National Library of Energy BETA

Sample records for nitride ingan samples

  1. Low Cost Production of InGaN for Next-Generation Photovoltaic Devices

    SciTech Connect (OSTI)

    Nick M. Sbrockey, Shangzhu Sun, Gary S. Tompa,

    2012-07-09

    The goal of this project is to develop a low-cost and low-energy technology for production of photovoltaic devices based on InGaN materials. This project builds on the ongoing development by Structured Materials Industries (SMI), of novel thin film deposition technology for Group III-Nitride materials, which is capable of depositing Group-III nitride materials at significantly lower costs and significantly lower energy usage compared to conventional deposition techniques. During this project, SMI demonstrated deposition of GaN and InGaN films using metalorganic sources, and demonstrated compatibility of the process with standard substrate materials and hardware components.

  2. Realizing InGaN monolithic solar-photoelectrochemical cells for artificial photosynthesis

    SciTech Connect (OSTI)

    Dahal, R.; Pantha, B. N.; Li, J.; Lin, J. Y.; Jiang, H. X., E-mail: hx.jiang@ttu.edu [Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, Texas 79409 (United States)

    2014-04-07

    InGaN alloys are very promising for solar water splitting because they have direct bandgaps that cover almost the whole solar spectrum. The demonstration of direct solar-to-fuel conversion without external bias with the sunlight being the only energy input would pave the way for realizing photoelectrochemical (PEC) production of hydrogen by using InGaN. A monolithic solar-PEC cell based on InGaN/GaN multiple quantum wells capable to directly generate hydrogen gas under zero bias via solar water splitting is reported. Under the irradiation by a simulated sunlight (1-sun with 100 mW/cm{sup 2}), a 1.5% solar-to-fuel conversion efficiency has been achieved under zero bias, setting a fresh benchmark of employing III-nitrides for artificial photosynthesis. Time dependent hydrogen gas production photocurrent measured over a prolonged period (measured for 7 days) revealed an excellent chemical stability of InGaN in aqueous solution of hydrobromic acid. The results provide insights into the architecture design of using InGaN for artificial photosynthesis to provide usable clean fuel (hydrogen gas) with the sunlight being the only energy input.

  3. Design of Integrated III-Nitride/Non-III-Nitride Tandem Photovoltaic Devices

    SciTech Connect (OSTI)

    Toledo, N. G.; Friedman, D.J.; Farrell, R. M.; Perl, E. E.; Lin, C. T.; Bowers, J. E.; Speck, J. S.; Mishra, U. K.

    2012-03-01

    The integration of III-nitride and non-III-nitride materials for tandem solar cell applications can improve the efficiency of the photovoltaic device due to the added power contributed by the III-nitride top cell to that of high-efficiency multi-junction non-III-nitride solar cells if the device components are properly designed and optimized. The proposed tandem solar cell is comprised of a III-nitride top cell bonded to a non-III-nitride, series-constrained, multi-junction subcell. The top cell is electrically isolated, but optically coupled to the underlying subcell. The use of a III-nitride top cell is potentially beneficial when the top junction of a stand-alone non-III-nitride subcell generates more photocurrent than the limiting current of the non-III-nitride subcell. Light producing this excess current can either be redirected to the III-nitride top cell through high energy photon absorption, redirected to the lower junctions through layer thickness optimization, or a combination of both, resulting in improved total efficiency. When the non-III-nitride cell's top junction is the limiting junction, the minimum power conversion efficiency that the III-nitride top cell must contribute should compensate for the spectrum filtered from the multi-junction subcell for this design to be useful. As the III-nitride absorption edge wavelength, {lambda}{sub N}, increases, the performance of the multi-junction subcell decreases due to spectral filtering. In the most common spectra of interest (AM1.5G, AM1.5 D, and AM0), the technology to grow InGaN cells with {lambda}{sub N}<520 nm is found to be sufficient for III-nitride top cell applications. The external quantum efficiency performance, however, of state-of-the-art InGaN solar cells still needs to be improved. The effects of surface/interface reflections are also presented. The management of these reflection issues determines the feasibility of the integrated III-nitride/non-III-nitride design to improve overall cell efficiency.

  4. Preparing titanium nitride powder

    DOE Patents [OSTI]

    Bamberger, Carlos E.

    1989-01-01

    A process for making titanium nitride powder by reaction of titanium phosphates with sodium cyanide.

  5. Crystallographically uniform arrays of ordered (In)GaN nanocolumns

    SciTech Connect (OSTI)

    Gačević, Ž. Bengoechea-Encabo, A.; Albert, S.; Calleja, E.

    2015-01-21

    In this work, through a comparative study of self-assembled (SA) and selective area grown (SAG) (In)GaN nanocolumn (NC) ensembles, we first give a detailed insight into improved crystallographic uniformity (homogeneity of crystallographic tilts and twists) of the latter ones. The study, performed making use of: reflective high energy electron diffraction, X-ray diffraction and scanning electron microscopy, reveals that unlike their SA counterparts, the ensembles of SAG NCs show single epitaxial relationship to both sapphire(0001) and Si(111) underlying substrates. In the second part of the article, making use of X-ray diffraction, we directly show that the selective area growth leads to improved compositional uniformity of InGaN NC ensembles. This further leads to improved spectral purity of their luminescence, as confirmed by comparative macro-photoluminescence measurements performed on SA and SAG InGaN NC ensembles. An improved crystallographic uniformity of NC ensembles facilitates their integration into optoelectronic devices, whereas their improved compositional uniformity allows for their employment in single-color optoelectronic applications.

  6. Preparation of uranium nitride

    DOE Patents [OSTI]

    Potter, Ralph A.; Tennery, Victor J.

    1976-01-01

    A process for preparing actinide-nitrides from massive actinide metal which is suitable for sintering into low density fuel shapes by partially hydriding the massive metal and simultaneously dehydriding and nitriding the dehydrided portion. The process is repeated until all of the massive metal is converted to a nitride.

  7. Nanoselective area growth and characterization of dislocation-free InGaN

    Office of Scientific and Technical Information (OSTI)

    nanopyramids on AlN buffered Si(111) templates (Journal Article) | SciTech Connect Nanoselective area growth and characterization of dislocation-free InGaN nanopyramids on AlN buffered Si(111) templates Citation Details In-Document Search Title: Nanoselective area growth and characterization of dislocation-free InGaN nanopyramids on AlN buffered Si(111) templates We report the metal organic chemical vapor deposition growth of dislocation-free 100 nm thick hexagonal InGaN nanopyramid arrays

  8. Nitrided Metallic Bipolar Plates

    Broader source: Energy.gov [DOE]

    This presentation, which focuses on nitrided metallic bipolar plates, was given by M. P. Brady of ORNL at a February 2007 meeting on new fuel cell projects.

  9. InGaN Quantum Dot Fabrication using Quantum Size Controlled

    Office of Scientific and Technical Information (OSTI)

    Photoelectrochemical Etching. (Conference) | SciTech Connect InGaN Quantum Dot Fabrication using Quantum Size Controlled Photoelectrochemical Etching. Citation Details In-Document Search Title: InGaN Quantum Dot Fabrication using Quantum Size Controlled Photoelectrochemical Etching. Abstract not provided. Authors: Fischer, Arthur Joseph ; Xiao, Xiaoyin ; Lu, Ping ; Tsao, Jeffrey Yeenien ; Wang, George T. ; Koleske, Daniel ; Subramania, Ganapathi Subramanian ; Coltrin, Michael Elliott

  10. Quantum-Size-Controlled Photoelectrochemical Fabrication of Epitaxial InGaN

    Office of Scientific and Technical Information (OSTI)

    Quantum Dots (Journal Article) | SciTech Connect Quantum-Size-Controlled Photoelectrochemical Fabrication of Epitaxial InGaN Quantum Dots Citation Details In-Document Search Title: Quantum-Size-Controlled Photoelectrochemical Fabrication of Epitaxial InGaN Quantum Dots Authors: Xiao, Xiaoyin ; Fischer, Arthur J. ; Wang, George T. ; Lu, Ping ; Koleske, Daniel D. ; Coltrin, Michael E. ; Wright, Jeremy B. ; Liu, Sheng ; Brener, Igal ; Subramania, Ganesh ; Tsao, Jeffrey Y. Publication Date:

  11. Methods of forming boron nitride

    DOE Patents [OSTI]

    Trowbridge, Tammy L; Wertsching, Alan K; Pinhero, Patrick J; Crandall, David L

    2015-03-03

    A method of forming a boron nitride. The method comprises contacting a metal article with a monomeric boron-nitrogen compound and converting the monomeric boron-nitrogen compound to a boron nitride. The boron nitride is formed on the same or a different metal article. The monomeric boron-nitrogen compound is borazine, cycloborazane, trimethylcycloborazane, polyborazylene, B-vinylborazine, poly(B-vinylborazine), or combinations thereof. The monomeric boron-nitrogen compound is polymerized to form the boron nitride by exposure to a temperature greater than approximately 100.degree. C. The boron nitride is amorphous boron nitride, hexagonal boron nitride, rhombohedral boron nitride, turbostratic boron nitride, wurzite boron nitride, combinations thereof, or boron nitride and carbon. A method of conditioning a ballistic weapon and a metal article coated with the monomeric boron-nitrogen compound are also disclosed.

  12. Superconducting structure with layers of niobium nitride and aluminum nitride

    DOE Patents [OSTI]

    Murduck, James M.; Lepetre, Yves J.; Schuller, Ivan K.; Ketterson, John B.

    1989-01-01

    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.

  13. Superconducting structure with layers of niobium nitride and aluminum nitride

    DOE Patents [OSTI]

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

    1989-07-04

    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.

  14. Method for preparing actinide nitrides

    DOE Patents [OSTI]

    Bryan, G.H.; Cleveland, J.M.; Heiple, C.R.

    1975-12-01

    Actinide nitrides, and particularly plutonium and uranium nitrides, are prepared by reacting an ammonia solution of an actinide compound with an ammonia solution of a reactant or reductant metal, to form finely divided actinide nitride precipitate which may then be appropriately separated from the solution. The actinide nitride precipitate is particularly suitable for forming nuclear fuels.

  15. Boron nitride nanotubes

    DOE Patents [OSTI]

    Smith, Michael W.; Jordan, Kevin; Park, Cheol

    2012-06-06

    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.

  16. Boron nitride composites

    DOE Patents [OSTI]

    Kuntz, Joshua D.; Ellsworth, German F.; Swenson, Fritz J.; Allen, Patrick G.

    2016-02-16

    According to one embodiment, a composite product includes hexagonal boron nitride (hBN), and a plurality of cubic boron nitride (cBN) particles, wherein the plurality of cBN particles are dispersed in a matrix of the hBN. According to another embodiment, a composite product includes a plurality of cBN particles, and one or more borate-containing binders.

  17. Nanoscale selective area growth of thick, dense, uniform, In-rich, InGaN

    Office of Scientific and Technical Information (OSTI)

    nanostructure arrays on GaN/sapphire template (Journal Article) | SciTech Connect Nanoscale selective area growth of thick, dense, uniform, In-rich, InGaN nanostructure arrays on GaN/sapphire template Citation Details In-Document Search Title: Nanoscale selective area growth of thick, dense, uniform, In-rich, InGaN nanostructure arrays on GaN/sapphire template Authors: Sundaram, S. [1] ; Puybaret, R. [2] ; El Gmili, Y. [1] ; Li, X. [2] ; Bonanno, P. L. [1] ; Pantzas, K. [3] Search SciTech

  18. Cubic nitride templates

    DOE Patents [OSTI]

    Burrell, Anthony K; McCleskey, Thomas Mark; Jia, Quanxi; Mueller, Alexander H; Luo, Hongmei

    2013-04-30

    A polymer-assisted deposition process for deposition of epitaxial cubic metal nitride films and the like is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures under a suitable atmosphere to yield metal nitride films and the like. Such films can be used as templates for the development of high quality cubic GaN based electronic devices.

  19. Comparative study of polar and semipolar (112?2) InGaN layers grown by metalorganic vapour phase epitaxy

    SciTech Connect (OSTI)

    Dinh, Duc V. E-mail: peter.parbrook@tyndall.ie; Zubialevich, V. Z.; Oehler, F.; Kappers, M. J.; Humphreys, C. J.; Alam, S. N.; Parbrook, P. J. E-mail: peter.parbrook@tyndall.ie; Caliebe, M.; Scholtz, F.

    2014-10-21

    InGaN layers were grown simultaneously on (112?2) GaN and (0001) GaN templates by metalorganic vapour phase epitaxy. At higher growth temperature (?750C), the indium content (<15%) of the (112?2) and (0001) InGaN layers was similar. However, for temperatures less than 750C, the indium content of the (112?2) InGaN layers (15%26%) were generally lower than those with (0001) orientation (15%32%). The compositional deviation was attributed to the different strain relaxations between the (112?2) and (0001) InGaN layers. Room temperature photoluminescence measurements of the (112?2) InGaN layers showed an emission wavelength that shifts gradually from 380 nm to 580 nm with decreasing growth temperature (or increasing indium composition). The peak emission wavelength of the (112?2) InGaN layers with an indium content of more than 10% blue-shifted a constant value of ?(5060) nm when using higher excitation power densities. This blue-shift was attributed to band filling effects in the layers.

  20. Superplastic forging nitride ceramics

    DOE Patents [OSTI]

    Panda, Prakash C.; Seydel, Edgar R.; Raj, Rishi

    1988-03-22

    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.

  1. III-Nitride Nanowires

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

    III-Nitride Nanowires - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Fuel Cycle Defense Waste Management Programs Advanced

  2. Electrochemical nitridation of metal surfaces

    DOE Patents [OSTI]

    Wang, Heli; Turner, John A.

    2015-06-30

    Electrochemical nitridation of metals and the produced metals are disclosed. An exemplary method of electrochemical nitridation of metals comprises providing an electrochemical solution at low temperature. The method also comprises providing a three-electrode potentiostat system. The method also comprises stabilizing the three-electrode potentiostat system at open circuit potential. The method also comprises applying a cathodic potential to a metal.

  3. Silicon nitride ceramic comprising samaria and ytterbia

    DOE Patents [OSTI]

    Yeckley, Russell L.

    1996-01-01

    This invention relates to a sintered silicon nitride ceramic comprising samaria and ytterbia for enhanced toughness.

  4. Gallium nitride nanotube lasers

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

    Li, Changyi; Liu, Sheng; Hurtado, Antonio; Wright, Jeremy Benjamin; Xu, Huiwen; Luk, Ting Shan; Figiel, Jeffrey J.; Brener, Igal; Brueck, Steven R. J.; Wang, George T.

    2015-01-01

    Lasing is demonstrated from gallium nitride nanotubes fabricated using a two-step top-down technique. By optically pumping, we observed characteristics of lasing: a clear threshold, a narrow spectral, and guided emission from the nanotubes. In addition, annular lasing emission from the GaN nanotube is also observed, indicating that cross-sectional shape control can be employed to manipulate the properties of nanolasers. The nanotube lasers could be of interest for optical nanofluidic applications or application benefitting from a hollow beam shape.

  5. Functionalized boron nitride nanotubes

    DOE Patents [OSTI]

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

    2014-04-22

    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.

  6. Synthesis and characterization of actinide nitrides

    SciTech Connect (OSTI)

    Jaques, Brian; Butt, Darryl P.; Marx, Brian M.; Hamdy, A.S.; Osterberg, Daniel; Balfour, Gordon

    2007-07-01

    A carbothermic reduction of the metal oxides in a hydrogen/nitrogen mixed gas stream prior to nitriding in a nitrogen gas stream was used to synthesize uranium nitride at 1500 deg. C, cerium nitride at 1400 deg. C, and dysprosium nitride at 1500 deg. C. Cerium nitride and dysprosium nitride were also synthesized via hydriding and nitriding the metal shavings at 900 deg. C and 1500 deg. C, respectively. Also, a novel ball-milling synthesis route was used to produce cerium nitride and dysprosium nitride from the metal shavings at room temperature. Dysprosium nitride was also produced by reacting the metal shavings in a high purity nitrogen gas stream at 1300 deg. C. All materials were characterized by phase analysis via X-ray diffraction. Only the high purity materials were further analyzed via chemical analysis to characterize the trace oxygen concentration. (authors)

  7. Cordierite silicon nitride filters

    SciTech Connect (OSTI)

    Sawyer, J.; Buchan, B. ); Duiven, R.; Berger, M. ); Cleveland, J.; Ferri, J. )

    1992-02-01

    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.

  8. Hard carbon nitride and method for preparing same

    DOE Patents [OSTI]

    Haller, Eugene E.; Cohen, Marvin L.; Hansen, William L.

    1992-01-01

    Novel crystalline .alpha. (silicon nitride-like)-carbon nitride and .beta. (silicon nitride-like)-carbon nitride are formed by sputtering carbon in the presence of a nitrogen atmosphere onto a single crystal germanium or silicon, respectively, substrate.

  9. Boron nitride converted carbon fiber

    DOE Patents [OSTI]

    Rousseas, Michael; Mickelson, William; Zettl, Alexander K.

    2016-04-05

    This disclosure provides systems, methods, and apparatus related to boron nitride converted carbon fiber. In one aspect, a method may include the operations of providing boron oxide and carbon fiber, heating the boron oxide to melt the boron oxide and heating the carbon fiber, mixing a nitrogen-containing gas with boron oxide vapor from molten boron oxide, and converting at least a portion of the carbon fiber to boron nitride.

  10. Method for producing refractory nitrides

    DOE Patents [OSTI]

    Quinby, Thomas C.

    1989-01-24

    A process for making fine, uniform metal nitride powders that can be hot pressed or sintered. A metal salt is placed in a solvent with Melamine and warmed until a metal-Melamine compound forms. The solution is cooled and the metal-Melamine precipitate is calcined at a temperature below 700.degree. C. to form the metal nitrides and to avoid formation of the metal oxide.

  11. Superplastic forging nitride ceramics

    DOE Patents [OSTI]

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

    1988-03-22

    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.

  12. Temperature-dependent efficiency droop of blue InGaN micro-light emitting diodes

    SciTech Connect (OSTI)

    Tian, Pengfei; McKendry, Jonathan J. D.; Herrnsdorf, Johannes; Ferreira, Ricardo; Watson, Ian M.; Gu, Erdan Dawson, Martin D.; Watson, Scott; Kelly, Anthony E.

    2014-10-27

    Temperature-dependent trends in radiative and Auger recombination coefficients have been determined at different injection carrier concentrations using InGaN micro-light emitting diodes 40 ?m in diameter. The differential lifetime was obtained first from the measured modulation bandwidth and was then employed to calculate the carrier concentration in the quantum well active region. When the temperature increases, the carrier concentration increases, but both the radiative and Auger recombination coefficients decrease. In addition, the temperature dependence of radiative and Auger recombination coefficients is weaker at a higher injection carrier concentration, which is strongly related to phase space filling.

  13. Sandia Energy - III-Nitride Nanowires

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

    III-Nitride NanowiresTara Camacho-Lopez2015-03-25T21:58:18+00:00 III-Nitride Nanowires: Novel Emitters for Lighting Speaker: George Wang, EFRC Thrust Leader Date: September 14,...

  14. Electrochemical Solution Growth: Gallium Nitride Crystal Growth...

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

    ID Number Title and Abstract Primary Lab Date Patent 7,435,297 Patent 7,435,297 Molten-salt-based growth of group III nitrides A method for growing Group III nitride...

  15. Photoelectrochemical etching of epitaxial InGaN thin films: Self-limited kinetics and nanostructuring

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

    Xiao, Xiaoyin; Fischer, Arthur J.; Coltrin, Michael E.; Lu, Ping; Koleske, Daniel D.; Wang, George T.; Polsky, Ronen; Tsao, Jeffrey Y.

    2014-10-22

    We report here the characteristics of photoelectrochemical (PEC) etching of epitaxial InGaN semiconductor thin films using narrowband lasers with linewidth less than ~1 nm. In the initial stages of PEC etching, when the thin film is flat, characteristic voltammogram shapes are observed. At low photo-excitation rates, voltammograms are S-shaped, indicating the onset of a voltage-independent rate-limiting process associated with electron-hole-pair creation and/or annihilation. At high photo-excitation rates, voltammograms are superlinear in shape, indicating, for the voltage ranges studied here, a voltage-dependent rate-limiting process associated with surface electrochemical oxidation. As PEC etching proceeds, the thin film becomes rough at the nanoscale,more » and ultimately evolves into an ensemble of nanoparticles. As a result, this change in InGaN film volume and morphology leads to a characteristic dependence of PEC etch rate on time: an incubation time, followed by a rise, then a peak, then a slow decay.« less

  16. Photoelectrochemical etching of epitaxial InGaN thin films: Self-limited kinetics and nanostructuring

    SciTech Connect (OSTI)

    Xiao, Xiaoyin; Fischer, Arthur J.; Coltrin, Michael E.; Lu, Ping; Koleske, Daniel D.; Wang, George T.; Polsky, Ronen; Tsao, Jeffrey Y.

    2014-10-22

    We report here the characteristics of photoelectrochemical (PEC) etching of epitaxial InGaN semiconductor thin films using narrowband lasers with linewidth less than ~1 nm. In the initial stages of PEC etching, when the thin film is flat, characteristic voltammogram shapes are observed. At low photo-excitation rates, voltammograms are S-shaped, indicating the onset of a voltage-independent rate-limiting process associated with electron-hole-pair creation and/or annihilation. At high photo-excitation rates, voltammograms are superlinear in shape, indicating, for the voltage ranges studied here, a voltage-dependent rate-limiting process associated with surface electrochemical oxidation. As PEC etching proceeds, the thin film becomes rough at the nanoscale, and ultimately evolves into an ensemble of nanoparticles. As a result, this change in InGaN film volume and morphology leads to a characteristic dependence of PEC etch rate on time: an incubation time, followed by a rise, then a peak, then a slow decay.

  17. Process for making transition metal nitride whiskers

    DOE Patents [OSTI]

    Bamberger, Carlos E.

    1989-01-01

    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.

  18. Silicon nitride/silicon carbide composite powders

    DOE Patents [OSTI]

    Dunmead, Stephen D.; Weimer, Alan W.; Carroll, Daniel F.; Eisman, Glenn A.; Cochran, Gene A.; Susnitzky, David W.; Beaman, Donald R.; Nilsen, Kevin J.

    1996-06-11

    Prepare silicon nitride-silicon carbide composite powders by carbothermal reduction of crystalline silica powder, carbon powder and, optionally, crystalline silicon nitride powder. The crystalline silicon carbide portion of the composite powders has a mean number diameter less than about 700 nanometers and contains nitrogen. The composite powders may be used to prepare sintered ceramic bodies and self-reinforced silicon nitride ceramic bodies.

  19. Process for making transition metal nitride whiskers

    DOE Patents [OSTI]

    Bamberger, C.E.

    1988-04-12

    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.

  20. Structural studies of magnesium nitride fluorides by powder neutron diffraction

    SciTech Connect (OSTI)

    Brogan, Michael A.; Hughes, Robert W.; Smith, Ronald I.; Gregory, Duncan H.

    2012-01-15

    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.

  1. The Hardest Superconducting Metal Nitride

    SciTech Connect (OSTI)

    Wang, Shanmin; Antonio, Daniel; Yu, Xiaohui; Zhang, Jianzhong; Cornelius, Andrew L.; He, Duanwei; Zhao, Yusheng

    2015-09-03

    Transition–metal (TM) nitrides are a class of compounds with a wide range of properties and applications. Hard superconducting nitrides are of particular interest for electronic applications under working conditions such as coating and high stress (e.g., electromechanical systems). However, most of the known TM nitrides crystallize in the rock–salt structure, a structure that is unfavorable to resist shear strain, and they exhibit relatively low indentation hardness, typically in the range of 10–20 GPa. Here, we report high–pressure synthesis of hexagonal δ–MoN and cubic γ–MoN through an ion–exchange reaction at 3.5 GPa. The final products are in the bulk form with crystallite sizes of 50 – 80 μm. Based on indentation testing on single crystals, hexagonal δ–MoN exhibits excellent hardness of ~30 GPa, which is 30% higher than cubic γ–MoN (~23 GPa) and is so far the hardest among the known metal nitrides. The hardness enhancement in hexagonal phase is attributed to extended covalently bonded Mo–N network than that in cubic phase. The measured superconducting transition temperatures for δ–MoN and cubic γ–MoN are 13.8 and 5.5 K, respectively, in good agreement with previous measurements.

  2. The Hardest Superconducting Metal Nitride

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

    Wang, Shanmin; Antonio, Daniel; Yu, Xiaohui; Zhang, Jianzhong; Cornelius, Andrew L.; He, Duanwei; Zhao, Yusheng

    2015-09-03

    Transitionmetal (TM) nitrides are a class of compounds with a wide range of properties and applications. Hard superconducting nitrides are of particular interest for electronic applications under working conditions such as coating and high stress (e.g., electromechanical systems). However, most of the known TM nitrides crystallize in the rocksalt structure, a structure that is unfavorable to resist shear strain, and they exhibit relatively low indentation hardness, typically in the range of 1020 GPa. Here, we report highpressure synthesis of hexagonal ?MoN and cubic ?MoN through an ionexchange reaction at 3.5 GPa. The final products are in the bulk form withmorecrystallite sizes of 50 80 ?m. Based on indentation testing on single crystals, hexagonal ?MoN exhibits excellent hardness of ~30 GPa, which is 30% higher than cubic ?MoN (~23 GPa) and is so far the hardest among the known metal nitrides. The hardness enhancement in hexagonal phase is attributed to extended covalently bonded MoN network than that in cubic phase. The measured superconducting transition temperatures for ?MoN and cubic ?MoN are 13.8 and 5.5 K, respectively, in good agreement with previous measurements.less

  3. P-type gallium nitride

    DOE Patents [OSTI]

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

    1997-08-12

    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.

  4. P-type gallium nitride

    DOE Patents [OSTI]

    Rubin, Michael; Newman, Nathan; Fu, Tracy; Ross, Jennifer; Chan, James

    1997-01-01

    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.degree. 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.

  5. The Hardest Superconducting Metal Nitride

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

    Wang, Shanmin; Antonio, Daniel; Yu, Xiaohui; Zhang, Jianzhong; Cornelius, Andrew L.; He, Duanwei; Zhao, Yusheng

    2015-09-03

    Transition–metal (TM) nitrides are a class of compounds with a wide range of properties and applications. Hard superconducting nitrides are of particular interest for electronic applications under working conditions such as coating and high stress (e.g., electromechanical systems). However, most of the known TM nitrides crystallize in the rock–salt structure, a structure that is unfavorable to resist shear strain, and they exhibit relatively low indentation hardness, typically in the range of 10–20 GPa. Here, we report high–pressure synthesis of hexagonal δ–MoN and cubic γ–MoN through an ion–exchange reaction at 3.5 GPa. The final products are in the bulk form withmore » crystallite sizes of 50 – 80 μm. Based on indentation testing on single crystals, hexagonal δ–MoN exhibits excellent hardness of ~30 GPa, which is 30% higher than cubic γ–MoN (~23 GPa) and is so far the hardest among the known metal nitrides. The hardness enhancement in hexagonal phase is attributed to extended covalently bonded Mo–N network than that in cubic phase. The measured superconducting transition temperatures for δ–MoN and cubic γ–MoN are 13.8 and 5.5 K, respectively, in good agreement with previous measurements.« less

  6. Nitride based quantum well light-emitting devices having improved current injection efficiency

    DOE Patents [OSTI]

    Tansu, Nelson; Zhao, Hongping; Liu, Guangyu; Arif, Ronald

    2014-12-09

    A III-nitride based device provides improved current injection efficiency by reducing thermionic carrier escape at high current density. The device includes a quantum well active layer and a pair of multi-layer barrier layers arranged symmetrically about the active layer. Each multi-layer barrier layer includes an inner layer abutting the active layer; and an outer layer abutting the inner layer. The inner barrier layer has a bandgap greater than that of the outer barrier layer. Both the inner and the outer barrier layer have bandgaps greater than that of the active layer. InGaN may be employed in the active layer, AlInN, AlInGaN or AlGaN may be employed in the inner barrier layer, and GaN may be employed in the outer barrier layer. Preferably, the inner layer is thin relative to the other layers. In one embodiment the inner barrier and active layers are 15 .ANG. and 24 .ANG. thick, respectively.

