wetted with a solution containing a thermally decomposable organic salt of an alkaline earth metal. An aqueous solution of magnesium acetate is the preferred solution for this purpose. After wetting the boron nitride, the solution is dried by heating at a sufficiently low temperature to prevent rapid boiling and the creation of voids within the separator. The dried material is then calcined at an elevated temperature in excess of 400.degree. C. to provide a coating of an oxide of magnesium on the surface of the boron nitride fibers. A fabric or felt of boron nitride treated in this manner is easily wetted by molten electrolytic salts, such as the alkali metal halides or alkaline earth metal halides, that are used in high temperature, secondary electrochemical cells.

McCoy, Lowell R. (Woodland Hills, CA)

1982-01-01T23:59:59.000Z

314

Method of enhancing the wettability of boron nitride for use as an electrochemical cell separator  

DOE Patents (OSTI)

A felt or other fabric of boron nitride suitable for use as an interelectrode separator within an electrochemical cell is wetted with a solution containing a thermally decomposable organic salt of an alkaline earth metal. An aqueous solution of magnesium acetate is the preferred solution for this purpose. After wetting the boron nitride, the solution is dried by heating at a sufficiently low temperature to prevent rapid boiling and the creation of voids within the separator. The dried material is then calcined at an elevated temperature in excess of 400/sup 0/C to provide a coating of an oxide of magnesium on the surface of the boron nitride fibers. A fabric or felt of boron nitride treated in this manner is easily wetted by molten electrolytic salts, such as the alkali metal halides or alkaline earth metal halides, that are used in high temperature, secondary electrochemical cells.

McCoy, L.R.

1981-01-23T23:59:59.000Z

315

E-Print Network 3.0 - aluminium nitrides Sample Search Results  

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

111,Volume 3, novembre 1993 Summary: ,Badgasteiner Str: 3, 2800Bremen 33, Germany Abstract Aluminium nitride (AlN) is a ve interestin ceramic because... the use %of lasma...

316

On bulk viscosity and moduli decay  

E-Print Network (OSTI)

This pedagogically intended lecture, one of four under the header "Basics of thermal QCD", reviews an interesting relationship, originally pointed out by Bodeker, that exists between the bulk viscosity of Yang-Mills theory (of possible relevance to the hydrodynamics of heavy ion collision experiments) and the decay rate of scalar fields coupled very weakly to a heat bath (appearing in some particle physics inspired cosmological scenarios). This topic serves, furthermore, as a platform on which a number of generic thermal field theory concepts are illustrated. The other three lectures (on the QCD equation of state and the rates of elastic as well as inelastic processes experienced by heavy quarks) are recapitulated in brief encyclopedic form.

M. Laine

2010-07-15T23:59:59.000Z

317

Electron transport in the bulk photovoltaic effect  

Science Journals Connector (OSTI)

The spontaneous motion of electrons in the bulk photovoltaic effect in pyroelectric materials may be explained by separating the processes into two steps: the generation of photoelectrons whose distribution is asymmetric in momentum and a subsequent normal diffusion of the carriers. Asymmetric generation violates time-reversal symmetry and is shown to be only possible for local states in polar systems. Transport properties are calculated for the short-circuit and the open-end case. It is shown that in high-resistivity materials the short-circuit current is not affected by impurities other than those supplying the asymmetric photoelectrons. The open-end saturation field is proportional to the short-circuit current Es=Jsc?, where ? is the photoconductivity. Both results agree with experiment.

H. Heyszenau

1978-08-15T23:59:59.000Z

318

Organic hybrid planar-nanocrystalline bulk heterojunctions  

DOE Patents (OSTI)

A photosensitive optoelectronic device having an improved hybrid planar bulk heterojunction includes a plurality of photoconductive materials disposed between the anode and the cathode. The photoconductive materials include a first continuous layer of donor material and a second continuous layer of acceptor material. A first network of donor material or materials extends from the first continuous layer toward the second continuous layer, providing continuous pathways for conduction of holes to the first continuous layer. A second network of acceptor material or materials extends from the second continuous layer toward the first continuous layer, providing continuous pathways for conduction of electrons to the second continuous layer. The first network and the second network are interlaced with each other. At least one other photoconductive material is interspersed between the interlaced networks. This other photoconductive material or materials has an absorption spectra different from the donor and acceptor materials.

Forrest, Stephen R. (Ann Arbor, MI); Yang, Fan (Piscataway, NJ)

2011-03-01T23:59:59.000Z

319

Organic hybrid planar-nanocrystalline bulk heterojunctions  

DOE Patents (OSTI)

A photosensitive optoelectronic device having an improved hybrid planar bulk heterojunction includes a plurality of photoconductive materials disposed between the anode and the cathode. The photoconductive materials include a first continuous layer of donor material and a second continuous layer of acceptor material. A first network of donor material or materials extends from the first continuous layer toward the second continuous layer, providing continuous pathways for conduction of holes to the first continuous layer. A second network of acceptor material or materials extends from the second continuous layer toward the first continuous layer, providing continuous pathways for conduction of electrons to the second continuous layer. The first network and the second network are interlaced with each other. At least one other photoconductive material is interspersed between the interlaced networks. This other photoconductive material or materials has an absorption spectra different from the donor and acceptor materials.

Forrest, Stephen R.; Yang, Fan

2013-04-09T23:59:59.000Z

320

DEPLOYMENT OF THE BULK TRITIUM SHIPPING PACKAGE  

SciTech Connect

A new Bulk Tritium Shipping Package (BTSP) was designed by the Savannah River National Laboratory to be a replacement for a package that has been used to ship tritium in a variety of content configurations and forms since the early 1970s. The BTSP was certified by the National Nuclear Safety Administration in 2011 for shipments of up to 150 grams of Tritium. Thirty packages were procured and are being delivered to various DOE sites for operational use. This paper summarizes the design features of the BTSP, as well as associated engineered material improvements. Fabrication challenges encountered during production are discussed as well as fielding requirements. Current approved tritium content forms (gas and tritium hydrides), are reviewed, as well as, a new content, tritium contaminated water on molecular sieves. Issues associated with gas generation will also be discussed.

Blanton, P.

2013-10-10T23:59:59.000Z

Note: This page contains sample records for the topic "bulk gallium nitride" 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

Impurity-induced disorder in III-nitride materials and devices  

DOE Patents (OSTI)

A method for impurity-induced disordering in III-nitride materials comprises growing a III-nitride heterostructure at a growth temperature and doping the heterostructure layers with a dopant during or after the growth of the heterostructure and post-growth annealing of the heterostructure. The post-growth annealing temperature can be sufficiently high to induce disorder of the heterostructure layer interfaces.

Wierer, Jr., Jonathan J; Allerman, Andrew A

2014-11-25T23:59:59.000Z

322

Surface hardening of metallic alloys by electrospark deposition followed by plasma nitriding  

Science Journals Connector (OSTI)

This paper presents the results of a study concerned with the surface hardening of nonferrous and ferrous alloys, by integrating the electrospark deposition and plasma nitriding processes. Specimens of an aluminium bronze and of a grey cast iron were firstly electrospark coated with AISI-304 stainless steel and, then, ion nitrided in a 25%N2 + 75%H2 dc plasma. It is shown that by using these two treatments, the surface hardness of this two materials can be substantially increased.

M.A. Béjar; W. Schnake; W. Saavedra; J.P. Vildósola

2006-01-01T23:59:59.000Z

323

Nitride III-V Activities at Sandia National Labs  

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

Lighting: Lighting: Synergisms with Office of Science Materials Programs Jerry A. Simmons Semiconductor Materials and Device Sciences Sandia National Laboratories March 13, 2001 EMaCC Meeting OUTLINE *Brief overview of prospects & promise of SSL *National Initiative *Grand Challenge LDRD at Sandia *BES-supported activities at Sandia provided core capabilities *Other NS applications of nitride materials science Will only discuss inorganic materials and devices here. Major motivation for SSL is energy savings: lighting is large fraction of energy consumption 1 10 100 1000 1970 1980 1990 2000 2010 2020 Energy Electricity Illumination (assuming 20% of electricity) Projected WORLD Energy Consumption (Quads) Year 400 Quads 130 Quads 25 Quads 1998 1970 1980 1990 2000 2010 2020 Energy Electricity Illumination

324

Graphene interconnects fully encapsulated in layered insulator hexagonal boron nitride  

Science Journals Connector (OSTI)

We demonstrate improvements in the electrical performance of graphene interconnects with full encapsulation by lattice-matching layered insulator, hexagonal boron nitride (h-BN). A novel layer-based transfer method is developed to assemble the top passivating layer of h-BN on the graphene surface to construct the h-BN/graphene/h-BN heterostructures. The encapsulated graphene interconnects (EGIs) are characterized and compared with graphene interconnects on either SiO2 or h-BN substrates with no top passivating h-BN layer. We observe significant improvements in both the maximum current density and breakdown voltage in EGIs. Compared with the uncovered structures, EGIs also show an appreciable increase (~67%) in power density at breakdown. These improvements are achieved without degrading the carrier transport characteristics in graphene wires. In addition, EGIs exhibit a minimal environment impact, showing electrical behavior insensitive to ambient conditions.

Nikhil Jain; Chris A Durcan; Robin Jacobs-Gedrim; Yang Xu; Bin Yu

2013-01-01T23:59:59.000Z

325

Single-layer graphene on silicon nitride micromembrane resonators  

SciTech Connect

Due to their low mass, high quality factor, and good optical properties, silicon nitride (SiN) micromembrane resonators are widely used in force and mass sensing applications, particularly in optomechanics. The metallization of such membranes would enable an electronic integration with the prospect for exciting new devices, such as optoelectromechanical transducers. Here, we add a single-layer graphene on SiN micromembranes and compare electromechanical coupling and mechanical properties to bare dielectric membranes and to membranes metallized with an aluminium layer. The electrostatic coupling of graphene covered membranes is found to be equal to a perfectly conductive membrane, without significantly adding mass, decreasing the superior mechanical quality factor or affecting the optical properties of pure SiN micromembranes. The concept of graphene-SiN resonators allows a broad range of new experiments both in applied physics and fundamental basic research, e.g., for the mechanical, electrical, or optical characterization of graphene.

Schmid, Silvan; Guillermo Villanueva, Luis; Amato, Bartolo; Boisen, Anja [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, 2800 Kongens Lyngby (Denmark); Bagci, Tolga; Zeuthen, Emil; Sřrensen, Anders S.; Usami, Koji; Polzik, Eugene S. [QUANTOP, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen (Denmark); Taylor, Jacob M. [Joint Quantum Institute/NIST, College Park, Maryland 20899 (United States); Herring, Patrick K.; Cassidy, Maja C. [School of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts 02138 (United States); Marcus, Charles M. [Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen (Denmark); Cheol Shin, Yong; Kong, Jing [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2014-02-07T23:59:59.000Z

326

Spectroscopic ellipsometry characterization of thin-film silicon nitride  

SciTech Connect

We have measured and analyzed the optical characteristics of a series of silicon nitride thin films prepared by plasma-enhanced chemical vapor deposition on silicon substrates for photovoltaic applications. Spectroscopic ellipsometry measurements were made by using a two-channel spectroscopic polarization modulator ellipsometer that measures N, S, and C data simultaneously. The data were fit to a model consisting of air / roughness / SiN / crystalline silicon. The roughness was modeled using the Bruggeman effective medium approximation, assuming 50% SiN, 50% voids. The optical functions of the SiN film were parameterized using a model by Jellison and Modine. All the {Chi}{sup 2} are near 1, demonstrating that this model works extremely well for all SiN films. The measured dielectric functions were used to make optimized SiN antireflection coatings for crystalline silicon solar cells.

Jellison, G.E. Jr.; Modine, F.A. [Oak Ridge National Lab., TN (United States); Doshi, P.; Rohatgi, A. [Georiga Inst. of Technology, Atlanta, GA (United States)

1997-05-01T23:59:59.000Z

327

Reference Data for the Density and Viscosity of Liquid Cadmium, Cobalt, Gallium, Indium, Mercury, Silicon, Thallium, and Zinc  

SciTech Connect

The available experimental data for the density and viscosity of liquid cadmium, cobalt, gallium, indium, mercury, silicon, thallium, and zinc have been critically examined with the intention of establishing both a density and a viscosity standard. All experimental data have been categorized into primary and secondary data according to the quality of measurement, the technique employed and the presentation of the data, as specified by a series of criteria. The proposed standard reference correlations for the density of liquid cadmium, cobalt, gallium, indium, silicon, thallium, and zinc are characterized by percent deviations at the 95% confidence level of 0.6, 2.1, 0.4, 0.5, 2.2, 0.9, and 0.7, respectively. In the case of mercury, since density reference values already exist, no further work was carried out. The standard reference correlations for the viscosity of liquid cadmium, cobalt, gallium, indium, mercury, silicon, thallium, and zinc are characterized by percent deviations at the 95% confidence level of 9.4, 14.0, 13.5, 2.1, 7.3, 15.7, 5.1, and 9.3, respectively.

Assael, Marc J.; Armyra, Ivi J.; Brillo, Juergen; Stankus, Sergei V.; Wu Jiangtao; Wakeham, William A. [Chemical Engineering Department, Aristotle University, 54124 Thessaloniki (Greece); Institut fuer Materialphysik im Weltraum, Deutsches Zentrum fuer Luft- und Raumfahrt, 51170 Koeln (Germany); Kutateladze Institute of Thermophysics, Siberian Brunch of the Russian Academy of Sciences, Lavrentyev ave. 1, 630090 Novosibirsk (Russian Federation); Center of Thermal and Fluid Science, School of Energy and Power Engineering, Xi'an Jiaotong University, Shaanxi 710049 (China); Chemical Engineering Department, Imperial College, London SW7 2BY (United Kingdom)

2012-09-15T23:59:59.000Z

328

Evaluation of critical materials for five advanced design photovoltaic cells with an assessment of indium and gallium  

SciTech Connect

The objective of this study is to identify potential material supply constraints due to the large-scale deployment of five advanced photovoltaic (PV) cell designs, and to suggest strategies to reduce the impacts of these production capacity limitations and potential future material shortages. This report presents the results of the screening of the five following advanced PV cell designs: polycrystalline silicon, amorphous silicon, cadmium sulfide/copper sulfide frontwall, polycrystalline gallium arsenide MIS, and advanced concentrator-500X. Each of these five cells is screened individually assuming that they first come online in 1991, and that 25 GWe of peak capacity is online by the year 2000. A second computer screening assumes that each cell first comes online in 1991 and that each cell has 5 GWe of peak capacity by the year 2000, so that the total online cpacity for the five cells is 25 GWe. Based on a review of the preliminary basline screening results, suggestions were made for varying such parameters as the layer thickness, cell production processes, etc. The resulting PV cell characterizations were then screened again by the CMAP computer code. Earlier DOE sponsored work on the assessment of critical materials in PV cells conclusively identtified indium and gallium as warranting further investigation as to their availability. Therefore, this report includes a discussion of the future availability of gallium and indium. (WHK)

Watts, R.L.; Gurwell, W.E.; Jamieson, W.M.; Long, L.W.; Pawlewicz, W.T.; Smith, S.A.; Teeter, R.R.

1980-05-01T23:59:59.000Z

329

RAPID/BulkTransmission/General Construction | Open Energy Information  

Open Energy Info (EERE)

RAPIDBulkTransmissionGeneral Construction < RAPID | BulkTransmission Jump to: navigation, search RAPID Regulatory and Permitting Information Desktop Toolkit BETA RAPID Toolkit...

330

On Eling-Oz formula for the holographic bulk viscosity  

E-Print Network (OSTI)

Recently Eling and Oz [1] proposed a simple formula for the bulk viscosity of holographic plasma. They argued that the formula is valid in the high temperature (near-conformal) regime, but is expected to break down at low temperatures. We point out that the formula is in perfect agreement with the previous computations of the bulk viscosity of the cascading plasma [2,3], as well as with the previous computations of the bulk viscosity of N=2^* plasma [4,5]. In the latter case it correctly reproduces the critical behaviour of the bulk viscosity in the vicinity of the critical point with the vanishing speed of sound.

Alex Buchel

2011-03-19T23:59:59.000Z

331

Bulk viscosity of QCD matter near the critical temperature  

E-Print Network (OSTI)

Kubo's formula relates bulk viscosity to the retarded Green's function of the trace of the energy-momentum tensor. Using low energy theorems of QCD for the latter we derive the formula which relates the bulk viscosity to the energy density and pressure of hot matter. We then employ the available lattice QCD data to extract the bulk viscosity as a function of temperature. We find that close to the deconfinement temperature bulk viscosity becomes large, with viscosity-to-entropy ratio zeta/s about 1.

D. Kharzeev; K. Tuchin

2007-05-29T23:59:59.000Z

332

Innovative approaches to improve bulk heterojuction organic photovoltaic device performance.  

E-Print Network (OSTI)

??In this thesis we studied the electrical properties of bulk heterojunction organic photovoltaic (OPV) devices fabricated using a variety of conjugated polymers, including regioregular P3HT,… (more)

Zhang, Ye

2010-01-01T23:59:59.000Z

333

Regulatory Roadmap Workshop for Federal Bulk Transmission Regulations...  

Open Energy Info (EERE)

Regulatory Roadmapping Pgower's picture Submitted by Pgower(45) Member 7 August, 2014 - 13:19 One-day workshop to review regulatory roadmaps for bulk transmission. Date:...

334

RAPID/BulkTransmission/Arizona | Open Energy Information  

Open Energy Info (EERE)

Entity responsible for coordinating and promoting Bulk Electric System reliability in the Western Interconnection, including Arizona. WECC also provides an environment for...

335

RAPID/BulkTransmission/New Mexico | Open Energy Information  

Open Energy Info (EERE)

Information Desktop Toolkit BETA RAPID Toolkit About Bulk Transmission Geothermal Solar Resources Contribute Contact Us Regulatory Information Overviews Search for other...

336

Bulk Fuel Procurement Process & Alternative Drop-in Fuel  

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

Jeanne Binder, DLA Energy, presentation on Bulk Fuel Procurement Process & Alternative Drop-in Fuel at the Advanced Biofuels Industry Roundtable.

337

Strategies for High Thermoelectric zT in Bulk Materials  

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

Zintl principle in chemistry, complex electronic band structures, and incorporation of nanometer sized particles were used to explore, optimize and improve bulk thermoelectric materials

338

Recent Device Developments with Advanced Bulk Thermoelectric Materials at RTI  

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

Reviews work in engineered thin-film nanoscale thermoelectric materials and nano-bulk materials with high ZT undertaken by RTI in collaboration with its research partners

339

High Heat Flux Thermoelectric Module Using Standard Bulk Material  

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

Presents high heat flux thermoelectric module design for cooling using a novel V-shaped shunt configuration with bulk TE elements achieving high area packing fractions

340

Control Center and Data Management Improvements Modernize Bulk...  

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

Operations Corporation's (GSOC) Smart Grid Investment Grant (SGIG) project modernized bulk power management and control center operations for 38 electric membership...

Note: This page contains sample records for the topic "bulk gallium nitride" 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

RAPID/BulkTransmission/Air Quality | Open Energy Information  

Open Energy Info (EERE)

RAPIDBulkTransmissionAir Quality < RAPID | BulkTransmission Jump to: navigation, search RAPID Regulatory and Permitting Information Desktop Toolkit BETA RAPID Toolkit About...