  7. Could Aluminum Nitride Produce Quantum Bits?

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

    Home » News & Publications » NERSC News » Science News » Could Aluminum Nitride Produce Quantum Bits? Could Aluminum Nitride Produce Quantum Bits? After running simulations at NERSC researchers believe it's possible May 2, 2016 Linda Vu, lvu@lbl.gov, 510.495.2402 Graphical Abstract AlN Sci Rep no logo cropped This graphic illustrates an engineered nitrogen vacancy in aluminum nitride. Quantum computers have the potential to break common cryptography techniques, search huge datasets and

  8. Light-Emitting Diodes on Semipolar Bulk Gallium Nitride Substrate...

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

    Light-Emitting Diodes on Semipolar Bulk Gallium Nitride Substrate Light-Emitting Diodes on Semipolar Bulk Gallium Nitride Substrate Presenter: Arpan Chakraborty, Soraa Inc. This ...

  9. Boron nitride ablation studies in arc jet facilities (Conference...

    Office of Scientific and Technical Information (OSTI)

    Conference: Boron nitride ablation studies in arc jet facilities Citation Details In-Document Search Title: Boron nitride ablation studies in arc jet facilities You are ...

  10. Uranium Nitride: Enabling New Applications for TRISO Fuel Particles...

    Office of Scientific and Technical Information (OSTI)

    Uranium Nitride: Enabling New Applications for TRISO Fuel Particles Citation Details In-Document Search Title: Uranium Nitride: Enabling New Applications for TRISO Fuel Particles ...

  11. Epitaxial ternary nitride thin films prepared by a chemical solution...

    Office of Scientific and Technical Information (OSTI)

    Epitaxial ternary nitride thin films prepared by a chemical solution method Citation Details In-Document Search Title: Epitaxial ternary nitride thin films prepared by a chemical ...

  12. Nanostructure, Chemistry and Crystallography of Iron Nitride...

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

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

  13. Silicon nitride having a high tensile strength

    DOE Patents [OSTI]

    Pujari, Vimal K.; Tracey, Dennis M.; Foley, Michael R.; Paille, Norman I.; Pelletier, Paul J.; Sales, Lenny C.; Willkens, Craig A.; Yeckley, Russell L.

    1998-01-01

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

  14. Nitrided Metallic Bipolar Plates | Department of Energy

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

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

  15. Method of preparation of uranium nitride

    DOE Patents [OSTI]

    Kiplinger, Jaqueline Loetsch; Thomson, Robert Kenneth James

    2013-07-09

    Method for producing terminal uranium nitride complexes comprising providing a suitable starting material comprising uranium; oxidizing the starting material with a suitable oxidant to produce one or more uranium(IV)-azide complexes; and, sufficiently irradiating the uranium(IV)-azide complexes to produce the terminal uranium nitride complexes.

  16. Molten-Salt-Based Growth of Group III Nitrides

    DOE Patents [OSTI]

    Waldrip, Karen E.; Tsao, Jeffrey Y.; Kerley, Thomas M.

    2008-10-14

    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.

  17. Hard carbon nitride and method for preparing same

    DOE Patents [OSTI]

    Haller, E.E.; Cohen, M.L.; Hansen, W.L.

    1992-05-05

    Novel crystalline [alpha](silicon nitride-like)-carbon nitride and [beta](silicon nitride-like)-carbon nitride are formed by sputtering carbon in the presence of a nitrogen atmosphere onto a single crystal germanium or silicon, respectively, substrate. 1 figure.

  18. Photodetectors using III-V nitrides

    DOE Patents [OSTI]

    Moustakas, Theodore D.; Misra, Mira

    1997-01-01

    A photodetector using a III-V nitride and having predetermined electrical properties is disclosed. The photodetector includes a substrate with interdigitated electrodes formed on its surface. The substrate has a sapphire base layer, a buffer layer formed from a III-V nitride and a single crystal III-V nitride film. The three layers are formed by electron cyclotron resonance microwave plasma-assisted molecular beam epitaxy (ECR-assisted MBE). Use of the ECR-assisted MBE process allows control and predetermination of the electrical properties of the photodetector.

  19. Photodetectors using III-V nitrides

    DOE Patents [OSTI]

    Moustakas, T.D.; Misra, M.

    1997-10-14

    A photodetector using a III-V nitride and having predetermined electrical properties is disclosed. The photodetector includes a substrate with interdigitated electrodes formed on its surface. The substrate has a sapphire base layer, a buffer layer formed from a III-V nitride and a single crystal III-V nitride film. The three layers are formed by electron cyclotron resonance microwave plasma-assisted molecular beam epitaxy (ECR-assisted MBE). Use of the ECR-assisted MBE process allows control and predetermination of the electrical properties of the photodetector. 24 figs.

  20. Method of nitriding refractory metal articles

    DOE Patents [OSTI]

    Tiegs, Terry N.; Holcombe, Cressie E.; Dykes, Norman L.; Omatete, Ogbemi O.; Young, Albert C.

    1994-01-01

    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.

  1. Silicon nitride having a high tensile strength

    DOE Patents [OSTI]

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

    1998-06-02

    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.

  2. Low temperature route to uranium nitride

    DOE Patents [OSTI]

    Burrell, Anthony K.; Sattelberger, Alfred P.; Yeamans, Charles; Hartmann, Thomas; Silva, G. W. Chinthaka; Cerefice, Gary; Czerwinski, Kenneth R.

    2009-09-01

    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.

  3. Method of nitriding refractory metal articles

    DOE Patents [OSTI]

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

    1994-03-15

    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.

  4. Silicon nitride reinforced with molybdenum disilicide

    DOE Patents [OSTI]

    Petrovic, John J.; Honnell, Richard E.

    1991-01-01

    Compositions of matter comprised of silicon nitride and molybdenum disilicide and methods of making the compositions, where the molybdenum disilicide is present in amounts ranging from about 5 to about 50 vol. %.

  5. Band anticrossing in dilute nitrides

    SciTech Connect (OSTI)

    Shan, W.; Yu, K.M.; Walukiewicz, W.; Wu, J.; Ager III, J.W.; Haller, E.E.

    2003-12-23

    Alloying III-V compounds with small amounts of nitrogen leads to dramatic reduction of the fundamental band-gap energy in the resulting dilute nitride alloys. The effect originates from an anti-crossing interaction between the extended conduction-band states and localized N states. The interaction splits the conduction band into two nonparabolic subbands. The downward shift of the lower conduction subband edge is responsible for the N-induced reduction of the fundamental band-gap energy. The changes in the conduction band structure result in significant increase in electron effective mass and decrease in the electron mobility, and lead to a large enhance of the maximum doping level in GaInNAs doped with group VI donors. In addition, a striking asymmetry in the electrical activation of group IV and group VI donors can be attributed to mutual passivation process through formation of the nearest neighbor group-IV donor nitrogen pairs.

  6. The Nitrogen-Nitride Anode.

    SciTech Connect (OSTI)

    Delnick, Frank M.

    2014-10-01

    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.

  7. Smooth cubic commensurate oxides on gallium nitride

    SciTech Connect (OSTI)

    Paisley, Elizabeth A.; Gaddy, Benjamin E.; LeBeau, James M.; Shelton, Christopher T.; Losego, Mark D.; Mita, Seiji; Collazo, Ramn; Sitar, Zlatko; Irving, Douglas L.; Maria, Jon-Paul; Biegalski, Michael D.; Christen, Hans M.

    2014-02-14

    Smooth, commensurate alloys of ?111?-oriented Mg{sub 0.52}Ca{sub 0.48}O (MCO) thin films are demonstrated on Ga-polar, c+ [0001]-oriented GaN by surfactant-assisted molecular beam epitaxy and pulsed laser deposition. These are unique examples of coherent cubic oxide|nitride interfaces with structural and morphological perfection. Metal-insulator-semiconductor capacitor structures were fabricated on n-type GaN. A comparison of leakage current density for conventional and surfactant-assisted growth reveals a nearly 100 reduction in leakage current density for the surfactant-assisted samples. HAADF-STEM images of the MCO|GaN interface show commensurate alignment of atomic planes with minimal defects due to lattice mismatch. STEM and DFT calculations show that GaN c/2 steps create incoherent boundaries in MCO over layers which manifest as two in-plane rotations and determine consequently the density of structural defects in otherwise coherent MCO. This new understanding of interfacial steps between HCP and FCC crystals identifies the steps needed to create globally defect-free heterostructures.

  8. Effect of hydrogen passivation on charge storage in silicon quantum dots embedded in silicon nitride film

    SciTech Connect (OSTI)

    Cho, Chang-Hee; Kim, Baek-Hyun; Kim, Tae-Wook; Park, Seong-Ju; Park, Nae-Man; Sung, Gun-Yong

    2005-04-04

    The effect of hydrogen passivation on the charge storage characteristics of two types of silicon nitride films containing silicon quantum dots (Si QDs) grown by SiH{sub 4}+N{sub 2} and SiH{sub 4}+NH{sub 3} plasma was investigated. The transmission electron microscope analysis and the capacitance-voltage measurement showed that the silicon nitride film grown by SiH{sub 4}+NH{sub 3} plasma has a lower interface trap density and a higher density of Si QDs compared to that grown by SiH{sub 4}+N{sub 2} plasma. It was also found that the charge retention characteristics in the Si QDs were greatly enhanced in the samples grown by means of SiH{sub 4}+NH{sub 3} plasma, due to the hydrogen passivation of the defects in the silicon nitride films by NH{sub 3} during the growth of the Si QDs.

  9. Red-emitting manganese-doped aluminum nitride phosphor

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

    Cherepy, Nerine J.; Payne, Stephen A.; Harvey, Nicholas M.; Aberg, Daniel; Seeley, Zachary M.; Holliday, Kiel S.; Tran, Ich C.; Zhou, Fei; Martinez, H. Paul; Demeyer, Jessica M.; et al

    2016-02-10

    Here, we report high efficiency luminescence with a manganese-doped aluminum nitride red-emitting phosphor under 254 nm excitation, as well as its excellent lumen maintenance in fluorescent lamp conditions, making it a candidate replacement for the widely deployed europium-doped yttria red phosphor. Solid-state reaction of aluminum nitride powders with manganese metal at 1900 °C, 10 atm N2 in a reducing environment results in nitrogen deficiency, as revealed diffuse reflectance spectra. When these powders are subsequently annealed in flowing nitrogen at 1650 °C, higher nitrogen content is recovered, resulting in white powders. Silicon was added to samples as an oxygen getter tomore » improve emission efficiency. NEXAFS spectra and DFT calculations indicate that the Mn dopant is divalent. From DFT calculations, the UV absorption band is proposed to be due to an aluminum vacancy coupled with oxygen impurity dopants, and Mn2+ is assumed to be closely associated with this site. In contrast with some previous reports, we find that the highest quantum efficiency with 254 nm excitation (Q.E. = 0.86 ± 0.14) is obtained in aluminum nitride with a low manganese doping level of 0.06 mol.%. The principal Mn2+ decay of 1.25 ms is assigned to non-interacting Mn sites, while additional components in the microsecond range appear with higher Mn doping, consistent with Mn clustering and resultant exchange coupling. Slower components are present in samples with low Mn doping, as well as strong afterglow, assigned to trapping on shallow traps followed by detrapping and subsequent trapping on Mn.« less

  10. Method of manufacture of atomically thin boron nitride

    DOE Patents [OSTI]

    Zettl, Alexander K

    2013-08-06

    The present invention provides a method of fabricating at least one single layer hexagonal boron nitride (h-BN). In an exemplary embodiment, the method includes (1) suspending at least one multilayer boron nitride across a gap of a support structure and (2) performing a reactive ion etch upon the multilayer boron nitride to produce the single layer hexagonal boron nitride suspended across the gap of the support structure. The present invention also provides a method of fabricating single layer hexagonal boron nitride. In an exemplary embodiment, the method includes (1) providing multilayer boron nitride suspended across a gap of a support structure and (2) performing a reactive ion etch upon the multilayer boron nitride to produce the single layer hexagonal boron nitride suspended across the gap of the support structure.

  11. Silicon nitride ceramic having high fatigue life and high toughness

    DOE Patents [OSTI]

    Yeckley, Russell L.

    1996-01-01

    A sintered silicon nitride ceramic comprising between about 0.6 mol % and about 3.2 mol % rare earth as rare earth oxide, and between about 85 w/o and about 95 w/o beta silicon nitride grains, wherein at least about 20% of the beta silicon nitride grains have a thickness of greater than about 1 micron.

  12. In vitro bio-functionality of gallium nitride sensors for radiation biophysics

    SciTech Connect (OSTI)

    Hofstetter, Markus; Howgate, John; Schmid, Martin; Schoell, Sebastian; Sachsenhauser, Matthias; Adiguezel, Denis; Stutzmann, Martin; Sharp, Ian D.; Thalhammer, Stefan

    2012-07-27

    Highlights: Black-Right-Pointing-Pointer Gallium nitride based sensors show promising characteristics to monitor cellular parameters. Black-Right-Pointing-Pointer Cell growth experiments reveal excellent biocompatibiltiy of the host GaN material. Black-Right-Pointing-Pointer We present a biofunctionality assay using ionizing radiation. Black-Right-Pointing-Pointer DNA repair is utilized to evaluate material induced alterations in the cellular behavior. Black-Right-Pointing-Pointer GaN shows no bio-functional influence on the cellular environment. -- Abstract: There is an increasing interest in the integration of hybrid bio-semiconductor systems for the non-invasive evaluation of physiological parameters. High quality gallium nitride and its alloys show promising characteristics to monitor cellular parameters. Nevertheless, such applications not only request appropriate sensing capabilities but also the biocompatibility and especially the biofunctionality of materials. Here we show extensive biocompatibility studies of gallium nitride and, for the first time, a biofunctionality assay using ionizing radiation. Analytical sensor devices are used in medical settings, as well as for cell- and tissue engineering. Within these fields, semiconductor devices have increasingly been applied for online biosensing on a cellular and tissue level. Integration of advanced materials such as gallium nitride into these systems has the potential to increase the range of applicability for a multitude of test devices and greatly enhance sensitivity and functionality. However, for such applications it is necessary to optimize cell-surface interactions and to verify the biocompatibility of the semiconductor. In this work, we present studies of mouse fibroblast cell activity grown on gallium nitride surfaces after applying external noxa. Cell-semiconductor hybrids were irradiated with X-rays at air kerma doses up to 250 mGy and the DNA repair dynamics, cell proliferation, and cell growth dynamics of adherent cells were compared to control samples. The impact of ionizing radiation on DNA, along with the associated cellular repair mechanisms, is well characterized and serves as a reference tool for evaluation of substrate effects. The results indicate that gallium nitride does not require specific surface treatments to ensure biocompatibility and suggest that cell signaling is not affected by micro-environmental alterations arising from gallium nitride-cell interactions. The observation that gallium nitride provides no bio-functional influence on the cellular environment confirms that this material is well suited for future biosensing applications without the need for additional chemical surface modification.

  13. Silicon-nitride and metal composite

    DOE Patents [OSTI]

    Landingham, R.L.; Huffsmith, S.A.

    A composite and a method for bonding the composite are described. The composite includes a ceramic portion of silicon nitride, a refractory metal portion and a layer of MoSi/sub 2/ indirectly bonding the composite together. The method includes contacting the layer of MoSi/sub 2/ with a surface of the silicon nitride and with a surface of the metal; heating the layer to a temperature below 1400/sup 0/C; and, simultaneously, compressing the layer such that the contacting is with a pressure of at least 30 MPa. This composite overcomes useful life problems in the fabrication of parts for a helical expander for use in power generation.

  14. Silicon-nitride and metal composite

    DOE Patents [OSTI]

    Landingham, Richard L.; Huffsmith, Sarah A.

    1981-01-01

    A composite and a method for bonding the composite. The composite includes a ceramic portion of silicon nitride, a refractory metal portion and a layer of MoSi.sub.2 indirectly bonding the composite together. The method includes contacting the layer of MoSi.sub.2 with a surface of the silicon nitride and with a surface of the metal; heating the layer to a temperature below 1400.degree. C.; and, simultaneously with the heating, compressing the layer such that the contacting is with a pressure of at least 30 MPa. This composite overcomes useful life problems in the fabrication of parts for a helical expander for use in power generation.

  15. Boron nitride solid state neutron detector

    DOE Patents [OSTI]

    Doty, F. Patrick

    2004-04-27

    The present invention describes an apparatus useful for detecting neutrons, and particularly for detecting thermal neutrons, while remaining insensitive to gamma radiation. Neutrons are detected by direct measurement of current pulses produced by an interaction of the neutrons with hexagonal pyrolytic boron nitride.

  16. Titanium nitride electrodes for thermoelectric generators

    DOE Patents [OSTI]

    Novak, Robert F.; Schmatz, Duane J.; Hunt, Thomas K.

    1987-12-22

    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.

  17. Solar cell with a gallium nitride electrode

    DOE Patents [OSTI]

    Pankove, Jacques I.

    1979-01-01

    A solar cell which comprises a body of silicon having a P-N junction therein with a transparent conducting N-type gallium nitride layer as an ohmic contact on the N-type side of the semiconductor exposed to solar radiation.

  18. Silicon nitride having a high tensile strength

    DOE Patents [OSTI]

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

    1996-11-05

    A silicon nitride ceramic is disclosed comprising: (a) inclusions no greater than 25 microns in length, (b) agglomerates no greater than 20 microns in diameter, and (c) a surface finish of less than about 8 microinches, said ceramic having a four-point flexural strength of at least about 900 MPa. 4 figs.

  19. Silicon nitride having a high tensile strength

    DOE Patents [OSTI]

    Pujari, Vimal K.; Tracey, Dennis M.; Foley, Michael R.; Paille, Norman I.; Pelletier, Paul J.; Sales, Lenny C.; Willkens, Craig A.; Yeckley, Russell L.

    1996-01-01

    A silicon nitride ceramic comprising: a) inclusions no greater than 25 microns in length, b) agglomerates no greater than 20 microns in diameter, and c) a surface finish of less than about 8 microinches, said ceramic having a four-point flexural strength of at least about 900 MPa.

  20. Gallium nitride junction field-effect transistor

    DOE Patents [OSTI]

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

    1999-02-02

    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.

  1. Gallium nitride junction field-effect transistor

    DOE Patents [OSTI]

    Zolper, John C.; Shul, Randy J.

    1999-01-01

    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.

  2. Photodetectors using III-V nitrides

    DOE Patents [OSTI]

    Moustakas, Theodore D.

    1998-01-01

    A bandpass photodetector using a III-V nitride and having predetermined electrical properties. The bandpass photodetector detects electromagnetic radiation between a lower transition wavelength and an upper transition wavelength. That detector comprises two low pass photodetectors. The response of the two low pass photodetectors is subtracted to yield a response signal.

  3. Photodetectors using III-V nitrides

    DOE Patents [OSTI]

    Moustakas, T.D.

    1998-12-08

    A bandpass photodetector using a III-V nitride and having predetermined electrical properties is disclosed. The bandpass photodetector detects electromagnetic radiation between a lower transition wavelength and an upper transition wavelength. That detector comprises two low pass photodetectors. The response of the two low pass photodetectors is subtracted to yield a response signal. 24 figs.

  4. Intrinsic ferromagnetism in hexagonal boron nitride nanosheets

    SciTech Connect (OSTI)

    Si, M. S.; Gao, Daqiang E-mail: xueds@lzu.edu.cn; Yang, Dezheng; Peng, Yong; Zhang, Z. Y.; Xue, Desheng E-mail: xueds@lzu.edu.cn; Liu, Yushen; Deng, Xiaohui; Zhang, G. P.

    2014-05-28

    Understanding the mechanism of ferromagnetism in hexagonal boron nitride nanosheets, which possess only s and p electrons in comparison with normal ferromagnets based on localized d or f electrons, is a current challenge. In this work, we report an experimental finding that the ferromagnetic coupling is an intrinsic property of hexagonal boron nitride nanosheets, which has never been reported before. Moreover, we further confirm it from ab initio calculations. We show that the measured ferromagnetism should be attributed to the localized π states at edges, where the electron-electron interaction plays the role in this ferromagnetic ordering. More importantly, we demonstrate such edge-induced ferromagnetism causes a high Curie temperature well above room temperature. Our systematical work, including experimental measurements and theoretical confirmation, proves that such unusual room temperature ferromagnetism in hexagonal boron nitride nanosheets is edge-dependent, similar to widely reported graphene-based materials. It is believed that this work will open new perspectives for hexagonal boron nitride spintronic devices.

  5. Fabrication and characterization of hexagonal boron nitride powder by spray drying and calcining-nitriding technology

    SciTech Connect (OSTI)

    Shi Xiaoliang Wang Sheng; Yang Hua; Duan Xinglong; Dong Xuebin

    2008-09-15

    Hexagonal boron nitride (hBN) powder was fabricated prepared by the spray drying and calcining-nitriding technology. The effects of nitrided temperature on the phases, morphology and particle size distribution of hBN powder, were investigated. The synthesized powders were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), Fourier transformed infrared spectrum, ultraviolet-visible (UV-vis) spectrum and photoluminescence (PL) spectrum. UV-vis spectrum revealed that the product had one obvious band gap (4.7 eV) and PL spectrum showed that it had a visible emission at 457 nm ({lambda}{sub ex}=230 nm). FESEM image indicated that the particle size of the synthesized hBN was mainly in the range of 0.5-1.5 {mu}m in diameter, and 50-150 nm in thickness. The high-energy ball-milling process following 900 deg. C calcining process was very helpful to obtain fully crystallized hBN at lower temperature. - Graphical abstract: hBN powder was fabricated prepared by spray drying and calcining-nitriding technology. The results indicated that spray drying and calcining-nitriding technology assisted with high-energy ball-milling process following calcined process was a hopeful way to manufacture hBN powder with high crystallinity in industrial scale.

  6. Low-loss binder for hot pressing boron nitride

    DOE Patents [OSTI]

    Maya, Leon

    1991-01-01

    Borazine derivatives used as low-loss binders and precursors for making ceramic boron nitride structures. The derivative forms the same composition as the boron nitride starting material, thereby filling the voids with the same boron nitride material upon forming and hot pressing. The derivatives have a further advantage of being low in carbon thus resulting in less volatile byproduct that can result in bubble formation during pressing.

  7. Synthesis and characterization of nitrides of iridium and palladiums

    SciTech Connect (OSTI)

    Crowhurst, Jonathan C.; Goncharov, Alexander F.; Sadigh, B.; Zaug, J.M.; Aberg, D.; Meng, Yue; Prakapenka, Vitali B.

    2008-08-14

    We describe the synthesis of nitrides of iridium and palladium using the laser-heated diamond anvil cell. We have used the in situ techniques of x-ray powder diffraction and Raman scattering to characterize these compounds and have compared our experimental findings where possible to the results of first-principles theoretical calculations. We suggest that palladium nitride is isostructural with pyrite, while iridium nitride has a monoclinic symmetry and is isostructural with baddeleyite.

  8. Boron nitride ablation studies in arc jet facilities (Conference...

    Office of Scientific and Technical Information (OSTI)

    The use of boron nitride as an ablative material for antenna windows on high performance reentry vehicles necessitated an experimental study of its ablative behavior and thermal ...

  9. Light-Emitting Diodes on Semipolar Bulk Gallium Nitride Substrate

    Broader source: Energy.gov [DOE]

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

  10. Method for locating metallic nitride inclusions in metallic alloy ingots

    DOE Patents [OSTI]

    White, Jack C.; Traut, Davis E.; Oden, Laurance L.; Schmitt, Roman A.

    1992-01-01

    A method of determining the location and history of metallic nitride and/or oxynitride inclusions in metallic melts. The method includes the steps of labeling metallic nitride and/or oxynitride inclusions by making a coreduced metallic-hafnium sponge from a mixture of hafnium chloride and the chloride of a metal, reducing the mixed chlorides with magnesium, nitriding the hafnium-labeled metallic-hafnium sponge, and seeding the sponge to be melted with hafnium-labeled nitride inclusions. The ingots are neutron activated and the hafnium is located by radiometric means. Hafnium possesses exactly the proper metallurgical and radiochemical properties for this use.

  11. Design and Implementation of Silicon Nitride Valves for Heavy...

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

    Design and Implementation of Silicon Nitride Valves for Heavy Duty Diesel Engines Poster presentation at the 2007 Diesel Engine-Efficiency & Emissions Research Conference (DEER ...

  12. Local residual stress monitoring of aluminum nitride MEMS using...

    Office of Scientific and Technical Information (OSTI)

    micro-Raman spectroscopy This content will become publicly available on January 6, 2017 Title: Local residual stress monitoring of aluminum nitride MEMS using UV micro-Raman ...

  13. Design of defect spins in piezoelectric aluminum nitride for...

    Office of Scientific and Technical Information (OSTI)

    Design of defect spins in piezoelectric aluminum nitride for solid-state hybrid quantum technologies Citation Details In-Document Search Title: Design of defect spins in ...

  14. Molybdenum enhanced low-temperature deposition of crystalline silicon nitride

    DOE Patents [OSTI]

    Lowden, Richard A.

    1994-01-01

    A process for chemical vapor deposition of crystalline silicon nitride 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.

  15. Process for making boron nitride using sodium cyanide and boron

    DOE Patents [OSTI]

    Bamberger, Carlos E.

    1990-01-01

    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.

  16. Method for producing silicon nitride/silicon carbide composite

    DOE Patents [OSTI]

    Dunmead, Stephen D.; Weimer, Alan W.; Carroll, Daniel F.; Eisman, Glenn A.; Cochran, Gene A.; Susnitzky, David W.; Beaman, Donald R.; Nilsen, Kevin J.

    1996-07-23

    Silicon carbide/silicon nitride composites are prepared by carbothermal reduction of crystalline silica powder, carbon powder and optionally crsytalline silicon nitride powder. The crystalline silicon carbide portion of the composite has a mean number diameter less than about 700 nanometers and contains nitrogen.

  17. Nitriding of super alloys for enhancing physical properties

    DOE Patents [OSTI]

    Purohit, A.