342

Nanostructured High-Temperature Bulk Thermoelectric Energy Conversion...  

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

High Temperature Bulk Thermoelectric Energy Conversion for Efficient Waste Heat Recovery Project Overview 2 * Start: October 2011 * End: September 2015 * Percent complete -...

343

RAPID/BulkTransmission/About | Open Energy Information  

Open Energy Info (EERE)

Contribute Contact Us About Bulk Transmission Lattice.jpg High-voltage transmission lines form the backbone of electricity systems. Transmission lines are designed to carry...

344

RAPID/BulkTransmission/Water Quality | Open Energy Information  

Open Energy Info (EERE)

RAPIDBulkTransmissionWater Quality < RAPID | BulkTransmission Jump to: navigation, search RAPID Regulatory and Permitting Information Desktop Toolkit BETA RAPID Toolkit About...

345

Biofuels production from hydrotreating of vegetable oil using supported noble metals, and transition metal carbide and nitride.  

E-Print Network (OSTI)

?? The focus of this research is to prepare non-sulfided hydrotreating catalysts, supported noble metal and transition metal carbide/ nitride, and evaluate their hydrocracking activities… (more)

Wang, Huali

2012-01-01T23:59:59.000Z

346

Improving Bulk Microphysics Parameterizations in Simulations of Aerosol Effects  

SciTech Connect

To improve the microphysical parameterizations for simulations of the aerosol indirect effect (AIE) in regional and global climate models, a double-moment bulk microphysical scheme presently implemented in the Weather Research and Forecasting (WRF) model is modified and the results are compared against atmospheric observations and simulations produced by a spectral bin microphysical scheme (SBM). Rather than using prescribed aerosols as in the original bulk scheme (Bulk-OR), a prognostic doublemoment aerosol representation is introduced to predict both the aerosol number concentration and mass mixing ratio (Bulk-2M). The impacts of the parameterizations of diffusional growth and autoconversion and the selection of the embryonic raindrop radius on the performance of the bulk microphysical scheme are also evaluated. Sensitivity modeling experiments are performed for two distinct cloud regimes, maritime warm stratocumulus clouds (SC) over southeast Pacific Ocean from the VOCALS project and continental deep convective clouds (DCC) in the southeast of China from the Department of Energy/ARM Mobile Facility (DOE/AMF) - China field campaign. The results from Bulk-2M exhibit a much better agreement in the cloud number concentration and effective droplet radius in both the SC and DCC cases with those from SBM and field measurements than those from Bulk-OR. In the SC case particularly, Bulk-2M reproduces the observed drizzle precipitation, which is largely inhibited in Bulk-OR. Bulk-2M predicts enhanced precipitation and invigorated convection with increased aerosol loading in the DCC case, consistent with the SBM simulation, while Bulk-OR predicts the opposite behaviors. Sensitivity experiments using four different types of autoconversion schemes reveal that the autoconversion parameterization is crucial in determining the raindrop number, mass concentration, and drizzle formation for warm 2 stratocumulus clouds. An embryonic raindrop size of 40 ?m is determined as a more realistic setting in the autoconversion parameterization. The saturation adjustment employed in calculating condensation/evaporation in the bulk scheme is identified as the main factor responsible for the large discrepancies in predicting cloud water in the SC case, suggesting that an explicit calculation of diffusion growth with predicted supersaturation is necessary for further improvements of the bulk microphysics scheme. Lastly, a larger rain evaporation rate below cloud is found in the bulk scheme in comparison to the SBM simulation, which could contribute to a lower surface precipitation in the bulk scheme.

Wang, Yuan; Fan, Jiwen; Zhang, Renyi; Leung, Lai-Yung R.; Franklin, Charmaine N.

2013-06-05T23:59:59.000Z

347

Material Profile Influences in Bulk-Heterojunctions  

SciTech Connect

he morphology in mixed bulk-heterojunction films are compared using three different quantitative measurement techniques. We compare the vertical composition changes using high-angle annular dark-field scanning transmission electron microscopy with electron tomography and neutron and x-ray reflectometry. The three measurement techniques yield qualita-tively comparable vertical concentration measurements. The presence of a metal cathode during thermal annealing is observed to alter the fullerene concentration throughout the thickness of the film for all measurements. However, the abso-lute vertical concentration of fullerene is quantitatively different for the three measurements. The origin of the quantitative measurement differences is discussed. The authors thank Luna Innovations, Inc. for donating the endohedral fullerenes used in this study and Plextronics for the P3HT. They are gratefully thank the National Science Foundation Energy for Sustainability Program, Award No. 0933435. This work benefited from the use of the Lujan Neutron Scattering Center at Los Alamos Neutron Science Center funded by the DOE Office of Basic Energy Sciences and Los Alamos National Laboratory under DOE Contract DE-AC52-06NA25396. This research was also supported in part by Laboratory Directed Research & Development program at PNNL. The Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy under contract DE-AC05-76RL01830.

Roehling, John D.; Rochester, Christopher W.; Ro, Hyun W.; Wang, Peng; Majewski, Jaroslaw; Batenburg, Kees J.; Arslan, Ilke; Delongchamp, Dean M.; Moule, Adam J.

2014-10-01T23:59:59.000Z

348

Leptonic contribution to the bulk viscosity of nuclear matter  

SciTech Connect

For {beta}-equilibrated nuclear matter we estimate the contribution to the bulk viscosity from purely leptonic processes, namely the conversion of electrons to and from muons. For oscillation frequencies in the kilohertz range, we find that this process provides the dominant contribution to the bulk viscosity when the temperature is well below the critical temperature for superconductivity or superfluidity of the nuclear matter.

Alford, Mark G.; Good, Gerald [Physics Department, Washington University, St. Louis, Missouri 63130 (United States)

2010-11-15T23:59:59.000Z

349

BULK TITANIUM MICROFLUIDIC NETWORKS FOR PROTEIN SELF-ASSEMBLY STUDIES  

E-Print Network (OSTI)

BULK TITANIUM MICROFLUIDIC NETWORKS FOR PROTEIN SELF-ASSEMBLY STUDIES E.R. Parker1 , L.S. Hirst2 developed micromachining technique to fabricate microfluidic networks in thin titanium foils. These devices relevant conditions. Keywords: bulk titanium, cytoskeleton proteins, microfluidics, surface modification 1

MacDonald, Noel C.

350

MORPHOLOGY DEPENDENT SHORT CIRCUIT CURRENT IN BULK HETEROJUNCTION SOLAR CELL  

E-Print Network (OSTI)

a relatively inexpensive option for the future solar cell technology, provided its efficiency increases beyondMORPHOLOGY DEPENDENT SHORT CIRCUIT CURRENT IN BULK HETEROJUNCTION SOLAR CELL Biswajit Ray, Pradeep, West Lafayette, Indiana, USA ABSTRACT Polymer based bulk heterostructure (BH) solar cell offers

Alam, Muhammad A.

351

Bulk Hydrogen Storage - Strategic Directions for Hydrogen Delivery Workshop  

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

Hydrogen Hydrogen Storage Strategic Directions for Hydrogen Delivery Workshop May 7-8, 2003 Crystal City, Virginia Breakout Session - Bulk Hydrogen Storage Main Themes/Caveats Bulk Storage = Anything not on the vehicle 10's of Tons -- End use point 50-100 Tons - Terminals/City Gates 1000's Tons - Between Production Facility and Terminal/City Gate Bulk storage requirements less restrictive and different from on-board storage Uncertainty about evolution of infrastructure requires multiple pathways to be considered Bulk storage is an economic solution to address supply/demand imbalance Breakout Session - Bulk Hydrogen Storage Targets/Objectives Hard to quantify - scenario & end-use dependent Storage Materials (solid state) and container require different targets

352

Carbon nanotubes grown on bulk materials and methods for fabrication  

DOE Patents (OSTI)

Disclosed are structures formed as bulk support media having carbon nanotubes formed therewith. The bulk support media may comprise fibers or particles and the fibers or particles may be formed from such materials as quartz, carbon, or activated carbon. Metal catalyst species are formed adjacent the surfaces of the bulk support material, and carbon nanotubes are grown adjacent the surfaces of the metal catalyst species. Methods employ metal salt solutions that may comprise iron salts such as iron chloride, aluminum salts such as aluminum chloride, or nickel salts such as nickel chloride. Carbon nanotubes may be separated from the carbon-based bulk support media and the metal catalyst species by using concentrated acids to oxidize the carbon-based bulk support media and the metal catalyst species.

Menchhofer, Paul A. (Clinton, TN); Montgomery, Frederick C. (Oak Ridge, TN); Baker, Frederick S. (Oak Ridge, TN)

2011-11-08T23:59:59.000Z

353

Silicon bulk micromachined hybrid dimensional artifact.  

SciTech Connect

A mesoscale dimensional artifact based on silicon bulk micromachining fabrication has been developed and manufactured with the intention of evaluating the artifact both on a high precision coordinate measuring machine (CMM) and video-probe based measuring systems. This hybrid artifact has features that can be located by both a touch probe and a video probe system with a k=2 uncertainty of 0.4 {micro}m, more than twice as good as a glass reference artifact. We also present evidence that this uncertainty could be lowered to as little as 50 nm (k=2). While video-probe based systems are commonly used to inspect mesoscale mechanical components, a video-probe system's certified accuracy is generally much worse than its repeatability. To solve this problem, an artifact has been developed which can be calibrated using a commercially available high-accuracy tactile system and then be used to calibrate typical production vision-based measurement systems. This allows for error mapping to a higher degree of accuracy than is possible with a glass reference artifact. Details of the designed features and manufacturing process of the hybrid dimensional artifact are given and a comparison of the designed features to the measured features of the manufactured artifact is presented and discussed. Measurement results from vision and touch probe systems are compared and evaluated to determine the capability of the manufactured artifact to serve as a calibration tool for video-probe systems. An uncertainty analysis for calibration of the artifact using a CMM is presented.

Claudet, Andre A.; Tran, Hy D.; Bauer, Todd Marks; Shilling, Katherine Meghan; Oliver, Andrew David

2010-03-01T23:59:59.000Z

354

Reaction injection molding of silicon nitride ceramics having crystallized grain boundary phases  

SciTech Connect

A reaction injection molding process is described for preparing a sintered, silicon nitride-containing ceramic article comprising; (1) injecting into a heated mold a fluid, nondilatant mixture comprising (a) at least 40% by volume of a powder mixture of (i) from about 20 wt.% to about 98 wt.% silicon nitride, (ii) from about 0.5 wt.% to about 20 wt.% of a silicate glass-forming sintering aid, and (iii) from about 0.001 wt.% to about 80 wt.% of a high metal content transition metal silicide or a transition metal or metal compound that forms a high metal content silicide with silicon nitride under the conditions defined in steps (2) or (3), and (b) a curable silicon nitride precursor binder that is a liquid below its curing temperature, to cure the binder and produce a hardened molded article, (2) heating the hardened mol suitable atmosphere to a temperature sufficient to convert the cured binder to a silicon nitride-containing ceramic, and (3) sintering the article by (i) heating at a temperature of 1,300 to 1,800 C until a silicate glass forms, and (ii) further heating at a temperature of 1,300 to 1,800 C under a vacuum until oxygen is removed from the silicate glass and the glass crystallizes.

Lukacs, A. III; Matsumoto, R.L.K.

1993-08-31T23:59:59.000Z

355

Process for producing silicon nitride based articles of high fracture toughness and strength  

DOE Patents (OSTI)

A process for producing a silicon nitride-based article of improved fracture toughness and strength. The process involves densifying to at least 98% of theoretical density a mixture including (a) a bimodal silicon nitride powder blend consisting essentially of about 10-30% by weight of a first silicon nitride powder of an average particle size of about 0.2 .mu.m and a surface area of about 8-12 m.sup.2 /g, and about 70-90% by weight of a second silicon nitride powder of an average particle size of about 0.4-0.6 .mu.m and a surface area of about 2-4 m.sup.2 /g, (b) about 10-50 percent by volume, based on the volume of the densified article, of refractory whiskers or fibers having an aspect ratio of about 3-150 and having an equivalent diameter selected to produce in the densified article an equivalent diameter ratio of the whiskers or fibers to grains of silicon nitride of greater than 1.0, and (c) an effective amount of a suitable oxide densification aid. Optionally, the mixture may be blended with a binder and injection molded to form a green body, which then may be densified by, for example, hot isostatic pressing.

Huckabee, Marvin (Marlboro, MA); Buljan, Sergej-Tomislav (Acton, MA); Neil, Jeffrey T. (Acton, MA)

1991-01-01T23:59:59.000Z

356

Process for producing silicon nitride based articles of high fracture toughness and strength  

DOE Patents (OSTI)

A process for producing a silicon nitride-based article of improved fracture toughness and strength is disclosed. The process involves densifying to at least 98% of theoretical density a mixture including (a) a bimodal silicon nitride powder blend consisting essentially of about 10-30% by weight of a first silicon nitride powder of an average particle size of about 0.2 [mu]m and a surface area of about 8-12 m[sup 2]/g, and about 70-90% by weight of a second silicon nitride powder of an average particle size of about 0.4-0.6 [mu]m and a surface area of about 2-4 m[sup 2]/g, (b) about 10-50 percent by volume, based on the volume of the densified article, of refractory whiskers or fibers having an aspect ratio of about 3-150 and having an equivalent diameter selected to produce in the densified article an equivalent diameter ratio of the whiskers or fibers to grains of silicon nitride of greater than 1.0, and (c) an effective amount of a suitable oxide densification aid. Optionally, the mixture may be blended with a binder and injection molded to form a green body, which then may be densified by, for example, hot isostatic pressing.

Huckabee, M.; Buljan, S.T.; Neil, J.T.

1991-09-10T23:59:59.000Z

357

Examination on surface films of plasma nitrided and post-stream oxidised H13 steel  

Science Journals Connector (OSTI)

Different surface structures have been obtained on H13 steel by plasma nitriding under a mix current of ammonia and argon at 520°C, and a simple current of ammonia at 550°C. Post-stream oxidation gives the H13 samples a compact oxide film. The surface films and structures of these samples have been investigated with optical microscopy, X-ray diffraction, scanning electron microscopy and high distinguishability energy diffraction spectrometry. Only a single nitrogen diffusion layer is obtained on the 520°C-nitrided H13 samples, while a white Fe2-3N nitride film and a deeper diffusion layer with needle-like nitride is obtained on the 550°C-nitrided samples. These two type samples are covered by the films of Me3O4 mainly as well as Fe2O3 after post-oxidation. It is also discussed on the application chances of the duplex treatment, which is cleaner and more environment friendly than conventional salt bath or gaseous techniques.

Yongan Min; Xiaochun Wu; Luoping Xu

2008-01-01T23:59:59.000Z

358

SUMMARY ON TITANIUM NITRIDE COATING OF SNS RING VACUUM CHAMBERS.  

SciTech Connect

The inner surfaces of the 248 m Spallation Neutron Source (SNS) accumulator ring vacuum chambers are coated with {approx}100nm of titanium nitride (TiN) to reduce the secondary electron yield (SEY) of the chamber walls. There are approximately 135 chambers and kicker modules, some up to 5m in length and 36cm in diameter, coated with TiN. The coating is deposited by means of reactive DC magnetron sputtering -using a - cylindrical cathode with internal permanent magnets. This cathode configuration generates a deposition-rate sufficient to meet the required production schedule and produces stoichiometric films with good adhesion, low SEY and acceptable outgassing. Moreover, the cathode magnet configuration allows for simple changes in length and has been adapted to coat the wide variety of chambers and components contained within the arcs, injection, extraction, collimation and RF straight sections. Chamber types and quantities as well as the cathode configurations are presented herein. The unique coating requirements of the injection kicker ceramic chambers and the extraction kicker ferrite surface will be emphasized. A brief summary of the salient coating properties is given including the interdependence of SEY as a function of surface roughness and its effect on outgassing.

TODD, R.; HE, P.; HSEUH, H.C.; WEISS, D.

2005-05-16T23:59:59.000Z

359

Radial elasticity of multi-walled boron nitride nanotubes  

SciTech Connect

We investigated the radial mechanical properties of multi-walled boron nitride nanotubes (MW-BNNTs) using atomic force microscopy. The employed MW-BNNTs were synthesized using pressurized vapor/condenser (PVC) methods and were dispersed in aqueous solution using ultrasonication methods with the aid of ionic surfactants. Our nanomechanical measurements reveal the elastic deformational behaviors of individual BNNTs with two to four tube walls in their transverse directions. Their effective radial elastic moduli were obtained through interpreting their measured radial deformation profiles using Hertzian contact mechanics models. Our results capture the dependences of the effective radial moduli of MW-BNNTs on both the tube outer diameter and the number of tube layers. The effective radial moduli of double-walled BNNTs are found to be several-fold higher than those of single-walled BNNTs within the same diameter range. Our work contributes directly to a complete understanding of the fundamental structural and mechanical properties of BNNTs and the pursuits of their novel structural and electronics applications.

Michael W. Smith, Cheol Park, Meng Zheng, Changhong Ke ,In-Tae Bae, Kevin Jordan

2012-02-01T23:59:59.000Z

360

III-nitride core–shell nanowire arrayed solar cells  

Science Journals Connector (OSTI)

A solar cell based on a hybrid nanowire–film architecture consisting of a vertically aligned array of InGaN/GaN multi-quantum well core–shell nanowires which are electrically connected by a coalesced p-InGaN canopy layer is demonstrated. This unique hybrid structure allows for standard planar device processing, solving a key challenge with nanowire device integration, while enabling various advantages by the nanowire absorbing region such as higher indium composition InGaN layers by elastic strain relief, more efficient carrier collection in thinner layers, and enhanced light trapping from nano-scale optical index changes. This hybrid structure is fabricated into working solar cells exhibiting photoresponse out to 2.1 eV and short-circuit current densities of ~1 mA cm?2 under 1 sun AM1.5G. This proof-of-concept nanowire-based device demonstrates a route forward for high-efficiency III-nitride solar cells.

Jonathan J Wierer Jr; Qiming Li; Daniel D Koleske; Stephen R Lee; George T Wang

2012-01-01T23:59:59.000Z

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


361

CX-000845: Categorical Exclusion Determination | Department of Energy  

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

0845: Categorical Exclusion Determination 0845: Categorical Exclusion Determination CX-000845: Categorical Exclusion Determination 25A2445 - Ammonothermal Bulk Gallium Nitride (GaN) Crystal Growth for Energy Efficient Lighting CX(s) Applied: B3.6 Date: 01/15/2010 Location(s): New York Office(s): Advanced Research Projects Agency - Energy This project plans to address the vast energy loss and consumption associated with conventional lighting by developing a new route to large, high-quality, single crystals of gallium nitride. These crystals will serve as substrates for light emitting diodes offering high-efficiency lighting. DOCUMENT(S) AVAILABLE FOR DOWNLOAD CX-000845.pdf More Documents & Publications CX-009889: Categorical Exclusion Determination Power Electronics Research and Development Program Plan

362

The different adsorption mechanism of methane molecule onto a boron nitride and a graphene flakes  

SciTech Connect

Graphene and single layer hexagonal boron-nitride are two newly discovered 2D materials with wonderful physical properties. Using density functional theory, we study the adsorption mechanism of a methane molecule over a hexagonal flake of single layer hexagonal boron-nitride (h-BN) and compare the results with those of graphene. We found that independent of the used functional in our ab-initio calculations, the adsorption energy in the h-BN flake is larger than that for graphene. Despite of the adsorption energy profile of methane over a graphene flake, we show that there is a long range behavior beyond minimum energy in the adsorption energy of methane over h-BN flake. This result reveals the higher sensitivity of h-BN sheet to the adsorption of a typical closed shell molecule with respect to graphene. The latter gives insight in the recent experiments of graphene over hexagonal boron nitride.

Seyed-Talebi, Seyedeh Mozhgan [Shahid Chamran University, Golestan boulevard, Ahvaz, Khouzestan (Iran, Islamic Republic of); Neek-Amal, M., E-mail: neekamal@srttu.edu [Shahid Rajaee Teacher Training University, Lavizan, Tehran (Iran, Islamic Republic of)

2014-10-21T23:59:59.000Z

363

Formation of Protective Nitride Surfaces for PEM Fuel Cell Metallic Bipolar Plates  

SciTech Connect

Selective gas nitridation of model Ni-base alloys was used to form dense, electrically-conductive and corrosion-resistant nitride surface layers, including TiN, VN, CrN, Cr2N, as well as a complex NiNbVN phase. Evaluation for use as a protective surface for metallic bipolar plates in proton exchange membrane fuel cells (PEMFC) indicated that CrN/Cr2N base surfaces hold promise to meet Department of Energy (DOE) performance goals for automotive applications. The thermally grown CrN/Cr2N surface formed on model Ni-Cr base alloys exhibited good stability and low electrical resistance in single-cell fuel cell testing under simulated drive-cycle conditions. Recent results indicate that similar protective Cr-nitride surfaces can be formed on less expensive Fe-Cr base alloys potentially capable of meeting DOE cost goals.

Brady, Michael P [ORNL; Yang, Bing [ORNL; Wang, Heli [National Renewable Energy Laboratory (NREL); Turner, John [National Renewable Energy Laboratory (NREL); More, Karren Leslie [ORNL; Wilson, Mahlon [Los Alamos National Laboratory (LANL); Garzon, Fernando [Los Alamos National Laboratory (LANL)

2006-01-01T23:59:59.000Z

364

Thermodynamic stability and unusual strength of ultra-incompressible rhenium nitrides  

SciTech Connect

We report on a comprehensive study of thermodynamic and mechanical properties as well as a bond-deformation mechanism on ultra-incompressible Re{sub 2} N and Re{sub 3} N. The introduction of nitrogen into the rhenium lattice leads to thermodynamic instability in Re{sub 2} N at ambient conditions and enhanced incompressibility and strength for both rhenium nitrides. Rhenium nitrides, however, show substantially lower ideal shear strength than hard ReB{sub 2} and superhard c -BN, suggesting that they cannot be intrinsically superhard. An intriguing soft “ionic bond mediated plastic deformation” mechanism is revealed to underline the physical origin of their unusual mechanical strength. These results suggest a need to reformulate the design concept of intrinsically superhard transition-metal nitrides, borides, and carbides.

Zhang, R. F.; Lin, Zhijun; Mao, Ho-kwang; Zhao, Yusheng

2011-01-01T23:59:59.000Z

365

Bulk viscosity, chemical equilibration and flow at RHIC  

E-Print Network (OSTI)

We study the effects of bulk viscosity on p_T spectra and elliptic flow in heavy ion collisions at RHIC. We argue that direct effect of the bulk viscosity on the evolution of the velocity field is small, but corrections to the freezeout distributions can be significant. These effects are dominated by chemical non-equilibration in the hadronic phase. We show that a non-zero bulk viscosity in the range $\\zeta/s \\lsim 0.05$ improves the description of spectra and flow at RHIC.

Thomas Schaefer; Kevin Dusling

2012-10-15T23:59:59.000Z

366

Brane-Bulk energy exchange and agegraphic dark energy  

E-Print Network (OSTI)

We consider the agegraphic models of dark energy in a braneworld scenario with brane-bulk energy exchange. We assume that the adiabatic equation for the dark matter is satisfied while it is violated for the agegraphic dark energy due to the energy exchange between the brane and the bulk. Our study shows that with the brane-bulk interaction, the equation of state parameter of agegraphic dark energy on the brane, $w_D$, can have a transition from normal state where $w_D >-1 $ to the phantom regime where $w_D energy always satisfies $w^{\\mathrm{eff}}_D\\geq-1$.

Ahmad Sheykhi

2010-02-06T23:59:59.000Z

367

Novel Approaches to High-Efficiency III-V Nitride Heterostructure Emitters for Next-Generation Lighting Applications  

SciTech Connect

We report research activities and technical progress on the development of high-efficiency long wavelength ({lambda} {approx} 540nm) green light emitting diodes which covers whole years of the three-year program 'Novel approaches to high-efficiency III-V nitride heterostructure emitters for next-generation lighting applications'. The research activities were focused on the development of p-type layer that has less/no detrimental thermal annealing effect on as well as excellent structural and electrical properties and the development of green LED active region that has superior luminescence quality for {lambda}{approx}540nm green LEDs. We have also studied (1) the thermal annealing effect on blue and green LED active region during the p-type layer growth; (2) the effect of growth parameters and structural factors for LED active region on electroluminescence properties; (3) the effect of substrates and orientation on electrical and electro-optical properties of green LEDs. As a progress highlight, we obtained green-LED-active-region-friendly In{sub 0.04}Ga{sub 0.96}N:Mg exhibiting low resistivity with higher hole concentration (p=2.0 x 10{sup 18} cm{sup -3} and a low resistivity of 0.5 {omega}-cm) and improved optical quality green LED active region emitting at {approx}540nm by electroluminescence. The LEDs with p-InGaN layer can act as a quantum-confined Stark effect mitigation layer by reducing strain in the QW. We also have achieved (projected) peak IQE of {approx}25% at {lambda}{approx}530 nm and of {approx}13% at {lambda}{approx}545 nm. Visible LEDs on a non-polar substrate using (11-20) {alpha}-plane bulk substrates. The absence of quantum-confined Stark effect was confirmed but further improvement in electrical and optical properties is required.

Russell Dupuis

2007-06-30T23:59:59.000Z

368

Effects of surface grinding conditions on the reciprocating friction and wear behavior of silicon nitride  

SciTech Connect

The relationship between two significantly different surface grinding conditions and the reciprocating ball-on-flat friction and wear behavior of a high-quality, structural silicon nitride material (GS-44) was investigated. The slider materials were silicon nitride NBD 200 and 440C stainless steel. Two machining conditions were selected based on extensive machining and flexural strength test data obtained under the auspices of an international, interlaboratory grinding study. The condition categorized as {open_quotes}low strength{close_quote} grinding used a coarse 80 grit wheel and produced low flexure strength due to machining-induced flaws in the surface. The other condition, regarded as {open_quotes}high strength grinding,{close_quotes} utilized a 320 grit wheel and produced a flexural strength nearly 70% greater. Grinding wheel surface speeds were 35 and 47 m/s. Reciprocating sliding tests were conducted following the procedure described in a newly-published ASTM standard (G- 133) for linearly-reciprocating wear. Tests were performed in directions both parallel and perpendicular to the grinding marks (lay) using a 25 N load, 5 Hz reciprocating frequency, 10 mm stroke length, and 100 m of sliding at room temperature. The effects of sliding direction relative to the lay were more pronounced for stainless steel than for silicon nitride sliders. The wear of stainless steel was less than the wear of the silicon nitride slider materials because of the formation of transfer particles which covered the sharp edges of the silicon nitride grinding grooves and reduced abrasive contact. The wear of the GS-44 material was much greater for the silicon nitride sliders than for the stainless steel sliders. The causes for the effects of surface-grinding severity and sliding direction on friction and wear of GS-44 and its counterface materials are explained.

Blau, P.J.; Martin, R.L.; Zanoria, E.S.

1997-12-31T23:59:59.000Z

369

Alternative Liquid Fuel Effects on Cooled Silicon Nitride Marine Gas Turbine Airfoils  

SciTech Connect

With prior support from the Office of Naval Research, DARPA, and U.S. Department of Energy, United Technologies is developing and engine environment testing what we believe to be the first internally cooled silicon nitride ceramic turbine vane in the United States. The vanes are being developed for the FT8, an aeroderivative stationary/marine gas turbine. The current effort resulted in further manufacturing and development and prototyping by two U.S. based gas turbine grade silicon nitride component manufacturers, preliminary development of both alumina, and YTRIA based environmental barrier coatings (EBC's) and testing or ceramic vanes with an EBC coating.

Holowczak, J.

2002-03-01T23:59:59.000Z

370

Proton exchange membrane fuel cells with chromium nitride nanocrystals as electrocatalysts  

Science Journals Connector (OSTI)

Polymer electrolyte membrane fuel cells(PEMFCs) are energy conversion devices that produce electricity from a supply of fuel such as hydrogen. One of the major challenges in achieving efficient energy conversion is the development of cost-effective materials that can act as electrocatalysts for PEMFCs. In this letter we demonstrate that instead of conventional noble metals such as platinum chromium nitride nanocrystals of fcc structure exhibit attractive catalytic activity for PEMFCs. Device testing indicates good stability of nitride nanocrystals in low temperature fuel cell operational environment.

Hexiang Zhong; Xiaobo Chen; Huamin Zhang; Meiri Wang; Samuel S. Mao

2007-01-01T23:59:59.000Z

371

Efficient boron nitride nanotube formation via combined laser-gas flow levitation  

DOE Patents (OSTI)

A process for producing boron nitride nanotubes and/or boron-carbon-nitrogen nanotubes of the general formula B.sub.xC.sub.yN.sub.z. The process utilizes a combination of laser light and nitrogen gas flow to support a boron ball target during heating of the boron ball target and production of a boron vapor plume which reacts with nitrogen or nitrogen and carbon to produce boron nitride nanotubes and/or boron-carbon-nitrogen nanotubes of the general formula B.sub.xC.sub.yN.sub.z.

Whitney, R. Roy; Jordan, Kevin; Smith, Michael

2014-03-18T23:59:59.000Z

372

Cubic boron nitride: a new prospective material for ultracold neutron application  

E-Print Network (OSTI)

For the first time, the neutron optical wall-potential of natural cubic boron nitride (cBN) was measured at the ultracold neutron (UCN) source of the research reactor TRIGA Mainz using the time-of-flight method (TOF). The samples investigated had a wall-potential of (305 +/- 15) neV. This value is in good agreement with the result extracted from neutron reflectometry data and theoretical expectations. Because of its high critical velocity for UCN and its good dielectric characteristics, cubic boron nitride coatings (isotopically enriched) will be useful for a number of applications in UCN experiments.

Sobolev, Yu; Borisov, Yu; Daum, M; Fresne, N du; Goeltl, L; Hampel, G; Heil, W; Knecht, A; Keunecke, M; Kratz, J V; Lang, T; Meister, M; Plonka-Spehr, Ch; Pokotilovski, Yu; Reichert, P; Schmidt, U; Krist, Th; Wiehl, N; Zenner, J

2009-01-01T23:59:59.000Z

373

ARM - Campaign Instrument - ec-convair580-bulk  

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

govInstrumentsec-convair580-bulk govInstrumentsec-convair580-bulk Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign Instrument : Environment Canada Convair 580 Bulk Parameters (EC-CONVAIR580-BULK) Instrument Categories Aerosols, Cloud Properties, Airborne Observations Campaigns Indirect and Semi-Direct Aerosol Campaign (ISDAC) [ Download Data ] North Slope Alaska, 2008.04.01 - 2008.04.30 Primary Measurements Taken The following measurements are those considered scientifically relevant. Refer to the datastream (netcdf) file headers for the list of all available measurements, including those recorded for diagnostic or quality assurance purposes. Ice water content Liquid water content Hydrometeor size Cloud particle number concentration Aerosol concentration

374

Bulk Energy Storage Webinar Rescheduled for February 9, 2012 | Department  

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

Bulk Energy Storage Webinar Rescheduled for February 9, 2012 Bulk Energy Storage Webinar Rescheduled for February 9, 2012 Bulk Energy Storage Webinar Rescheduled for February 9, 2012 February 1, 2012 - 12:48pm Addthis The U.S. Department of Energy (DOE) and the Iowa Stored Energy Park (ISEP) are conducting a free, 1-hour webinar, Lessons from Iowa: The Economic, Market, and Organizational Issues in Making Bulk Energy Storage Work, on Thursday, February 9, 2012 at 1 p.m. ET. Presenters include Dr. Imre Gyuk of DOE's Office of Electricity Deliverability and Energy Reliability and Bob Schulte from ISEP. The webinar was original scheduled for January 20, 2012, but experienced technical difficulties due to the large number of participants and was rescheduled. All participants must reregister. Funded by a DOE grant and managed by Sandia National Laboratories, ISEP's

375

Design of Bulk Nanocomposites as High Efficiency Thermoelectric Materials |  

Office of Science (SC) Website

Design of Bulk Nanocomposites as High Design of Bulk Nanocomposites as High Efficiency Thermoelectric Materials Energy Frontier Research Centers (EFRCs) EFRCs Home Centers Research Science Highlights Highlight Archives News & Events Publications Contact BES Home 04.27.12 Design of Bulk Nanocomposites as High Efficiency Thermoelectric Materials Print Text Size: A A A RSS Feeds FeedbackShare Page Scientific Achievement A newly synthesized bulk thermoelectric material that contains nanocrystals with the same orientation and structure as the host material breaks thermoelectric efficiency records by blocking thermal, but not electrical, conductivity. Significance and Impact A new strategy to design inexpensive materials that more efficiently convert heat to electricity. Research Details Thermoelectric materials directly generate electrical power from heat, but

376

Producing bulk residual stresses in gas turbine blades  

Science Journals Connector (OSTI)

Inhomogeneous plastic strain has been used to produce a pattern of bulk compressive stresses that counteract macrodefect formation and growth in machine components, which increases the working life. Studies ha...

V. A. Boguslaev; A. P. Lopatenko; N. B. Makarenko; N. I. Obodan

1993-02-01T23:59:59.000Z

377

Bulk viscosity of anisotropically expanding hot QCD plasma  

SciTech Connect

The bulk viscosity, {zeta} and its ratio with the shear viscosity, {zeta}/{eta} have been studied in an anisotropically expanding pure glue plasma in the presence of turbulent color fields. It has been shown that the anisotropy in the momentum distribution function of gluons, which has been determined from a linearized transport equation eventually leads to the bulk viscosity. For the isotropic (equilibrium) state, a recently proposed quasiparticle model of pure SU(3) lattice QCD equation of state has been employed where the interactions are encoded in the effective fugacity. It has been argued that the interactions present in the equation of state, significantly contribute to the bulk viscosity. Its ratio with the shear viscosity is significant even at 1.5T{sub c}. Thus, one needs to take in account the effects of the bulk viscosity while studying the hydrodynamic expansion of quark-gluon plasma in the Relativistic Heavy Ion Collider and the Large Hadron Collider.

Chandra, Vinod [Department of Theoretical Physics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai-400005 (India)

2011-11-01T23:59:59.000Z

378

Bulk viscosity in nuclear and quark matter: A short review  

E-Print Network (OSTI)

The history and recent progresses in the study of bulk viscosity in nuclear and quark matter are reviewed. The constraints from baryon number conservation and electric neutrality in quark matter on particle densities and fluid velocity divergences are discussed.

Hui Dong; Nan Su; Qun Wang

2007-02-07T23:59:59.000Z

379

Solar Heating Test Design Facility for Bulk PCM Storage  

Science Journals Connector (OSTI)

This experimentation, conducted by the “Centre d’Energétique de l’ENSMP”, was designed to analyze the interest of bulk PCM storage centralized in a real water active solar heating system consisting of a low tempe...

P. Achard; B. Amann; D. Mayer

1984-01-01T23:59:59.000Z

380

Stresses resulting from compression of bulk cotton lint fibers  

E-Print Network (OSTI)

The modulus of elasticity, Poisson's ratio and shear modulus of bulk cotton lint fibers were determined. The cotton lint was compressed in an MTS machine to a predetermined density, and the resilient forces induced by the cotton lint after being...

Chimbombi, Ezekiel Maswe

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "bulk gallium nitride" 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

A bulk-flow model of angled injection Lomakin bearings  

E-Print Network (OSTI)

A bulk-flow model for determination of the leakage and dynamic force characteristics of angled injection Lomakin bearings is presented. Zeroth- and first-order equations describe the equilibrium flow for a centered bearing and the perturbed flow...

Soulas, Thomas Antoine Theo

2001-01-01T23:59:59.000Z

382

Study of organic solar cells with stacked bulk heterojunction structure  

Science Journals Connector (OSTI)

Organic solar cells with stacked bulk heterojunction(BHJ) are investigated ... as inter-layer to connect the upper BHJ cell and the lower cell. The structures are ITO/PEDOT:PSS/MEH...V OC) of a st...

Xin-fang Zhang; Zheng Xu; Su-ling Zhao; Fu-jun Zhang; Yan Li…

2008-07-01T23:59:59.000Z

383

Photonic integration in a commercial scaled bulk-CMOS process  

E-Print Network (OSTI)

We demonstrate the first photonic chip designed for a commercial bulk CMOS process (65 nm-node) using standard process layers combined with post-processing, enabling dense photonic integration with high-performance ...

Kaertner, Franz X.

384

Proposal of a Bulk HTSC Staggered Array Undulator  

SciTech Connect

We proposed a new type of undulator based on bulk high-T{sub c} superconductors (HTSC) which consists of a single solenoid and a stacked array of bulk HTSC. The main advantage of this configuration is that a mechanical structure is not required to produce and control the undulator field. In order to perform a proof of principle experiment, we have developed a prototype of bulk HTSC staggered array undulator using 11 pairs of DyBaCuO bulk superconductors and a normal conducting solenoid. Experimental results obtained by using the prototype undulator and numerical results obtained by a loop current model based on the Bean mode for a type-II superconductor were compared.

Kii, Toshiteru; Kinjo, Ryota; Bakr, Mahmoud A.; Sonobe, Taro; Higashimura, Keisuke; Masuda, Kai; Ohgaki, Hideaki; Yoshida, Kyohei [Institute of Advanced Energy, Kyoto University, Kyoto, 611-0011 (Japan); Zen, Heisyun [Institute for Molecular Science, National Institute of Natural Sciences, Aichi 444-8585 (Japan)

2010-06-23T23:59:59.000Z

385

CMI Unique Facility: Bulk Combinatoric Materials Synthesis Facility...  

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

is in the form of a thin film. CMI researchers at The Ames Laboratory have adapted an additive manufacturing tool (sometimes known as a "3-D printer") to produce arrays of bulk...