    1984-06-25

    The invention teaches the improvement of certain super alloys by exposing the alloy to an atmosphere of elemental nitrogen at elevated temperatures in excess of 750/sup 0/C but less than 1150/sup 0/C for an extended duration, viz., by nitriding the surface of the alloy, to establish barrier nitrides of the order of 25 to 100 micrometers thickness. These barrier

  18. METHOD OF COATING GRAPHITE WITH STABLE METAL CARBIDES AND NITRIDES

    DOE Patents [OSTI]

    Gurinsky, D.H.

    1959-10-27

    A method is presented for forming protective stable nitride and carbide compounds on the surface of graphite. This is accomplished by contacting the graphite surface with a fused heavy liquid metal such as bismuth or leadbismuth containing zirconium, titanium, and hafnium dissolved or finely dispersed therein to form a carbide and nitride of at least one of the dissolved metals on the graphite surface.

  19. Process for producing ceramic nitrides anc carbonitrides and their precursors

    DOE Patents [OSTI]

    Brown, G.M.; Maya, L.

    1987-02-25

    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.

  20. Solitary pulse-on-demand production by optical injection locking of passively Q-switched InGaN diode laser near lasing threshold

    SciTech Connect (OSTI)

    Zeng, X. E-mail: dmitri.boiko@csem.ch; Stadelmann, T.; Grossmann, S.; Hoogerwerf, A. C.; Boko, D. L. E-mail: dmitri.boiko@csem.ch; Sulmoni, L.; Lamy, J.-M.; Grandjean, N.

    2015-02-16

    In this letter, we investigate the behavior of a Q-switched InGaN multi-section laser diode (MSLD) under optical injection from a continuous wave external cavity diode laser. We obtain solitary optical pulse generation when the slave MSLD is driven near free running threshold, and the peak output power is significantly enhanced with respect to free running configuration. When the slave laser is driven well above threshold, optical injection reduces the peak power. Using standard semiconductor laser rate equation model, we find that both power enhancement and suppression effects are the result of partial bleaching of the saturable absorber by externally injected photons.

  1. Monolithic integration of InGaN segments emitting in the blue, green, and red spectral range in single ordered nanocolumns

    SciTech Connect (OSTI)

    Albert, S.; Bengoechea-Encabo, A.; Sanchez-Garcia, M. A.; Calleja, E.

    2013-05-06

    This work reports on the selective area growth by plasma-assisted molecular beam epitaxy and characterization of InGaN/GaN nanocolumnar heterostructures. The optimization of the In/Ga and total III/V ratios, as well as the growth temperature, provides control on the emission wavelength, either in the blue, green, or red spectral range. An adequate structure tailoring and monolithic integration in a single nanocolumnar heterostructure of three InGaN portions emitting in the red-green-blue colors lead to white light emission.

  2. A monolithic white LED with an active region based on InGaN QWs separated by short-period InGaN/GaN superlattices

    SciTech Connect (OSTI)

    Tsatsulnikov, A. F. Lundin, W. V.; Sakharov, A. V.; Zavarin, E. E.; Usov, S. O.; Nikolaev, A. E.; Kryzhanovskaya, N. V.; Synitsin, M. A.; Sizov, V. S.; Zakgeim, A. L.; Mizerov, M. N.

    2010-06-15

    A new approach to development of effective monolithic white-light emitters is described based on using a short-period InGaN/GaN superlattice as a barrier layer in the active region of LED structures between InGaN quantum wells emitting in the blue and yellow-green spectral ranges. The optical properties of structures of this kind have been studied, and it is demonstrated that the use of such a superlattice makes it possible to obtain effective emission from the active region.

  3. Titanium nitride thin films for minimizing multipactoring

    DOE Patents [OSTI]

    Welch, Kimo M.

    1979-01-01

    Applying a thin film coating to the surface of a workpiece, in particular, applying a coating of titanium nitride to a klystron window by means of a crossed-field diode sputtering array. The array is comprised of a cohesive group of numerous small hollow electrically conducting cylinders and is mounted so that the open ends of the cylinders on one side of the group are adjacent a titanium cathode plate. The workpiece is mounted so as to face the open ends of the other side of the group. A magnetic field is applied to the array so as to be coaxial with the cylinders and a potential is applied across the cylinders and the cathode plate, the cylinders as an anode being positive with respect to the cathode plate. The cylinders, the cathode plate and the workpiece are situated in an atmosphere of nitrogen which becomes ionized such as by field emission because of the electric field between the cylinders and cathode plate, thereby establishing an anode-cathode discharge that results in sputtering of the titanium plate. The sputtered titanium coats the workpiece and chemically combines with the nitrogen to form a titanium nitride coating on the workpiece. Gas pressure, gas mixtures, cathode material composition, voltages applied to the cathode and anode, the magnetic field, cathode, anode and workpiece spacing, and the aspect ratio (ratio of length to inner diameter) of the anode cylinders, all may be controlled to provide consistent optimum thin film coatings of various compositions and thicknesses. Another facet of the disclosure is the coating of microwave components per se with titanium nitride to reduce multipactoring under operating conditions of the components.

  4. Stability analysis of zigzag boron nitride nanoribbons

    SciTech Connect (OSTI)

    Rai, Hari Mohan Late, Ravikiran; Saxena, Shailendra K.; Kumar, Rajesh; Sagdeo, Pankaj R.; Jaiswal, Neeraj K.; Srivastava, Pankaj

    2015-05-15

    We have explored the structural stability of bare and hydrogenated zigzag boron nitride nanoribbons (ZBNNRs). In order to investigate the structural stability, we calculate the cohesive energy for bare, one-edge and both edges H-terminated ZBNNRs with different widths. It is found that the ZBNNRs with width Nz=8 are energetically more favorable than the lower-width counterparts (Nz<8). Bare ZBNNRs have been found energetically most stable as compared to the edge terminated ribbons. Our analysis reveals that the structural stability is a function of ribbon-width and it is not affected significantly by the type of edge-passivation (one-edge or both-edges)

  5. Magnesium doping of boron nitride nanotubes

    DOE Patents [OSTI]

    Legg, Robert; Jordan, Kevin

    2015-06-16

    A method to fabricate boron nitride nanotubes incorporating magnesium diboride in their structure. In a first embodiment, magnesium wire is introduced into a reaction feed bundle during a BNNT fabrication process. In a second embodiment, magnesium in powder form is mixed into a nitrogen gas flow during the BNNT fabrication process. MgB.sub.2 yarn may be used for superconducting applications and, in that capacity, has considerably less susceptibility to stress and has considerably better thermal conductivity than these conventional materials when compared to both conventional low and high temperature superconducting materials.

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

    DOE Patents [OSTI]

    Wang, George T.; Li, Qiming; Creighton, J. Randall

    2010-03-02

    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.

  7. Hard and low friction nitride coatings and methods for forming the same

    DOE Patents [OSTI]

    Erdemir, Ali; Urgen, Mustafa; Cakir, Ali Fuat; Eryilmaz, Osman Levent; Kazmanli, Kursat; Keles, Ozgul

    2007-05-01

    An improved coating material possessing super-hard and low friction properties and a method for forming the same. The improved coating material includes the use of a noble metal or soft metal homogeneously distributed within a hard nitride material. The addition of small amounts of such metals into nitrides such as molybdenum nitride, titanium nitride, and chromium nitride results in as much as increasing of the hardness of the material as well as decreasing the friction coefficient and increasing the oxidation resistance.

  8. Cordierite silicon nitride filters. Final report

    SciTech Connect (OSTI)

    Sawyer, J.; Buchan, B.; Duiven, R.; Berger, M.; Cleveland, J.; Ferri, J.

    1992-02-01

    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.

  9. Conductive and robust nitride buffer layers on biaxially textured substrates

    DOE Patents [OSTI]

    Sankar, Sambasivan [Chicago, IL; Goyal, Amit [Knoxville, TN; Barnett, Scott A [Evanston, IL; Kim, Ilwon [Skokie, IL; Kroeger, Donald M [Knoxville, TN

    2009-03-31

    The present invention relates to epitaxial, electrically conducting and mechanically robust, cubic nitride buffer layers deposited epitaxially on biaxially textured substrates such as metals and alloys. The invention comprises of a biaxially textured substrate with epitaxial layers of nitrides. The invention also discloses a method to form such epitaxial layers using a high rate deposition method as well as without the use of forming gases. The invention further comprises epitaxial layers of oxides on the biaxially textured nitride layer. In some embodiments the article further comprises electromagnetic devices which may have superconducting properties.

  10. Silicon nitride protective coatings for silvered glass mirrors

    DOE Patents [OSTI]

    Tracy, C. Edwin; Benson, David K.

    1988-01-01

    A protective diffusion barrier for metalized mirror structures is provided by a layer or coating of silicon nitride which is a very dense, transparent, dielectric material that is impervious to water, alkali, and other impurities and corrosive substances that typically attack the metal layers of mirrors and cause degradation of the mirrors' reflectivity. The silicon nitride layer can be deposited on the substrate before metal deposition to stabilize the metal/substrate interface, and it can be deposited over the metal to encapsulate it and protect the metal from corrosion or other degradation. Mirrors coated with silicon nitride according to this invention can also be used as front surface mirrors.

  11. Silicon nitride protective coatings for silvered glass mirrors

    DOE Patents [OSTI]

    Tracy, C.E.; Benson, D.K.

    1984-07-20

    A protective diffusion barrier for metalized mirror structures is provided by a layer or coating of silicon nitride which is a very dense, transparent, dielectric material that is impervious to water, alkali, and other impurities and corrosive substances that typically attack the metal layers of mirrors and cause degradation of the mirrors' reflectivity. The silicon nitride layer can be deposited on the substrate prior to metal deposition thereon to stabilize the metal/substrate interface, and it can be deposited over the metal to encapsulate it and protect the metal from corrosion or other degradation. Mirrors coated with silicon nitride according to this invention can also be used as front surface mirrors.

  12. Nitriding of super alloys for enhancing physical properties

    DOE Patents [OSTI]

    Purohit, Ankur

    1986-01-01

    The invention teaches the improvement of certain super alloys by exposing the alloy to an atmosphere of elemental nitrogen at elevated temperatures in excess of 750.degree. C. but less than 1150.degree. C. for an extended duration, viz., by nitriding the surface of the alloy, to establish barrier nitrides of the order of 25-100 micrometers thickness. These barrier nitrides appear to shield the available oxidizing metallic species of the alloy for up to a sixfold improved resistance against oxidation and also appear to impede egress of surface dislocations for increased fatigue and creep strengths.

  13. Conductive and robust nitride buffer layers on biaxially textured substrates

    DOE Patents [OSTI]

    Sankar, Sambasivan; Goyal, Amit; Barnett, Scott A.; Kim, Ilwon; Kroeger, Donald M.

    2004-08-31

    The present invention relates to epitaxial, electrically conducting and mechanically robust, cubic nitride buffer layers deposited epitaxially on biaxially textured substrates such as metal and alloys. The invention comprises of a biaxially textured substrate with epitaxial layers of nitrides. The invention also discloses a method to form such epitaxial layers using a high rate deposition method as well as without the use of forming gases. The invention further comprises epitaxial layers of oxides on the biaxially textured nitride layers. In some embodiments the article further comprises electromagnetic devices which may be super conducting properties.

  14. High efficiency III-nitride light-emitting diodes

    DOE Patents [OSTI]

    Crawford, Mary; Koleske, Daniel; Cho, Jaehee; Zhu, Di; Noemaun, Ahmed; Schubert, Martin F; Schubert, E. Fred

    2013-05-28

    Tailored doping of barrier layers enables balancing of the radiative recombination among the multiple-quantum-wells in III-Nitride light-emitting diodes. This tailored doping enables more symmetric carrier transport and uniform carrier distribution which help to reduce electron leakage and thus reduce the efficiency droop in high-power III-Nitride LEDs. Mitigation of the efficiency droop in III-Nitride LEDs may enable the pervasive market penetration of solid-state-lighting technologies in high-power lighting and illumination.

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

    SciTech Connect (OSTI)

    2012-01-01

    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 todays 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.

  16. Vibronic fine structure in high-resolution x-ray absorption spectra from ion-bombarded boron nitride nanotubes

    SciTech Connect (OSTI)

    Petravic, Mladen; Peter, Robert; Varasanec, Marijana; Li Luhua; Chen Ying; Cowie, Bruce C. C.

    2013-05-15

    The authors have applied high-resolution near-edge x-ray absorption fine structure measurements around the nitrogen K-edge to study the effects of ion-bombardment on near-surface properties of boron nitride nanotubes. A notable difference has been observed between surface sensitive partial electron yield (PEY) and bulk sensitive total electron yield (TEY) fine-structure measurements. The authors assign the PEY fine structure to the coupling of excited molecular vibrational modes to electronic transitions in NO molecules trapped just below the surface. Oxidation resistance of the boron nitride nanotubes is significantly reduced by low energy ion bombardment, as broken B-N bonds are replaced by N-O bonds involving oxygen present in the surface region. In contrast to the PEY spectra, the bulk sensitive TEY measurements on as-grown samples do not exhibit any fine structure while the ion-bombarded samples show a clear vibronic signature of molecular nitrogen.

  17. Process for manufacture of semipermeable silicon nitride membranes

    DOE Patents [OSTI]

    Galambos, Paul Charles; Shul, Randy J.; Willison, Christi Gober

    2003-12-09

    A new class of semipermeable membranes, and techniques for their fabrication, have been developed. These membranes, formed by appropriate etching of a deposited silicon nitride layer, are robust, easily manufacturable, and compatible with a wide range of silicon micromachining techniques.

  18. Apparatus for silicon nitride precursor solids recovery

    DOE Patents [OSTI]

    Crosbie, Gary M.; Predmesky, Ronald L.; Nicholson, John M.

    1995-04-04

    Method and apparatus are provided for collecting reaction product solids entrained in a gaseous outflow from a reaction situs, wherein the gaseous outflow includes a condensable vapor. A condensate is formed of the condensable vapor on static mixer surfaces within a static mixer heat exchanger. The entrained reaction product solids are captured in the condensate which can be collected for further processing, such as return to the reaction situs. In production of silicon imide, optionally integrated into a production process for making silicon nitride caramic, wherein reactant feed gas comprising silicon halide and substantially inert carrier gas is reacted with liquid ammonia in a reaction vessel, silicon imide reaction product solids entrained in a gaseous outflow comprising residual carrier gas and vaporized ammonia can be captured by forming a condensate of the ammonia vapor on static mixer surfaces of a static mixer heat exchanger.

  19. Method for silicon nitride precursor solids recovery

    DOE Patents [OSTI]

    Crosbie, Gary M.; Predmesky, Ronald L.; Nicholson, John M.

    1992-12-15

    Method and apparatus are provided for collecting reaction product solids entrained in a gaseous outflow from a reaction situs, wherein the gaseous outflow includes a condensable vapor. A condensate is formed of the condensable vapor on static mixer surfaces within a static mixer heat exchanger. The entrained reaction product solids are captured in the condensate which can be collected for further processing, such as return to the reaction situs. In production of silicon imide, optionally integrated into a production process for making silicon nitride caramic, wherein reactant feed gas comprising silicon halide and substantially inert carrier gas is reacted with liquid ammonia in a reaction vessel, silicon imide reaction product solids entrained in a gaseous outflow comprising residual carrier gas and vaporized ammonia can be captured by forming a condensate of the ammonia vapor on static mixer surfaces of a static mixer heat exchanger.

  20. Process for preparing titanium nitride powder

    DOE Patents [OSTI]

    Bamberger, C.E.

    1988-06-17

    A process for making titanium nitride powder by reaction of titanium phosphates with sodium cyanide. The process of this invention may comprise mixing one or more phosphates of Ti with a cyanide salt in the absence of oxygen and heating to a temperature sufficient to cause reaction to occur. In the preferred embodiment the ratio of cyanide salt to Ti should be at least 2 which results in the major Ti-containing product being TiN rather than sodium titanium phosphate byproducts. The process is an improvement over prior processes since the byproducts are water soluble salts of sodium which can easily be removed from the preferred TiN product by washing. 2 tabs.

  1. Nitrogen Atom Transfer From High Valent Iron Nitrides

    SciTech Connect (OSTI)

    Johnson, Michael D.; Smith, Jeremy M.

    2015-10-14

    This report describes the synthesis and reactions of high valent iron nitrides. Organonitrogen compounds such as aziridines are useful species for organic synthesis, but there are few efficient methods for their synthesis. Using iron nitrides to catalytically access these species may allow for their synthesis in an energy-and atom-efficient manner. We have developed a new ligand framework to achieve these goals as well as providing a method for inducing previously unknown reactivity.

  2. Molybdenum enhanced low-temperature deposition of crystalline silicon nitride

    DOE Patents [OSTI]

    Lowden, R.A.

    1994-04-05

    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.

  3. Apparatus for the production of boron nitride nanotubes

    SciTech Connect (OSTI)

    Smith, Michael W; Jordan, Kevin

    2014-06-17

    An apparatus for the large scale production of boron nitride nanotubes comprising; a pressure chamber containing; a continuously fed boron containing target; a source of thermal energy preferably a focused laser beam; a cooled condenser; a source of pressurized nitrogen gas; and a mechanism for extracting boron nitride nanotubes that are condensed on or in the area of the cooled condenser from the pressure chamber.

  4. III-Nitride Nanowires: Emerging Materials for Lighting and Energy

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

    Applications | MIT-Harvard Center for Excitonics III-Nitride Nanowires: Emerging Materials for Lighting and Energy Applications March 20, 2012 at 3pm/36-428 George T. Wang Advanced Materials Science, Sandia National Laboratories Wang001_000 Abstract: Nanowires based on the III nitride (AlGaInN) materials system have attracted attention as potential nanoscale building blocks in LEDs, lasers, sensors, photovoltaics, and high power and high speed electronics. Compared to planar films,

  5. Uranium Nitride: Enabling New Applications for TRISO Fuel Particles

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Conference: Uranium Nitride: Enabling New Applications for TRISO Fuel Particles Citation Details In-Document Search Title: Uranium Nitride: Enabling New Applications for TRISO Fuel Particles Authors: Powers, Jeffrey J [1] ; Terrani, Kurt A [1] + Show Author Affiliations ORNL [ORNL Publication Date: 2013-01-01 OSTI Identifier: 1093735 DOE Contract Number: DE-AC05-00OR22725 Resource Type: Conference Resource Relation: Conference: 2013 LWR Fuel Performance

  6. Spherical boron nitride particles and method for preparing them

    DOE Patents [OSTI]

    Phillips, Jonathan; Gleiman, Seth S.; Chen, Chun-Ku

    2003-11-25

    Spherical and polyhedral particles of boron nitride and method of preparing them. Spherical and polyhedral particles of boron nitride are produced from precursor particles of hexagonal phase boron nitride suspended in an aerosol gas. The aerosol is directed to a microwave plasma torch. The torch generates plasma at atmospheric pressure that includes nitrogen atoms. The presence of nitrogen atoms is critical in allowing boron nitride to melt at atmospheric pressure while avoiding or at least minimizing decomposition. The plasma includes a plasma hot zone, which is a portion of the plasma that has a temperature sufficiently high to melt hexagonal phase boron nitride. In the hot zone, the precursor particles melt to form molten particles that acquire spherical and polyhedral shapes. These molten particles exit the hot zone, cool, and solidify to form solid particles of boron nitride with spherical and polyhedral shapes. The molten particles can also collide and join to form larger molten particles that lead to larger spherical and polyhedral particles.

  7. Facile synthesis of efficient photocatalytic tantalum nitride nanoparticles

    SciTech Connect (OSTI)

    Wang, Zheng; Wang, Jiangting; Hou, Jungang; Huang, Kai; Jiao, Shuqiang; Zhu, Hongmin

    2012-11-15

    Graphical abstract: Tantalum nitride nanoparticles as a visible-light-driven photocatalyst prepared by a novel homogeneously chemical reduction of tantalum pentachloride using sodium in liquid ammonia and the morphologies, visible-light photocatalytic properties and stability of tantalum nitride nanoparticles were investigated. Highlights: ? Tantalum nitride nanoparticles have been prepared by a homogeneously chemical reduction. ? The crystal structure of tantalum nitride was determined by Rietveld refinement and XRD patterns. ? The Tantalum nitride nanoparticle size was in the range of 2050 nm. ? Much high photocatalytic activities of Ta{sub 3}N{sub 5} nanoparticles were obtained under visible-light irradiation. -- Abstract: Tantalum nitride nanoparticles, as visible-light photocatalysts were synthesized by a two-step homogeneously chemical reduction without any polymers and templates. The well-crystallized Ta{sub 3}N{sub 5} nanoparticles with a range of 2050 nm in size have been characterized by a number of techniques, such as XRD, XPS, SEM, TEM, BET and UVVis spectrum. Most importantly, the Ta{sub 3}N{sub 5} nanoparticles with good stability exhibited higher photooxidation activities in the water splitting and degradation of methylene blue under visible light irradiation than bulk Ta{sub 3}N{sub 5} particles and commercial P25 TiO{sub 2}, demonstrating that Ta{sub 3}N{sub 5} nanoparticle is a promising candidate as a visible-light photocatalyst.

  8. Excitation dependent two-component spontaneous emission and ultrafast amplified spontaneous emission in dislocation-free InGaN nanowires

    SciTech Connect (OSTI)

    You, Guanjun; Zhang, Chunfeng; Xu, Jian; Guo, Wei; Bhattacharya, Pallab; Henderson, Ron

    2013-03-04

    Amplified spontaneous emission (ASE) at 456 nm from In{sub 0.2}Ga{sub 0.8}N nanowires grown on (001) silicon by catalyst-free molecular beam epitaxy was observed at room temperature under femtosecond excitation. The photoluminescence spectra below ASE threshold consist of two spontaneous emission bands centered at {approx}555 nm and {approx}480 nm, respectively, revealing the co-existence of deeply and shallowly localized exciton states in the nanowires. The ASE peak emerges from the 480 nm spontaneous emission band when the excitation density exceeds {approx}120 {mu}J/cm{sup 2}, indicating that optical gain arises from the radiative recombination of shallowly localized excitons in the nanowires. Time-resolved photoluminescence measurements revealed that the ASE process completes within 1.5 ps, suggesting a remarkably high stimulated emission recombination rate in one-dimensional InGaN nanowires.

  9. Influence of pH on the quantum-size-controlled photoelectrochemical etching of epitaxial InGaN quantum dots

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

    Xiao, Xiaoyin; Lu, Ping; Fischer, Arthur J.; Coltrin, Michael E.; Wang, George T.; Koleske, Daniel D.; Tsao, Jeffrey Y.

    2015-11-18

    Illumination by a narrow-band laser has been shown to enable photoelectrochemical (PEC) etching of InGaN thin films into quantum dots with sizes controlled by the laser wavelength. Here, we investigate and elucidate the influence of solution pH on such quantum-size-controlled PEC etch process. We find that although a pH above 5 is often used for PEC etching of GaN-based materials, oxides (In2O3 and/or Ga2O3) form which interfere with quantum dot formation. Furthermore, at pH below 3, however, oxide-free QDs with self-terminated sizes can be successfully realized.

  10. Influence of pH on the quantum-size-controlled photoelectrochemical etching of epitaxial InGaN quantum dots

    SciTech Connect (OSTI)

    Xiao, Xiaoyin; Lu, Ping; Fischer, Arthur J.; Coltrin, Michael E.; Wang, George T.; Koleske, Daniel D.; Tsao, Jeffrey Y.

    2015-11-18

    Illumination by a narrow-band laser has been shown to enable photoelectrochemical (PEC) etching of InGaN thin films into quantum dots with sizes controlled by the laser wavelength. Here, we investigate and elucidate the influence of solution pH on such quantum-size-controlled PEC etch process. We find that although a pH above 5 is often used for PEC etching of GaN-based materials, oxides (In2O3 and/or Ga2O3) form which interfere with quantum dot formation. Furthermore, at pH below 3, however, oxide-free QDs with self-terminated sizes can be successfully realized.

  11. Summer 2011 Intern Project- Jonathan Waltman | Center for Energy...

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

    High efficiency solar cells require multiple junctions optimized for different wavelengths, and indium gallium nitride (InGaN) has the potential to further improve the efficiency ...

  12. Silicon nitride/silicon carbide composite densified materials prepared using composite powders

    DOE Patents [OSTI]

    Dunmead, S.D.; Weimer, A.W.; Carroll, D.F.; Eisman, G.A.; Cochran, G.A.; Susnitzky, D.W.; Beaman, D.R.; Nilsen, K.J.

    1997-07-01

    Prepare silicon nitride-silicon carbide composite powders by carbothermal reduction of crystalline silica powder, carbon powder and, optionally, crystalline silicon nitride powder. The crystalline silicon carbide portion of the composite powders has a mean number diameter less than about 700 nanometers and contains nitrogen. The composite powders may be used to prepare sintered ceramic bodies and self-reinforced silicon nitride ceramic bodies.

  13. Fluorescent lighting with aluminum nitride phosphors

    DOE Patents [OSTI]

    Cherepy, Nerine J.; Payne, Stephen A.; Seeley, Zachary M.; Srivastava, Alok M.

    2016-05-10

    A fluorescent lamp includes a glass envelope; at least two electrodes connected to the glass envelope; mercury vapor and an inert gas within the glass envelope; and a phosphor within the glass envelope, wherein the phosphor blend includes aluminum nitride. The phosphor may be a wurtzite (hexagonal) crystalline structure Al.sub.(1-x)M.sub.xN phosphor, where M may be drawn from beryllium, magnesium, calcium, strontium, barium, zinc, scandium, yttrium, lanthanum, cerium, praseodymium, europium, gadolinium, terbium, ytterbium, bismuth, manganese, silicon, germanium, tin, boron, or gallium is synthesized to include dopants to control its luminescence under ultraviolet excitation. The disclosed Al.sub.(1-x)M.sub.xN:Mn phosphor provides bright orange-red emission, comparable in efficiency and spectrum to that of the standard orange-red phosphor used in fluorescent lighting, Y.sub.2O.sub.3:Eu. Furthermore, it offers excellent lumen maintenance in a fluorescent lamp, and does not utilize "critical rare earths," minimizing sensitivity to fluctuating market prices for the rare earth elements.

  14. Cooled silicon nitride stationary turbine vane risk reduction. Final report

    SciTech Connect (OSTI)

    Holowczak, John

    1999-12-31

    The purpose of this program was to reduce the technical risk factors for demonstration of air cooled silicon nitride turbine vanes. The effort involved vane prototype fabrication efforts at two U.S. based gas turbine grade silicon nitride component manufacturers. The efficacy of the cooling system was analyzed via a thermal time/temperature flow test technique previously at UTRC. By having multiple vendors work on parts fabrication, the chance of program success increased for producing these challenging components. The majority of the effort under this contract focused on developing methods for, and producing, the complex thin walled silicon nitride vanes. Components developed under this program will undergo engine environment testing within N00014-96-2-0014.

  15. Active Control of Nitride Plasmonic Dispersion in the Far Infrared.

    SciTech Connect (OSTI)

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

    2014-11-01

    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.

  16. Synthesis of uranium nitride and uranium carbide powder by carbothermic reduction

    SciTech Connect (OSTI)

    Dunwoody, J.T.; Stanek, C.R.; McClellan, K.J.; Voit, S.L.; Volz, H.M.; Hickman, R.R.

    2007-07-01

    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)

  17. Process for synthesizing titanium carbide, titanium nitride and titanium carbonitride

    DOE Patents [OSTI]

    Koc, Rasit; Glatzmaier, Gregory C.

    1995-01-01

    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.

  18. Process for producing wurtzitic or cubic boron nitride

    DOE Patents [OSTI]

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

    1992-04-28

    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.

  19. Process for synthesizing titanium carbide, titanium nitride and titanium carbonitride

    DOE Patents [OSTI]

    Koc, R.; Glatzmaier, G.C.

    1995-05-23

    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.

  20. Process for producing wurtzitic or cubic boron nitride

    DOE Patents [OSTI]

    Holt, J. Birch; Kingman, deceased, Donald D.; Bianchini, Gregory M.

    1992-01-01

    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.

  1. Process for producing amorphous and crystalline silicon nitride

    DOE Patents [OSTI]

    Morgan, Peter E. D.; Pugar, Eloise A.

    1985-01-01

    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.

  2. Process for producing amorphous and crystalline silicon nitride

    DOE Patents [OSTI]

    Morgan, P.E.D.; Pugar, E.A.

    1985-11-12

    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 C to about 1,200 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 C. 6 figs.

  3. Synthesis and Optimization of the Sintering Kinetics of Actinide Nitrides

    SciTech Connect (OSTI)

    Drryl P. Butt; Brian Jaques

    2009-03-31

    Research conducted for this NERI project has advanced the understanding and feasibility of nitride nuclear fuel processing. In order to perform this research, necessary laboratory infrastructure was developed; including basic facilities and experimental equipment. Notable accomplishments from this project include: the synthesis of uranium, dysprosium, and cerium nitrides using a novel, low-cost mechanical method at room temperature; the synthesis of phase pure UN, DyN, and CeN using thermal methods; and the sintering of UN and (Ux, Dy1-x)N (0.7 ≤ X ≤ 1) pellets from phase pure powder that was synthesized in the Advanced Materials Laboratory at Boise State University.

  4. Communication: Water on hexagonal boron nitride from diffusion Monte Carlo

    SciTech Connect (OSTI)

    Al-Hamdani, Yasmine S.; Ma, Ming; Michaelides, Angelos; Alf, Dario; Lilienfeld, O. Anatole von

    2015-05-14

    Despite a recent flurry of experimental and simulation studies, an accurate estimate of the interaction strength of water molecules with hexagonal boron nitride is lacking. Here, we report quantum Monte Carlo results for the adsorption of a water monomer on a periodic hexagonal boron nitride sheet, which yield a water monomer interaction energy of ?84 5 meV. We use the results to evaluate the performance of several widely used density functional theory (DFT) exchange correlation functionals and find that they all deviate substantially. Differences in interaction energies between different adsorption sites are however better reproduced by DFT.

  5. Methods for improved growth of group III nitride buffer layers

    DOE Patents [OSTI]

    Melnik, Yurity; Chen, Lu; Kojiri, Hidehiro

    2014-07-15

    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).

  6. Continuous Fiber Ceramic Composite (CFCC) Program: Gaseous Nitridation

    SciTech Connect (OSTI)

    R. Suplinskas G. DiBona; W. Grant

    2001-10-29

    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

  7. Process for producing ceramic nitrides and carbonitrides and their precursors

    DOE Patents [OSTI]

    Brown, Gilbert M.; Maya, Leon

    1988-01-01

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

  8. Lattice matched crystalline substrates for cubic nitride semiconductor growth

    DOE Patents [OSTI]

    Norman, Andrew G; Ptak, Aaron J; McMahon, William E

    2015-02-24

    Disclosed embodiments include methods of fabricating a semiconductor layer or device and devices fabricated thereby. The methods include, but are not limited to, providing a substrate having a cubic crystalline surface with a known lattice parameter and growing a cubic crystalline group III-nitride alloy layer on the cubic crystalline substrate by coincident site lattice matched epitaxy. The cubic crystalline group III-nitride alloy may be prepared to have a lattice parameter (a') that is related to the lattice parameter of the substrate (a). The group III-nitride alloy may be a cubic crystalline In.sub.xGa.sub.yAl.sub.1-x-yN alloy. The lattice parameter of the In.sub.xGa.sub.yAl.sub.1-x-yN or other group III-nitride alloy may be related to the substrate lattice parameter by (a')= 2(a) or (a')=(a)/ 2. The semiconductor alloy may be prepared to have a selected band gap.

  9. Impact of annealing temperature on the mechanical and electrical properties of sputtered aluminum nitride thin films

    SciTech Connect (OSTI)

    Gillinger, M.; Schneider, M.; Bittner, A.; Schmid, U.; Nicolay, P.

    2015-02-14

    Aluminium nitride (AlN) is a promising material for challenging sensor applications such as process monitoring in harsh environments (e.g., turbine exhaust), due to its piezoelectric properties, its high temperature stability and good thermal match to silicon. Basically, the operational temperature of piezoelectric materials is limited by the increase of the leakage current as well as by enhanced diffusion effects in the material at elevated temperatures. This work focuses on the characterization of aluminum nitride thin films after post deposition annealings up to temperatures of 1000 °C in harsh environments. For this purpose, thin film samples were temperature loaded for 2 h in pure nitrogen and oxygen gas atmospheres and characterized with respect to the film stress and the leakage current behaviour. The X-ray diffraction results show that AlN thin films are chemically stable in oxygen atmospheres for 2 h at annealing temperatures of up to 900 °C. At 1000 °C, a 100 nm thick AlN layer oxidizes completely. For nitrogen, the layer is stable up to 1000 °C. The activation energy of the samples was determined from leakage current measurements at different sample temperatures, in the range between 25 and 300 °C. Up to an annealing temperature of 700 °C, the leakage current in the thin film is dominated by Poole-Frenkel behavior, while at higher annealing temperatures, a mixture of different leakage current mechanisms is observed.

  10. Defect-Reduction Mechanism for Improving Radiative Efficiency in InGaN/GaN Light-Emitting Diodes using InGaN Underlayers

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

    Armstrong, Andrew M.; Bryant, Benjamin N.; Crawford, Mary H.; Koleske, Daniel D.; Lee, Stephen R.; Wierer, Jr., Jonathan J.

    2015-04-01

    The influence of a dilute InxGa1-xN (x~0.03) underlayer (UL) grown below a single In0.16Ga0.84N quantum well (SQW), within a light-emitting diode(LED), on the radiative efficiency and deep level defect properties was studied using differential carrier lifetime (DCL) measurements and deep level optical spectroscopy (DLOS). DCL measurements found that inclusion of the UL significantly improved LED radiative efficiency. At low current densities, the non-radiative recombination rate of the LED with an UL was found to be 3.9 times lower than theLED without an UL, while the radiative recombination rates were nearly identical. This, then, suggests that the improved radiative efficiency resultedmore » from reduced non-radiative defect concentration within the SQW. DLOS measurement found the same type of defects in the InGaN SQWs with and without ULs. However, lighted capacitance-voltage measurements of the LEDs revealed a 3.4 times reduction in a SQW-related near-mid-gap defect state for the LED with an UL. Furthermore, quantitative agreement in the reduction of both the non-radiative recombination rate (3.9×) and deep level density (3.4×) upon insertion of an UL corroborates deep level defect reduction as the mechanism for improved LED efficiency.« less

  11. Progress of nitride fuel cycle research for transmutation of minor actinides

    SciTech Connect (OSTI)

    Arai, Yasuo; Akabori, Mitsuo; Minato, Kazuo

    2007-07-01

    Recent progress of nitride fuel cycle research for transmutation of MA is summarized. Preparation of MA-bearing nitride pellets, such as (Np,Am)N, (Am,Pu)N and (Np,Pu,Am,Cm)N, was carried out. Irradiation behavior of U-free nitride fuel was investigated by the irradiation test of (Pu,Zr)N and PuN+TiN fuels, in which ZrN and TiN were added as a possible diluent material. Further, pyrochemical process of spent nitride fuel was developed by electrorefining in a molten chloride salt and subsequent re-nitridation of actinides in liquid Cd cathode electro-deposits. Nitride fuel cycle for transmutation of MA has been demonstrated in a laboratory scale by the experimental study with MA and Pu. (authors)

  12. Bright Lights and Even Brighter Ideas | Department of Energy

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

    and Even Brighter Ideas Bright Lights and Even Brighter Ideas July 3, 2013 - 2:04pm Addthis Kim Kisslinger, a researcher at Brookhaven Lab's Center for Functional Nanomaterials seen here with a focused-ion beam instrument, reduced the indium gallium nitride (InGaN) samples to a thickness of just 20 nanometers to prepare them for electron microscopy. | Photo courtesy of Brookhaven National Laboratory. Kim Kisslinger, a researcher at Brookhaven Lab's Center for Functional Nanomaterials seen here

  13. Epitaxial ternary nitride thin films prepared by a chemical solution method

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Epitaxial ternary nitride thin films prepared by a chemical solution method Citation Details In-Document Search Title: Epitaxial ternary nitride thin films prepared by a chemical solution method It is indispensable to use thin films for many technological applications. This is the first report of epitaxial growth of ternary nitride AMN2 films. Epitaxial tetragonal SrTiN2 films have been successfully prepared by a chemical solution approach,

  14. Boron-Nitride Nanotubes Show Potential in Cancer Treatment | Jefferson Lab

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

    Boron-Nitride Nanotubes Show Potential in Cancer Treatment 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 double the effectiveness of Irreversible Electroporation, a minimally invasive treatment for soft tissue tumors in the liver, lung, prostate, head and neck, kidney and pancreas. Although this research is in the very early stages, it could one day lead to

  15. HIGH-QUALITY, LOW-COST BULK GALLIUM NITRIDE SUBSTRATES GROWN BY THE

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

    ELECTROCHEMICAL SOLUTION GROWTH METHOD | Department of Energy HIGH-QUALITY, LOW-COST BULK GALLIUM NITRIDE SUBSTRATES GROWN BY THE ELECTROCHEMICAL SOLUTION GROWTH METHOD HIGH-QUALITY, LOW-COST BULK GALLIUM NITRIDE SUBSTRATES GROWN BY THE ELECTROCHEMICAL SOLUTION GROWTH METHOD MEMC Electronic Materials, Inc. - St. Peters, MO Efficient manufacturing of gallium nitride (GaN) could reduce the cost of and improve the output for light-emitting diodes, solid-state lighting, laser displays, and other

  16. III-nitrides on oxygen- and zinc-face ZnO substrates (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect SciTech Connect Search Results Journal Article: III-nitrides on oxygen- and zinc-face ZnO substrates Citation Details In-Document Search Title: III-nitrides on oxygen- and zinc-face ZnO substrates The characteristics of III-nitrides grown on zinc- and oxygen-face ZnO by plasma-assisted molecular beam epitaxy were investigated. The reflection high-energy electron diffraction pattern indicates formation of a cubic phase at the interface between III-nitride and both Zn- and

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

    DOE Patents [OSTI]

    Hui, Rongqing; Jiang,Hong-Xing; Lin, Jing-Yu

    2008-03-18

    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.

  18. The phase diagram and hardness of carbon nitrides

    SciTech Connect (OSTI)

    Dong, Huafeng; Oganov, Artem R.; Zhu, Qiang; Zhu, Qiang; Qian, Guang-Rui

    2015-05-06

    Novel superhard materials, especially those with superior thermal and chemical stability, are needed to replace diamond. Carbon nitrides (C-N), which are likely to possess these characteristics and have even been expected to be harder than diamond, are excellent candidates. Here we report three new superhard and thermodynamically stable carbon nitride phases. Based on a systematic evolutionary structure searches, we report a complete phase diagram of the C-N system at 0–300 GPa and analyze the hardest metastable structures. Surprisingly, we find that at zero pressure, the earlier proposed graphitic-C3N4 structure (P6-bar m2) is dynamically unstable, and we find the lowest-energy structure based on s-triazine unit and s-heptazine unit.

  19. Identification of microscopic hole-trapping mechanisms in nitride semiconductors

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

    John L. Lyons; Krishnaswamy, Karthik; Luke Gordon; Van de Walle, Chris G.; Anderson, Janotti

    2015-12-17

    Hole trapping has been observed in nitride heterostructure devices, where the Fermi level is in the vicinity of the valence-band maximum. Using hybrid density functional calculations, we examine microscopic mechanisms for hole trapping in GaN and AlN. In a defect-free material, hole trapping does not spontaneously occur, but trapping can occur in the vicinity of impurities, such as C-a common unintentional impurity in nitrides. As a result, using Schrödinger-Poisson simulations, we assess the effects of C-derived hole traps on N-face high-electron mobility transistors, which we find to be more detrimental than the previously proposed interface traps.

  20. The phase diagram and hardness of carbon nitrides

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

    Dong, Huafeng; Oganov, Artem R.; Zhu, Qiang; Qian, Guang-Rui

    2015-05-06

    Novel superhard materials, especially those with superior thermal and chemical stability, are needed to replace diamond. Carbon nitrides (C-N), which are likely to possess these characteristics and have even been expected to be harder than diamond, are excellent candidates. Here we report three new superhard and thermodynamically stable carbon nitride phases. Based on a systematic evolutionary structure searches, we report a complete phase diagram of the C-N system at 0–300 GPa and analyze the hardest metastable structures. Surprisingly, we find that at zero pressure, the earlier proposed graphitic-C3N4 structure (P6-bar m2) is dynamically unstable, and we find the lowest-energy structuremore » based on s-triazine unit and s-heptazine unit.« less

  1. Method of preparing uranium nitride or uranium carbonitride bodies

    DOE Patents [OSTI]

    Wilhelm, Harley A.; McClusky, James K.

    1976-04-27

    Sintered uranium nitride or uranium carbonitride bodies having a controlled final carbon-to-uranium ratio are prepared, in an essentially continuous process, from U.sub.3 O.sub.8 and carbon by varying the weight ratio of carbon to U.sub.3 O.sub.8 in the feed mixture, which is compressed into a green body and sintered in a continuous heating process under various controlled atmospheric conditions to prepare the sintered bodies.

  2. Electrically Integrated Graphene on Silicon Nitride Liquid Flow Cells for

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

    High Resolution TEM - Energy Innovation Portal Energy Storage Energy Storage Advanced Materials Advanced Materials Find More Like This Return to Search Electrically Integrated Graphene on Silicon Nitride Liquid Flow Cells for High Resolution TEM Lawrence Berkeley National Laboratory Contact LBL About This Technology Technology Marketing Summary A Berkeley Lab research team led by Paul Alivisatos and Alex Zettl has developed liquid flow cells providing unprecedented resolution and contrast in

  3. Tunable electrical and optical properties of hafnium nitride thin films

    SciTech Connect (OSTI)

    Farrell, I. L.; Reeves, R. J.; Preston, A. R. H.; Ludbrook, B. M.; Ruck, B. J.; Downes, J. E.; Durbin, S. M.

    2010-02-15

    We report structural and electronic properties of epitaxial hafnium nitride films grown on MgO by plasma-assisted pulsed laser deposition. The electronic structure measured using soft x-ray absorption and emission spectroscopy is in excellent agreement with the results of a band structure calculation. We show that by varying the growth conditions we can extend the films' reflectance further toward the UV, and we relate this observation to the electronic structure.

  4. Use of silicon in liquid sintered silicon nitrides and sialons

    DOE Patents [OSTI]

    Raj, Rishi; Baik, Sunggi

    1984-12-11

    This invention relates to the production of improved high density nitrogen based ceramics by liquid-phase densification of silicon nitride or a compound of silicon-nitrogen-oxygen-metal, e.g. a sialon. In the process and compositions of the invention minor amounts of finely divided silicon are employed together with the conventional liquid phase producing additives to enhance the densification of the resultant ceramic.

  5. Use of silicon in liquid sintered silicon nitrides and sialons

    DOE Patents [OSTI]

    Raj, R.; Baik, S.

    1984-12-11

    This invention relates to the production of improved high density nitrogen based ceramics by liquid-phase densification of silicon nitride or a compound of silicon-nitrogen-oxygen-metal, e.g. a sialon. In the process and compositions of the invention minor amounts of finely divided silicon are employed together with the conventional liquid phase producing additives to enhance the densification of the resultant ceramic. 4 figs.

  6. BES Web Highlight: Single-mode gallium nitride nanowire lasers

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

    Web Highlight: Single-mode gallium nitride nanowire lasers - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Fuel Cycle Defense

  7. Nitridation under ammonia of high surface area vanadium aerogels

    SciTech Connect (OSTI)

    Merdrignac-Conanec, Odile [Laboratoire Verres et Ceramiques, UMR CNRS 6512, Institut de Chimie de Rennes, Universite de Rennes 1, Campus de Beaulieu, F-35042 Rennes Cedex (France)]. E-mail: odile.merdrignac@univ-rennes1.fr; El Badraoui, Khadija [Laboratoire Verres et Ceramiques, UMR CNRS 6512, Institut de Chimie de Rennes, Universite de Rennes 1, Campus de Beaulieu, F-35042 Rennes Cedex (France); L'Haridon, Paul [Laboratoire Verres et Ceramiques, UMR CNRS 6512, Institut de Chimie de Rennes, Universite de Rennes 1, Campus de Beaulieu, F-35042 Rennes Cedex (France)

    2005-01-15

    Vanadium pentoxide gels have been obtained from decavanadic acid prepared by ion exchange on a resin from ammonium metavanadate solution. The progressive removal of water by solvent exchange in supercritical conditions led to the formation of high surface area V{sub 2}O{sub 5}, 1.6H{sub 2}O aerogels. Heat treatment under ammonia has been performed on these aerogels in the 450-900 deg. C temperature range. The oxide precursors and oxynitrides have been characterized by XRD, SEM, TGA, BET. Nitridation leads to divided oxynitride powders in which the fibrous structure of the aerogel is maintained. The use of both very low heating rates and high surface area aerogel precursors allows a higher rate and a lower threshold of nitridation than those reported in previous works. By adjusting the nitridation temperature, it has been possible to prepare oxynitrides with various nitrogen enrichment and vanadium valency states. Whatever the V(O,N) composition, the oxidation of the oxynitrides in air starts between 250 and 300 deg. C. This determines their potential use as chemical gas sensors at a maximum working temperature of 250 deg. C.

  8. FY07 LDRD Final Report Synthesis under High Pressure and Temperature of New Metal Nitrides

    SciTech Connect (OSTI)

    Crowhurst, J C; Sadigh, B; Aberg, D; Zaug, J M; Goncharov, A F

    2008-09-23

    The original aim of this LDRD was to determine with unprecedented precision the melting curve of iron to geophysically relevant pressures. In the course of developing much of the technology and techniques required to obtain this information we have encountered and studied novel chemical reactions some of whose products are stable or metastable under ambient conditions. Specifically we have synthesized nitrides of the platinum group metals including platinum, iridium, and palladium. We have also carried out in depth first principles theoretical investigations into the nature of these materials. We believed that the scientific impact of continuing this work would be greater than that of the original goals of this project. Indeed the work has led to a number of high profile publications with additional publications in preparation. While nitrides of the transition metals are generally of tremendous technological importance, those of the noble metals in particular have enjoyed much experimental and theoretical attention in the very short time since they were first synthesized. The field was and clearly remains open for further study. While the scientific motivation for this research is different from that originally proposed, many of the associated methods in which we have now gained experience are similar or identical. These include use of the diamond anvil cell combined with technologies to generate high temperatures, the in-situ technique of Raman scattering using our purpose-built, state-of-the-art system, analytical techniques for determining the composition of recovered samples such as x-ray photoelectron spectroscopy, and finally synchrotron-based techniques such as x-ray diffraction for structural and equation of state determinations. Close interactions between theorists and experimentalists has and will continue to allow our group to rapidly and reliably interpret complicated results on the structure and dynamics of these compounds and also additional novel materials. Although the purely scientific dividends of this project have been substantial, there remains the possibility of a technological application--now that nitrides with likely desirable properties have been shown to exist, large-scale synthesis techniques can be considered.

  9. Protections: Sampling

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

    Protections: Sampling Protections: Sampling Protection #3: Sampling for known and unexpected contaminants August 1, 2013 Monitoring stormwater in Los Alamos Canyon Monitoring stormwater in Los Alamos Canyon The Environmental Sampling Board, a key piece of the Strategy, ensures that LANL collects relevant and appropriate data to answer questions about the protection of human and environmental health, and to satisfy regulatory requirements. LANL must demonstrate the data are technically justified

  10. Electrolysis of uranium nitride containing fission product elements (Mo, Pd, Nd) in a molten LiCl-KCl eutectic

    SciTech Connect (OSTI)

    Satoh, Takumi; Iwai, Takashi; Arai, Yasuo

    2007-07-01

    The electrolysis of burnup-simulated uranium nitride, UN, containing representative solid fission product elements (Mo, Pd, Nd) was investigated in the molten LiCl-KCl eutectic salt with 0.54 wt% UCl{sub 3} from the view point of application of pyrochemical reprocessing to nitride fuel cycle. It was found from cyclic voltammetry and anodic polarization curve measurement that anodic dissolution of UN began at about -0.75 V vs. Ag/AgCl reference electrode in all samples. After the electrolysis at the constant anodic potential of -0.65 {approx} -0.60 V vs. Ag/AgCl, most of UN was dissolved into LiCl- KCl as UCl{sub 3} at the anode, and U was recovered in the liquid Cd cathode in all samples. Further, Nd was dissolved into LiCl-KCl as NdCl{sub 3}, while Mo and Pd were not dissolved but remained at the anode. (authors)

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

    DOE Patents [OSTI]

    Raffetto, Mark; Bharathan, Jayesh; Haberern, Kevin; Bergmann, Michael; Emerson, David; Ibbetson, James; Li, Ting

    2012-01-03

    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.

  12. One step process for producing dense aluminum nitride and composites thereof

    DOE Patents [OSTI]

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

    1989-10-31

    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 1,000 atmospheres or higher. The process enables the production of aluminum nitride bodies to be formed directly in a mold of any desired shape.

  13. One step process for producing dense aluminum nitride and composites thereof

    DOE Patents [OSTI]

    Holt, J. Birch; Kingman, Donald D.; Bianchini, Gregory M.

    1989-01-01

    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.

  14. Analytical and Experimental Evaluation of Joining Silicon Carbide to Silicon Carbide and Silicon Nitride to Silicon Nitride for Advanced Heat Engine Applications Phase II

    SciTech Connect (OSTI)

    Sundberg, G.J.

    1994-01-01

    Techniques were developed to produce reliable silicon nitride to silicon nitride (NCX-5101) curved joins which were used to manufacture spin test specimens as a proof of concept to simulate parts such as a simple rotor. Specimens were machined from the curved joins to measure the following properties of the join interlayer: tensile strength, shear strength, 22 C flexure strength and 1370 C flexure strength. In parallel, extensive silicon nitride tensile creep evaluation of planar butt joins provided a sufficient data base to develop models with accurate predictive capability for different geometries. Analytical models applied satisfactorily to the silicon nitride joins were Norton's Law for creep strain, a modified Norton's Law internal variable model and the Monkman-Grant relationship for failure modeling. The Theta Projection method was less successful. Attempts were also made to develop planar butt joins of siliconized silicon carbide (NT230).

  15. Nitrided iron catalysts for the Fischer-Tropsch synthesis in the eighties

    SciTech Connect (OSTI)

    Anderson, R.B.

    1980-01-01

    Nitrided iron catalysts are active and durable and have an unusal selectivity. They do not produce significant amounts of wax, which should be advantageous in situations where gasoline is the desired product. The low yield of wax permits operation of nitrided iron in fluidized fixed-bed or entrained reactors at 230 to 255/sup 0/C. Conventional reduced iron catalysts in these reactors must be operated at about 325/sup 0/C to prevent formation of higher hydrocarbon that leads to agglomeration of the fluidized particles. At 325/sup 0/C carbon deposition and other processes leading to catalyst deterioration proceed rapidly. The yields of methane and ethane from nitrided iron are larger than desired for most purposes. Possibly promoters may be found to improve the selectivity of nitrided iron catalysts. The Bureau of Mines did not conduct a systematic catalyst development program on iron nitrides. (DP) 5 fgures, 6 tables.

  16. Iron-based alloy and nitridation treatment for PEM fuel cell bipolar plates

    DOE Patents [OSTI]

    Brady, Michael P. [Oak Ridge, TN; Yang, Bing [Oak Ridge, TN; Maziasz, Philip J. [Oak Ridge, TN

    2010-11-09

    A corrosion resistant electrically conductive component that can be used as a bipolar plate in a PEM fuel cell application is composed of an alloy substrate which has 10-30 wt. % Cr, 0.5 to 7 wt. % V, and base metal being Fe, and a continuous surface layer of chromium nitride and vanadium nitride essentially free of base metal. A oxide layer of chromium vanadium oxide can be disposed between the alloy substrate and the continuous surface nitride layer. A method to prepare the corrosion resistant electrically conductive component involves a two-step nitridization sequence by exposing the alloy to a oxygen containing gas at an elevated temperature, and subsequently exposing the alloy to an oxygen free nitrogen containing gas at an elevated temperature to yield a component where a continuous chromium nitride layer free of iron has formed at the surface.

  17. Protections: Sampling

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

    and unexpected contaminants August 1, 2013 Monitoring stormwater in Los Alamos Canyon Monitoring stormwater in Los Alamos Canyon The Environmental Sampling Board, a key piece...

  18. Protections: Sampling

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

    Protection 3: Sampling for known and unexpected contaminants August 1, 2013 Monitoring stormwater in Los Alamos Canyon Monitoring stormwater in Los Alamos Canyon The Environmental ...

  19. Nitride Stabilized Core-Shell Nanoparticles - Energy Innovation Portal

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

    Nitride Stabilized Core-Shell Nanoparticles Brookhaven National Laboratory Contact BNL About This Technology <br type="_moz" /> (A) Comparison of surface strain versus predicted binding energy of oxygen (BE-O) on the Pt<sub>2</sub>MLNi<sub>4</sub>N and Pt nanoparticle models with ~1.7 nm. (B) Pt specific activity against BE-O on PtNiN/C and Pt/C. (C) Schematic of the inner Pt diffusion process to the defective sites at the vertex during cycling in the

  20. Field emission characteristics from graphene on hexagonal boron nitride

    SciTech Connect (OSTI)

    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)

    2014-06-02

    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.

  1. Preparation of superhydrophobic nanodiamond and cubic boron nitride films

    SciTech Connect (OSTI)

    Zhou, Y. B.; Liu, W. M.; Wang, P. F.; Yang, Y.; Ye, Q.; He, B.; Pan, X. J.; Zhang, W. J.; Bello, I.; Lee, S. T.; Zou, Y. S.

    2010-09-27

    Superhydrophobic surfaces were achieved on the hardest and the second hardest materials, diamond and cubic boron nitride (cBN) films. Various surface nanostructures of nanocrystalline diamond (ND) and cBN films were constructed by carrying out bias-assisted reactive ion etching in hydrogen/argon plasmas; and it is shown that surface nanostructuring may enhance dramatically the hydrophobicity of ND and cBN films. Together with surface fluorination, superhydrophobic ND and cBN surfaces with a contact angle greater than 150 deg. and a sliding angle smaller than 10 deg. were demonstrated. The origin of hydrophobicity enhancement is discussed based on the Cassie model.