386

Bulk viscosity and the conformal anomaly in the pion gas  

E-Print Network (OSTI)

We calculate the bulk viscosity of the massive pion gas within Unitarized Chiral Perturbation Theory. We obtain a low temperature peak arising from explicit conformal breaking due to the pion mass and another peak near the critical temperature, dominated by the conformal anomaly through gluon condensate terms. The correlation between bulk viscosity and conformal breaking supports a recent QCD proposal. We discuss the role of resonances, heavier states and large-$N_c$ counting.

D. Fernandez-Fraile; A. Gomez Nicola

2008-09-26T23:59:59.000Z

387

Costs, Savings and Financing Bulk Tanks on Texas Dairy Farms.  

E-Print Network (OSTI)

\\ BULLETIN 904 MAY 1958 .t(. :a ,s - / cwdh\\@ Costs, Savi~gs;.itd Financing Bulk Tanks on Texas Dairy Farms . ?. I I 1 i I I ! ,:ravings in hauling - 10 cents I \\ \\ 1 \\ savings in hauling - 15 cents -----------____--- 'savings... in hauling - 20 cents Annual production, 1,000 pounds Estimated number of years required for savings from a bulk tank to equal additional costs at different levels of production and savings in hauling costs. TEXAS AGRICULTURAL EXPERIMEN'T STATION R. D...

Moore, Donald S.; Stelly, Randall; Parker, Cecil A.

1958-01-01T23:59:59.000Z

388

Compositional ordering and stability in nanostructured, bulk thermoelectric alloys.  

SciTech Connect

Thermoelectric materials have many applications in the conversion of thermal energy to electrical power and in solid-state cooling. One route to improving thermoelectric energy conversion efficiency in bulk material is to embed nanoscale inclusions. This report summarize key results from a recently completed LDRD project exploring the science underpinning the formation and stability of nanostructures in bulk thermoelectric and the quantitative relationships between such structures and thermoelectric properties.

Hekmaty, Michelle A.; Faleev, S.; Medlin, Douglas L.; Leonard, F.; Lensch-Falk, J.; Sharma, Peter Anand; Sugar, J. D.

2009-09-01T23:59:59.000Z

389

Hydrogeologic investigation of petrochemical contamination at a bulk storage facility  

E-Print Network (OSTI)

in 1953 and began receiving petroleum products through a pipeline in 1954. Other industrial facilities which developed in the area include Duke City Distributing, a food distributor; the Texaco Refining and Marketing bulk terminal; General Electric... in 1953 and began receiving petroleum products through a pipeline in 1954. Other industrial facilities which developed in the area include Duke City Distributing, a food distributor; the Texaco Refining and Marketing bulk terminal; General Electric...

Fryar, Dennis Gene

2012-06-07T23:59:59.000Z

390

The thermal conductivity of silicon nitride with molybdenum disilicide additions  

SciTech Connect

Room-temperature thermal conductivity has been measured for a series of silicon nitride (Si{sub 3}N{sub 4}) matrix composites with molybdenum disilicide (MoSi{sub 2}) additions of 2, 5 10, 25 and 50 wt. %. Included in these measurements were a pure MoSi{sub 2} sample and a Si{sub 3}N{sub 4} sample containing only sintering aids. Aluminum oxide (Al{sub 2}O{sub 3}) and yttrium oxide (Y{sub 2}O{sub 3}) were added as the sintering aids, at approximately 6 and 2 respectively. When the amount of MoSi{sub 2} was increased to greater than 10 wt. %, the amount of the sintering aids necessary to densify the composite was decreased. No sintering aids were added to the pure MoSi{sub 2} sample. Thermal conductivities of the Si{sub 3}N{sub 4} sample without MoSi{sub 2} and the pure MoSi{sub 2} sample wee 36 W/m.K and 52 W/m.K respectively, which agree very well with the literature values for similar materials. No statistically significant changes were observed in the thermal conductivity for those samples containing up to 10 wt. % MoSi{sub 2}. However, between 10 and 25 wt. % MoSi{sub 2} there was a dramatic decrease in the thermal conductivity from 37 to 20.9 W/m.K. The thermal conductivity then increased steadily with further additions of MoSi{sub 2} up to 52 W/m.K for the pure MoSi{sub 2} specimen.

Beecher, S.C.; Dinwiddie, R.B.; Abeel, A.M.; Lowden, R.A.

1993-12-31T23:59:59.000Z

391

Finsler geometric perspective on the bulk flow in the universe  

E-Print Network (OSTI)

Astronomical observations showed that there may exist a bulk flow with peculiar velocities in the universe, which contradicts with the (\\Lambda)CDM model. The bulk flow reveals that the observational universe is anisotropic at large scales. In fact, a more reliable observation on the anisotropy of spacetime comes from the CMB power spectra. The WMAP and Planck satellites both show that there is a hemispherical power asymmetry at large-angular scales. In this paper, we propose a "wind" scenario to the bulk flow (or the anisotropy of spacetime). Under the influence of the "wind", the spacetime metric could become a Finsler structure. By resolving the null geodesic equation, we obtain the modified luminosity distance, which has a dipolar form at the leading order. Thus, the "wind" describes well the bulk flow. In addition, we perform a least-(\\chi^2) fit to the data of type Ia supernovae (SNe Ia) in the Union2.1 compilation. The peculiar velocity of the bulk flow has an upper limit (v_{bulk}\\lesssim 4000 \\rm{km/s}), which is compatible with all the existing observational values.

Zhe Chang; Ming-Hua Li; Sai Wang

2013-03-07T23:59:59.000Z

392

The reaction of carbon tetrachloride with gallium arsenide ,,001... L. Li., S, Gan, B.-K. Han, H. Qi, and R. F. Hicksa)  

E-Print Network (OSTI)

The reaction of carbon tetrachloride with gallium arsenide ,,001... L. Li., S, Gan, B.-K. Han, H, California 90095 Received 26 June 1997; accepted for publication 30 December 1997 Carbon tetrachloride of steps during the vapor-phase epitaxial growth of III­V compound semiconductors.3,4 Carbon tetrachloride

Li, Lian

393

,"U.S. Refinery, Bulk Terminal, and Natural Gas Plant Stocks...  

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

Stocks at Refineries, Bulk Terminals, and Natural Gas Plants (Thousand Barrels)","U.S. Gasoline Blending Components Stocks at Refineries, Bulk Terminals, and Natural Gas Plants...

394

Solar Cells: Spin-Cast Bulk Heterojunction Solar Cells: A Dynamical...  

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

Solar Cells: Spin-Cast Bulk Heterojunction Solar Cells: A Dynamical Investigation Solar Cells: Spin-Cast Bulk Heterojunction Solar Cells: A Dynamical Investigation Print Wednesday,...

395

A Combined FTIR and TPD Study on the Bulk and Surface Dehydroxylation...  

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

and TPD Study on the Bulk and Surface Dehydroxylation and Decarbonation of Synthetic Goethite. A Combined FTIR and TPD Study on the Bulk and Surface Dehydroxylation and...

396

The Role of Surface Chemistry and Bulk Properties on the Cycling...  

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

The Role of Surface Chemistry and Bulk Properties on the Cycling and Rate Capability of Lithium Positive Electrode Materials The Role of Surface Chemistry and Bulk Properties on...

397

Hands-On Session 6: Monolayer Boron Nitride BerkeleyGW Workshop  

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

Hands-On Session 6: Monolayer Boron Nitride Hands-On Session 6: Monolayer Boron Nitride BerkeleyGW Workshop 11/23/2013 Diana Qiu Goals: 1. Demonstrate a GW-BSE calculation for a 2D semiconductor 2. Look at the behavior of ε -1 00 (q) for a system with a truncated Coulomb interaction 3. Learn how to use BerkeleyGW's visualization tools to look at the exciton wave function Instructions: Please copy the example directory into your scratch directory >> cp -rP /project/projectdirs/m1694/BGW-2013/6-boron_nitride $SCRATCH/ 1-MF ● Please go the directory ``6-boron_nitride/1-mf/`` ● Enter each directory in numerical order and follow the instructions in the README files. Some things to note for 2D calculations: ● The system is in a periodic supercell. Though we will not do so in this calculation, you should always converge the k-grid sampling and amount of vacuum between

398

Growth Mechanisms of Vertically-aligned Carbon, Boron Nitride, and Zinc Oxide Nanotubes  

SciTech Connect

Nanotubes are one-dimensional nanomaterials with all atoms located near the surface. This article provides a brief review on the possible growth mechanisms of a series of inorganic nanotubes, in particular, vertically-aligned (VA) carbon nanotubes (CNTs), boron nitride nanotubes (BNNTs), and ZnO nanotubes (ZnO NTs).

Yap, Yoke Khin [Department of Physics, Michigan Technological University, 118 Fisher Hall, 1400 Townsend Drive, Houghton, MI 49931 (United States)

2009-07-07T23:59:59.000Z

399

Disordered graphene and boron nitride in a microwave tight-binding analogue S. Barkhofen,1  

E-Print Network (OSTI)

Disordered graphene and boron nitride in a microwave tight-binding analogue S. Barkhofen,1 M Sophia-Antipolis, 06108 Nice, France (Dated: December 20, 2012) Experiments on hexagonal graphene of the high flexibility of the discs positions, consequences of the disorder introduced in the graphene

Paris-Sud XI, Université de

400

Numerical simulation of the heat transfer in amorphous silicon nitride membrane-based microcalorimeters  

E-Print Network (OSTI)

Numerical simulation of the heat transfer in amorphous silicon nitride membrane July 2003 Numerical simulations of the two-dimensional 2D heat flow in a membrane-based microcalorimeter have been performed. The steady-state isotherms and time-dependent heat flow have been calculated

Hellman, Frances

Note: This page contains sample records for the topic "bulk gallium nitride" 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

Silicon-doped boron nitride coated fibers in silicon melt infiltrated composites  

DOE Patents (OSTI)

A fiber-reinforced silicon--silicon carbide matrix composite having improved oxidation resistance at high temperatures in dry or water-containing environments is produced. The invention also provides a method for protecting the reinforcing fibers in the silicon--silicon carbide matrix composites by coating the fibers with a silicon-doped boron nitride coating.

Corman, Gregory Scot (Ballston Lake, NY); Luthra, Krishan Lal (Schenectady, NY)

1999-01-01T23:59:59.000Z

402

Silicon-doped boron nitride coated fibers in silicon melt infiltrated composites  

DOE Patents (OSTI)

A fiber-reinforced silicon-silicon carbide matrix composite having improved oxidation resistance at high temperatures in dry or water-containing environments is produced. The invention also provides a method for protecting the reinforcing fibers in the silicon-silicon carbide matrix composites by coating the fibers with a silicon-doped boron nitride coating.

Corman, Gregory Scot (Ballston Lake, NY); Luthra, Krishan Lal (Schenectady, NY)

2002-01-01T23:59:59.000Z

403

Method for Improving Mg Doping During Group-III Nitride MOCVD  

DOE Patents (OSTI)

A method for improving Mg doping of Group III-N materials grown by MOCVD preventing condensation in the gas phase or on reactor surfaces of adducts of magnesocene and ammonia by suitably heating reactor surfaces between the location of mixing of the magnesocene and ammonia reactants and the Group III-nitride surface whereon growth is to occur.

Creighton, J. Randall (Albuquerque, NM); Wang, George T. (Albuquerque, NM)

2008-11-11T23:59:59.000Z

404

Formation of Nickel Silicide from Direct-Liquid-Injection Chemical-Vapor-Deposited Nickel Nitride Films  

E-Print Network (OSTI)

. Published April 28, 2010. Metal silicides such as TiSi2 and CoSi2 have been commonly used as the contactsFormation of Nickel Silicide from Direct-Liquid-Injection Chemical-Vapor-Deposited Nickel Nitride as the intermediate for subsequent conversion into nickel silicide NiSi , which is a key material for source, drain

405

Graphene field-effect transistors based on boron nitride gate dielectrics Inanc Meric1  

E-Print Network (OSTI)

Graphene field-effect transistors based on boron nitride gate dielectrics Inanc Meric1 , Cory Dean1, 10027 Tel: (212) 854-2529, Fax: (212) 932-9421, Email: shepard@ee.columbia.edu Abstract Graphene field of graphene, as the gate dielectric. The devices ex- hibit mobility values exceeding 10,000 cm2 /V

Shepard, Kenneth

406

Characterization of the nitrogen split interstitial defect in wurtzite aluminum nitride using density functional theory  

SciTech Connect

We carried out Heyd-Scuseria-Ernzerhof hybrid density functional theory plane wave supercell calculations in wurtzite aluminum nitride in order to characterize the geometry, formation energies, transition levels, and hyperfine tensors of the nitrogen split interstitial defect. The calculated hyperfine tensors may provide useful fingerprint of this defect for electron paramagnetic resonance measurement.

Szállás, A., E-mail: szallas.attila@wigner.mta.hu [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Szász, K. [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Institute of Physics, Eötvös University, Pázmány Péter sétány 1/A, H-1117 Budapest (Hungary); Trinh, X. T.; Son, N. T.; Janzén, E. [Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping (Sweden); Gali, A., E-mail: gali.adam@wigner.mta.hu [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Department of Atomic Physics, Budapest University of Technology and Economics, Budafoki út 8, H-1111 Budapest (Hungary)

2014-09-21T23:59:59.000Z

407

Tuning the optical properties of dilute nitride site controlled quantum dots  

SciTech Connect

We show that deterministic control of the properties of pyramidal site-controlled quantum dots (QD) could be achieved by exposing the QD layer to nitrogen precursor unsymmetrical dimethylhydrazine (UDMHy). The properties that could be tuned include an expected emission reduction in dilute nitride materials, excitonic pattern (biexciton binding energy) and improved carrier confinement potential symmetry (reduced fine-structure splitting)

Juska, G.; Dimastrodonato, V.; Mereni, L. O.; Gocalinska, A.; Pelucchi, E. [Tyndall National Institute, University College Cork, Lee Maltings, Cork (Ireland)

2013-12-04T23:59:59.000Z

408

Electronic structure and pairwise interactions in substoichiometric transition metal carbides and nitrides  

E-Print Network (OSTI)

1001 Electronic structure and pairwise interactions in substoichiometric transition metal carbides observations expéri- mentales. Abstract 2014 In substoichiometric transition metal carbides and nitrides This paper is devoted to the study of the ordering processes in substoichiometric transition metal carbi- des

Paris-Sud XI, Université de

409

ORDER AND DISORDER IN CARBIDES AND NITRIDES Ch. H. DE NOVION and V. MAURICE  

E-Print Network (OSTI)

transition metals, rare earths and actinides react with carbon and nitrogen to form metallic carbides experimental evidence for short and long-range ordering of point defects in metallic transition metal, rareCOMPOUNDS. ORDER AND DISORDER IN CARBIDES AND NITRIDES Ch. H. DE NOVION and V. MAURICE SESI, C

Paris-Sud XI, Université de

410

Formation of BN and AlBN during nitridation of sapphire using RF plasma sources[Radiofrequency  

SciTech Connect

Evidence is presented that nitrogen plasma sources utilizing a pyrolytic boron nitride liner may be a significant source of B contamination during growth and processing. Auger electron spectroscopy analysis performed during nitridation of sapphire indicate the resulting layers contain a significant amount of BN. The formation of Al{sub 1{minus}x}B{sub x}N would explain the observation of a lattice constant several percent smaller than AlN as measured by reflection high-energy electron diffraction. The presence of cubic inclusions in layers grown on such a surface may be related to the segregation of BN during the nitridation into its cubic phase.

Ptak, A.J.; Ziemer, K.S.; Holbert, L.J.; Stinespring, C.D.; Myers, T.H.

2000-07-01T23:59:59.000Z

411

Chemical vapor deposition of refractory ternary nitrides for advanced diffusion barriers  

SciTech Connect

Refractory ternary nitride films for diffusion barriers in microelectronics have been grown using chemical vapor deposition. Thin films of titanium-silicon-nitride, tungsten-boron-nitride, and tungsten-silicon-nitride of various compositions have been deposited on 150 mm Si wafers. The microstructure of the films are either fully amorphous for the tungsten based films, or nauocrystalline TiN in an amorphous matrix for titanium-silicon-nitride. All films exhibit step coverages suitable for use in future microelectronics generations. Selected films have been tested as diffusion barriers between copper and silicon, and generally perform extremely weH. These fiIms are promising candidates for advanced diffusion barriers for microelectronics applications. The manufacturing of silicon wafers into integrated circuits uses many different process and materials. The manufacturing process is usually divided into two parts: the front end of line (FEOL) and the back end of line (BEOL). In the FEOL the individual transistors that are the heart of an integrated circuit are made on the silicon wafer. The responsibility of the BEOL is to wire all the transistors together to make a complete circuit. The transistors are fabricated in the silicon itself. The wiring is made out of metal, currently aluminum and tungsten, insulated by silicon dioxide, see Figure 1. Unfortunately, silicon will diffuse into aluminum, causing aluminum spiking of junctions, killing transistors. Similarly, during chemical vapor deposition (CVD) of tungsten from ~fj, the reactivity of the fluorine can cause "worn-holes" in the silicon, also destroying transistors. The solution to these problems is a so-called diffusion barrier, which will allow current to pass from the transistors to the wiring, but will prevent reactions between silicon and the metal.

Custer, Jonathan S.; Fleming, James G.; Roherty-Osmun, Elizabeth; Smith, Paul Martin

1998-09-22T23:59:59.000Z

412

Dark goo: bulk viscosity as an alternative to dark energy  

SciTech Connect

We present a simple (microscopic) model in which bulk viscosity plays a role in explaining the present acceleration of the universe. The effect of bulk viscosity on the Friedmann equations is to turn the pressure into an 'effective' pressure containing the bulk viscosity. For a sufficiently large bulk viscosity, the effective pressure becomes negative and could mimic a dark energy equation of state. Our microscopic model includes self-interacting spin-zero particles (for which the bulk viscosity is known) that are added to the usual energy content of the universe. We study both background equations and linear perturbations in this model. We show that a dark energy behavior is obtained for reasonable values of the two parameters of the model (i.e. the mass and coupling of the spin-zero particles) and that linear perturbations are well-behaved. There is no apparent fine tuning involved. We also discuss the conditions under which hydrodynamics holds, in particular that the spin-zero particles must be in local equilibrium today for viscous effects to be important.

Gagnon, Jean-Sebastien [Technische Universität Darmstadt, Schlossgartenstrasse 2, 64289, Darmstadt (Germany); Lesgourgues, Julien, E-mail: jean-sebastien.gagnon@physik.tu-darmstadt.de, E-mail: julien.lesgourgues@cern.ch [École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne (Switzerland)

2011-09-01T23:59:59.000Z

413

Bulk emission of scalars by a rotating black hole  

E-Print Network (OSTI)

We study in detail the scalar-field Hawking radiation emitted into the bulk by a higher-dimensional, rotating black hole. We numerically compute the angular eigenvalues, and solve the radial equation of motion in order to find transmission factors. The latter are found to be enhanced by the angular momentum of the black hole, and to exhibit the well-known effect of superradiance. The corresponding power spectra for scalar fields show an enhancement with the number of dimensions, as in the non-rotating case. We compute the total mass loss rate of the black hole for a variety of black-hole angular momenta and bulk dimensions, and find that, in all cases, the bulk emission remains significantly smaller than the brane emission. The angular-momentum loss rate is also computed and found to have a smaller value in the bulk than on the brane. We present accurate bulk-to-brane emission ratios for a range of scenarios.