  2. Method of nitriding niobium to form a superconducting surface

    SciTech Connect (OSTI)

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

    2014-08-19

    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.

  3. Metal Nitride Catalysts to Enhance Hydrogen Evolution Reactions - Energy

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

    Innovation Portal Solar Photovoltaic Solar Photovoltaic Hydrogen and Fuel Cell Hydrogen and Fuel Cell Find More Like This Return to Search Metal Nitride Catalysts to Enhance Hydrogen Evolution Reactions Brookhaven National Laboratory Contact BNL About This Technology TEM image of catalyst ink comprised of Co<sub>0.6</sub>Mo<sub>1.4</sub>N<sub>2</sub> dispersed on carbon black TEM image of catalyst ink comprised of Co0.6Mo1.4N2 dispersed on carbon black

  4. Boron nitride nanosheets as oxygen-atom corrosion protective coatings

    SciTech Connect (OSTI)

    Yi, Min; Shen, Zhigang; Zhao, Xiaohu; Liang, Shuaishuai; Liu, Lei

    2014-04-07

    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.

  5. Process for growing epitaxial gallium nitride and composite wafers

    DOE Patents [OSTI]

    Weber, Eicke R.; Subramanya, Sudhir G.; Kim, Yihwan; Kruger, Joachim

    2003-05-13

    A novel growth procedure to grow epitaxial Group III metal nitride thin films on lattice-mismatched substrates is proposed. Demonstrated are the quality improvement of epitaxial GaN layers using a pure metallic Ga buffer layer on c-plane sapphire substrate. X-ray rocking curve results indicate that the layers had excellent structural properties. The electron Hall mobility increases to an outstandingly high value of .mu.>400 cm.sup.2 /Vs for an electron background concentration of 4.times.10.sup.17 cm.sup.-3.

  6. SAMPLING SYSTEM

    DOE Patents [OSTI]

    Hannaford, B.A.; Rosenberg, R.; Segaser, C.L.; Terry, C.L.

    1961-01-17

    An apparatus is given for the batch sampling of radioactive liquids such as slurries from a system by remote control, while providing shielding for protection of operating personnel from the harmful effects of radiation.

  7. Sampling box

    DOE Patents [OSTI]

    Phillips, Terrance D.; Johnson, Craig

    2000-01-01

    An air sampling box that uses a slidable filter tray and a removable filter cartridge to allow for the easy replacement of a filter which catches radioactive particles is disclosed.

  8. Morphological development and oxidation mechanisms of aluminum nitride whiskers

    SciTech Connect (OSTI)

    Hou Xinmei; Yue Changsheng; Kumar Singh, Ankit; Zhang Mei; Chou Kuochih

    2010-04-15

    Hexagonal aluminum nitride (AlN) whiskers have been synthesized at 1873 K under a flowing nitrogen atmosphere. The synthesized whiskers are long straight filaments with diameters between 1 and 5 {mu}m and length in the cm range. In order to investigate its 'oxidation resistance', a series of experiments have been performed. The oxidation behavior was quite different in the experimental temperature range assigned, which can be attributed to the kinetic factor and the morphological development during oxidation process. It was chemical controlled at lower temperature while both chemical reaction and diffusion controlled at medium temperature. Further accelerating of temperature to 1473 K, AlN whiskers was peeled into smaller parts, which increased the oxidation rate and hence showed powder-like oxidation behavior. Our new kinetic theory has been applied to study the oxidation behavior of AlN whiskers. The comparison of the experimental data with the theoretical ones validates the applicability of the new model. - Hexagonal aluminum nitride (AlN) whiskers have been synthesized at 1873 K under a flowing nitrogen atmosphere. The synthesized whiskers are long straight filaments with diameters between 1 and 5 {mu}m and length in the cm range.

  9. Consolidation of cubic and hexagonal boron nitride composites

    SciTech Connect (OSTI)

    Du Frane, W. L.; Cervantes, O.; Ellsworth, G. F.; Kuntz, J. D.

    2015-12-08

    When we Consolidate cubic boron nitride (cBN) it typically requires either a matrix of metal bearing materials that are undesirable for certain applications, or very high pressures within the cBN phase stability field that are prohibitive to manufacturing size and cost. We present new methodology for consolidating high stiffness cBN composites within a hexagonal boron nitride (hBN) matrix (15–25 vol%) with the aid of a binder phase (0–6 vol%) at moderate pressures (0.5–1.0 GPa) and temperatures (900–1300 °C). The composites are demonstrated to be highly tailorable with a range of compositions and resulting physical/mechanical properties. Ultrasonic measurements indicate that in some cases these composites have elastic mechanical properties that exceed those of the highest strength steel alloys. Moreover, two methods were identified to prevent phase transformation of the metastable cBN phase into hBN during consolidation: 1. removal of hydrocarbons, and 2. increased cBN particle size. Lithium tetraborate worked better as a binder than boron oxide, aiding consolidation without enhancing cBN to hBN phase transformation kinetics. These powder mixtures consolidated within error of their full theoretical mass densities at 1 GPa, and had only slightly lower densities at 0.5 GPa. This shows potential for consolidation of these composites into larger parts, in a variety of shapes, at even lower pressures using more conventional manufacturing methods, such as hot-pressing.

  10. Transport properties of ultrathin black phosphorus on hexagonal boron nitride

    SciTech Connect (OSTI)

    Doganov, Rostislav A.; zyilmaz, Barbaros; Koenig, Steven P.; Yeo, Yuting; Watanabe, Kenji; Taniguchi, Takashi

    2015-02-23

    Ultrathin black phosphorus, or phosphorene, is a two-dimensional material that allows both high carrier mobility and large on/off ratios. Similar to other atomic crystals, like graphene or layered transition metal dichalcogenides, the transport behavior of few-layer black phosphorus is expected to be affected by the underlying substrate. The properties of black phosphorus have so far been studied on the widely utilized SiO{sub 2} substrate. Here, we characterize few-layer black phosphorus field effect transistors on hexagonal boron nitridean atomically smooth and charge trap-free substrate. We measure the temperature dependence of the field effect mobility for both holes and electrons and explain the observed behavior in terms of charged impurity limited transport. We find that in-situ vacuum annealing at 400?K removes the p-doping of few-layer black phosphorus on both boron nitride and SiO{sub 2} substrates and reduces the hysteresis at room temperature.

  11. Radiation tolerance of piezoelectric bulk single-crystal aluminum nitride

    SciTech Connect (OSTI)

    David A. Parks; Bernhard R. Tittmann

    2014-07-01

    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.

  12. Tunneling characteristics in chemical vapor deposited graphenehexagonal boron nitridegraphene junctions

    SciTech Connect (OSTI)

    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)

    2014-03-24

    Large area chemical vapor deposited graphene and hexagonal boron nitride was used to fabricate graphenehexagonal boron nitridegraphene symmetric field effect transistors. Gate control of the tunneling characteristics is observed similar to previously reported results for exfoliated graphenehexagonal boron nitridegraphene 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.

  13. Electron transport in zinc-blende wurtzite biphasic gallium nitride nanowires and GaNFETs

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

    Jacobs, Benjamin W.; Ayres, Virginia M.; Stallcup, Richard E.; Hartman, Alan; Tupta, Mary Ann; Baczewski, Andrew David; Crimp, Martin A.; Halpern, Joshua B.; He, Maoqi; Shaw, Harry C.

    2007-10-19

    Two-point and four-point probe electrical measurements of a biphasic gallium nitride nanowire and current–voltage characteristics of a gallium nitride nanowire based field effect transistor are reported. The biphasic gallium nitride nanowires have a crystalline homostructure consisting of wurtzite and zinc-blende phases that grow simultaneously in the longitudinal direction. There is a sharp transition of one to a few atomic layers between each phase. Here, all measurements showed high current densities. Evidence of single-phase current transport in the biphasic nanowire structure is discussed.

  14. SAMPLING OSCILLOSCOPE

    DOE Patents [OSTI]

    Sugarman, R.M.

    1960-08-30

    An oscilloscope is designed for displaying transient signal waveforms having random time and amplitude distributions. The oscilloscopc is a sampling device that selects for display a portion of only those waveforms having a particular range of amplitudes. For this purpose a pulse-height analyzer is provided to screen the pulses. A variable voltage-level shifter and a time-scale rampvoltage generator take the pulse height relative to the start of the waveform. The variable voltage shifter produces a voltage level raised one step for each sequential signal waveform to be sampled and this results in an unsmeared record of input signal waveforms. Appropriate delay devices permit each sample waveform to pass its peak amplitude before the circuit selects it for display.

  15. Sampling apparatus

    DOE Patents [OSTI]

    Gordon, N.R.; King, L.L.; Jackson, P.O.; Zulich, A.W.

    1989-07-18

    A sampling apparatus is provided for sampling substances from solid surfaces. The apparatus includes first and second elongated tubular bodies which telescopically and sealingly join relative to one another. An absorbent pad is mounted to the end of a rod which is slidably received through a passageway in the end of one of the joined bodies. The rod is preferably slidably and rotatably received through the passageway, yet provides a selective fluid tight seal relative thereto. A recess is formed in the rod. When the recess and passageway are positioned to be coincident, fluid is permitted to flow through the passageway and around the rod. The pad is preferably laterally orientable relative to the rod and foldably retractable to within one of the bodies. A solvent is provided for wetting of the pad and solubilizing or suspending the material being sampled from a particular surface. 15 figs.

  16. Sampling apparatus

    DOE Patents [OSTI]

    Gordon, Norman R.; King, Lloyd L.; Jackson, Peter O.; Zulich, Alan W.

    1989-01-01

    A sampling apparatus is provided for sampling substances from solid surfaces. The apparatus includes first and second elongated tubular bodies which telescopically and sealingly join relative to one another. An absorbent pad is mounted to the end of a rod which is slidably received through a passageway in the end of one of the joined bodies. The rod is preferably slidably and rotatably received through the passageway, yet provides a selective fluid tight seal relative thereto. A recess is formed in the rod. When the recess and passageway are positioned to be coincident, fluid is permitted to flow through the passageway and around the rod. The pad is preferably laterally orientable relative to the rod and foldably retractable to within one of the bodies. A solvent is provided for wetting of the pad and solubilizing or suspending the material being sampled from a particular surface.

  17. Laser nitriding for niobium superconducting radio-frequency accelerator cavities

    SciTech Connect (OSTI)

    Senthilraja Singaravelu, John Klopf, Gwyn Williams, Michael Kelley

    2010-10-01

    Particle accelerators are a key tool for scientific research ranging from fundamental studies of matter to analytical studies at light sources. Cost-forperformance is critical, both in terms of initial capital outlay and ongoing operating expense, especially for electricity. It depends on the niobium superconducting radiofrequency (SRF) accelerator cavities at the heart of most of these machines. Presently Nb SRF cavities operate near 1.9 K, well (and expensively) below the 4.2 K atmospheric boiling point of liquid He. Transforming the 40 nm thick active interior surface layer from Nb to delta NbN (Tc = 17 K instead of 9.2 K) appears to be a promising approach. Traditional furnace nitriding appears to have not been successful for this. Further, exposing a complete SRF cavity to the time-temperature history required for nitriding risks mechanical distortion. Gas laser nitriding instead has been applied successfully to other metals [P.Schaaf, Prog. Mat. Sci. 47 (2002) 1]. The beam dimensions and thermal diffusion length permit modeling in one dimension to predict the time course of the surface temperature for a range of per-pulse energy densities. As with the earlier work, we chose conditions just sufficient for boiling as a reference point. We used a Spectra Physics HIPPO nanosecond laser (l = 1064 nm, Emax= 0.392 mJ, beam spot@ 34 microns, PRF =15 – 30 kHz) to obtain an incident fluence of 1.73 - 2.15 J/cm2 for each laser pulse at the target. The target was a 50 mm diameter SRF-grade Nb disk maintained in a nitrogen atmosphere at a pressure of 550 – 625 torr and rotated at a constant speed of 9 rpm. The materials were examined by scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and x-ray diffraction (XRD). The SEM images show a sharp transition with fluence from a smooth, undulating topography to significant roughening, interpreted here as the onset of ablation. EPMA measurements of N/Nb atom ratio as a function of depth found a constant value to depths greater than the SRF active layer thickness. Certain irradiation conditions resulted in values consistent with formation of delta NbN. Under certain irradiation conditions, XRD data were consistent only with delta NbN on top of Nb metal. Funding: authored by Jefferson Science Associates LLC under US DOE Contract De-AC05-06OR23177. We are indebted to Prof. P. Schaaf (Goettingen) for the simulation code and helpful discussions.

  18. PPPL News sample:

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

    PPPL News sample:

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

    DOE Patents [OSTI]

    McCoy, L.R.

    1981-01-23

    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.

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

    DOE Patents [OSTI]

    McCoy, Lowell R.

    1982-01-01

    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.

  1. HIGH-QUALITY, LOW-COST BULK GALLIUM NITRIDE SUBSTRATES GROWN...

    Office of Environmental Management (EM)

    Efficient manufacturing of gallium nitride (GaN) could reduce the cost of and improve the output for light-emitting diodes, solid-state lighting, laser displays, and other power ...

  2. Aluminum nitride transitional layer for reducing dislocation density and cracking of AIGan epitaxial films

    DOE Patents [OSTI]

    Allerman, Andrew A.; Crawford, Mary H.; Koleske, Daniel D.; Lee, Stephen R.

    2011-03-29

    A denticulated Group III nitride structure that is useful for growing Al.sub.xGa.sub.1-xN to greater thicknesses without cracking and with a greatly reduced threading dislocation (TD) density.

  3. Sandia Energy - III-Nitride core-shell nanowire arrayed solar...

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

    for other III-nitride devices such as light-emitting diodes (LEDs). Abstract: A solar cell based on a hybrid nanowire-film architecture consisting of a vertically aligned...

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

    DOE Patents [OSTI]

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

    1992-01-01

    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.

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

    DOE Patents [OSTI]

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

    1992-10-13

    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.

  6. Precursors in the preparation of transition metal nitrides and transition metal carbonitrides and their reaction intermediates

    DOE Patents [OSTI]

    Maya, Leon

    1991-01-01

    A process for making ammonolytic precursors to nitride and carbonitride ceramics. Extreme reaction conditions are not required and the precursor is a powder-like substance that produces ceramics of improved purity and morphology upon pyrolysis.

  7. Process for preparing transition metal nitrides and transition metal carbonitrides and their reaction intermediates

    DOE Patents [OSTI]

    Maya, Leon

    1988-05-24

    A process for making ammonolytic precursors to nitride and carbonitride ceramics. Extreme reaction conditions are not required and the precursor is a powder-like substance that produces ceramics of improved purity and morphology upon pyrolysis.

  8. Anomalous response of superconducting titanium nitride resonators to terahertz radiation

    SciTech Connect (OSTI)

    Bueno, J. Baselmans, J. J. A; Coumou, P. C. J. J.; Zheng, G.; Visser, P. J. de; Klapwijk, T. M.; Driessen, E. F. C.; Doyle, S.

    2014-11-10

    We present an experimental study of kinetic inductance detectors (KIDs) fabricated of atomic layer deposited TiN films and characterized at radiation frequencies of 350 GHz. The responsivity to radiation is measured and found to increase with the increase in radiation powers, opposite to what is expected from theory and observed for hybrid niobium titanium nitride/aluminium (NbTiN/Al) and all-aluminium (all-Al) KIDs. The noise is found to be independent of the level of the radiation power. The noise equivalent power improves with higher radiation powers, also opposite to what is observed and well understood for hybrid NbTiN/Al and all-Al KIDs. We suggest that an inhomogeneous state of these disordered superconductors should be used to explain these observations.

  9. The electron beam hole drilling of silicon nitride thin films

    SciTech Connect (OSTI)

    Howitt, D. G.; Chen, S. J.; Gierhart, B. C.; Smith, R. L.; Collins, S. D.

    2008-01-15

    The mechanism by which an intense electron beam can produce holes in thin films of silicon nitride has been investigated using a combination of in situ electron energy loss spectrometry and electron microscopy imaging. A brief review of electron beam interactions that lead to material loss in different materials is also presented. The loss of nitrogen and silicon decreases with decreasing beam energy and although still observable at a beam energy of 150 keV ceases completely at 120 keV. The linear behavior of the loss rate coupled with the energy dependency indicates that the process is primarily one of direct displacement, involving the sputtering of atoms from the back surface of the specimen with the rate controlling mechanism being the loss of nitrogen.

  10. High-Efficiency Nitride-Based Photonic Crystal Light Sources

    Broader source: Energy.gov [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.

  11. Submicron cubic boron nitride as hard as diamond

    SciTech Connect (OSTI)

    Liu, Guoduan; Kou, Zili E-mail: yanxz@hpstar.ac.cn; Lei, Li; Peng, Fang; Wang, Qiming; Wang, Kaixue; Wang, Pei; Li, Liang; Li, Yong; Wang, Yonghua; Yan, Xiaozhi E-mail: yanxz@hpstar.ac.cn; Li, Wentao; Bi, Yan; Leng, Yang; He, Duanwei

    2015-03-23

    Here, we report the sintering of aggregated submicron cubic boron nitride (sm-cBN) at a pressure of 8 GPa. The sintered cBN compacts exhibit hardness values comparable to that of single crystal diamond, fracture toughness about 5-fold that of cBN single crystal, in combination with a high oxidization temperature. Thus, another way has been demonstrated to improve the mechanical properties of cBN besides reducing the grain size to nano scale. In contrast to other ultrahard compacts with similar hardness, the sm-cBN aggregates are better placed for potential industrial application, as their relative low pressure manufacturing perhaps be easier and cheaper.

  12. Methods for improved growth of group III nitride semiconductor compounds

    DOE Patents [OSTI]

    Melnik, Yuriy; Chen, Lu; Kojiri, Hidehiro

    2015-03-17

    Methods are disclosed for growing group III-nitride semiconductor compounds with advanced buffer layer technique. In an embodiment, a method includes providing a suitable substrate in a processing chamber of a hydride vapor phase epitaxy processing system. The method includes forming an AlN buffer layer by flowing an ammonia gas into a growth zone of the processing chamber, flowing an aluminum halide containing precursor to the growth zone and at the same time flowing additional hydrogen halide or halogen gas into the growth zone of the processing chamber. The additional hydrogen halide or halogen gas that is flowed into the growth zone during buffer layer deposition suppresses homogeneous AlN particle formation. The hydrogen halide or halogen gas may continue flowing for a time period while the flow of the aluminum halide containing precursor is turned off.

  13. DEVELOPMENT OF TITANIUM NITRIDE COATING FOR SNS RING VACUUM CHAMBERS.

    SciTech Connect (OSTI)

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

    2001-06-18

    The inner surface of the ring vacuum chambers of the US Spallation Neutron Source (SNS) will be coated with {approximately}100 nm of Titanium Nitride (TiN). This is to minimize the secondary electron yield (SEY) from the chamber wall, and thus avoid the so-called e-p instability caused by electron multipacting as observed in a few high-intensity proton storage rings. Both DC sputtering and DC-magnetron sputtering were conducted in a test chamber of relevant geometry to SNS ring vacuum chambers. Auger Electron Spectroscopy (AES) and Rutherford Back Scattering (RBS) were used to analyze the coatings for thickness, stoichiometry and impurity. Excellent results were obtained with magnetron sputtering. The development of the parameters for the coating process and the surface analysis results are presented.

  14. Spectroscopic ellipsometry characterization of thin-film silicon nitride

    SciTech Connect (OSTI)

    Jellison, G.E. Jr.; Modine, F.A.; Doshi, P.; Rohatgi, A.

    1997-05-01

    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.

  15. Epitaxial ternary nitride thin films prepared by a chemical solution method

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Journal Article: Epitaxial ternary nitride thin films prepared by a chemical solution method Citation Details In-Document Search Title: Epitaxial ternary nitride thin films prepared by a chemical solution method × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional

  16. Impurity-induced disorder in III-nitride materials and devices

    DOE Patents [OSTI]

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

    2014-11-25

    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.

  17. Design of defect spins in piezoelectric aluminum nitride for solid-state

    Office of Scientific and Technical Information (OSTI)

    hybrid quantum technologies (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: Design of defect spins in piezoelectric aluminum nitride for solid-state hybrid quantum technologies Citation Details In-Document Search Title: Design of defect spins in piezoelectric aluminum nitride for solid-state hybrid quantum technologies Spin defects in wide-band gap semiconductors are promising systems for the realization of quantum bits, or qubits, in solid-state

  18. Use of aluminum nitride to obtain temperature measurements in a high temperature and high radiation environment

    DOE Patents [OSTI]

    Wernsman, Bernard R.; Blasi, Raymond J.; Tittman, Bernhard R.; Parks, David A.

    2016-04-26

    An aluminum nitride piezoelectric ultrasonic transducer successfully operates at temperatures of up to 1000.degree. C. and fast (>1 MeV) neutron fluencies of more than 10.sup.18 n/cm.sup.2. The transducer comprises a transparent, nitrogen rich aluminum nitride (AlN) crystal wafer that is coupled to an aluminum cylinder for pulse-echo measurements. The transducer has the capability to measure in situ gamma heating within the core of a nuclear reactor.

  19. Hafnium nitride buffer layers for growth of GaN on silicon

    DOE Patents [OSTI]

    Armitage, Robert D.; Weber, Eicke R.

    2005-08-16

    Gallium nitride is grown by plasma-assisted molecular-beam epitaxy on (111) and (001) silicon substrates using hafnium nitride buffer layers. Wurtzite GaN epitaxial layers are obtained on both the (111) and (001) HfN/Si surfaces, with crack-free thickness up to 1.2 {character pullout}m. However, growth on the (001) surface results in nearly stress-free films, suggesting that much thicker crack-free layers could be obtained.

  20. Consolidation of cubic and hexagonal boron nitride composites

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

    Du Frane, W. L.; Cervantes, O.; Ellsworth, G. F.; Kuntz, J. D.

    2015-12-08

    When we Consolidate cubic boron nitride (cBN) it typically requires either a matrix of metal bearing materials that are undesirable for certain applications, or very high pressures within the cBN phase stability field that are prohibitive to manufacturing size and cost. We present new methodology for consolidating high stiffness cBN composites within a hexagonal boron nitride (hBN) matrix (15–25 vol%) with the aid of a binder phase (0–6 vol%) at moderate pressures (0.5–1.0 GPa) and temperatures (900–1300 °C). The composites are demonstrated to be highly tailorable with a range of compositions and resulting physical/mechanical properties. Ultrasonic measurements indicate that inmore » some cases these composites have elastic mechanical properties that exceed those of the highest strength steel alloys. Moreover, two methods were identified to prevent phase transformation of the metastable cBN phase into hBN during consolidation: 1. removal of hydrocarbons, and 2. increased cBN particle size. Lithium tetraborate worked better as a binder than boron oxide, aiding consolidation without enhancing cBN to hBN phase transformation kinetics. These powder mixtures consolidated within error of their full theoretical mass densities at 1 GPa, and had only slightly lower densities at 0.5 GPa. This shows potential for consolidation of these composites into larger parts, in a variety of shapes, at even lower pressures using more conventional manufacturing methods, such as hot-pressing.« less

  1. Preparation and properties of hexagonal boron nitride fibers used as high temperature membrane filter

    SciTech Connect (OSTI)

    Hou, Xinmei Yu, Ziyou; Li, Yang; Chou, Kuo-Chih

    2014-01-01

    Graphical abstract: - Highlights: • h-BN fibers were successfully fabricated using H{sub 3}BO{sub 3} and C{sub 3}H{sub 6}N{sub 6} as raw materials. • The obtained BN fibers were polycrystalline and uniform in morphology. • It exhibited good oxidation resistance and low thermal expansion coefficient. - Abstract: Hexagonal boron nitride fibers were synthesized via polymeric precursor method using boric acid (H{sub 3}BO{sub 3}) and melamine (C{sub 3}H{sub 6}N{sub 6}) as raw materials. The precursor fibers were synthesized by water bath and BN fibers were prepared from the precursor at 1873 K for 3 h in flowing nitrogen atmosphere. The crystalline phase and microstructures of BN fibers were examined by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy and high resolution electron microscopy. The results showed that h-BN fibers with uniform morphology were successfully fabricated. The well-synthesized BN fibers were polycrystalline with 0.4–1.5 μm in diameter and 200–500 μm in length. The as-prepared samples exhibited good oxidation resistance and low thermal expansion coefficient at high temperature.

  2. Use of additives to improve microstructures and fracture resistance of silicon nitride ceramics

    DOE Patents [OSTI]

    Becher, Paul F.; Lin, Hua-Tay

    2011-06-28

    A high-strength, fracture-resistant silicon nitride ceramic material that includes about 5 to about 75 wt-% of elongated reinforcing grains of beta-silicon nitride, about 20 to about 95 wt-% of fine grains of beta-silicon nitride, wherein the fine grains have a major axis of less than about 1 micron; and about 1 to about 15 wt-% of an amorphous intergranular phase comprising Si, N, O, a rare earth element and a secondary densification element. The elongated reinforcing grains have an aspect ratio of 2:1 or greater and a major axis measuring about 1 micron or greater. The elongated reinforcing grains are essentially isotropically oriented within the ceramic microstructure. The silicon nitride ceramic exhibits a room temperature flexure strength of 1,000 MPa or greater and a fracture toughness of 9 MPa-m.sup.(1/2) or greater. The silicon nitride ceramic exhibits a peak strength of 800 MPa or greater at 1200 degrees C. Also included are methods of making silicon nitride ceramic materials which exhibit the described high flexure strength and fracture-resistant values.

  3. Advanced Epi Tools for Gallium Nitride Light Emitting Diode Devices

    SciTech Connect (OSTI)

    Patibandla, Nag; Agrawal, Vivek

    2012-12-01

    Over the course of this program, Applied Materials, Inc., with generous support from the United States Department of Energy, developed a world-class three chamber III-Nitride epi cluster tool for low-cost, high volume GaN growth for the solid state lighting industry. One of the major achievements of the program was to design, build, and demonstrate the world’s largest wafer capacity HVPE chamber suitable for repeatable high volume III-Nitride template and device manufacturing. Applied Materials’ experience in developing deposition chambers for the silicon chip industry over many decades resulted in many orders of magnitude reductions in the price of transistors. That experience and understanding was used in developing this GaN epi deposition tool. The multi-chamber approach, which continues to be unique in the ability of the each chamber to deposit a section of the full device structure, unlike other cluster tools, allows for extreme flexibility in the manufacturing process. This robust architecture is suitable for not just the LED industry, but GaN power devices as well, both horizontal and vertical designs. The new HVPE technology developed allows GaN to be grown at a rate unheard of with MOCVD, up to 20x the typical MOCVD rates of 3{micro}m per hour, with bulk crystal quality better than the highest-quality commercial GaN films grown by MOCVD at a much cheaper overall cost. This is a unique development as the HVPE process has been known for decades, but never successfully commercially developed for high volume manufacturing. This research shows the potential of the first commercial-grade HVPE chamber, an elusive goal for III-V researchers and those wanting to capitalize on the promise of HVPE. Additionally, in the course of this program, Applied Materials built two MOCVD chambers, in addition to the HVPE chamber, and a robot that moves wafers between them. The MOCVD chambers demonstrated industry-leading wavelength yield for GaN based LED wafers and industry-leading uptime enabled in part by a novel in-situ cleaning process developed in this program.