M. Casals; S. R. Dolan; P. Kanti; E. Winstanley

2008-07-17T23:59:59.000Z

414

Tunnel-injection quantum dot deep-ultraviolet light-emitting diodes with polarization-induced doping in III-nitride heterostructures  

SciTech Connect

Efficient semiconductor optical emitters in the deep-ultraviolet spectral window are encountering some of the most deep rooted problems of semiconductor physics. In III-Nitride heterostructures, obtaining short-wavelength photon emission requires the use of wide bandgap high Al composition AlGaN active regions. High conductivity electron (n-) and hole (p-) injection layers of even higher bandgaps are necessary for electrical carrier injection. This approach requires the activation of very deep dopants in very wide bandgap semiconductors, which is a difficult task. In this work, an approach is proposed and experimentally demonstrated to counter the challenges. The active region of the heterostructure light emitting diode uses ultrasmall epitaxially grown GaN quantum dots. Remarkably, the optical emission energy from GaN is pushed from 365?nm (3.4?eV, the bulk bandgap) to below 240?nm (>5.2?eV) because of extreme quantum confinement in the dots. This is possible because of the peculiar bandstructure and band alignments in the GaN/AlN system. This active region design crucially enables two further innovations for efficient carrier injection: Tunnel injection of carriers and polarization-induced p-type doping. The combination of these three advances results in major boosts in electroluminescence in deep-ultraviolet light emitting diodes and lays the groundwork for electrically pumped short-wavelength lasers.

Verma, Jai, E-mail: jverma@nd.edu; Islam, S. M.; Protasenko, Vladimir; Kumar Kandaswamy, Prem; Xing, Huili; Jena, Debdeep [Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

2014-01-13T23:59:59.000Z

415

In situ chemical sensing in AlGaN/GaN high electron mobility transistor metalorganic chemical vapor deposition process for real-time  

E-Print Network (OSTI)

; accepted 14 June 2005; published 18 July 2005 Gallium nitride and its alloys promise to be key materials.1116/1.1993616 I. INTRODUCTION In recent years, gallium-nitride GaN - and aluminum- gallium-nitride AlGaN -based are grown at high temperatures e.g., up to 1100 °C using large concentrations of H2 carrier and NH3 N source

Rubloff, Gary W.

416

High Accuracy Predictions of the Bulk Properties of Water | Argonne  

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

High Accuracy Predictions of the Bulk Properties of Water High Accuracy Predictions of the Bulk Properties of Water High Accuracy Predictions of the Bulk Properties of Water PI Name: Mark Gordon PI Email: mark@si.msg.chem.iastate.edu Institution: Iowa State University Allocation Program: ESP Allocation Hours at ALCF: 150 Million Year: 2010 to 2013 Research Domain: Chemistry Among the ab initio methods, second-order perturbation theory (MP2) predicts highly accurate structures and relative energies for water clusters. Researchers will carry out molecular dynamics simulations of water at the MP2 level. However, full MP2 calculations of even modest-sized water clusters are far too time-consuming for dynamical simulations, even on the next-generation Blue Gene. Therefore, a key element of the current approach will be the use of MP2 in conjunction with the Fragment Molecular

417

Bulk Viscosity, Decaying Dark Matter, and the Cosmic Acceleration  

E-Print Network (OSTI)

We discuss a cosmology in which cold dark-matter particles decay into relativistic particles. We argue that such decays could lead naturally to a bulk viscosity in the cosmic fluid. For decay lifetimes comparable to the present hubble age, this bulk viscosity enters the cosmic energy equation as an effective negative pressure. We investigate whether this negative pressure is of sufficient magnitude to account fo the observed cosmic acceleration. We show that a single decaying species in a flat, dark-matter dominated cosmology without a cosmological constant cannot reproduce the observed magnitude-redshift relation from Type Ia supernovae. However, a delayed bulk viscosity, possibly due to a cascade of decaying particles may be able to account for a significant fraction of the apparent cosmic acceleration. Possible candidate nonrelativistic particles for this scenario include sterile neutrinos or gauge-mediated decaying supersymmetric particles.

James R. Wilson; Grant J. Mathews; George M. Fuller

2006-09-25T23:59:59.000Z

418

Properties of Bulk Sintered Silver As a Function of Porosity  

SciTech Connect

This report summarizes a study where various properties of bulk-sintered silver were investigated over a range of porosity. This work was conducted within the National Transportation Research Center's Power Device Packaging project that is part of the DOE Vehicle Technologies Advanced Power Electronics and Electric Motors Program. Sintered silver, as an interconnect material in power electronics, inherently has porosity in its produced structure because of the way it is made. Therefore, interest existed in this study to examine if that porosity affected electrical properties, thermal properties, and mechanical properties because any dependencies could affect the intended function (e.g., thermal transfer, mechanical stress relief, etc.) or reliability of that interconnect layer and alter how its performance is modeled. Disks of bulk-sintered silver were fabricated using different starting silver pastes and different sintering conditions to promote different amounts of porosity. Test coupons were harvested out of the disks to measure electrical resistivity and electrical conductivity, thermal conductivity, coefficient of thermal expansion, elastic modulus, Poisson's ratio, and yield stress. The authors fully recognize that the microstructure of processed bulk silver coupons may indeed not be identical to the microstructure produced in thin (20-50 microns) layers of sintered silver. However, measuring these same properties with such a thin actual structure is very difficult, requires very specialized specimen preparation and unique testing instrumentation, is expensive, and has experimental shortfalls of its own, so the authors concluded that the herein measured responses using processed bulk sintered silver coupons would be sufficient to determine acceptable values of those properties. Almost all the investigated properties of bulk sintered silver changed with porosity content within a range of 3-38% porosity. Electrical resistivity, electrical conductivity, thermal conductivity, elastic modulus, Poisson's ratio, and yield stress all depended on the porosity content in bulk-sintered silver. The only investigated property that was independent of porosity in that range was coefficient of thermal expansion.

Wereszczak, Andrew A [ORNL; Vuono, Daniel J [ORNL; Wang, Hsin [ORNL; Ferber, Mattison K [ORNL; Liang, Zhenxian [ORNL

2012-06-01T23:59:59.000Z

419

Boron nitride nanotubes as novel sorbent for solid-phase microextraction of polycyclic aromatic hydrocarbons in environmental water samples  

Science Journals Connector (OSTI)

Boron nitride nanotube (BNNT) is a novel material that shows potential ability in capturing organic pollutants. In this study, BNNTs fixed on a stainless steel fiber by a sol–gel technique were used as sorbent fo...

Meizhen Fu; Hanzhu Xing; Xiangfeng Chen…

2014-09-01T23:59:59.000Z

420

Bulk viscosity of strongly coupled plasmas with holographic duals  

E-Print Network (OSTI)

We explain a method for computing the bulk viscosity of strongly coupled thermal plasmas dual to supergravity backgrounds supported by one scalar field. Whereas earlier investigations required the computation of the leading dissipative term in the dispersion relation for sound waves, our method requires only the leading frequency dependence of an appropriate Green's function in the low-frequency limit. With a scalar potential chosen to mimic the equation of state of QCD, we observe a slight violation of the lower bound on the ratio of the bulk and shear viscosities conjectured in arXiv:0708.3459.

Steven S. Gubser; Silviu S. Pufu; Fabio D. Rocha

2008-06-02T23:59:59.000Z

Note: This page contains sample records for the topic "bulk gallium nitride" 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

Bulk viscosity of the gluon plasma in a holographic approach  

E-Print Network (OSTI)

A gravity-scalar model in 5-dim. Riemann space is adjusted to the thermodynamics of SU(3) gauge field theory in the temperature range 1 - 10 $T/T_c$ to calculate holographically the bulk viscosity in 4-dim. Minkowski space. Various settings are compared, and it is argued that, upon an adjustment of the scalar potential to reproduce exactly the lattice data within a restricted temperature interval above $T_c$, rather robust values of the bulk viscosity to entropy density ratio are obtained.

R. Yaresko; B. Kampfer

2014-03-14T23:59:59.000Z

422

An experiment to test the viability of a gallium-arsenide cathode in a SRF electron gun  

SciTech Connect

Strained gallium arsenide cathodes are used in electron guns for the production of polarized electrons. In order to have a sufficient quantum efficiency lifetime of the cathode the vacuum in the gun must be 10{sup -11} Torr or better, so that the cathode is not destroyed by ion back bombardment or through contamination with residual gases. All successful polarized guns are DC guns, because such vacuum levels can not be obtained in normal conducting RF guns. A superconductive RF gun may provide a sufficient vacuum level due to cryo-pumping of the cavity walls. We report on the progress of our experiment to test such a gun with normal GaAs-Cs crystals.

Kewisch,J.; Ben-Zvi, I.; Rao, T.; Burrill, A.; Pate, D.; Wu, Q.; Todd, R.; Wang, E.; Bluem, H.; Holmes, D.; Schultheiss, T.

2009-05-04T23:59:59.000Z

423

Analyse og konstruksjon av en klasse B effektforsterker i GaN teknologi; Class B power amplifier design with GaN technology.  

E-Print Network (OSTI)

??De senere ĺrene har vist en stadig řkende interesse for transistorer basert pĺ GalliumNitrid, spesielt i design av effektforsterkere for trĺdlřse applikasjoner. Denne rapportenbeskriver to… (more)

Mogstad, Einar Berge

2010-01-01T23:59:59.000Z

424

IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 51, NO. 2, FEBRUARY 2003 643 High Linearity and High Efficiency of Class-B Power  

E-Print Network (OSTI)

Identifier 10.1109/TMTT.2002.807682 The gallium­nitride material system is a leading contender for microwave

Rodwell, Mark J. W.

425

MRS Online Publications Page 1 of 10 http://www.mrs.org/publications/epubs/proceedings/fall2002/l/ 07/22/03  

E-Print Network (OSTI)

.C. Chen, D.B. Fenner, T.D. Moustakas, and George Chu Growth of Oriented Gallium Nitride Films on Amorphous

Wetzel, Christian M.

426

CX-009000: Categorical Exclusion Determination | Department of Energy  

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

0: Categorical Exclusion Determination 0: Categorical Exclusion Determination CX-009000: Categorical Exclusion Determination "High Quality, Low Cost Bulk Gallium Nitride (GaN) Substrates Grown by the Electrochemical Solution Growth Method CX(s) Applied: A9, B3.6 Date: 08/20/2012 Location(s): Missouri Offices(s): Golden Field Office The U.S. Department of Energy (DOE) is proposing to provide federal funding to MEMC Electronic Materials, Inc. MEMC would conduct research and development activities for a two phase project to develop a new process method for growing large bulk gallium nitrate (GaN) crystals at low cost with improved functional properties." CX-009000.pdf More Documents & Publications CX-000845: Categorical Exclusion Determination Energy Storage Systems 2010 Update Conference Presentations - Day 3,

427

Characteristics of trap-filled gallium arsenide photoconductive switches used in high gain pulsed power applications  

SciTech Connect

The electrical properties of semi-insulating (SI) Gallium Arsenide (GaAs) have been investigated for some time, particularly for its application as a substrate in microelectronics. Of late this material has found a variety of applications other than as an isolation region between devices, or the substrate of an active device. High resistivity SI GaAs is increasingly being used in charged particle detectors and photoconductive semiconductor switches (PCSS). PCSS made from these materials operating in both the linear and non-linear modes have applications such as firing sets, as drivers for lasers, and in high impedance, low current Q-switches or Pockels cells. In the non-linear mode, it has also been used in a system to generate Ultra-Wideband (UWB) High Power Microwaves (HPM). The choice of GaAs over silicon offers the advantage that its material properties allow for fast, repetitive switching action. Furthermore photoconductive switches have advantages over conventional switches such as improved jitter, better impedance matching, compact size, and in some cases, lower laser energy requirement for switching action. The rise time of the PCSS is an important parameter that affects the maximum energy transferred to the load and it depends, in addition to other parameters, on the bias or the average field across the switch. High field operation has been an important goal in PCSS research. Due to surface flashover or premature material breakdown at higher voltages, most PCSS, especially those used in high power operation, need to operate well below the inherent breakdown voltage of the material. The lifetime or the total number of switching operations before breakdown, is another important switch parameter that needs to be considered for operation at high bias conditions. A lifetime of {approximately} 10{sup 4} shots has been reported for PCSS's used in UWB-HPM generation [5], while it has exceeded 10{sup 8} shots for electro-optic drivers. Much effort is currently being channeled in the study related to improvements of these two parameters high bias operation and lifetime improvement for switches used in pulsed power applications. The contact material and profiles are another important area of study. Although these problems are being pursued through the incorporation of different contact materials and introducing doping near contacts, it is important that the switch properties and the conduction mechanism in these switches be well understood such that the basic nature of the problems can be properly addressed. In this paper the authors report on these two basic issues related to the device operation, i.e., mechanisms for increasing the hold-off characteristics through neutron irradiation, and the analysis of transport processes at varying field conditions in trap dominated SI GaAs in order to identify the breakdown mechanism during device operation. It is expected that this study would result in a better understanding of photoconductive switches, specifically those used in high power operation.

ISLAM,N.E.; SCHAMILOGLU,E.; MAR,ALAN; LOUBRIEL,GUILLERMO M.; ZUTAVERN,FRED J.; JOSHI,R.P.

2000-05-30T23:59:59.000Z

428

Stress tensor and bulk viscosity in relativistic nuclear collisions  

E-Print Network (OSTI)

We discuss the influence of different initial conditions for the stress tensor and the effect of bulk viscosity on the expansion and cooling of the fireball created in relativistic heavy ion collisions. In particular, we explore the evolution...however, it does not significantly increase the entropy produced....

Fries, Rainer J.; Mueller, Berndt; Schaefer, Andreas.

2008-01-01T23:59:59.000Z

429

Development of Bulk Nanocrystalline Cemented Tungsten Carbide for Industrial Applicaitons  

SciTech Connect

This report contains detailed information of the research program entitled "Development of Bulk Nanocrystalline Cemented Tungsten Carbide Materials for Industrial Applications". The report include the processes that were developed for producing nanosized WC/Co composite powders, and an ultrahigh pressure rapid hot consolidation process for sintering of nanosized powders. The mechanical properties of consolidated materials using the nanosized powders are also reported.

Z. Zak Fang, H. Y. Sohn

2009-03-10T23:59:59.000Z

430

Bulk Metallic Glass Nanowire Architecture for Electrochemical Applications  

Science Journals Connector (OSTI)

bulk metallic glasses; nanowires; electrocatalysts; fuel cells; PEMFC; DAFC ... (8) Thus, there has been considerable interest in the development of nanowire fuel cell catalysts. ... To develop such catalysts, several characteristics have to be taken into consideration for their synthesis and assembly. ...

Marcelo Carmo; Ryan C. Sekol; Shiyan Ding; Golden Kumar; Jan Schroers; André D. Taylor

2011-03-03T23:59:59.000Z

431

Non-Destructive Spent Fuel Characterization with Semi-Conducting Gallium Arsinde Neutron Imaging Arrays  

SciTech Connect

High resistivity bulk grown GaAs has been used to produce thermal neutron imaging devices for use in neutron radiography and characterizing burnup in spent fuel. The basic scheme utilizes a portable Sb/Be source for monoenergetic (24 keV) neutron radiation source coupled to an Fe filter with a radiation hard B-coated pixellated GaAs detector array as the primary neutron detector. The coated neutron detectors have been tested for efficiency and radiation hardness in order to determine their fitness for the harsh environments imposed by spent fuel. Theoretical and experimental results are presented, showing detector radiation hardness, expected detection efficiency and the spatial resolution from such a scheme. A variety of advanced neutron detector designs have been explored, with experimental results achieving 13% thermal neutron detection efficiency while projecting the possibility of over 30% thermal neutron detection efficiency.

Douglas S. McGregor; Holly K. Gersch; Jeffrey D. Sanders; John C. Lee; Mark D. Hammig; Michael R. Hartman; Yong Hong Yang; Raymond T. Klann; Brian Van Der Elzen; John T. Lindsay; Philip A. Simpson

2002-01-30T23:59:59.000Z

432

Characterization of Chemically Vapor Deposited Silicon Nitride Films from Disilane and Ammonia  

Science Journals Connector (OSTI)

Amorphous silicon nitride films a:SiNx were prepared by low pressure chemical vapor deposition (LPCVD) from disilane ( Si2H6) and ammonia ( NH3). Most of the depositions were performed at 600° C with various NH3/Si2H6 gas ratios ranging from 4 to 50. Different deposits with composition (x= N/Si) ranging from silicon-rich to stoichiometric silicon nitride were characterized by means of infrared spectroscopy (FTIR), ellipsometry, electron energy loss spectroscopy (EELS), and their structure analysed by transmission electron microscopy (TEM). Transmission infrared measurements showed low hydrogen content (x= N/Si) and density of the films were correlated with their refractive index and discussed.

Redhouane Henda; Larbi Laanab; Emmanuel Scheid; Robert Fourmeaux

1995-01-01T23:59:59.000Z

433

Ternary silicon germanium nitrides: A class of tunable band gap materials  

Science Journals Connector (OSTI)

Ternary silicon germanium nitrides with compositions of both Si1?xGexN and (Si1?xGex)3N4 are predicted to have a band gap that decreases as the germanium:silicon ratio increases. The band gap is indirect for the silicon-rich compounds but becomes direct as the germanium content increases, due to greater mixing of s and p states in the conduction band. This effect of band gap tunability has recently been reported for (Si1?xGex)3N4 in the spinel structure [Boyko et al., Phys. Rev. B 81, 155207 (2010)]. Our results suggest that this is a more general effect and that ternary group-14 nitrides should form a class of semiconducting materials for which the band gap can be tuned by controlling the composition.

Judy N. Hart; Neil L. Allan; Frederik Claeyssens

2011-12-27T23:59:59.000Z

434

Phase transformations of nano-sized cubic boron nitride to white graphene and white graphite  

SciTech Connect

We report quantum-mechanical investigations that predict the formation of white graphene and nano-sized white graphite from the first-order phase transformations of nano-sized boron nitride thin-films. The phase transformations from the nano-sized diamond-like structure, when the thickness d?>?1.4?nm, to the energetically more stable nano-sized white graphite involve low activation energies of less than 1.0?eV. On the other hand, the diamond-like structure transforms spontaneously to white graphite when d???1.4?nm. In particular, the two-dimensional structure with single-layer boron nitride, the so-called white graphene, could be formed as a result of such transformation.

Dang, Hongli; Liu, Yingdi; Xue, Wenhua; Anderson, Ryan S.; Sewell, Cody R. [Department of Physics and Engineering Physics, The University of Tulsa, Tulsa, Oklahoma 74104 (United States); Xue, Sha; Crunkleton, Daniel W. [Department of Chemical Engineering, The University of Tulsa, Tulsa, Oklahoma 74104 (United States); Institute of Alternate Energy, The University of Tulsa, Tulsa, Oklahoma 74104 (United States); Shen, Yaogen [Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon (Hong Kong); Wang, Sanwu, E-mail: sanwu-wang@utulsa.edu [Department of Physics and Engineering Physics, The University of Tulsa, Tulsa, Oklahoma 74104 (United States); Institute of Alternate Energy, The University of Tulsa, Tulsa, Oklahoma 74104 (United States)

2014-03-03T23:59:59.000Z

435

Pulsed-ion-beam nitriding and smoothing of titanium surface in a vacuum  

SciTech Connect

Both nitriding and smoothing of titanium have been achieved under irradiation of intense pulsed ion beam in a vacuum of 2x10{sup -2} Pa. Applying a screening method, we find that medium ion-beam intensity and multi-shot irradiation are effective for the processing, where repetitive surface melting with limited ablation favored Ti nitride formation as well as surface smoothing. The present results demonstrate that ambient gas atoms/molecules can be efficiently incorporated in metal matrices to form compounds under the ion-beam irradiation. The finding is of great significance for extending application scope of the ion-beam technique in materials research and processing, combined with the recent success in introducing ambient gas into the processing chamber.

Zhu, X.P.; Suematsu, Hisayuki; Jiang Weihua; Yatsui, Kiyoshi; Lei, M.K. [Extreme Energy-Density Research Institute, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 (Japan); Surface Engineering Laboratory, Department of Materials Engineering, Dalian University of Technology, Dalian 116024 (China)

2005-08-29T23:59:59.000Z

436

Nondestructive evaluation of silicon-nitride ceramic valves from engine duration test.  

SciTech Connect

In this study, we investigated impact and wear damage in silicon-nitride ceramic valves that were subjected to an engine duration test in a natural-gas engine. A high-speed automated laser-scattering system was developed for the nondestructive evaluation (NDE) of 10 SN235P silicon-nitride valves. The NDE system scans the entire valve surface and generates a two-dimensional scattering image that is used to identify location, size and relative severity of subsurface damage in the valves. NED imaging data were obtained at before and at 100 and 500 hours of the engine duration test. The NDE data were analyzed and compared with surface photomicrographs. Wear damage was found in the impact surface of all valves, expecially for exhaust valves. However, the NDE examination did not detect subsurface damage such as cracks or spalls in these engine-tested valves.

Sun, J. G.; Trethewey, J. S.; Vanderspiegle, N. N.; Jensen, J. A.; Nuclear Engineering Division; Caterpillar, Inc.

2008-01-01T23:59:59.000Z

437

Effects of plasma-deposited silicon nitride passivation on the radiation hardness of CMOS integrated circuits  

SciTech Connect

The use of plasma-deposited silicon nitride as a final passivation over metal-gate CMOS integrated circuits degrades the radiation hardness of these devices. The hardness degradation is manifested by increased radiation-induced threshold voltage shifts caused principally by the charging of new interface states and, to a lesser extent, by the trapping of holes created upon exposure to ionizing radiation. The threshold voltage shifts are a strong function of the deposition temperature, and show very little dependence on thickness for films deposited at 300/sup 0/C. There is some correlation between the threshold voltage shifts and the hydrogen content of the PECVD silicon nitride films used as the final passivation layer as a function of deposition temperature. The mechanism by which the hydrogen contained in these films may react with the Si/SiO/sub 2/ interface is not clear at this point.

Clement, J. J.

1980-01-01T23:59:59.000Z

438

Soliton mechanism of the uranium nitride microdynamics and heat conductivity at high temperatures  

SciTech Connect

The microdynamics of soliton waves and localized modes of nonlinear acoustic and optical oscillations in uranium nitride has been investigated. It is shown that, upon heating, the energies of solitons in the gap between the optical and acoustic phonon bands increase, while the energies of local modes decrease. The experimentally observed quasi-resonance features, which are shifted in the gap with a change in temperature, can be manifestations of the revealed soliton waves and local modes. The microdynamics of uranium nitride heat conductivity with the stochastic generation of the observed solitons and local modes at remote energy absorption have been investigated. The temperature dependence of the heat conductivity coefficient has been determined from the temperature gradient and energy flux within the standard approach (which is to be generalized).

Semenov, V. A.; Dubovsky, O. A., E-mail: dubov@ippe.ru; Orlov, A. V. [State Scientific Center of the Russian Federation Leipunsky Institute for Physics and Power Engineering (Russian Federation)

2011-12-15T23:59:59.000Z

439

Heteroepitaxy of group IV-VI nitrides by atomic layer deposition  

SciTech Connect

Heteroepitaxial growth of selected group IV-VI nitrides on various orientations of sapphire (?-Al{sub 2}O{sub 3}) is demonstrated using atomic layer deposition. High quality, epitaxial films are produced at significantly lower temperatures than required by conventional deposition methods. Characterization of electrical and superconducting properties of epitaxial films reveals a reduced room temperature resistivity and increased residual resistance ratio for films deposited on sapphire compared to polycrystalline samples deposited concurrently on fused quartz substrates.

Klug, Jeffrey A., E-mail: jklug@anl.gov; Groll, Nickolas R.; Pellin, Michael J.; Proslier, Thomas, E-mail: prolier@anl.gov [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)] [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Becker, Nicholas G.; Cao, Chaoyue; Zasadzinski, John F. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States) [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Weimer, Matthew S. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States) [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Chemistry, Illinois Institute of Technology, Chicago, Illinois 60616 (United States)

2013-11-18T23:59:59.000Z

440

Ab initio study of phase transition of boron nitride between zinc-blende and rhombohedral structures  

SciTech Connect

Boron nitride has polymorphs such as zinc-blende (c-BN), wurtzite (w-BN), rhombohedral (r-BN), and graphite-like (h-BN) forms. We simulate the direct conversion of r-BN to c-BN through electronic excitation. In our calculation, the conversion is made possible by increasing the hole concentration to over 0.06/atom. This conversion should be experimentally possible by hole-doping via an electric double layer transistor (EDLT) or capacitor.

Nishida, S.; Funashima, H.; Sato, K.; Katayama-Yoshida, H. [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)

2013-12-04T23:59:59.000Z

Note: This page contains sample records for the topic "bulk gallium nitride" 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

Amber light-emitting diode comprising a group III-nitride nanowire active region  

DOE Patents (OSTI)

A temperature stable (color and efficiency) III-nitride based amber (585 nm) light-emitting diode is based on a novel hybrid nanowire-planar structure. The arrays of GaN nanowires enable radial InGaN/GaN quantum well LED structures with high indium content and high material quality. The high efficiency and temperature stable direct yellow and red phosphor-free emitters enable high efficiency white LEDs based on the RGYB color-mixing approach.

Wang, George T.; Li, Qiming; Wierer, Jr., Jonathan J.; Koleske, Daniel

2014-07-22T23:59:59.000Z

442

Integrated rig for the production of boron nitride nanotubes via the pressurized vapor-condenser method  

DOE Patents (OSTI)

An integrated production apparatus for production of boron nitride nanotubes via the pressure vapor-condenser method. The apparatus comprises: a pressurized reaction chamber containing a continuously fed boron containing target having a boron target tip, a source of pressurized nitrogen and a moving belt condenser apparatus; a hutch chamber proximate the pressurized reaction chamber containing a target feed system and a laser beam and optics.

Smith, Michael W; Jordan, Kevin C

2014-03-25T23:59:59.000Z

443

Quantifying the Solubility of Boron Nitride Nanotubes and Sheets with Static Light Scattering and Refractometry  

SciTech Connect

The dissolution of nanoparticles, particularly those containing boron, is an important area of interest for polymer nanocomposite formation and material development. In this work, the solubility of boron nitride nanotubes (BNNT), functionalized boron nitride nanotubes (FBNNT), and boron nitride sheets (BNZG) is quantified in toluene and THF with static light scattering, refractometry, UV vis spectroscopy, and physical observations. UV vis spectroscopy provides a method to determine the concentration and solubility limits of the solutions tested. Using light scattering, the second virial coefficient, A2, is determined and used to calculate , the solute solvent interaction parameter. The Hildebrand solubility parameter, , is then extracted from this data using the Hildebrand Scatchard Solution Theory. A list of potential good solvents based on the estimated value is provided for each nanoparticle. Single-walled carbon nanotubes (SWNTs) and prepolymers (EN4 and EN8) used to synthesize polyurethanes were also tested, because the published and molar attraction constants of these materials provided a selfconsistent check. The dn/dc of SWNTs and boron-containing particles was measured for the first time in this work. A solvent screen for BN-ZG provides additional information that supports the obtained and . Three systems were found to have values below 0.5 and were thermodynamically soluble: BNNT in THF, EN8 in THF, and EN8 in toluene.

Mutz, M [The University of Tennessee; Eastwood, Eric Allen [ORNL; Dadmun, Mark D [ORNL

2013-01-01T23:59:59.000Z

444

An electrochemical method suitable for preparing nine metal-nitride powders  

SciTech Connect

We present an electrochemical method that is suitable for the preparation of metal-nitride ceramic materials that is both simple and general. We begin with a single-compartment electrochemical cell containing suitable metal (M) anodes and cathodes (M=Al, Mo, Nb, Ni, Ti, V, W, Zn, or Zr) and a NH{sub 3}/NH{sub 4}X (X=Br or Cl) electrolyte solution. Application of a sufficiently high voltage results in oxidation and dissolution of M to M{sup n+} at the anode and reduction of NH{sub 3} to NH{sub 2}- at the cathode. When M=Al, this results in formation of an insoluble inorganic polymer, which can subsequently be calcined above 600{degrees}C to yield phase-pure AlN. For some of the other metals, a simple ammoniated metal ion is formed at the anode, but calcination of this material also leads to the corresponding metal nitride. The phases and morphologies of the powders depends strongly on the calcining conditions. The important point is that this method is general for the preparation of metal-nitride powders even though the pathway that leads to the powders is metal-dependent. This talk will focus primarily on the preparation of AlN, which is an important packaging material for the electronics industry, and NbN, which is a superconductor (T{sub c}{approximately}17 K) with important technological applications.

Wade, T.; Crooks, R.M. [Texas A& M Univ., College Station, TX (United States)

1995-12-31T23:59:59.000Z

445

Recombination in polymer-fullerene bulk heterojunction solar cells  

Science Journals Connector (OSTI)

Recombination of photogenerated charge carriers in polymer bulk heterojunction (BHJ) solar cells reduces the short circuit current (Jsc) and the fill factor (FF). Identifying the mechanism of recombination is, therefore, fundamentally important for increasing the power conversion efficiency. Light intensity and temperature-dependent current-voltage measurements on polymer BHJ cells made from a variety of different semiconducting polymers and fullerenes show that the recombination kinetics are voltage dependent and evolve from first-order recombination at short circuit to bimolecular recombination at open circuit as a result of increasing the voltage-dependent charge carrier density in the cell. The “missing 0.3 V” inferred from comparison of the band gaps of the bulk heterojunction materials and the measured open-circuit voltage at room-temperature results from the temperature dependence of the quasi-Fermi levels in the polymer and fullerene domains—a conclusion based on the fundamental statistics of fermions.

Sarah R. Cowan; Anshuman Roy; Alan J. Heeger

2010-12-16T23:59:59.000Z

446

Differentiating surface and bulk interactions in nanoplasmonic interferometric sensor arrays  

E-Print Network (OSTI)

Detecting specific target analytes and differentiating them from interfering background effects is a crucial but challenging task in complex multi-component solutions commonly encountered in environmental, chemical, biological, and medical sensing applications. Here we present a simple nanoplasmonic interferometric sensor platform that can differentiate the adsorption of a thin protein layer on the sensor surface (surface effects) from bulk refractive index changes (interfering background effects) at a single sensing spot, exploiting the different penetration depths of multiple propagating surface plasmon polaritons excited in the ring-hole nanostructures. A monolayer of bovine serum albumin (BSA) molecules with an effective thickness of 1.91nm is detected and differentiated from a 10-3 change in the bulk refractive index unit of the solution. The noise level of the retrieved real-time sensor output compares favorably with traditional prism-based surface plasmon resonance sensors, but is achieved using a sign...

Zeng, Beibei; Bartoli, Filbert J

2014-01-01T23:59:59.000Z

447

Method of fabricating an optoelectronic device having a bulk heterojunction  

DOE Patents (OSTI)

A method of fabricating an optoelectronic device comprises: depositing a first layer having protrusions over a first electrode, in which the first layer comprises a first organic small molecule material; depositing a second layer on the first layer such that the second layer is in physical contact with the first layer; in which the smallest lateral dimension of the protrusions are between 1 to 5 times the exciton diffusion length of the first organic small molecule material; and depositing a second electrode over the second layer to form the optoelectronic device. A method of fabricating an organic optoelectronic device having a bulk heterojunction is also provided and comprises: depositing a first layer with protrusions over an electrode by organic vapor phase deposition; depositing a second layer on the first layer where the interface of the first and second layers forms a bulk heterojunction; and depositing another electrode over the second layer.

Shtein, Max (Ann Arbor, MI); Yang, Fan (Princeton, NJ); Forrest, Stephen R. (Princeton, NJ)

2008-10-14T23:59:59.000Z

448

Coefficients of the second viscosity in bulk liquid helium  

Science Journals Connector (OSTI)

The coefficients of the second viscosity in bulk liquid helium are evaluated explicitly as a function of temperature via interactions between the anomalous excitation spectrums. The four coefficients of the second viscosity exhibit a T-1 dependence at low temperatures (well below 0.6 K), which is due to three-phonon processes originating from the anomalous dispersion at very low momenta and temperatures.

Chung-In Um; Chul-Won Jun; Thomas F. George

1992-09-01T23:59:59.000Z

449

Standard practice for bulk sampling of liquid uranium hexafluoride  

E-Print Network (OSTI)

1.1 This practice covers methods for withdrawing representative samples of liquid uranium hexafluoride (UF6) from bulk quantities of the material. Such samples are used for determining compliance with the applicable commercial specification, for example Specification C787 and Specification C996. 1.2 It is assumed that the bulk liquid UF6 being sampled comprises a single quality and quantity of material. This practice does not address any special additional arrangements that might be required for taking proportional or composite samples, or when the sampled bulk material is being added to UF6 residues already in a container (“heels recycle”). 1.3 The number of samples to be taken, their nominal sample weight, and their disposition shall be agreed upon between the parties. 1.4 The scope of this practice does not include provisions for preventing criticality incidents. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of th...

American Society for Testing and Materials. Philadelphia

2001-01-01T23:59:59.000Z

450

Power mixture and green body for producing silicon nitride base articles of high fracture toughness and strength  

DOE Patents (OSTI)

A powder mixture and a green body for producing a silicon nitride-based article of improved fracture toughness and strength are disclosed. The powder mixture includes (a) a bimodal silicon nitride powder blend consisting essentially of about 10-30% by weight of a first silicon nitride powder of an average particle size of about 0.2 [mu]m and a surface area of about 8-12m[sup 2]g, and about 70-90% by weight of a second silicon nitride powder of an average particle size of about 0.4-0.6 [mu]m and a surface area of about 2-4 m[sup 2]/g, (b) about 10-50 percent by volume, based on the volume of the densified article, of refractory whiskers or fibers having an aspect ratio of about 3-150 and having an equivalent diameter selected to produce in the densified article an equivalent diameter ratio of the whiskers or fibers to grains of silicon nitride of greater than 1.0, and (c) an effective amount of a suitable oxide densification aid. The green body is formed from the powder mixture, an effective amount of a suitable oxide densification aid, and an effective amount of a suitable organic binder. No Drawings

Huckabee, M.L.; Buljan, S.T.; Neil, J.T.

1991-09-17T23:59:59.000Z

451

Published in 'Silicon Carbide, III-Nitrides and Related Materials', Year: 1998, pp: 829-832 Periodical: Materials Science Forum Vols. 264-268  

E-Print Network (OSTI)

Published in 'Silicon Carbide, III-Nitrides and Related Materials', Year: 1998, pp: 829@scientific.net © 1998 by Trans Tech Publications Ltd., Switzerland, http://www.ttp.net #12;Published in 'Silicon Carbide Publications Ltd., Switzerland, http://www.ttp.net #12;Published in 'Silicon Carbide, III-Nitrides and Related

Steckl, Andrew J.

452

Published in 'Silicon Carbide, III-Nitrides and Related Materials', Year: 1998, pp: 1149-1152 Periodical: Materials Science Forum Vols. 264-268  

E-Print Network (OSTI)

Published in 'Silicon Carbide, III-Nitrides and Related Materials', Year: 1998, pp: 1149@scientific.net © 1998 by Trans Tech Publications Ltd., Switzerland, http://www.ttp.net #12;Published in 'Silicon Carbide Publications Ltd., Switzerland, http://www.ttp.net #12;Published in 'Silicon Carbide, III-Nitrides and Related

Steckl, Andrew J.

453

The Hessian biased force field for silicon nitride ceramics: Predictions of thermodynamic and mechanical properties for CX-and @S&N4  

E-Print Network (OSTI)

that these calculations provide the first reliable data on such fundamental properties of silicon nitride. This MSXX force in diesel en- gines, industrial heat exchangers, and gas turbines, to name but a few potential applications for engines insulated with silicon nitride, leads to an increased efficiency of these en- gines. However

Goddard III, William A.

454

Process for the production of hydrogen and carbonyl sulfide from hydrogen sulfide and carbon monoxide using a metal boride, nitride, carbide and/or silicide catalyst  

SciTech Connect

Hydrogen and carbonyl sulfide are produced by a process comprising contacting gaseous hydrogen sulfide with gaseous carbon monoxide in the presence of a metal boride, carbide, nitride and/or silicide catalyst, such as titanium carbide, vanadium boride, manganese nitride or molybdenum silicide.

McGuiggan, M.F.; Kuch, P.L.

1984-05-08T23:59:59.000Z

455

Corrugated aluminum nitride energy harvesters for high energy conversion effectiveness This article has been downloaded from IOPscience. Please scroll down to see the full text article.  

E-Print Network (OSTI)

Corrugated aluminum nitride energy harvesters for high energy conversion effectiveness This article aluminum nitride energy harvesters for high energy conversion effectiveness Ting-Ta Yen1, Taku Hirasawa of micromachining processes with high energy conversion effectiveness. Corrugated cantilever design with a single

Lin, Liwei

456

The near-edge structure in energy-loss spectroscopy: many-electron and magnetic effects in transition metal nitrides and carbides  

E-Print Network (OSTI)

in transition metal nitrides and carbides This article has been downloaded from IOPscience. Please scroll down-loss spectroscopy: many-electron and magnetic effects in transition metal nitrides and carbides A T Paxton, M van energies are systematically overestimated by 4.22 ± 0.44 eV in twelve transition metal carbides

Paxton, Anthony T.

457

File:08COaBulkTransmissionSitingProcess.pdf | Open Energy Information  

Open Energy Info (EERE)

COaBulkTransmissionSitingProcess.pdf Jump to: navigation, search File File history File usage Metadata File:08COaBulkTransmissionSitingProcess.pdf Size of this preview: 463 599...

458

Notes 10. A thermohydrodynamic bulk-flow model for fluid film bearings  

E-Print Network (OSTI)

The complete set of bulk-flow equations for the analysis of turbulent flow fluid film bearings. Importance of thermal effects in process fluid applications. A CFD method for solution of the bulk-flow equations....