  4. Controlled Growth of Ordered III-Nitride Core-Shell Nanostructure Arrays for Visible Optoelectronic Devices

    SciTech Connect (OSTI)

    Rishinaramangalam, Ashwin K.; Mishkat Ul Masabih, Saadat; Fairchild, Michael N.; Wright, Jeremy Benjamin; Shima, Darryl M.; Balakrishnan, Ganesh; Brener, Igal; Brueck, Steven R.J.; Feezell, Daniel F.

    2014-10-21

    In our paper, we demonstrate the growth of ordered arrays of nonpolar {101 0} coreshell nanowalls and semipolar {101 1} coreshell pyramidal nanostripes on c-plane (0001) sapphire substrates using selective-area epitaxy and metal organic chemical vapor deposition. The nanostructure arrays are controllably patterned into LED mesa regions, demonstrating a technique to impart secondary lithography features into the arrays. Moreover, we study the dependence of the nanostructure cores on the epitaxial growth conditions and show that the geometry and morphology are strongly influenced by growth temperature, V/III ratio, and pulse interruption time. We also demonstrate the growth of InGaN quantum well shells on the nanostructures and characterize the structures by using micro-photoluminescence and cross-section scanning tunneling electron microscopy.

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

    DOE Patents [OSTI]

    Huckabee, Marvin; Buljan, Sergej-Tomislav; Neil, Jeffrey T.

    1991-01-01

    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.

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

    DOE Patents [OSTI]

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

    1991-09-10

    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.

  7. Brazing of titanium-vapor-coated silicon nitride

    SciTech Connect (OSTI)

    Santella, M.L. )

    1988-09-01

    A technique for brazing Si{sub 3}N{sub 4} with metallic alloys was evaluated. The process involved vapor coating the ceramic with a 1.0-{mu}-thick layer of titanium before the brazing operation. The coating improved wetting of the Si{sub 3}N{sub 4} surfaces to the extent that strong bonding between the solidified braze filler metal and the ceramic occurred. Braze joints of Si{sub 3}N{sub 4} were made with Ag-Cu, Au-Ni, and Au-Ni-Pd alloys at temperatures of 790{degree}, 970{degree}, and 1,130{degree}C. Silicon nitride specimens were also brazed with a Ag-Cu alloy to the molybdenum alloy TZM, titanium, and A286 steel at 790{degree}C. Residual stresses resulting from mismatch of thermal expansion coefficients between the Si{sub 3}N{sub 4} and the metals caused all of the ceramic-to-metal joints to spontaneously crack in the Si{sub 3}N{sub 4} upon cooling from the brazing temperature.

  8. Mechanical deformations of boron nitride nanotubes in crossed junctions

    SciTech Connect (OSTI)

    Zhao, Yadong; Chen, Xiaoming; Ke, Changhong; Park, Cheol; Fay, Catharine C.; Stupkiewicz, Stanislaw

    2014-04-28

    We present a study of the mechanical deformations of boron nitride nanotubes (BNNTs) in crossed junctions. The structure and deformation of the crossed tubes in the junction are characterized by using atomic force microscopy. Our results show that the total tube heights are reduced by 20%33% at the crossed junctions formed by double-walled BNNTs with outer diameters in the range of 2.214.67?nm. The measured tube height reduction is found to be in a nearly linear relationship with the summation of the outer diameters of the two tubes forming the junction. The contact force between the two tubes in the junction is estimated based on contact mechanics theories and found to be within the range of 4.27.6 nN. The Young's modulus of BNNTs and their binding strengths with the substrate are quantified, based on the deformation profile of the upper tube in the junction, and are found to be 1.07??0.11 TPa and 0.180.29 nJ/m, respectively. Finally, we perform finite element simulations on the mechanical deformations of the crossed BNNT junctions. The numerical simulation results are consistent with both the experimental measurements and the analytical analysis. The results reported in this paper contribute to a better understanding of the structural and mechanical properties of BNNTs and to the pursuit of their applications.

  9. Thermal transport across graphene and single layer hexagonal boron nitride

    SciTech Connect (OSTI)

    Zhang, Jingchao E-mail: yyue@whu.edu.cn; Hong, Yang; Yue, Yanan E-mail: yyue@whu.edu.cn

    2015-04-07

    As the dimensions of nanocircuits and nanoelectronics shrink, thermal energies are being generated in more confined spaces, making it extremely important and urgent to explore for efficient heat dissipation pathways. In this work, the phonon energy transport across graphene and hexagonal boron-nitride (h-BN) interface is studied using classic molecular dynamics simulations. Effects of temperature, interatomic bond strength, heat flux direction, and functionalization on interfacial thermal transport are investigated. It is found out that by hydrogenating graphene in the hybrid structure, the interfacial thermal resistance (R) between graphene and h-BN can be reduced by 76.3%, indicating an effective approach to manipulate the interfacial thermal transport. Improved in-plane/out-of-plane phonon couplings and broadened phonon channels are observed in the hydrogenated graphene system by analyzing its phonon power spectra. The reported R results monotonically decrease with temperature and interatomic bond strengths. No thermal rectification phenomenon is observed in this interfacial thermal transport. Results reported in this work give the fundamental knowledge on graphene and h-BN thermal transport and provide rational guidelines for next generation thermal interface material designs.

  10. Method of synthesizing bulk transition metal carbide, nitride and phosphide catalysts

    DOE Patents [OSTI]

    Choi, Jae Soon; Armstrong, Beth L; Schwartz, Viviane

    2015-04-21

    A method for synthesizing catalyst beads of bulk transmission metal carbides, nitrides and phosphides is provided. The method includes providing an aqueous suspension of transition metal oxide particles in a gel forming base, dropping the suspension into an aqueous solution to form a gel bead matrix, heating the bead to remove the binder, and carburizing, nitriding or phosphiding the bead to form a transition metal carbide, nitride, or phosphide catalyst bead. The method can be tuned for control of porosity, mechanical strength, and dopant content of the beads. The produced catalyst beads are catalytically active, mechanically robust, and suitable for packed-bed reactor applications. The produced catalyst beads are suitable for biomass conversion, petrochemistry, petroleum refining, electrocatalysis, and other applications.

  11. Si Passivation and Chemical Vapor Deposition of Silicon Nitride: Final Technical Report, March 18, 2007

    SciTech Connect (OSTI)

    Atwater, H. A.

    2007-11-01

    This report investigated chemical and physical methods for Si surface passivation for application in crystalline Si and thin Si film photovoltaic devices. Overall, our efforts during the project were focused in three areas: i) synthesis of silicon nitride thin films with high hydrogen content by hot-wire chemical vapor deposition; ii) investigation of the role of hydrogen passivation of defects in crystalline Si and Si solar cells by out diffusion from hydrogenated silicon nitride films; iii) investigation of the growth kinetics and passivation of hydrogenated polycrystalline. Silicon nitride films were grown by hot-wire chemical vapor deposition and film properties have been characterized as a function of SiH4/NH3 flow ratio. It was demonstrated that hot-wire chemical vapor deposition leads to growth of SiNx films with controllable stoichiometry and hydrogen.

  12. Influence of slurry flocculation on the character and compaction of spray-dried silicon nitride granules

    SciTech Connect (OSTI)

    Takahashi, Hideo; Shinohara, Nobuhiro; Okumiya, Masataro; Uematsu, Keizo; JunIchiro, Tsubaki; Iwamoto, Yuji; Kamiya, Hidehiro

    1995-04-01

    The effect of slurry flocculation on the characteristics of silicon nitride granules prepared by the spray drying process is investigated. The flocculation state of an aqueous silicon nitride slurry is controlled by adding nitric acid and evaluated as a function of pH. Dense and hard silicon nitride granules result from a well-dispersed slurry having a high pH (e.g., 10.8). These hard granules retain their shape in green compacts and form detrimental defects. Lowering the pH of the slurry to a certain value (e.g., pH 7.9) results in slurry flocculation. Granules prepared from this flocculated slurry have low density and low diametral compression strength and contribute to the elimination large pores in green compacts.

  13. Synthesis of fine-grained .alpha.-silicon nitride by a combustion process

    DOE Patents [OSTI]

    Holt, J. Birch; Kingman, Donald D.; Bianchini, Gregory M.

    1990-01-01

    A combustion synthesis process for the preparation of .alpha.-silicon nitride and composites thereof is disclosed. Preparation of the .alpha.-silicon nitride comprises the steps of dry mixing silicon powder with an alkali metal azide, such as sodium azide, cold-pressing the mixture into any desired shape, or loading the mixture into a fused, quartz crucible, loading the crucible into a combustion chamber, pressurizing the chamber with nitrogen and igniting the mixture using an igniter pellet. The method for the preparation of the composites comprises dry mixing silicon powder (Si) or SiO.sub.2, with a metal or metal oxide, adding a small amount of an alkali metal azide such as sodium azide, introducing the mixture into a suitable combustion chamber, pressurizing the combustion chamber with nitrogen, igniting the mixture within the combustion chamber, and isolating the .alpha.-silicon nitride formed as a reaction product.

  14. Structural modifications due to interface chemistry at metal-nitride interfaces

    SciTech Connect (OSTI)

    Yadav, S. K.; Shao, S.; Wang, J.; Liu, X. -Y.

    2015-11-27

    Based on accurate first principles density functional theory (DFT) calculations, an unusual phenomenon of interfacial structural modifications, due to the interface chemistry influence is identified at two metal-nitride interfaces with strong metal-nitrogen affinity, Al/TiN {111} and Al/VN {111} interfaces. It is shown that at such interfaces, a faulted stacking structure is energetically preferred on the Al side of the interface. And both intrinsic and extrinsic stacking fault energies in the vicinity Al layers are negligibly small. However, such phenomenon does not occur in Pt/TiN and Pt/VN interfaces because of the weak Pt-N affinity. As a result, corresponding to structural energies of metal-nitride interfaces, the linear elasticity analysis predicts characteristics of interfacial misfit dislocations at metal-nitride interfaces.

  15. Nitrided iron catalysts for the Fischer-Tropsch synthesis in the eighties

    SciTech Connect (OSTI)

    Anderson, R.B.

    1980-01-01

    A survey covers the preparation and structure of nitrided iron catalysts and their activity, selectivity, and stability for the reaction of synthesis gas in comparison with iron catalysts pretreated by various other methods, as measured in laboratory reactors; a comparison of product distributions obtained in fluidized-bed, slurry, and oil-circulation fixed bed pilot plants with nitrided catalysts and by the Kellogg entrained catalyst process SASOL, which uses a reduced iron catalyst; and possible methods for refining the Fischer-Tropsch products from nitrided iron catalysts for producing gasoline, including bauxite treatment, the Mobil process for converting oxygenates to high-octane gasoline and C/sub 3/-C/sub 4/ olefins, and an alkylation-polymerization process for converting the C/sub 3/-C/sub 4/ fraction to high-octane blending stocks.

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

    SciTech Connect (OSTI)

    Seyed-Talebi, Seyedeh Mozhgan; Neek-Amal, M.

    2014-10-21

    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.

  17. Structural modifications due to interface chemistry at metal-nitride interfaces

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

    Yadav, S. K.; Shao, S.; Wang, J.; Liu, X. -Y.

    2015-11-27

    Based on accurate first principles density functional theory (DFT) calculations, an unusual phenomenon of interfacial structural modifications, due to the interface chemistry influence is identified at two metal-nitride interfaces with strong metal-nitrogen affinity, Al/TiN {111} and Al/VN {111} interfaces. It is shown that at such interfaces, a faulted stacking structure is energetically preferred on the Al side of the interface. And both intrinsic and extrinsic stacking fault energies in the vicinity Al layers are negligibly small. However, such phenomenon does not occur in Pt/TiN and Pt/VN interfaces because of the weak Pt-N affinity. As a result, corresponding to structural energiesmore » of metal-nitride interfaces, the linear elasticity analysis predicts characteristics of interfacial misfit dislocations at metal-nitride interfaces.« less

  18. Synthesis of a mixed-valent tin nitride and considerations of its possible crystal structures

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

    Caskey, Christopher M.; Holder, Aaron; Shulda, Sarah; Christensen, Steven T.; Diercks, David; Schwartz, Craig P.; Biagioni, David; Nordlund, Dennis; Kukliansky, Alon; Natan, Amir; et al

    2016-04-12

    Recent advances in theoretical structure prediction methods and high-throughput computational techniques are revolutionizing experimental discovery of the thermodynamically stable inorganic materials. Metastable materials represent a new frontier for these studies, since even simple binary non ground state compounds of common elements may be awaiting discovery. However, there are significant research challenges related to non-equilibrium thin film synthesis and crystal structure predictions, such as small strained crystals in the experimental samples and energy minimization based theoretical algorithms. Here we report on experimental synthesis and characterization, as well as theoretical first-principles calculations of a previously unreported mixed-valent binary tin nitride. Thin filmmore » experiments indicate that this novel material is N-deficient SnN with tin in the mixed II/IV valence state and a small low-symmetry unit cell. Theoretical calculations suggest that the most likely crystal structure has the space group 2 (SG2) related to the distorted delafossite (SG166), which is nearly 0.1 eV/atom above the ground state SnN polymorph. This observation is rationalized by the structural similarity of the SnN distorted delafossite to the chemically related Sn3N4 spinel compound, which provides a fresh scientific insight into the reasons for growth of polymorphs of the metastable material. In addition to reporting on the discovery of the simple binary SnN compound, this study illustrates a possible way of combining a wide range of advanced characterization techniques with the first-principle property calculation methods, to elucidate the most likely crystal structure of the previously unreported metastable materials.« less

  19. Thermal oxidation of polycrystalline and single crystalline aluminum nitride wafers (Prop 2003-054)

    SciTech Connect (OSTI)

    Speakman, Scott A; Gu, Z; Edgar, J H; Blom, Douglas Allen; Perrin, J; Chaudhuri, J

    2006-10-01

    Two types of aluminum nitride (AlN) samples were oxidized in flowing oxygen between 900 C and 1150 C for up to 6 h - highly (0001) textured polycrystalline AlN wafers and low defect density AlN single crystals. The N-face consistently oxidized at a faster rate than the Al-face. At 900 C and 1000 C after 6 h, the oxide was 15% thicker on the N-face than on the Al-face of polycrystalline AlN. At 1100 C and 1150 C, the oxide was only 5% thicker on the N-face, as the rate-limiting step changed from kinetically-controlled to diffusion-controlled with the oxide thickness. A linear parabolic model was established for the thermal oxidation of polycrystalline AlN on both the Al- and N-face. Transmission electron microscopy (TEM) confirmed the formation of a thicker crystalline oxide film on the N-face than on the Al-face, and established the crystallographic relationship between the oxide film and substrate. The oxidation of high-quality AlN single crystals resulted in a more uniform colored oxide layer compared to polycrystalline AlN. The aluminum oxide layer was crystalline with a rough AlN/oxide interface. The orientation relationship between AlN and Al{sub 2}O{sub 3} was (0001) AlN//(10{bar 1}0) Al{sub 2}O{sub 3} and (1{bar 1}00) AlN//(01{bar 1}2) Al{sub 2}O{sub 3}.

  20. Thermal conductivity of nitride films of Ti, Cr, and W deposited by reactive magnetron sputtering

    SciTech Connect (OSTI)

    Jagannadham, Kasichainula

    2015-05-15

    Nitride films of Ti, Cr, and W were deposited using reactive magnetron sputtering from metal targets in argon and nitrogen plasma. TiN films with (200) orientation were achieved on silicon (100) at the substrate temperature of 500 and 600?C. The films were polycrystalline at lower temperature. An amorphous interface layer was observed between the TiN film and Si wafer deposited at 600?C. TiN film deposited at 600?C showed the nitrogen to Ti ratio to be near unity, but films deposited at lower temperature were nitrogen deficient. CrN film with (200) orientation and good stoichiometry was achieved at 600?C on Si(111) wafer but the film deposited at 500?C showed cubic CrN and hexagonal Cr{sub 2}N phases with smaller grain size and amorphous back ground in the x-ray diffraction pattern. An amorphous interface layer was not observed in the cubic CrN film on Si(111) deposited at 600?C. Nitride film of tungsten deposited at 600?C on Si(100) wafer was nitrogen deficient, contained both cubic W{sub 2}N and hexagonal WN phases with smaller grain size. Nitride films of tungsten deposited at 500?C were nonstoichiometric and contained cubic W{sub 2}N and unreacted W phases. There was no amorphous phase formed along the interface for the tungsten nitride film deposited at 600?C on the Si wafer. Thermal conductivity and interface thermal conductance of all the nitride films of Ti, Cr, and W were determined by transient thermoreflectance technique. The thermal conductivity of the films as function of deposition temperature, microstructure, nitrogen stoichiometry and amorphous interaction layer at the interface was determined. Tungsten nitride film containing both cubic and hexagonal phases was found to exhibit much higher thermal conductivity and interface thermal conductance. The amorphous interface layer was found to reduce effective thermal conductivity of TiN and CrN films.

  1. Enhancement of the oxygen reduction on nitride stabilized pt-M (M=Fe, Co,

    Office of Scientific and Technical Information (OSTI)

    and Ni) core-shell nanoparticle electrocatalysts (Journal Article) | SciTech Connect Enhancement of the oxygen reduction on nitride stabilized pt-M (M=Fe, Co, and Ni) core-shell nanoparticle electrocatalysts Citation Details In-Document Search This content will become publicly available on June 10, 2017 Title: Enhancement of the oxygen reduction on nitride stabilized pt-M (M=Fe, Co, and Ni) core-shell nanoparticle electrocatalysts Authors: Kuttiyiel, Kurian A. ; Choi, YongMan ; Hwang, Sun-Mi

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

    DOE Patents [OSTI]

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

    2014-03-18

    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.

  3. Metal/semiconductor phase transition in chromium nitride(001) grown by

    Office of Scientific and Technical Information (OSTI)

    rf-plasma-assisted molecular-beam epitaxy (Journal Article) | SciTech Connect Metal/semiconductor phase transition in chromium nitride(001) grown by rf-plasma-assisted molecular-beam epitaxy Citation Details In-Document Search Title: Metal/semiconductor phase transition in chromium nitride(001) grown by rf-plasma-assisted molecular-beam epitaxy Structural and electronic properties of stoichiometric single-phase CrN(001) thin films grown on MgO(001) substrates by radio-frequency N

  4. Half metallic ferromagnetism in alkali metal nitrides MN (M = Rb, Cs): A first principles study

    SciTech Connect (OSTI)

    Murugan, A. Rajeswarapalanichamy, R. Santhosh, M. Sudhapriyanga, G.; Kanagaprabha, S.

    2014-04-24

    The structural, electronic and elastic properties of two alkali metal nitrides (MN: M= Rb, Cs) are investigated by the first principles calculations based on density functional theory using the Vienna ab-initio simulation package. At ambient pressure the two nitrides are stable in ferromagnetic state with CsCl structure. The calculated lattice parameters are in good agreement with the available results. The electronic structure reveals that these materials are half metallic in nature. A pressure-induced structural phase transition from CsCl to ZB phase is observed in RbN and CsN.

  5. Improved porous mixture of molybdenum nitride and tantalum oxide as a charge storage material

    SciTech Connect (OSTI)

    Deng, C.Z.; Pynenburg, R.A.J.; Tsai, K.C.

    1998-04-01

    High surface area {gamma}-molybdenum nitride has shown promise as a charge storage material. The addition of amorphous tantalum oxide to the molybdenum nitride system not only improves the film cohesion tremendously, but also widens the voltage stability window from 0.8 to 1.1 V. This occurs without adversely effecting the capacitance. Ultracapacitors, also called supercapacitors or electrochemical capacitors, are high power storage devices which have found application in products as diverse as cardiac pacemakers, cellular phones, electric vehicles, and air bags.

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

    SciTech Connect (OSTI)

    Holowczak, J.

    2002-03-01

    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.

  7. Anisotropic Hexagonal Boron Nitride Nanomaterials - Synthesis and Applications

    SciTech Connect (OSTI)

    Han,W.Q.

    2008-08-01

    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].

  8. Summer 2010 Intern Project- Ali Al-Heji | Center for Energy Efficient...

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

    Mentor: Robert M. Farrell Faculty Advisor: James S. Speck Department: Materials Indium gallium nitride (InGaN) solar cells show promise for absorbing high-energy photons with ...

  9. Understanding Drooping Light Emitting Diodes CEEM | U.S. DOE...

    Office of Science (SC) Website

    Understanding "droop" may result in cheaper, more efficient LEDs; LEDs are more energy ... indium in Indium Gallium Nitride (InGaN) green LEDs caused a decrease in light intensity. ...

  10. The influence of random indium alloy fluctuations in indium gallium nitride quantum wells on the device behavior

    SciTech Connect (OSTI)

    Yang, Tsung-Jui; Wu, Yuh-Renn; Shivaraman, Ravi; Speck, James S.

    2014-09-21

    In this paper, we describe the influence of the intrinsic indium fluctuation in the InGaN quantum wells on the carrier transport, efficiency droop, and emission spectrum in GaN-based light emitting diodes (LEDs). Both real and randomly generated indium fluctuations were used in 3D simulations and compared to quantum wells with a uniform indium distribution. We found that without further hypothesis the simulations of electrical and optical properties in LEDs such as carrier transport, radiative and Auger recombination, and efficiency droop are greatly improved by considering natural nanoscale indium fluctuations.

  11. Cycling Endurance of SONOS Non-Volatile Memory Stacks Prepared with Nitrided SiO(2)/Si(100) Intefaces

    SciTech Connect (OSTI)

    Habermehl, S.; Nasby, R.D.; Rightley, M.J.

    1999-01-11

    The effects of nitrided SiO{sub 2}/Si(100) interfaces upon cycling endurance in silicon-oxide-nitride-oxide-silicon (SONOS) non-volatile memory transistors are investigated. Analysis of MOSFET sub-threshold characteristics indicate cycling degradation to be a manifestation of interface state (D{sub it}) generation at the tunnel oxide/silicon interface. After 10{sup 6} write/erase cycles, SONOS film stacks prepared with nitrided tunnel oxides exhibit enhanced cycling endurance with {Delta}D{sub it}=3x10{sup 12} V{sup -1}cm{sup -2}, compared to {Delta}D{sub it}=2x10{sup 13} V{sup -l}cm{sup -2} for non-nitrided tunnel oxides. Additionally, if the capping oxide is formed by steam oxidation, rather than by deposition, SONOS stacks prepared with non-nitrided tunnel oxides exhibit endurance characteristics similar to stacks with nitrided tunnel oxides. From this observation it is concluded that latent nitridation of the tunnel oxidehilicon interface occurs during steam oxide cap formation.

  12. Organic additive systems for spray-drying and dry pressing silicon nitride

    SciTech Connect (OSTI)

    Walker, W.J. Jr.; Reed, J.S.

    1996-06-01

    Silicon nitride granules for dry pressing were prepared by spray-drying slurries containing polyethylene glycol as the primary binder combined with other organic additives. Differences in slurry viscosity, granule character, pressing behavior and green strength were found to depend on the choice of deflocculant.

  13. Method for Improving Mg Doping During Group-III Nitride MOCVD

    DOE Patents [OSTI]

    Creighton, J. Randall; Wang, George T.

    2008-11-11

    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.

  14. Reaction layer characterization of the braze joint of silicon nitride to stainless steel

    SciTech Connect (OSTI)

    Xu, R.; Indacochea, J.E. . Civil and Materials Engineering Dept.)

    1994-10-01

    This investigation studies the role of titanium in the development of the reaction layer in braze joining silicon nitride to stainless steel using titanium-active copper-silver filler metals. This reaction layer formed as a result of titanium diffusing to the filler metal/silicon nitride interface and reacting with the silicon nitride to form the intermetallics, titanium nitride (TiN) and titanium silicide (Ti[sub 5]Si[sub 3]). This reaction layer, as recognized in the literature, allows wetting of the ceramic substrate by the molten filler metal. The reaction layer thickness increases with temperature and time. Its growth rate obeys the parabolic relationship. Activation energies of 220.1 and 210.9 kJ/mol were calculated for growth of the reaction layer for the two filler metals used. These values are close to the activation energy of nitrogen in TiN (217.6 kJ/mol). Two filler metals were used in this study, Ticusil (68.8 wt% Ag, 26.7 wt% Cu, 4.5 wt% Ti) and CB4 (70.5 wt% Ag, 26.5 wt% Cu, 3.0 wt% Ti). The joints were processed in vacuum at temperatures of 840 to 900 C at various times. Bonding strength is affected by reaction layer thickness in the absence of Ti-Cu intermetallics in the filler metal matrix.

  15. Silicon-doped boron nitride coated fibers in silicon melt infiltrated composites

    DOE Patents [OSTI]

    Corman, Gregory Scot; Luthra, Krishan Lal

    2002-01-01

    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.

  16. Silicon-doped boron nitride coated fibers in silicon melt infiltrated composites

    DOE Patents [OSTI]

    Corman, Gregory Scot; Luthra, Krishan Lal

    1999-01-01

    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.

  17. Method of chemical vapor deposition of boron nitride using polymeric cyanoborane

    DOE Patents [OSTI]

    Maya, Leon

    1994-01-01

    Polymeric cyanoborane is volatilized, decomposed by thermal or microwave plasma energy, and deposited on a substrate as an amorphous film containing boron, nitrogen and carbon. Residual carbon present in the film is removed by ammonia treatment at an increased temperature, producing an adherent, essentially stoichiometric boron nitride film.

  18. Reactive spark plasma sintering (SPS) of nitride reinforced titanium alloy composites

    SciTech Connect (OSTI)

    Borkar, Tushar; Nag, Soumya; Ren, Yang; Tiley, Jaimie; Banerjee, Rajarshi

    2014-12-25

    Coupled in situ alloying and nitridation of titanium–vanadium alloys, has been achieved by introducing reactive nitrogen gas during the spark plasma sintering (SPS) of blended titanium and vanadium elemental powders, leading to a new class of nitride reinforced titanium alloy composites. The resulting microstructure includes precipitates of the d-TiN phase with the NaCl structure, equiaxed (or globular) precipitates of a nitrogen enriched hcp a(Ti,N) phase with a c/a ratio more than what is expected for pure hcp Ti, and fine scale plate-shaped precipitates of hcp a-Ti, distributed within a bcc b matrix. During SPS processing, the d-TiN phase appears to form at a temperature of 1400 C, while only hcp a(Ti,N) and a-Ti phases form at lower processing temperatures. Consequently, the highest microhardness is exhibited by the composite processed at 1400 C while those processed at 1300 C or below exhibit lower values. Processing at temperatures below 1300 C, resulted in an incomplete alloying of the blend of titanium and vanadium powders. These d-TiN precipitates act as heterogeneous nucleation sites for the a(Ti,N) precipitates that appear to engulf and exhibit an orientation relationship with the nitride phase at the center. Furthermore, fine scale a-Ti plates are precipitated within the nitride precipitates, presumably resulting from the retrograde solubility of nitrogen in titanium.

  19. Preparation of carbon nanoparticles and carbon nitride from high nitrogen compound

    DOE Patents [OSTI]

    Huynh, My Hang V.; Hiskey, Michael A.