San Andres, Luis

2009-01-01T23:59:59.000Z

459

Efficient Organic Solar Cells Based on a Stacked Bulk Heterojunction Structure  

Science Journals Connector (OSTI)

Bulk generated charge carriers need to percolate within the bulk blend toward their specific electrodes. That may lead to reduced charge carrier mobility by the intermixing of two compounds which again limits the...

Zhang Xinfang; Xu Zheng; Chen Yuening…

2009-01-01T23:59:59.000Z

460

Bulk viscosity of superfluid hyperon stars Mikhail E. Gusakov and Elena M. Kantor  

E-Print Network (OSTI)

Bulk viscosity of superfluid hyperon stars Mikhail E. Gusakov and Elena M. Kantor Ioffe Physical; published 14 October 2008) We calculate the bulk viscosity due to nonequilibrium weak processes bulk viscosity coefficients, with only three of them being independent. In addition, we correct

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


461

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

462

Identification of Avalanche Precursors by Acoustic Probing in the Bulk of Tilted Granular Layers  

E-Print Network (OSTI)

Identification of Avalanche Precursors by Acoustic Probing in the Bulk of Tilted Granular Layers M simultaneously caracterize precursors on the free surface with an optical method and in the bulk with acoustic to probe rearrangements in the bulk of the granular material. A linear method can also be used provided

Paris-Sud XI, Université de

463

Laboratory Directed Research and Development (LDRD) on Mono-uranium Nitride Fuel Development for SSTAR and Space Applications  

SciTech Connect

The US National Energy Policy of 2001 advocated the development of advanced fuel and fuel cycle technologies that are cleaner, more efficient, less waste-intensive, and more proliferation resistant. The need for advanced fuel development is emphasized in on-going DOE-supported programs, e.g., Global Nuclear Energy Initiative (GNEI), Advanced Fuel Cycle Initiative (AFCI), and GEN-IV Technology Development. The Directorates of Energy & Environment (E&E) and Chemistry & Material Sciences (C&MS) at Lawrence Livermore National Laboratory (LLNL) are interested in advanced fuel research and manufacturing using its multi-disciplinary capability and facilities to support a design concept of a small, secure, transportable, and autonomous reactor (SSTAR). The E&E and C&MS Directorates co-sponsored this Laboratory Directed Research & Development (LDRD) Project on Mono-Uranium Nitride Fuel Development for SSTAR and Space Applications. In fact, three out of the six GEN-IV reactor concepts consider using the nitride-based fuel, as shown in Table 1. SSTAR is a liquid-metal cooled, fast reactor. It uses nitride fuel in a sealed reactor vessel that could be shipped to the user and returned to the supplier having never been opened in its long operating lifetime. This sealed reactor concept envisions no fuel refueling nor on-site storage of spent fuel, and as a result, can greatly enhance proliferation resistance. However, the requirement for a sealed, long-life core imposes great challenges to research and development of the nitride fuel and its cladding. Cladding is an important interface between the fuel and coolant and a barrier to prevent fission gas release during normal and accidental conditions. In fabricating the nitride fuel rods and assemblies, the cladding material should be selected based on its the coolant-side corrosion properties, the chemical/physical interaction with the nitride fuel, as well as their thermal and neutronic properties. The US NASA space reactor, the SP-100 was designed to use mono-uranium nitride fuel. Although the SP-100 reactor was not commissioned, tens of thousand of nitride fuel pellets were manufactured and lots of them, cladded in Nb-1-Zr had been irradiated in fast test reactors (FFTF and EBR-II) with good irradiation results. The Russian Naval submarines also use nitride fuel with stainless steel cladding (HT-9) in Pb-Bi coolant. Although the operating experience of the Russian submarine is not readily available, such combination of fuel, cladding and coolant has been proposed for a commercial-size liquid-metal cooled fast reactor (BREST-300). Uranium mono-nitride fuel is studied in this LDRD Project due to its favorable properties such as its high actinide density and high thermal conductivity. The thermal conductivity of mono-nitride is 10 times higher than that of oxide (23 W/m-K for UN vs. 2.3 W/m-K for UO{sub 2} at 1000 K) and its melting temperature is much higher than that of metal fuel (2630 C for UN vs. 1132 C for U metal). It also has relatively high actinide density, (13.51 gU/cm{sup 3} in UN vs. 9.66 gU/cm{sup 3} in UO{sub 2}) which is essential for a compact reactor core design. The objective of this LDRD Project is to: (1) Establish a manufacturing capability for uranium-based ceramic nuclear fuel, (2) Develop a computational capability to analyze nuclear fuel performance, (3) Develop a modified UN-based fuel that can support a compact long-life reactor core, and (4) Collaborate with the Nuclear Engineering Department of UC Berkeley on nitride fuel reprocessing and disposal in a geologic repository.

Choi, J; Ebbinghaus, B; Meiers, T; Ahn, J

2006-02-09T23:59:59.000Z

464

Bulk Quantities of Single-Crystal Silicon Micro-/Nanoribbons Generated from  

E-Print Network (OSTI)

such as oxides (ZnO, SnO2, Ga2O3, Fe2O3, In2O3, CdO, PbO2, etc.),3 sulfides (CdS, ZnS),4 nitride (GaN),5, crystallinity, and doping levels. These methods can form membranes, tubes, and ribbons, with thicknesses

Rogers, John A.

465

Electrical Bias as an Alternate Method for Reproducible Measurement of Copper Indium Gallium Diselenide (CIGS) Photovoltaic Modules: Preprint  

SciTech Connect

Light-to-dark metastable changes in thin-film photovoltaic (PV) modules can introduce uncertainty when measuring module performance on indoor flash testing equipment. This study describes a method to stabilize module performance through forward-bias current injection rather than light exposure. Measurements of five pairs of thin-film copper indium gallium diselenide (CIGS) PV modules indicate that forward-bias exposure maintained the PV modules at a stable condition (within 1%) while the unbiased modules degraded in performance by up to 12%. It was additionally found that modules exposed to forward bias exhibited stable performance within about 3% of their long-term outdoor exposed performance. This carrier-injection method provides a way to reduce uncertainty arising from fast transients in thin-film module performance between the time a module is removed from light exposure and when it is measured indoors, effectively simulating continuous light exposure by injecting minority carriers that behave much as photocarriers do. This investigation also provides insight into the initial light-induced transients of thin-film modules upon outdoor deployment.

Deline, C.; Stokes, A.; Silverman, T. J.; Rummel, S.; Jordan, D.; Kurtz, S.

2012-08-01T23:59:59.000Z

466

CO{sub 2} laser-based dispersion interferometer utilizing orientation-patterned gallium arsenide for plasma density measurements  

SciTech Connect

A dispersion interferometer based on the second-harmonic generation of a carbon dioxide laser in orientation-patterned gallium arsenide has been developed for measuring electron density in plasmas. The interferometer includes two nonlinear optical crystals placed on opposite sides of the plasma. This instrument has been used to measure electron line densities in a pulsed radio-frequency generated argon plasma. A simple phase-extraction technique based on combining measurements from two successive pulses of the plasma has been used. The noise-equivalent line density was measured to be 1.7 × 10{sup 17} m{sup ?2} in a detection bandwidth of 950 kHz. One of the orientation-patterned crystals produced 13 mW of peak power at the second-harmonic wavelength from a carbon dioxide laser with 13 W of peak power. Two crystals arranged sequentially produced 58 mW of peak power at the second-harmonic wavelength from a carbon dioxide laser with 37 W of peak power.

Bamford, D. J.; Cummings, E. A.; Panasenko, D. [Physical Sciences Inc., 6652 Owens Drive, Pleasanton, California 94588 (United States)] [Physical Sciences Inc., 6652 Owens Drive, Pleasanton, California 94588 (United States); Fenner, D. B.; Hensley, J. M. [Physical Sciences Inc., 20 New England Business Center, Andover, Massachusetts 01810 (United States)] [Physical Sciences Inc., 20 New England Business Center, Andover, Massachusetts 01810 (United States); Boivin, R. L.; Carlstrom, T. N.; Van Zeeland, M. A. [General Atomics, P.O. Box 85608, San Diego, California 92186 (United States)] [General Atomics, P.O. Box 85608, San Diego, California 92186 (United States)

2013-09-15T23:59:59.000Z

467

Bulk Viscosity of a Gas of Massless Pions  

E-Print Network (OSTI)

In the hadronic phase, the dominant configuration of QCD with two flavors of massless quarks is a gas of massless pions. We calculate the bulk viscosity (zeta) using the Boltzmann equation with the kinetic theory generalized to incorporate the trace anomaly. We find that the dimensionless ratio zeta/s, s being the entropy density, is monotonic increasing below T=120 MeV, where chiral perturbation theory is applicable. This, combined with previous results, shows that zeta/s reaches its maximum near the phase transition temperature Tc, while eta/s, eta being the shear viscosity, reaches its minimum near Tc in QCD with massless quarks.

Jiunn-Wei Chen; Juven Wang

2007-11-30T23:59:59.000Z

468

Bulk Handling of Milk on Texas Dairy Farms.  

E-Print Network (OSTI)

areas dur- tem of handling milk. ing the spring and summer of 1957 on dairy - farms which have converted their operations to Dairymen interviewed in North Texas had tanks ranging from 150 gallons to 1,000 gallons, , the bulk system of producing... and handling milk. while tanks in the Corous Christi area raneDd Texas dairy farmers are operating larger from 200 gallons to 1,000 gallons. The average units, milking more cows, selling more milk and tank in North Texas had a capacity of 400 gal. generally...

Parker, Cecil A.; Stelly, Randall, Moore, Donald S.

1958-01-01T23:59:59.000Z

469

Radiative cooling of bulk silicon by incoherent light pump  

SciTech Connect

In contrast to radiative cooling by light up conversion caused exclusively by a low-entropy laser pump and employing thermally assisted fluorescence/luminescence as a power out, we demonstrate light down conversion cooling by incoherent pumps, 0.47–0.94??m light emitting diodes, and employing thermal emission (TE) as a power out. We demonstrate ?3.5?K bulk cooling of Si at 450?K because overall energy of multiple below bandgap TE photons exceeds the energy of a single above bandgap pump photon. We show that using large entropy TE as power out helps avoid careful tuning of an incoherent pump wavelength and cool indirect-bandgap semiconductors.

Malyutenko, V. K., E-mail: malyut@isp.kiev.ua; Bogatyrenko, V. V.; Malyutenko, O. Yu. [V. E. Lashkaryov Institute of Semiconductor Physics, 03028 Kiev (Ukraine)] [V. E. Lashkaryov Institute of Semiconductor Physics, 03028 Kiev (Ukraine)

2013-12-23T23:59:59.000Z

470

III-antimonide/nitride based semiconductors for optoelectronic materials and device studies : LDRD 26518 final report.  

SciTech Connect

The goal of this LDRD was to investigate III-antimonide/nitride based materials for unique semiconductor properties and applications. Previous to this study, lack of basic information concerning these alloys restricted their use in semiconductor devices. Long wavelength emission on GaAs substrates is of critical importance to telecommunication applications for cost reduction and integration into microsystems. Currently InGaAsN, on a GaAs substrate, is being commercially pursued for the important 1.3 micrometer dispersion minima of silica-glass optical fiber; due, in large part, to previous research at Sandia National Laboratories. However, InGaAsN has not shown great promise for 1.55 micrometer emission which is the low-loss window of single mode optical fiber used in transatlantic fiber. Other important applications for the antimonide/nitride based materials include the base junction of an HBT to reduce the operating voltage which is important for wireless communication links, and for improving the efficiency of a multijunction solar cell. We have undertaken the first comprehensive theoretical, experimental and device study of this material with promising results. Theoretical modeling has identified GaAsSbN to be a similar or potentially superior candidate to InGaAsN for long wavelength emission on GaAs. We have confirmed these predictions by producing emission out to 1.66 micrometers and have achieved edge emitting and VCSEL electroluminescence at 1.3 micrometers. We have also done the first study of the transport properties of this material including mobility, electron/hole mass, and exciton reduced mass. This study has increased the understanding of the III-antimonide/nitride materials enough to warrant consideration for all of the target device applications.

Kurtz, Steven Ross; Hargett, Terry W.; Serkland, Darwin Keith; Waldrip, Karen Elizabeth; Modine, Normand Arthur; Klem, John Frederick; Jones, Eric Daniel; Cich, Michael Joseph; Allerman, Andrew Alan; Peake, Gregory Merwin

2003-12-01T23:59:59.000Z

471

Very long single- and few-walled boron nitride nanotubes via the pressurized vapor/condenser method  

SciTech Connect

Boron nitride nanotubes (BNNTs) are desired for their exceptional mechanical, electronic, thermal, structural, textural, optical, and quantum properties. A new method for producing long, small-diameter, single- and few-walled, boron nitride nanotubes (BNNTs) in macroscopic quantities is reported. The pressurized vapor/condenser (PVC) method produces, without catalysts, highly crystalline, very long, small-diameter, BNNTs. Palm-sized, cotton-like masses of BNNT raw material were grown by this technique and spun directly into centimeters-long yarn. Nanotube lengths were observed to be 100 times that of those grown by the most closely related method. Self-assembly and growth models for these long BNNTs are discussed.

Michael W. Smith, Kevin Jordan, Cheol Park, Jae-Woo Kim, Peter Lillehei, Roy Crooks, Joycelyn Harrison

2009-11-01T23:59:59.000Z

472

Rf-plasma synthesis of nanosize silicon carbide and nitride. Final report  

SciTech Connect

A pulsed rf plasma technique is capable of generating ceramic particles of 10 manometer dimension. Experiments using silane/ammonia and trimethylchlorosilane/hydrogen gas mixtures show that both silicon nitride and silicon carbide powders can be synthesized with control of the average particle diameter from 7 to 200 nm. Large size dispersion and much agglomeration appear characteristic of the method, in contrast to results reported by another research group. The as produced powders have a high hydrogen content and are air and moisture sensitive. Post-plasma treatment in a controlled atmosphere at elevated temperature (800{degrees}C) eliminates the hydrogen and stabilizes the powder with respect to oxidation or hydrolysis.

Buss, R.J.

1997-02-01T23:59:59.000Z

473

High performance vertical tunneling diodes using graphene/hexagonal boron nitride/graphene hetero-structure  

SciTech Connect

A tunneling rectifier prepared from vertically stacked two-dimensional (2D) materials composed of chemically doped graphene electrodes and hexagonal boron nitride (h-BN) tunneling barrier was demonstrated. The asymmetric chemical doping to graphene with linear dispersion property induces rectifying behavior effectively, by facilitating Fowler-Nordheim tunneling at high forward biases. It results in excellent diode performances of a hetero-structured graphene/h-BN/graphene tunneling diode, with an asymmetric factor exceeding 1000, a nonlinearity of ?40, and a peak sensitivity of ?12?V{sup ?1}, which are superior to contending metal-insulator-metal diodes, showing great potential for future flexible and transparent electronic devices.

Hwan Lee, Seung; Lee, Jia; Ho Ra, Chang; Liu, Xiaochi; Hwang, Euyheon [Samsung-SKKU Graphene Center (SSGC), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Department of Nano Science and Technology, SKKU Advanced Institute of Nano-Technology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Sup Choi, Min [Department of Nano Science and Technology, SKKU Advanced Institute of Nano-Technology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Hee Choi, Jun [Frontier Research Laboratory, Samsung Advanced Institute of Technology, Samsung Electronics Co., Ltd., Yongin, Gyeonggi-do 446-711 (Korea, Republic of); Zhong, Jianqiang; Chen, Wei [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore); Jong Yoo, Won, E-mail: yoowj@skku.edu [Samsung-SKKU Graphene Center (SSGC), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Department of Nano Science and Technology, SKKU Advanced Institute of Nano-Technology (SAINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Center for Human Interface Nano Technology (HINT), Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of)

2014-02-03T23:59:59.000Z

474

Processing and mechanical properties of silicon nitride formed by robocasting aqueous slurries  

SciTech Connect

Robocasting is a new freeform fabrication technique for dense ceramics. It uses robotics to control deposition of ceramic slurries through an orifice. The optimization of concentrated aqueous Si{sub 3}N{sub 4} slurry properties to achieve high green density robocast bodies and subsequent high sintered densities was investigated. The effects of pH, electrolyte, additives and solids loading on the dispersion and rheological properties of Si{sub 3}N{sub 4} slurries were determined. The mechanical behavior of sintered robocast bars was determined and compared to conventionally produced silicon nitride ceramics.

HE,GUOPING; HIRSCHFELD,DEIDRE A.; CESARANO III,JOSEPH

2000-01-26T23:59:59.000Z

475

Titanium nitride thin films deposited by reactive pulsed-laser ablation in RF plasma  

Science Journals Connector (OSTI)

Titanium nitride thin films were deposited on Si (100) substrates by pulsed laser ablation of a titanium target in a N2 atmosphere (gas pressure approx. 10 Pa) using a doubled frequency Nd:YAG laser (532 nm) also assisted by a 13.56-MHz radio frequency (RF) plasma. Deposition was carried out at various substrate temperatures ranging from 373 up to 873 K and films were analyzed by X-ray diffractometry, scanning electron microscopy and optical emission spectroscopy. A comparison between the ‘normal’ pulsed laser deposition (PLD) and the RF plasma-assisted PLD showed the influence of the plasma on the structural characteristics of the thin films.

A. Giardini; V. Marotta; S. Orlando; G.P. Parisi

2002-01-01T23:59:59.000Z

476

A new stepwise-pressing reaction method for synthesizing pure turbostractic boron nitride  

SciTech Connect

A new stepwise-pressing reaction method is proposed, by which pure and near monodisperse turbostractic boron nitride (tBN) nano-particles with high yield (higher than 92%) are selectively synthesized via reacting BBr{sub 3} and (CH{sub 3}){sub 3}N at 260 {sup o}C in benzene. The obtained sample emits a strong photoluminescence band at 346 nm (under a excitation of 215 nm), making tBN a promising candidate for fabricating UV photoelectronic devices.

Yu, Lili; Wang, Tao; Luan, Chunhong [State Key Lab of Crystal Materials, Shandong University, Jinan 250100 (China)] [State Key Lab of Crystal Materials, Shandong University, Jinan 250100 (China); Wang, Qilong [State Key Lab of Crystal Materials, Shandong University, Jinan 250100 (China) [State Key Lab of Crystal Materials, Shandong University, Jinan 250100 (China); School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Cui, Deliang, E-mail: cuidl@sdu.edu.cn [State Key Lab of Crystal Materials, Shandong University, Jinan 250100 (China)] [State Key Lab of Crystal Materials, Shandong University, Jinan 250100 (China)

2010-09-15T23:59:59.000Z

477

Deposition of tungsten nitride on stainless steel substrates using plasma focus device  

Science Journals Connector (OSTI)

Tungsten nitride (WN) films were deposited on the stainless steel-304 substrate by a 2 kJ Mather-type plasma focus device. The preparation method and characterization data are presented. X-ray diffractometer (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) were employed for the characterization of the samples obtained with different number of focus shots, respectively. The average size of crystallites (from XRD), sub-micro-structures (from SEM) and particles (from AFM images) increase when the number of shots increase from 10 to 20 then 30, then they decrease when the substrate is exposed to 40 shots.