    2009-09-01

    The high-nitrogen compound 3,6-di(azido)-1,2,4,5-tetrazine (DiAT) was synthesized by a relatively simple method and used as a precursor for the preparation of carbon nanospheres and nanopolygons, and nitrogen-rich carbon nitrides.

  20. Group III-nitride thin films grown using MBE and bismuth

    DOE Patents [OSTI]

    Kisielowski, Christian K.; Rubin, Michael

    2000-01-01

    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.

  1. Group III-nitride thin films grown using MBE and bismuth

    DOE Patents [OSTI]

    Kisielowski, Christian K.; Rubin, Michael

    2002-01-01

    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.

  2. Method of chemical vapor deposition of boron nitride using polymeric cyanoborane

    DOE Patents [OSTI]

    Maya, L.

    1994-06-14

    Polymeric cyanoborane is volatilized, decomposed by thermal or microwave plasma energy, and deposited on a substrate as an amorphous film containing boron, nitrogen and carbon. Residual carbon present in the film is removed by ammonia treatment at an increased temperature, producing an adherent, essentially stoichiometric boron nitride film. 11 figs.

  3. LCLS Sample Preparation Laboratory | Sample Preparation Laboratories

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

    LCLS Sample Preparation Laboratory Kayla Zimmerman | (650) 926-6281 Lisa Hammon, LCLS Lab Coordinator Welcome to the LCLS Sample Preparation Laboratory. This small general use wet...

  4. Aluminum nitride transitional layer for reducing dislocation density and cracking of AlGaN epitaxial films

    DOE Patents [OSTI]

    Allerman, Andrew A.; Crawford, Mary H.; Lee, Stephen R.

    2013-01-08

    A denticulated Group III nitride structure that is useful for growing Al.sub.xGa.sub.1-xN to greater thicknesses without cracking and with a greatly reduced threading dislocation (TD) density.

  5. Using Monte Carlo ray tracing simulations to model the quantum harmonic oscillator modes observed in uranium nitride

    SciTech Connect (OSTI)

    Lin, J. Y. Y. [California Institute of Technology, Pasadena] [California Institute of Technology, Pasadena; Aczel, Adam A [ORNL] [ORNL; Abernathy, Douglas L [ORNL] [ORNL; Nagler, Stephen E [ORNL] [ORNL; Buyers, W. J. L. [National Research Council of Canada] [National Research Council of Canada; Granroth, Garrett E [ORNL] [ORNL

    2014-01-01

    Recently an extended series of equally spaced vibrational modes was observed in uranium nitride (UN) by performing neutron spectroscopy measurements using the ARCS and SEQUOIA time-of- flight chopper spectrometers [A.A. Aczel et al, Nature Communications 3, 1124 (2012)]. These modes are well described by 3D isotropic quantum harmonic oscillator (QHO) behavior of the nitrogen atoms, but there are additional contributions to the scattering that complicate the measured response. In an effort to better characterize the observed neutron scattering spectrum of UN, we have performed Monte Carlo ray tracing simulations of the ARCS and SEQUOIA experiments with various sample kernels, accounting for the nitrogen QHO scattering, contributions that arise from the acoustic portion of the partial phonon density of states (PDOS), and multiple scattering. These simulations demonstrate that the U and N motions can be treated independently, and show that multiple scattering contributes an approximate Q-independent background to the spectrum at the oscillator mode positions. Temperature dependent studies of the lowest few oscillator modes have also been made with SEQUOIA, and our simulations indicate that the T-dependence of the scattering from these modes is strongly influenced by the uranium lattice.

  6. Facility for low-temperature spin-polarized-scanning tunneling microscopy studies of magnetic/spintronic materials prepared in situ by nitride molecular beam epitaxy

    SciTech Connect (OSTI)

    Lin, Wenzhi; Foley, Andrew; Alam, Khan; Wang, Kangkang; Liu, Yinghao; Chen, Tianjiao; Pak, Jeongihm; Smith, Arthur R.

    2014-04-15

    Based on the interest in, as well as exciting outlook for, nitride semiconductor based structures with regard to electronic, optoelectronic, and spintronic applications, it is compelling to investigate these systems using the powerful technique of spin-polarized scanning tunneling microscopy (STM), a technique capable of achieving magnetic resolution down to the atomic scale. However, the delicate surfaces of these materials are easily corrupted by in-air transfers, making it unfeasible to study them in stand-alone ultra-high vacuum STM facilities. Therefore, we have carried out the development of a hybrid system including a nitrogen plasma assisted molecular beam epitaxy/pulsed laser epitaxy facility for sample growth combined with a low-temperature, spin-polarized scanning tunneling microscope system. The custom-designed molecular beam epitaxy growth system supports up to eight sources, including up to seven effusion cells plus a radio frequency nitrogen plasma source, for epitaxially growing a variety of materials, such as nitride semiconductors, magnetic materials, and their hetero-structures, and also incorporating in situ reflection high energy electron diffraction. The growth system also enables integration of pulsed laser epitaxy. The STM unit has a modular design, consisting of an upper body and a lower body. The upper body contains the coarse approach mechanism and the scanner unit, while the lower body accepts molecular beam epitaxy grown samples using compression springs and sample skis. The design of the system employs two stages of vibration isolation as well as a layer of acoustic noise isolation in order to reduce noise during STM measurements. This isolation allows the system to effectively acquire STM data in a typical lab space, which during its construction had no special and highly costly elements included, (such as isolated slabs) which would lower the environmental noise. The design further enables tip exchange and tip coating without breaking vacuum, and convenient visual access to the sample and tip inside a superconducting magnet cryostat. A sample/tip handling system is optimized for both the molecular beam epitaxy growth system and the scanning tunneling microscope system. The sample/tip handing system enables in situ STM studies on epitaxially grown samples, and tip exchange in the superconducting magnet cryostat. The hybrid molecular beam epitaxy and low temperature scanning tunneling microscopy system is capable of growing semiconductor-based hetero-structures with controlled accuracy down to a single atomic-layer and imaging them down to atomic resolution.

  7. High quality boron carbon nitride/ZnO-nanorods p-n heterojunctions based on magnetron sputtered boron carbon nitride films

    SciTech Connect (OSTI)

    Qian, J. C.; Jha, S. K. E-mail: apwjzh@cityu.edu.hk; Wang, B. Q.; Jelenkovi?, E. V.; Bello, I.; Klemberg-Sapieha, J. E.; Martinu, L.; Zhang, W. J. E-mail: apwjzh@cityu.edu.hk

    2014-11-10

    Boron carbon nitride (BCN) films were synthesized on Si (100) and fused silica substrates by radio-frequency magnetron sputtering from a B{sub 4}C target in an Ar/N{sub 2} gas mixture. The BCN films were amorphous, and they exhibited an optical band gap of ?1.0?eV and p-type conductivity. The BCN films were over-coated with ZnO nanorod arrays using hydrothermal synthesis to form BCN/ZnO-nanorods p-n heterojunctions, exhibiting a rectification ratio of 1500 at bias voltages of 5?V.

  8. Influence of granule character and compaction on the mechanical properties of sintered silicon nitride

    SciTech Connect (OSTI)

    Takahashi, Hideo; Shinohara, Nobuhiro; Uematsu, Keizo; JunIchiro, Tsubaki

    1996-04-01

    The influence of granule character and compaction on the mechanical properties of sintered silicon nitride was studied as a function of the pH of the spray-dry slurry. The character and the compaction behavior of the spray-dried silicon nitride granules considerably affect the mechanical properties of the sintered body. Dense and hard granules resulting from a well-dispersed slurry retained their shape in green compacts and caused numerous pore defects in sintered body. Decreasing the slurry pH to a certain value (e.g., 7.9) caused slurry flocculation and reduced the granule density as well as the diametral compression strength of the granules. Sintered bodies fabricated with these weak granules contained fewer defects and showed remarkable strength increase.

  9. High density hexagonal boron nitride prepared by hot isostatic pressing in refractory metal containers

    DOE Patents [OSTI]

    Hoenig, Clarence L.

    1992-01-01

    Boron nitride powder with less than or equal to the oxygen content of starting powder (down to 0.5% or less) is hot isostatically pressed in a refractory metal container to produce hexagonal boron nitride with a bulk density greater than 2.0 g/cc. The refractory metal container is formed of tantalum, niobium, tungsten, molybdenum or alloys thereof in the form of a canister or alternatively plasma sprayed or chemical vapor deposited onto a powder compact. Hot isostatic pressing at 1800.degree. C. and 30 KSI (206.8 MPa) argon pressure for four hours produces a bulk density of 2.21 g/cc. Complex shapes can be made.

  10. Slip casting and green body evaluation of 6% yttria, 2% alumina silicon nitride. Final report

    SciTech Connect (OSTI)

    Quinn, J.

    1991-12-01

    The superior high temperature properties of silicon nitride are well known. It has good strength, excellent high temperature strength, oxidation resistance, and is resistant to thermal shock. These properties make silicon nitride a good choice for many structural ceramics. Additionally, its high thermal conductivity and low dielectric constant make it a possible candidate for electronic substrates. Knowledge in the areas of characterization, machining, and proper firing parameters is growing and crucial to the production of modern ceramics. Such knowledge also makes it increasingly evident that a poor initial green body cannot result in a good final product. Many fabrication problems can be traced back to the processes such as casting and green body preparation and attention is being concentrated in these areas.

  11. Phase transformations of nano-sized cubic boron nitride to white graphene and white graphite

    SciTech Connect (OSTI)

    Dang, Hongli; Liu, Yingdi; Xue, Wenhua; Anderson, Ryan S.; Sewell, Cody R.; Xue, Sha; Crunkleton, Daniel W.; Shen, Yaogen; Wang, Sanwu

    2014-03-03

    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.

  12. Ultra-sensitive Hall sensors based on graphene encapsulated in hexagonal boron nitride

    SciTech Connect (OSTI)

    Dauber, Jan; Stampfer, Christoph; Sagade, Abhay A.; Neumaier, Daniel; Oellers, Martin; Watanabe, Kenji; Taniguchi, Takashi

    2015-05-11

    The encapsulation of graphene in hexagonal boron nitride provides graphene on substrate with excellent material quality. Here, we present the fabrication and characterization of Hall sensor elements based on graphene boron nitride heterostructures, where we gain from high mobility and low charge carrier density at room temperature. We show a detailed device characterization including Hall effect measurements under vacuum and ambient conditions. We achieve a current- and voltage-related sensitivity of up to 5700?V/AT and 3?V/VT, respectively, outpacing state-of-the-art silicon and III/V Hall sensor devices. Finally, we extract a magnetic resolution limited by low frequency electric noise of less than 50 nT/?(Hz) making our graphene sensors highly interesting for industrial applications.

  13. Resonant second harmonic generation in a gallium nitride two-dimensional photonic crystal on silicon

    SciTech Connect (OSTI)

    Zeng, Y.; Roland, I.; Checoury, X.; Han, Z.; El Kurdi, M.; Sauvage, S.; Boucaud, P.; Gayral, B.; Brimont, C.; Guillet, T.; Mexis, M.; Semond, F.

    2015-02-23

    We demonstrate second harmonic generation in a gallium nitride photonic crystal cavity embedded in a two-dimensional free-standing photonic crystal platform on silicon. The photonic crystal nanocavity is optically pumped with a continuous-wave laser at telecom wavelengths in the transparency window of the nitride material. The harmonic generation is evidenced by the spectral range of the emitted signal, the quadratic power dependence vs. input power, and the spectral dependence of second harmonic signal. The harmonic emission pattern is correlated to the harmonic polarization generated by the second-order nonlinear susceptibilities χ{sub zxx}{sup (2)}, χ{sub zyy}{sup (2)} and the electric fields of the fundamental cavity mode.

  14. Use of free silicon in liquid phase sintering of silicon nitrides and sialons

    DOE Patents [OSTI]

    Raj, R.; Baik, S.

    1985-11-12

    This invention relates to the production of improved high density nitrogen based ceramics by liquid-phase densification of silicon nitride or a compound of silicon-nitrogen-oxygen-metal, e.g. a sialon. In the process and compositions of the invention minor amounts of finely divided silicon are employed together with the conventional liquid phase producing additives to enhance the densification of the resultant ceramic. 4 figs.

  15. Integrated rig for the production of boron nitride nanotubes via the pressurized vapor-condenser method

    DOE Patents [OSTI]

    Smith, Michael W; Jordan, Kevin C

    2014-03-25

    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.

  16. Sandia Demonstrated First-Time, Single-Mode Lasing in Gallium-Nitride

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

    Nanowire Lasers Demonstrated First-Time, Single-Mode Lasing in Gallium-Nitride Nanowire Lasers - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization

  17. Amber light-emitting diode comprising a group III-nitride nanowire active region

    DOE Patents [OSTI]

    Wang, George T.; Li, Qiming; Wierer, Jr., Jonathan J.; Koleske, Daniel

    2014-07-22

    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.

  18. Use of free silicon in liquid phase sintering of silicon nitrides and sialons

    DOE Patents [OSTI]

    Raj, Rishi; Baik, Sunggi

    1985-11-12

    This invention relates to the production of improved high density nitrogen based ceramics by liquid-phase densification of silicon nitride or a compound of silicon-nitrogen-oxygen-metal, e.g. a sialon. In the process and compositions of the invention minor amounts of finely divided silicon are employed together with the conventional liquid phase producing additives to enhance the densification of the resultant ceramic.

  19. Enhanced optical nonlinearities in the near-infrared using III-nitride heterostructures coupled to metamaterials

    SciTech Connect (OSTI)

    Wolf, Omri E-mail: ibrener@sandia.gov; Ma, Xuedan; Brener, Igal E-mail: ibrener@sandia.gov; Allerman, Andrew A.; Wendt, Joel R.; Shaner, Eric A.; Song, Alex Y.

    2015-10-12

    We use planar metamaterial resonators to enhance by more than two orders of magnitude the near infrared second harmonic generation obtained from intersubband transitions in III-Nitride heterostructures. The improvement arises from two factors: employing an asymmetric double quantum well design and aligning the resonators' cross-polarized resonances with the intersubband transition energies. The resulting nonlinear metamaterial operates at wavelengths where single photon detection is available, and represents a different class of sources for quantum photonics related phenomena.

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

    Office of Science (SC) Website

    (SC) Boron-Nitride (BN) Nanotubes (BNNT) at TJNAF Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Applications of Nuclear Science Applications of Nuclear Science Archives Small Business Innovation Research / Small Business Technology Transfer Funding Opportunities Nuclear Science Advisory Committee (NSAC) Community Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington,

  1. Electronic structure and magnetic properties of RuFe{sub 3}N nitride

    SciTech Connect (OSTI)

    Santos, A.V. dos; Kuhnen, C.A.

    2009-11-15

    Self-consistent band structure calculations were performed on nitride RuFe{sub 3}N in order to investigate its magnetic and ground state properties. The Linear Muffin-Tin Orbital (LMTO) method was employed and calculations were performed at several lattice parameters so as to obtain the RuFe{sub 3}N equilibrium volume. Nonmagnetic and ferromagnetic LMTO calculations have shown that the RuFe{sub 3}N stable stage is ferromagnetic with constant lattice equilibrium of 7.2502 atomic units (a.u.). At equilibrium volume the LMTO calculations have given magnetic moments of 1.25 and 1.63 mu{sub B} at Ru and Fe sites, respectively, and no magnetic moment at N sites. The analysis of states density at equilibrium volume as well as the results for charge transfer illustrates why this ruthenium nitride is ferromagnetic. The LMTO calculations anticipate that the magnetic moment, the hyperfine field (the Fermi contact) and the isomer shift show a strong dependence on the lattice spacing. - Graphical Abstract: Total energy curves, versus lattice spacing for the RuFe{sub 3}N nitride. It is observed an energy difference between ferromagnetic and paramagnetic states, which provides high critic pressure.

  2. MOCVD synthesis of group III-nitride heterostructure nanowires for solid-state lighting.

    SciTech Connect (OSTI)

    Wang, George T.; Creighton, James Randall; Talin, Albert Alec

    2006-11-01

    Solid-state lighting (SSL) technologies, based on semiconductor light emitting devices, have the potential to reduce worldwide electricity consumption by more than 10%, which could significantly reduce U.S. dependence on imported energy and improve energy security. The III-nitride (AlGaInN) materials system forms the foundation for white SSL and could cover a wide spectral range from the deep UV to the infrared. For this LDRD program, we have investigated the synthesis of single-crystalline III-nitride nanowires and heterostructure nanowires, which may possess unique optoelectronic properties. These novel structures could ultimately lead to the development of novel and highly efficient SSL nanodevice applications. GaN and III-nitride core-shell heterostructure nanowires were successfully synthesized by metal organic chemical vapor deposition (MOCVD) on two-inch wafer substrates. The effect of process conditions on nanowire growth was investigated, and characterization of the structural, optical, and electrical properties of the nanowires was also performed.

  3. Water and Sediment Sampling

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

    L) (Bq/L) Sample of Opportunity * 9/13/2014 Below MDC Below MDC Sample of Opportunity * 9/13/2014 Below MDC Below MDC Sample of Opportunity * 9/13/2014 Below MDC Below MDC Sample of Opportunity (Dupe) * 9/13/2014 Below MDC Below MDC Sample of Opportunity * 9/13/2014 Below MDC Below MDC Sample of Opportunity * 9/13/2014 Below MDC Below MDC Blank 9/13/2014 Below MDC Below MDC Sample of Opportunity * 8/26/2014 Below MDC Below MDC Sample of Opportunity (Dupe) * 8/26/2014 Below MDC Below MDC Sample

  4. September 2004 Water Sampling

    Office of Legacy Management (LM)

    ... Treatment system locations 1202, 1205, and 1206 were not ... and types (alkalinity, temperature, specific conductance, ... and sampled using the low-flow sampling method and ...

  5. Power mixture and green body for producing silicon nitride base articles of high fracture toughness and strength

    DOE Patents [OSTI]

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

    1991-09-17

    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

  6. 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 (OSTI)

    McGuiggan, M.F.; Kuch, P.L.

    1984-05-08

    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.

  7. Fluid sampling tool

    DOE Patents [OSTI]

    Garcia, Anthony R.; Johnston, Roger G.; Martinez, Ronald K.

    2000-01-01

    A fluid-sampling tool for obtaining a fluid sample from a container. When used in combination with a rotatable drill, the tool bores a hole into a container wall, withdraws a fluid sample from the container, and seals the borehole. The tool collects fluid sample without exposing the operator or the environment to the fluid or to wall shavings from the container.

  8. Sample Preparation Laboratory Training - Course 204 | Sample...

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

    mandatory for: SLAC employees and non-employees who need unescorted access to SSRL or LCLS Sample Preparation Laboratories Note: This course may be taken in lieu of Course 199,...

  9. The Sample Preparation Laboratories | Sample Preparation Laboratories

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

    Cynthia Patty 1 Sam Webb 2 John Bargar 3 Arizona 4 Chemicals 5 Team Work 6 Bottles 7 Glass 8 Plan Ahead! See the tabs above for Laboratory Access and forms you'll need to complete. Equipment and Chemicals tabs detail resources already available on site. Avoid delays! Hazardous materials use may require a written Standard Operating Procedure (SOP) before you work. Check the Chemicals tab for more information. The Sample Preparation Laboratories The Sample Preparation Laboratories provide wet lab

  10. Rain sampling device

    DOE Patents [OSTI]

    Nelson, D.A.; Tomich, S.D.; Glover, D.W.; Allen, E.V.; Hales, J.M.; Dana, M.T.

    1991-05-14

    The present invention constitutes a rain sampling device adapted for independent operation at locations remote from the user which allows rainfall to be sampled in accordance with any schedule desired by the user. The rain sampling device includes a mechanism for directing wet precipitation into a chamber, a chamber for temporarily holding the precipitation during the process of collection, a valve mechanism for controllably releasing samples of the precipitation from the chamber, a means for distributing the samples released from the holding chamber into vessels adapted for permanently retaining these samples, and an electrical mechanism for regulating the operation of the device. 11 figures.

  11. Rain sampling device

    DOE Patents [OSTI]

    Nelson, Danny A. (Richland, WA); Tomich, Stanley D. (Richland, WA); Glover, Donald W. (Prosser, WA); Allen, Errol V. (Benton City, WA); Hales, Jeremy M. (Kennewick, WA); Dana, Marshall T. (Richland, WA)

    1991-01-01

    The present invention constitutes a rain sampling device adapted for independent operation at locations remote from the user which allows rainfall to be sampled in accordance with any schedule desired by the user. The rain sampling device includes a mechanism for directing wet precipitation into a chamber, a chamber for temporarily holding the precipitation during the process of collection, a valve mechanism for controllably releasing samples of said precipitation from said chamber, a means for distributing the samples released from the holding chamber into vessels adapted for permanently retaining these samples, and an electrical mechanism for regulating the operation of the device.

  12. The development of a porous silicon nitride crossflow filter; Final report, September 1988--September 1992

    SciTech Connect (OSTI)

    1992-09-01

    This report summarizes the work performed in developing a permeable form of silicon nitride for application to ceramic crossflow filters for use in advanced coal-fired electric power plants. The program was sponsored by the Department of Energy Morgantown Energy Technology Center and consisted of a design analysis and material development phase and a filter manufacture and demonstration phase. The crossflow filter design and operating requirements were defined. A filter design meeting the requirements was developed and thermal and stress analyses were performed. Material development efforts focused initially on reaction-bonded silicon nitride material. This approach was not successful, and the materials effort was refocused on the development of a permeable form of sintered silicon nitride (SSN). This effort was successful. The SSN material was used for the second phase of the program, filter manufacture and evaluation. Four half-scale SAN filter modules were fabricated. Three of the modules were qualified for filter performance tests. Tests were performed on two of the three qualified modules in the High-Temperature, High-Pressure facility at the Westinghouse Science and Technology Center. The first module failed on test when it expanded into the clamping device, causing dust leakage through the filter. The second module performed well for a cumulative 150-hr test. It displayed excellent filtration capability during the test. The blowback pulse cleaning was highly effective, and the module apparently withstood the stresses induced by the periodic pulse cleaning. Testing of the module resumed, and when the flow of combustion gas through the filter was doubled, cracks developed and the test was concluded.

  13. Pulsed DC magnetron sputtered piezoelectric thin film aluminum nitride – Technology and piezoelectric properties

    SciTech Connect (OSTI)

    Stoeckel, C. Kaufmann, C.; Hahn, R.; Schulze, R.; Billep, D.; Gessner, T.

    2014-07-21

    Pulsed DC magnetron sputtered aluminum nitride (AlN) thin films are prepared on several seed layers and at different sputtering conditions. The piezoelectric c-axis (002) orientation of the AlN is analyzed with X-ray diffraction method. The transverse piezoelectric coefficient d{sub 31} is determined with a Laser-Doppler-Vibrometer at cantilevers and membranes by analytical calculations and finite element method. Additionally, thin film AlN on bulk silicon is used to characterize the longitudinal piezoelectric charge coefficient d{sub 33}.

  14. Auger analysis of scandium, Sc-Oxide, Sc-Deuteride and Sc-Nitride

    SciTech Connect (OSTI)

    Moore, G.; Nelson, G.C.; Madden, H.H.

    1996-09-01

    Elemental scandium, Sc-oxide, Sc-hydride and Sc-nitride films were investigated using Auger electron spectroscopy in a study of the interaction of scandium with hydrogen and atmospheric gases. A catalog of Sc Auger spectra representative of Sc-metal, Sc-0, Sc-H and Sc-N bonding is presented. Changes in spectral features unique to the changes in scandium matrix are identified. Comparisons with theoretical calculations, along with variation in the experimental conditions for recording the Auger data, enabled the Sc spectra found in separate low and high energy regions to be identified with M-shell and L-shell core excitations, respectively.

  15. Strength and fatigue of NT551 silicon nitride and NT551 diesel exhaust valves

    SciTech Connect (OSTI)

    Andrews, M.J.; Werezczak, A.A.; Kirkland, T.P.; Breder, K.

    2000-02-01

    The content of this report is excerpted from Mark Andrew's Ph.D. Thesis (Andrews, 1999), which was funded by a DOE/OTT High Temperature Materials Laboratory Graduate Fellowship. It involves the characterization of NT551 and valves fabricated with it. The motivations behind using silicon nitride (Si{sub 3}N{sub 4}) as an exhaust valve for a diesel engine are presented in this section. There are several economic factors that have encouraged the design and implementation of ceramic components for internal combustion (IC) engines. The reasons for selecting the diesel engine valve for this are also presented.

  16. September 2004 Water Sampling

    Office of Legacy Management (LM)

    ... met when purging a Category I well: Was one pumptubing volume purged prior to sampling? ... Yes Was one pumptubing volume removed prior to sampling? Yes 9. Were duplicates taken at ...

  17. September 2004 Water Sampling

    Office of Legacy Management (LM)

    .........9 Sampling Quality Control Assessment ......the water level probe would become tangled with the dedicated pump tubing and power cable. ...