G.R. Etaati; M.T. Hosseinnejad; M. Ghoranneviss; M. Habibi; M. shirazi

2011-01-01T23:59:59.000Z

478

Mechanical Instability and Ideal Shear Strength of Transition Metal Carbides and Nitrides  

SciTech Connect

The ideal shear strength of transition metal carbides and nitrides is calculated with the use of the ab initio pseudopotential density functional method. The microscopic mechanism that limits the ideal strength is studied using full atomic and structural relaxation and the results of electronic structure calculations. It is shown that plasticity in perfect crystals can be triggered by electronic instabilities at finite strains. Our study explicitly demonstrates that the ideal strength in these materials is limited by the elastic instability which is in turn initiated by electronic instabilities. The potential application of alloy hardening due to the onset of instabilities at different strains is also discussed.

Jhi, Seung-Hoon; Louie, Steven G.; Cohen, Marvin L.; Morris, J. W.

2001-08-13T23:59:59.000Z

479

Multi-scale modelling of III-nitrides: from dislocations to the electronic structure  

E-Print Network (OSTI)

or public lighting nowadays use GaN-based LEDs. Significant effort is being invested in development of efficient and reliable LEDs which emit comfort- able white light, as there is a huge market potential for replacing bulbs and fluorescent tubes currently... of wurtzite forms of the III-nitrides. The range of the visible spectrum is shown on the wavelength axis. GaN and its alloys with aluminium or indium are in their stable form, wurtzite direct band gap semicon- ductors that have become the most important since...

Holec, David

480

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

Note: This page contains sample records for the topic "bulk gallium nitride" 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.


481

Detailed balance theory of excitonic and bulk heterojunction solar cells  

Science Journals Connector (OSTI)

A generalized solar cell model for excitonic and classical bipolar solar cells describes the combined transport and interaction of electrons, holes, and excitons in accordance with the principle of detailed balance. Conventional inorganic solar cells, single-phase organic solar cells and bulk heterojunction solar cells, i.e., nanoscale mixtures of two organic materials, are special cases of this model. For high mobilities, the compatibility with the principle of detailed balance ensures that our model reproduces the Shockley-Queisser limit irrespective of how the energy transport is achieved. For less ideal devices distinct differences become visible between devices that are described by linear differential equations and those with nonlinear effects, such as a voltage-dependent collection in bipolar p-i-n-type devices. These differences in current-voltage characteristics are also decisive for the validity of the reciprocity theorem between photovoltaic quantum efficiency and electroluminescent emission. Finally, we discuss the effect of band offset at the heterointerface in a bulk heterojunction cell and the effect of the average distances between these heterointerfaces on the performance of a solar cell in order to show how our detailed balance model includes also these empirically important quantities.

Thomas Kirchartz; Julian Mattheis; Uwe Rau

2008-12-29T23:59:59.000Z

482

Method of fabricating an optoelectronic device having a bulk heterojunction  

DOE Patents (OSTI)

A method of fabricating an organic optoelectronic device having a bulk heterojunction comprises the steps of: depositing a first layer over a first electrode by organic vapor phase deposition, wherein the first layer comprises a first organic small molecule material; depositing a second layer on the first layer such that the second layer is in physical contact with the first layer, wherein the interface of the second layer on the first layer forms a bulk heterojunction; and depositing a second electrode over the second layer to form the optoelectronic device. In another embodiment, a first layer having protrusions is deposited over the first electrode, wherein the first layer comprises a first organic small molecule material. For example, when the first layer is an electron donor layer, the first electrode is an anode, the second layer is an electron acceptor layer, and the second electrode is a cathode. As a further example, when the first layer is an electron acceptor layer, the first electrode is a cathode, the second layer is an electron donor layer, and the second electrode is an anode.

Shtein, Max (Princeton, NJ); Yang, Fan (Princeton, NJ); Forrest, Stephen R. (Princeton, NJ)

2008-09-02T23:59:59.000Z

483

CX-010895: Categorical Exclusion Determination  

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

Development and Industrialization of Indium Gallium Nitride/Gallium Nitride (InGaN/GaN) Light Emitting Diodes LEDs on Patterned Sapphire Substrate (PSS) for Low Cost Emitter Architecture CX(s) Applied: B3.6 Date: 06/27/2013 Location(s): California Offices(s): National Energy Technology Laboratory

484

Quantitative description of microstructure defects in hexagonal boron nitrides using X-ray diffraction analysis  

SciTech Connect

A routine for simultaneous quantification of turbostratic disorder, amount of puckering and the dislocation and stacking fault density in hexagonal materials was proposed and tested on boron nitride powder samples that were synthesised using different methods. The routine allows the individual microstructure defects to be recognised according to their effect on the anisotropy of the X-ray diffraction line broadening. For quantification of the microstructure defects, the total line broadening is regarded as a linear combination of the contributions from the particular defects. The total line broadening is obtained from the line profile fitting. As testing material, graphitic boron nitride (h-BN) was employed in the form of hot-isostatically pressed h-BN, pyrolytic h-BN or a h-BN, which was chemically vapour deposited at a low temperature. The kind of the dominant microstructure defects determined from the broadening of the X-ray diffraction lines was verified by high resolution transmission electron microscopy. Their amount was attempted to be verified by alternative methods. - Highlights: • Reliable method for quantification of microstructure defects in BN was suggested. • The method is based on the analysis of anisotropic XRD line broadening. • This XRD line broadening is unique and characteristic of the respective defect. • Thus, the quantification of coexistent microstructure defects is possible. • The method was tested on hexagonal BN, which was produced by different techniques.

Schimpf, C., E-mail: schimpf@iww.tu-freiberg.de; Motylenko, M.; Rafaja, D.

2013-12-15T23:59:59.000Z

485

Ferromagnetism in Doped Thin-Film Oxide and Nitride Semiconductors and Dielectrics  

SciTech Connect

The principal goal in the field of high-Tc ferromagnetic semiconductors is the synthesis, characterization and utilization of semiconductors which exhibit substantial carrier spin polarization at and above room temperature. Such materials are of critical importance in the emerging field of semiconductor spintronics. The interaction leading to carrier spin polarization, exchange coupling between the dopant spins and the valence or conduction band, is known to be sufficiently weak in conventional semiconductors, such as GaAs and Si, that magnetic ordering above cryogenic temperatures is essentially impossible. Since the provocative theoretical predictions of Tc above ambient in p-Mn:ZnO and p-Mn:GaN (T. Dietl et al., Science 287 1019 (2000)), and the observation of room-temperature ferromagnetism in Co:TiO2 anatase (Y. Matsumoto et al., Science 291 854 (2001)), there has been a flurry of work in oxides and nitrides doped with transition metals with unpaired d electrons. It has even been claimed that room-temperature ferromagnetism can be obtained in certain d0 transition metals oxides without a dopant. In this Report, the field of transition metal doped oxides and nitrides is critically reviewed and assessed from a materials science perspective. Since much of the field centers around thin film growth, this Report focuses on films prepared not only by conventional vacuum deposition methods, but also by spin coating colloidal nanoparticles.

Chambers, Scott A.

2006-10-01T23:59:59.000Z

486

Surface modification by gas nitriding for improving cavitation erosion resistance of CP-Ti  

Science Journals Connector (OSTI)

Abstract Gas nitriding process has been used to increase the surface hardness of titanium, in this study we used this technique to improve the cavitation erosion resistance (Rce) of commercial purity titanium (CP-Ti). We also studied microstructure, phase constituents, hardness and the effect of processing parameters on Rce of the treated samples. The results indicated that the Rce of the treated samples was related to the processing parameters. The sample treated at 850 °C for 4 h has the highest Rce, which was attributed to the compound layer (CL) with a hard, dense and free-defects microstructure. With increasing the nitriding temperature and duration, the Rce of the treated samples decreased due to the excessive oxide and defects formed in the CL. When the CL was removed, the treated sample exhibited an excellent cavitation erosion behavior. It was supposed to be due to the existence of the residual compressive stresses field in the nitrogen diffusion zone, which played an important role in preventing microcracks initiation and propagation to interior for cavitation damage.

Haibin Li; Zhenduo Cui; Zhaoyang Li; Shengli Zhu; Xianjin Yang

2014-01-01T23:59:59.000Z

487

Z .Surface and Coatings Technology 127 2000 260 265 Characterization of carbon nitride thin films deposited by  

E-Print Network (OSTI)

-screw adapter and monitored by measuring the back reflection power at the end of a water load. A mixture polycrystalline car- bon nitride films, and the resulting mechanical proper- ties are not as good as predicted a valve between the deposition chamber and the vacuum pumps. The microwave power was adjusted by a four

Gao, Hongjun

488

Power mixture and green body for producing silicon nitride base & articles of high fracture toughness and strength  

DOE Patents (OSTI)

A powder mixture and a green body for producing a silicon nitride-based article of improved fracture toughness and strength. The powder mixture includes 9a) a bimodal silicon nitride powder blend consisting essentially of about 10-30% by weight of a first silicon mitride powder of an average particle size of about 0.2 .mu.m and a surface area of about 8-12m.sup.2 g, and about 70-90% by weight of a second silicon nitride powder of an average particle size of about 0.4-0.6 .mu.m and a surface area of about 2-4 m.sup.2 /g, (b) about 10-50 percent by volume, based on the volume of the densified article, of refractory whiskers or fibers having an aspect ratio of about 3-150 and having an equivalent diameter selected to produce in the densified articel an equivalent diameter ratio of the whiskers or fibers to grains of silicon nitride of greater than 1.0, and (c) an effective amount of a suitable oxide densification aid. The green body is formed from the powder mixture, an effective amount of a suitable oxide densification aid, and an effective amount of a suitable organic binder.

Huckabee, Marvin L. (Marlboro, MA); Buljan, Sergej-Tomislav (Acton, MA); Neil, Jeffrey T. (Acton, MA)

1991-01-01T23:59:59.000Z

489

Theoretical study on interaction of hydrogen with single-walled boron nitride nanotubes. II. Collision, storage, and adsorption  

E-Print Network (OSTI)

of a true hydrogen storage capacity, thus it would be also true that some results of rather high storage storage material or not. Our previous study6 showed that the pristine CNT is not an effective hydrogenTheoretical study on interaction of hydrogen with single-walled boron nitride nanotubes. II

Goddard III, William A.

490

Coating of Titanium Nitride on Stainless Steel Targets by a 4 kJ Plasma Focus Device  

Science Journals Connector (OSTI)

Titanium nitride thin films were deposited on stainless steel (SS316L) targets by using a 4 kJ plasma focus device. The corresponding energy flux delivered to...13 kev cm?3 ns?1. X-ray diffraction analysis reveal...

M. Omrani; M. Habibi; R. Amrollahi

2012-08-01T23:59:59.000Z

491

First-Principles Study of MetalCarbide/Nitride Adhesion: Al/VC vs. Al/VN Donald J. Siegel  

E-Print Network (OSTI)

-oxide ce- ramics. Within this class, the transition metal carbides and ni- trides are a particularly knowledge, there have been only three studies of adhesion between metals and transition metal carbidesFirst-Principles Study of Metal­Carbide/Nitride Adhesion: Al/VC vs. Al/VN Donald J. Siegel

Adams, James B

492

Scanning Tunneling Macroscopy, Black Holes, and AdS/CFT Bulk Locality  

E-Print Network (OSTI)

We establish resolution bounds on reconstructing a bulk field from boundary data on a timelike hypersurface. If the bulk only supports propagating modes, reconstruction is complete. If the bulk also supports evanescent modes, local reconstruction is not achievable unless one has exponential precision in knowledge of the boundary data. Without exponential precision, for a Minkowski bulk, one can reconstruct a spatially coarse-grained bulk field, but only out to a depth set by the coarse-graining scale. For an asymptotically AdS bulk, reconstruction is limited to a spatial coarse-graining proper distance set by the AdS scale. AdS black holes admit evanescent modes. We study the resolution bound in the large AdS black hole background and provide a dual CFT interpretation. Our results demonstrate that, if there is a black hole of any size in the bulk, then sub-AdS bulk locality is no longer well-encoded in boundary data in terms of local CFT operators. Specifically, in order to probe the bulk on sub-AdS scales using only boundary data in terms of local operators, one must either have such data to exponential precision or make further assumptions about the bulk state.

Soo-Jong Rey; Vladimir Rosenhaus

2014-06-02T23:59:59.000Z

493

Methods of synthesizing hydroxyapatite powders and bulk materials  

DOE Patents (OSTI)

Methods are provided for producing non-porous controlled morphology hydroxyapatite granules of less than 8 .mu.m by a spray-drying process. Solid or hollow spheres or doughnuts can be formed by controlling the volume fraction and viscosity of the slurry as well as the spray-drying conditions. Methods of providing for homogenous cellular structure hydroxyapatite granules are also provided. Pores or channels or varying size and number can be formed by varying the temperature at which a hydroxyapatite slurry formed in basic, saturated ammonium hydroxide is spray-dried. Methods of providing non-porous controlled morphology hydroxyapatite granules in ammonium hydroxide are also provided. The hydroxyapatite granules and bulk materials formed by these methods are also provided.

Luo, Ping (2843A Forest Ave., Berkeley, CA 94705)

1999-01-12T23:59:59.000Z

494

Methods of synthesizing hydroxyapatite powders and bulk materials  

DOE Patents (OSTI)

Methods are provided for producing non-porous controlled morphology hydroxyapatite granules of less than 8 {micro}m by a spray-drying process. Solid or hollow spheres or doughnuts can be formed by controlling the volume fraction and viscosity of the slurry as well as the spray-drying conditions. Methods of providing for homogeneous cellular structure hydroxyapatite granules are also provided. Pores or channels or varying size and number can be formed by varying the temperature at which a hydroxyapatite slurry formed in basic, saturated ammonium hydroxide is spray-dried. Methods of providing non-porous controlled morphology hydroxyapatite granules in ammonium hydroxide are also provided. The hydroxyapatite granules and bulk materials formed by these methods are also provided. 26 figs.

Luo, P.

1999-01-12T23:59:59.000Z

495

FINITE ELEMENT ANALYSIS OF BULK TRITIUM SHIPPING PACKAGE  

SciTech Connect

The Bulk Tritium Shipping Package was designed by Savannah River National Laboratory. This package will be used to transport tritium. As part of the requirements for certification, the package must be shown to meet the scenarios of the Hypothetical Accident Conditions (HAC) defined in Code of Federal Regulations Title 10 Part 71 (10CFR71). The conditions include a sequential 30-foot drop event, 30-foot dynamic crush event, and a 40-inch puncture event. Finite Element analyses were performed to support and expand upon prototype testing. Cases similar to the tests were evaluated. Additional temperatures and orientations were also examined to determine their impact on the results. The peak stress on the package was shown to be acceptable. In addition, the strain on the outer drum as well as the inner containment boundary was shown to be acceptable. In conjunction with the prototype tests, the package was shown to meet its confinement requirements.

Jordan, J.

2010-06-02T23:59:59.000Z

496

Scenario Projections for Future Market Potentials of Biobased Bulk Chemicals  

Science Journals Connector (OSTI)

Product values are production costs plus profits, and they include variable costs, fixed costs, taxes, insurance fees, plant overheads, allowance for marketing, administration, and R&D, as well as a so-called capital charge representing depreciation and profits. ... Future fossil fuel prices depend on (global) political developments, developments of reserves, exploitation of different fossil resources, and demand. ... This research was partly supported by the European Commission (Research Directorate General), 5th Framework European Network (GROWTH) Program by support of the project “BREW” with the full title “Medium and long-term opportunities and risks of the biotechnological production of bulk chemicals from renewable resources” (Contract No. G5MA-CT-2002-00014). ...

Veronika Dornburg; Barbara G. Hermann; Martin K. Patel

2008-02-23T23:59:59.000Z

497

Bulk viscous FWR with time varying constants revisited  

E-Print Network (OSTI)

We study a full causal bulk viscous cosmological model with flat FRW symmetries and where the ``constants'' $G,c$ and $\\Lambda $ vary. We take into account the possible effects of a $c-$variable into the curvature tensor in order to outline the field equations. Using the Lie method we find the possible forms of the ``constants'' $G$ and $c$ that make integrable the field equations as well as the equation of state for the viscous parameter. It is found that $G,c$ and $\\Lambda $ follow a power law solution verifying the relationship $G/c^{2}=\\kappa .$ Once these possible forms have been obtained we calculate the thermodynamical quantities of the model in order to determine the possible values of the parameters that govern the quantities, finding that only a growing $G$ and $c$ are possible while $% \\Lambda $ behaves as a negative decreasing function.

J. A. Belinchón

2005-01-07T23:59:59.000Z

498

Factors affecting characterization of bulk high-temperature superconductors  

SciTech Connect

Three major factors affect the characterization of bulk high-temperature superconductors in terms of their levitation properties during interaction with permanent magnets. First, the appropriate parameter for the permanent magnet is internal magnetization, not the value of the magnetic field measured at the magnet`s surface. Second, although levitation force grows with superconductor thickness and surface area, for a given permanent magnet size, comparison of levitation force between samples is meaningful when minimum values are assigned to the superconductor size parameters. Finally, the effect of force creep must be considered when time-averaging the force measurements. In addition to levitational force, the coefficient of friction of a levitated rotating permanent magnet may be used to characterize the superconductor.

Hull, J.R. [Argonne National Lab., IL (United States). Energy Technology Div.

1997-11-01T23:59:59.000Z

499

Freeze-out by bulk viscosity driven instabilities  

E-Print Network (OSTI)

We describe a new scenario (first introduced in [G. Torrieri, B. Tom\\'a\\v{s}ik and I. Mishustin, Phys. Rev. C \\textbf{77}, 034903 (2008)]) for freezeout in heavy ion collisions that could solve the lingering problems associated with the so-called HBT puzzle. We argue that bulk viscosity increases as $T$ approaches $T_c$. The fluid {then} becomes unstable against small perturbations, and fragments into clusters of a size much smaller than the total size of the system. These clusters maintain the pre-existing outward-going flow, as a spray of droplets, but develop no flow of their own, and hadronize by evaporation. We show that this scenario can explain HBT data and suggest how it can be experimentally tested.

Torrieri, Giorgio; Mishustin, Igor

2008-01-01T23:59:59.000Z

500

Application of surface and bulk characterization techniques for coal preparation  

SciTech Connect

With the recent acceleration of development of surface-property-based processes for the beneficiation of ultrafine coal, it is essential to establish their underlying scientific principles and to develop mathematical models able to predict how the process will perform on an unknown coal. Various surface properties of importance, surface characterization techniques, and application of these techniques to coal are reviewed. Instrumental techniques used for analyzing bulk composition of organic and/or inorganic matter are also reviewed. The differences in coal and mineral matter properties are highlighted. The effect of particle history, including grinding and oxidation, on the surface properties of coal is discussed. The mechanisms of advanced physical beneficiation processes are reviewed, and the influence of surface properties on the effectiveness of separation between coal and the liberated mineral matter is discussed. Finally, recommendations for future areas of research are made. 121 refs., 19 figs., 17 tabs.

Gala, H.B. (Burns and Roe Services Corp., Pittsburgh, PA (USA)); Hucko, R.E. (USDOE Pittsburgh Energy Technology Center, PA (USA). Coal Preparation and Solids Transportation Div.)

1990-01-01T23:59:59.000Z