  18. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Sampling at the Falls City, Texas, Disposal Site July 2015 LMS/FCT/S00415 This page intentionally left blank U.S. Department of Energy DVP-April 2015, Falls City, Texas July 2015 RIN 15036899 Page i Contents Sampling Event Summary ...............................................................................................................1 Falls City, Texas, Disposal Site Sample Location Map...................................................................3 Data Assessment Summary

  19. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Sampling at the Hallam, Nebraska, Decommissioned Reactor Site September 2014 LMS/HAL/S00614 This page intentionally left blank U.S. Department of Energy DVP-June 2014, Hallam, Nebraska September 2014 RIN 14056211 Page i Contents Sampling Event Summary ...............................................................................................................1 Hallam, Nebraska, Sample Location Map .......................................................................................3 Data

  20. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Water Sampling at the Ambrosia Lake, New Mexico, Disposal Site February 2015 LMS/AMB/S01114 This page intentionally left blank U.S. Department of Energy DVP-November 2014, Ambrosia Lake, New Mexico February 2015 RIN 14116607 Page i Contents Sampling Event Summary ...............................................................................................................1 Ambrosia Lake, NM, Disposal Site Planned Sampling Map...........................................................3 Data

  1. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Sampling at the Ambrosia Lake, New Mexico, Disposal Site March 2016 LMS/AMB/S01215 This page intentionally left blank U.S. Department of Energy DVP-December 2015, Ambrosia Lake, New Mexico March 2016 RIN 15117494 Page i Contents Sampling Event Summary ...............................................................................................................1 Ambrosia Lake, NM, Disposal Site Planned Sampling Map...........................................................3 Data Assessment

  2. September 2004 Water Sampling

    Office of Legacy Management (LM)

    October 2013 Groundwater Sampling at the Bluewater, New Mexico, Disposal Site December 2013 LMS/BLU/S00813 This page intentionally left blank U.S. Department of Energy DVP-August and October 2013, Bluewater, New Mexico December 2013 RIN 13085537 and 13095651 Page i Contents Sampling Event Summary ...............................................................................................................1 Private Wells Sampled August 2013 and October 2013, Bluewater, NM, Disposal Site

  3. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Groundwater Sampling at the Bluewater, New Mexico, Disposal Site February 2015 LMS/BLU/S01114 This page intentionally left blank U.S. Department of Energy DVP-November 2014, Bluewater, New Mexico February 2015 RIN 14116606 Page i Contents Sampling Event Summary ...............................................................................................................1 Bluewater, New Mexico, Disposal Site, Sample Location Map......................................................5 Data

  4. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and Surface Water Sampling at the Monument Valley, Arizona, Processing Site February 2015 LMS/MON/S01214 This page intentionally left blank U.S. Department of Energy DVP-December 2014, Monument Valley, Arizona February 2015 RIN 14126645 Page i Contents Sampling Event Summary ...............................................................................................................1 Monument Valley, Arizona, Disposal Site Sample Location Map ..................................................5

  5. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and Surface Water Sampling at the Monticello, Utah, Processing Site July 2014 LMS/MNT/S00414 This page intentionally left blank U.S. Department of Energy DVP-April 2014, Monticello, Utah July 2014 RIN 14046077 Page i Contents Sampling Event Summary ...............................................................................................................1 Planned Sampling Map, April 2014, Monticello, Utah, Processing Site .........................................5 Data Assessment Summary

  6. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and Surface Water Sampling at the Monticello, Utah, Processing Site July 2015 LMS/MNT/S00415 This page intentionally left blank U.S. Department of Energy DVP-April 2015, Monticello, Utah July 2015 RIN 15046927 Page i Contents Sampling Event Summary ...............................................................................................................1 Monticello, Utah, Processing Site Sample Location Map ...............................................................5 Data Assessment

  7. September 2004 Water Sampling

    Office of Legacy Management (LM)

    3 Water Sampling at the Monticello, Utah, Processing Site January 2014 LMS/MNT/S01013 This page intentionally left blank U.S. Department of Energy DVP-October 2013, Monticello, Utah January 2014 RIN 13105661 and 13105711 Page i Contents Sampling Event Summary ...............................................................................................................1 Planned Sampling Map, Monticello, Utah, Processing and Disposal Site, October 2013 ..............5 Data Assessment Summary

  8. September 2004 Water Sampling

    Office of Legacy Management (LM)

    4 Alternate Water Supply System Sampling at the Riverton, Wyoming, Processing Site May 2014 LMS/RVT/S00314 This page intentionally left blank U.S. Department of Energy DVP-March 2014, Riverton, Wyoming May 2014 RIN 14035986 Page i Contents Sampling Event Summary ...............................................................................................................1 Riverton, WY, Processing Site, Sample Location Map ...................................................................3 Data

  9. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Groundwater, Surface Water, and Alternate Water Supply System Sampling at the Riverton, Wyoming, Processing Site December 2013 LMS/RVT/S00913 This page intentionally left blank U.S. Department of Energy DVP-September 2013, Riverton, Wyoming December 2013 RIN 13095603 Page i Contents Sampling Event Summary ...............................................................................................................1 Riverton, Wyoming, Sample Location Map

  10. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and May 2014 Groundwater and Surface Water Sampling at the Shiprock, New Mexico, Disposal Site June 2014 LMS/SHP/S00314 This page intentionally left blank U.S. Department of Energy DVP-March and May 2014, Shiprock, New Mexico June 2014 RIN 14036011, 14036013, and 14056142 Page i Contents Sampling Event Summary ...............................................................................................................1 Shiprock, New Mexico, Disposal Site, Sample Location Map

  11. September 2004 Water Sampling

    Office of Legacy Management (LM)

    2015 Groundwater and Surface Water Sampling at the Shiprock, New Mexico, Disposal Site June 2015 LMS/SHP/S00315 This page intentionally left blank U.S. Department of Energy DVP-March 2015, Shiprock, New Mexico June 2015 RIN 15036862 and 15036863 Page i Contents Sampling Event Summary ...............................................................................................................1 Planned Sampling Map Shiprock, New Mexico, Disposal Site

  12. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Sampling at the Shirley Basin South, Wyoming, Disposal Site September 2013 LMS/SBS/S00613 This page intentionally left blank U.S. Department of Energy DVP-June 2013, Shirley Basin South, Wyoming September 2013 RIN 13065426 Page i Contents Sampling Event Summary ...............................................................................................................1 Shirley Basin South, Wyoming, Disposal Site Sample Location Map ............................................3 Data Assessment

  13. September 2004 Water Sampling

    Office of Legacy Management (LM)

    February 2015 Groundwater and Surface Water Sampling at the Grand Junction, Colorado, Site April 2015 LMS/GJO/S00215 This page intentionally left blank U.S. Department of Energy DVP-February 2015, Grand Junction, Colorado, Site April 2015 RIN 15026795 Page i Contents Sampling Event Summary ...............................................................................................................1 Grand Junction, Colorado, Site Sample Location Map

  14. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Groundwater Sampling at the Grand Junction, Colorado, Disposal Site November 2014 LMS/GRJ/S00814 This page intentionally left blank U.S. Department of Energy DVP-August 2014, Grand Junction, Colorado November 2014 RIN 14076376 Page i Contents Sampling Event Summary ...............................................................................................................1 Grand Junction, Colorado, Disposal Site Sample Location Map ....................................................3 Data

  15. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Sampling at the Grand Junction, Colorado, Disposal Site November 2013 LMS/GRJ/S00813 This page intentionally left blank U.S. Department of Energy DVP-August 2013, Grand Junction, Colorado November 2013 RIN 13075515 Page i Contents Sampling Event Summary ...............................................................................................................1 Grand Junction, Colorado, Disposal Site Sample Location Map ....................................................3 Data Assessment

  16. September 2004 Water Sampling

    Office of Legacy Management (LM)

    4 Groundwater and Surface Water Sampling at the Gunnison, Colorado, Processing Site September 2014 LMS/GUP/S00414 This page intentionally left blank U.S. Department of Energy DVP-April and June 2014, Gunnison, Colorado September 2014 RIN 14046058 and 14066262 Page i Contents Sampling Event Summary ...............................................................................................................1 Gunnison, Colorado, Processing Site Planned Sampling Map

  17. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and Surface Water Sampling at the Naturita, Colorado Processing Site October 2013 LMS/NAP/S00713 This page intentionally left blank U.S. Department of Energy DVP-July 2013, Naturita, Colorado October 2013 RIN 13075483 Page i Contents Sampling Event Summary ...............................................................................................................1 Naturita, Colorado, Sample Location Map ......................................................................................3

  18. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Old and New Rifle, Colorado, Processing Sites August 2013 LMS/RFN/RFO/S00613 This page intentionally left blank U.S. Department of Energy DVP-June 2013, Rifle, Colorado August 2013 RIN 13065380 Page i Contents Sampling Event Summary ...............................................................................................................1 Sample Location Map, New Rifle, Colorado, Processing Site ........................................................5 Sample Location Map, Old Rifle,

  19. September 2004 Water Sampling

    Office of Legacy Management (LM)

    4 Groundwater and Surface Water Sampling at the Slick Rock, Colorado, Processing Sites December 2014 LMS/SRW/SRE/S00914 This page intentionally left blank U.S. Department of Energy DVP-September 2014, Slick Rock, Colorado December 2014 RIN 14096456 Page i Contents Sampling Event Summary ...............................................................................................................1 Slick Rock, Colorado, Processing Sites, Sample Location Map

  20. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Groundwater and Surface Water Sampling at the Slick Rock East and West, Colorado, Processing Sites November 2013 LMS/SRE/SRW/S0913 This page intentionally left blank U.S. Department of Energy DVP-September 2013, Slick Rock, Colorado November 2013 RIN 13095593 Page i Contents Sampling Event Summary ...............................................................................................................1 Slick Rock East and West, Colorado, Processing Sites, Sample Location Map

  1. Aerosol sampling system

    DOE Patents [OSTI]

    Masquelier, Donald A.

    2004-02-10

    A system for sampling air and collecting particulate of a predetermined particle size range. A low pass section has an opening of a preselected size for gathering the air but excluding particles larger than the sample particles. An impactor section is connected to the low pass section and separates the air flow into a bypass air flow that does not contain the sample particles and a product air flow that does contain the sample particles. A wetted-wall cyclone collector, connected to the impactor section, receives the product air flow and traps the sample particles in a liquid.

  2. Sample Proficiency Test exercise

    SciTech Connect (OSTI)

    Alcaraz, A; Gregg, H; Koester, C

    2006-02-05

    The current format of the OPCW proficiency tests has multiple sets of 2 samples sent to an analysis laboratory. In each sample set, one is identified as a sample, the other as a blank. This method of conducting proficiency tests differs from how an OPCW designated laboratory would receive authentic samples (a set of three containers, each not identified, consisting of the authentic sample, a control sample, and a blank sample). This exercise was designed to test the reporting if the proficiency tests were to be conducted. As such, this is not an official OPCW proficiency test, and the attached report is one method by which LLNL might report their analyses under a more realistic testing scheme. Therefore, the title on the report ''Report of the Umpteenth Official OPCW Proficiency Test'' is meaningless, and provides a bit of whimsy for the analyses and readers of the report.

  3. Growth and magnetic property of antiperovskite manganese nitride films doped with Cu by molecular beam epitaxy

    SciTech Connect (OSTI)

    Yu, Fengmei; Ren, Lizhu; Meng, Meng; Wang, Yunjia; Yang, Mei; Wu, Shuxiang; Li, Shuwei

    2014-04-07

    Manganese nitrides thin films on MgO (100) substrates with and without Cu-doping have been fabricated by plasma assisted molecular beam epitaxy. Antiperovskite compounds Mn{sub 3.6}Cu{sub 0.4}N have been grown in the case of Cu-doping, and the pure Mn{sub 3}N{sub 2} single crystal has been obtained without Cu-doping. The Mn{sub 3.6}Cu{sub 0.4}N exhibits ferrimagnetism, and the magnetization of Mn{sub 3.6}Cu{sub 0.4}N increases upon the temperature decreasing from 300 K to 5 K, similar to Mn{sub 4}N. The exchange bias (EB) effects emerge in the Mn{sub 3.6}Cu{sub 0.4}N films. The EB behavior is originated from the interfaces between ferrimagnetic Mn{sub 3.6}Cu{sub 0.4}N and antiferromagnetic metal Mn, which is verified to be formed by the data of x-ray photoelectron spectroscopy. The present results not only provide a strategy for producing functional antiperovskite manganese nitrides, but also shed promising light on fabricating the exchange bias part of spintronic devices.

  4. Electron trap level of hydrogen incorporated nitrogen vacancies in silicon nitride

    SciTech Connect (OSTI)

    Sonoda, Ken'ichiro Tsukuda, Eiji; Tanizawa, Motoaki; Yamaguchi, Yasuo

    2015-03-14

    Hydrogen incorporation into nitrogen vacancies in silicon nitride and its effects on electron trap level are analyzed using simulation based on density functional theory with temperature- and pressure-dependent hydrogen chemical potential. If the silicon dangling bonds around a nitrogen vacancy are well separated each other, hydrogen incorporation is energetically stable up to 900?C, which is in agreement with the experimentally observed desorption temperature. On the other hand, if the dangling bonds strongly interact, the incorporation is energetically unfavorable even at room temperature because of steric hindrance. An electron trap level caused by a nitrogen vacancy becomes shallow by the hydrogen incorporation. An electron is trapped in a deep level created by a silicon dangling bond before hydrogen incorporation, whereas it is trapped in a shallow level created by an anti-bonding state of a silicon-silicon bond after hydrogen incorporation. The simulation results qualitatively explain the experiment, in which reduced hydrogen content in silicon nitride shows superior charge retention characteristics.

  5. Power mixture and green body for producing silicon nitride base & articles of high fracture toughness and strength

    DOE Patents [OSTI]

    Huckabee, Marvin L.; Buljan, Sergej-Tomislav; Neil, Jeffrey T.

    1991-01-01

    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.

  6. First principle study of structural, electronic and magnetic properties of zigzag boron nitride nanoribbon: Role of vacancies

    SciTech Connect (OSTI)

    Kumar, Arun; Bahadur, Amar; Mishra, Madhukar; Vasudeva, Neena

    2015-05-15

    We study the effect of vacancies on the structural, electronic and magnetic properties of zigzag boron nitride nanoribbon (ZBNNR) by using first principle calculations. We find that the shift of the vacancies with respect to the ribbon edges causes change in the structural geometry, electronic structure and magnetization of ZBNNR. These vacancies also produce band gap modulation and consequently results the magnetization of ZBNNR.

  7. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and September 2013 Groundwater and Surface Water Sampling at the Durango, Colorado, Disposal and Processing Sites March 2014 LMS/DUD/DUP/S00613 This page intentionally left blank U.S. Department of Energy DVP-June and September 2013, Durango, Colorado March 2014 RIN 13055370 and 13085577 Page i Contents Sampling Event Summary ...............................................................................................................1 Durango, Colorado, Disposal Site Sample Location Map-June

  8. September 2004 Water Sampling

    Office of Legacy Management (LM)

    .........11 Sampling Quality Control Assessment ......Yes With the exception of well 83-70 which is an irrigation pump with power lines inside, ...

  9. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Data Surface Water and Treatment System Quality Data ... and types (alkalinity, temperature, specific conductance, ... met the Category I or II low-flow sampling criteria and ...

  10. Creating Sample Plans

    Energy Science and Technology Software Center (OSTI)

    1999-03-24

    The program has been designed to increase the accuracy and reduce the preparation time for completing sampling plans. It consists of our files 1. Analyte/Combination (AnalCombo) A list of analytes and combinations of analytes that can be requested of the onsite and offsite labs. Whenever a specific combination of analytes or suite names appear on the same line as the code number, this indicates that one sample can be placed in one bottle to bemore » analyzed for these paremeters. A code number is assigned for each analyte and combination of analytes. 2. Sampling Plans Database (SPDb) A database that contains all of the analytes and combinations of analytes along with the basic information required for preparing a sample plan. That basic information includes the following fields; matrix, hold time, preservation, sample volume, container size, if the bottle caps are taped, acceptable choices. 3. Sampling plans create (SPcreate) a file that will lookup information from the Sampling Plans Database and the Job Log File (JLF98) A major database used by Sample Managemnet Services for recording more than 100 fields of information.« less

  11. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Falls City, Texas, Disposal Site April 2014 LMS/FCT/S00214 This page intentionally left blank U.S. Department of Energy DVP-February 2014, Falls City, Texas April 2014 RIN 14025923 Page i Contents Sampling Event Summary ...............................................................................................................1 Falls City, Texas, Disposal Site, Sample Location Map..................................................................3 Data Assessment Summary

  12. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Parkersburg, West Virginia, Disposal Site February 2014 LMS/PKB/S01113 This page intentionally left blank U.S. Department of Energy DVP-November 2013, Parkersburg, West Virginia February 2014 13095640, 13115753 Page i Contents Sampling Event Summary ...............................................................................................................1 Parkersburg, West Virginia, Disposal Site Sample Location Map ..................................................5 Data Assessment Summary

  13. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Sherwood, Washington, Disposal Site July 2014 LMS/SHE/S00514 This page intentionally left blank U.S. Department of Energy DVP-May 2014, Sherwood, Washington July 2014 RIN 14056159 Page i Contents Sampling Event Summary ...............................................................................................................1 Sherwood, Washington, Disposal Site Sample Location Map ........................................................3 Data Assessment Summary

  14. Adaptive Sampling Proxy Application

    Energy Science and Technology Software Center (OSTI)

    2012-10-22

    ASPA is an implementation of an adaptive sampling algorithm [1-3], which is used to reduce the computational expense of computer simulations that couple disparate physical scales. The purpose of ASPA is to encapsulate the algorithms required for adaptive sampling independently from any specific application, so that alternative algorithms and programming models for exascale computers can be investigated more easily.

  15. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Canonsburg, Pennsylvania, Disposal Site February 2014 LMS/CAN/S01113 This page intentionally left blank U.S. Department of Energy DVP-November 2013, Canonsburg, Pennsylvania February 2014 RIN 13095639 Page i Contents Sampling Event Summary ...............................................................................................................1 Canonsburg, Pennsylvania, Disposal Site, Sample Location Map ..................................................3 Data Assessment Summary

  16. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Riverton, Wyoming, Processing Site September 2013 LMS/RVT/S00613 This page intentionally left blank U.S. Department of Energy DVP-June 2013, Riverton, Wyoming September 2013 RIN 13065379 Page i Contents Sampling Event Summary ...............................................................................................................1 Riverton, Wyoming, Processing Site, Sample Location Map .........................................................5 Data Assessment Summary

  17. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Riverton, Wyoming, Processing Site February 2016 LMS/RVT/S00915 This page intentionally left blank U.S. Department of Energy DVP-September 2015, Riverton, Wyoming February 2016 RINs 15097345, 15097346, and 15097347 Page i Contents Sampling Event Summary ...............................................................................................................1 Riverton, Wyoming, Processing Site Planned Sampling Location Map .........................................7 Data Assessment Summary

  18. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Durango, Colorado, Disposal and Processing Sites October 2015 LMS/___/S0 LMS/DUR/S00615 This page intentionally left blank U.S. Department of Energy DVP-June 2015, Durango, Colorado October 2015 RIN 15057084 Page i Contents Sampling Event Summary ...............................................................................................................1 Durango, Colorado, Disposal Site, Sample Location Map ..............................................................5 Durango, Colorado,

  19. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Grand Junction, Colorado, Site April 2014 LMS/GJO/S00214 This page intentionally left blank U.S. Department of Energy DVP-February 2014, Grand Junction, Colorado April 2014 RIN 14025928 Page i Contents Sampling Event Summary ...............................................................................................................1 Grand Junction, Colorado, Site Sample Location Map ...................................................................3 Data Assessment Summary

  20. September 2004 Water Sampling

    Office of Legacy Management (LM)

    July 2015 Groundwater and Surface Water Sampling at the Gunnison, Colorado, Processing Site February 2016 LMS/GUP/S00415 This page intentionally left blank U.S. Department of Energy DVP-April and July 2015, Gunnison, Colorado February 2016 RINs 15046911 and 15067187 Page i Contents Sampling Event Summary ...............................................................................................................1 Data Assessment Summary

  1. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Rifle, Colorado, New and Old Processing Sites January 2014 LMS/RFN/RFO/S01113 This page intentionally left blank U.S. Department of Energy DVP-November 2013, Rifle, Colorado January 2014 RIN 13115731 Page i Contents Sampling Event Summary ...............................................................................................................1 New Rifle, Colorado, Processing Site, Sample Location Map ........................................................5 Old Rifle, Colorado, Processing

  2. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Old and New Rifle, Colorado, Processing Sites January 2015 LMS/RFN/RFO/S01114 This page intentionally left blank U.S. Department of Energy DVP-November 2014, Rifle, Colorado January 2015 RINs 14106568 and 14106569 Page i Contents Sampling Event Summary ...............................................................................................................1 New Rifle, Colorado, Processing Site, Planned Sampling Map ......................................................3 Old Rifle,

  3. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Slick Rock, Colorado, Processing Sites January 2016 LMS/SRE/SRW/S00915 This page intentionally left blank U.S. Department of Energy DVP-September 2015, Slick Rock, Colorado January 2016 RINs 15087319 and 15107424 Page i Contents Sampling Event Summary ...............................................................................................................1 Slick Rock, Colorado, Processing Sites, Sample Location Map .....................................................5 Data Assessment

  4. Sampling system and method

    DOE Patents [OSTI]

    Decker, David L.; Lyles, Brad F.; Purcell, Richard G.; Hershey, Ronald Lee

    2013-04-16

    The present disclosure provides an apparatus and method for coupling conduit segments together. A first pump obtains a sample and transmits it through a first conduit to a reservoir accessible by a second pump. The second pump further conducts the sample from the reservoir through a second conduit.

  5. Biological sample collector

    DOE Patents [OSTI]

    Murphy, Gloria A.

    2010-09-07

    A biological sample collector is adapted to a collect several biological samples in a plurality of filter wells. A biological sample collector may comprise a manifold plate for mounting a filter plate thereon, the filter plate having a plurality of filter wells therein; a hollow slider for engaging and positioning a tube that slides therethrough; and a slide case within which the hollow slider travels to allow the tube to be aligned with a selected filter well of the plurality of filter wells, wherein when the tube is aligned with the selected filter well, the tube is pushed through the hollow slider and into the selected filter well to sealingly engage the selected filter well and to allow the tube to deposit a biological sample onto a filter in the bottom of the selected filter well. The biological sample collector may be portable.

  6. Analysis of Nitrogen Incorporation in Group III-Nitride-Arsenide Materials Using a Magnetic Sector Secondary-Ion Mass Spectrometry (SIMS) Instrument: Preprint

    SciTech Connect (OSTI)

    Reedy, R. C.; Geisz, J. F.; Kurtz, S. R.; Adams, R. O.; Perkins, C. L.

    2001-10-01

    Presented at the 2001 NCPV Program Review Meeting: Group III-nitride-arsenide materials were studied by SIMS, XRD, and Profiler to determine small amounts of nitrogen that can lower the alloys bandgap significantly.

  7. Water Sample Concentrator

    ScienceCinema (OSTI)

    Idaho National Laboratory

    2010-01-08

    Automated portable device that concentrates and packages a sample of suspected contaminated water for safe, efficient transport to a qualified analytical laboratory. This technology will help safeguard against pathogen contamination or chemical and biolog

  8. September 2004 Water Sampling

    Office of Legacy Management (LM)

    ... Yes 7. Were the following conditions met when purging a Category I well: Was one pump... Yes Was one pumptubing volume removed prior to sampling? Yes 9. Were duplicates taken at ...

  9. September 2004 Water Sampling

    Office of Legacy Management (LM)

    2014 LMSGRNS00614 This page intentionally left blank U.S. Department of Energy DVP-June 2014, Green River, Utah August 2014 RIN 14066228 Page i Contents Sampling Event Summary ...

  10. September 2004 Water Sampling

    Office of Legacy Management (LM)

    ... DATA QUALIFIERS: F Low flow sampling method used. G Possible ... 10302014 N001 1900 0 Temperature C 10302014 N001 10.06 ... yards downstream from Treatment System Outfall Parameter ...

  11. September 2004 Water Sampling

    Office of Legacy Management (LM)

    ... Yes 5. Were the number and types (alkalinity, temperature, ... met the Category I or II low-flow sampling criteria and ... The three treatment plant locations 1202, 1205, and 1206 ...

  12. Dissolution actuated sample container

    DOE Patents [OSTI]

    Nance, Thomas A.; McCoy, Frank T.

    2013-03-26

    A sample collection vial and process of using a vial is provided. The sample collection vial has an opening secured by a dissolvable plug. When dissolved, liquids may enter into the interior of the collection vial passing along one or more edges of a dissolvable blocking member. As the blocking member is dissolved, a spring actuated closure is directed towards the opening of the vial which, when engaged, secures the vial contents against loss or contamination.

  13. SAMPLING AND ANALYSIS PROTOCOLS

    SciTech Connect (OSTI)

    Jannik, T; P Fledderman, P

    2007-02-09

    Radiological sampling and analyses are performed to collect data for a variety of specific reasons covering a wide range of projects. These activities include: Effluent monitoring; Environmental surveillance; Emergency response; Routine ambient monitoring; Background assessments; Nuclear license termination; Remediation; Deactivation and decommissioning (D&D); and Waste management. In this chapter, effluent monitoring and environmental surveillance programs at nuclear operating facilities and radiological sampling and analysis plans for remediation and D&D activities will be discussed.

  14. Pt monolayer shell on nitrided alloy core — A path to highly stable oxygen reduction catalyst

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

    Hu, Jue; Kuttiyiel, Kurian A.; Sasaki, Kotaro; Su, Dong; Yang, Tae -Hyun; Park, Gu -Gon; Zhang, Chengxu; Chen, Guangyu; Adzic, Radoslav R.

    2015-07-22

    The inadequate activity and stability of Pt as a cathode catalyst under the severe operation conditions are the critical problems facing the application of the proton exchange membrane fuel cell (PEMFC). Here we report on a novel route to synthesize highly active and stable oxygen reduction catalysts by depositing Pt monolayer on a nitrided alloy core. The prepared PtMLPdNiN/C catalyst retains 89% of the initial electrochemical surface area after 50,000 cycles between potentials 0.6 and 1.0 V. By correlating electron energy-loss spectroscopy and X-ray absorption spectroscopy analyses with electrochemical measurements, we found that the significant improvement of stability of themore » PtMLPdNiN/C catalyst is caused by nitrogen doping while reducing the total precious metal loading.« less

  15. Contact-induced spin polarization of monolayer hexagonal boron nitride on Ni(111)

    SciTech Connect (OSTI)

    Ohtomo, Manabu; Entani, Shiro; Matsumoto, Yoshihiro; Naramoto, Hiroshi; Sakai, Seiji; Yamauchi, Yasushi; Kuzubov, Alex A.; Eliseeva, Natalya S.; Avramov, Pavel V.

    2014-02-03

    Hexagonal boron nitride (h-BN) is a promising barrier material for graphene spintronics. In this Letter, spin-polarized metastable de-excitation spectroscopy (SPMDS) is employed to study the spin-dependent electronic structure of monolayer h-BN/Ni(111). The extreme surface sensitivity of SPMDS enables us to elucidate a partial filling of the in-gap states of h-BN without any superposition of Ni 3d signals. The in-gap states are shown to have a considerable spin polarization parallel to the majority spin of Ni. The positive spin polarization is attributed to the π-d hybridization and the effective spin transfer to the nitrogen atoms at the h-BN/Ni(111) interface.

  16. Vacancies in fully hydrogenated boron nitride layer: implications for functional nanodevices

    SciTech Connect (OSTI)

    Zhou, Yungang; Wang, Zhiguo; Nie, JL; Yang, Ping; Sun, Xin; Khaleel, Mohammad A.; Zu, Xiaotao; Gao, Fei

    2012-03-01

    Using density functional theory, a series of calculations of structural and electronic properties of hydrogen vacancies in a fully hydrogenated boron nitride (fH-BN) layer were conducted. By dehydrogenating the fH-BN structure, B-terminated vacancies can be created which induce complete spin polarization around the Fermi level, irrespective of the vacancy size. On the contrary, the fH-BN structure with N-terminated vacancies can be a small-gap semiconductor, a typical spin gapless semiconductor, or a metal depending on the vacancy size. Utilizing such vacancy-induced band gap and magnetism changes, possible applications in spintronics are proposed, and a special fH-BN based quantum dot device is designed.

  17. Spintronics with graphene-hexagonal boron nitride van der Waals heterostructures

    SciTech Connect (OSTI)

    Kamalakar, M. Venkata Dankert, André; Bergsten, Johan; Ive, Tommy; Dash, Saroj P.

    2014-11-24

    Hexagonal boron nitride (h-BN) is a large bandgap insulating isomorph of graphene, ideal for atomically thin tunnel barrier applications. In this letter, we demonstrate large area chemical vapor deposited (CVD) h-BN as a promising spin tunnel barrier in graphene spin transport devices. In such structures, the ferromagnetic tunnel contacts with h-BN barrier are found to show robust tunneling characteristics over a large scale with resistances in the favorable range for efficient spin injection into graphene. The non-local spin transport and precession experiments reveal spin lifetime ≈500 ps and spin diffusion length ≈1.6 μm in graphene with tunnel spin polarization ≈11% at 100 K. The electrical and spin transport measurements at different injection bias current and gate voltages confirm tunnel spin injection through h-BN barrier. These results open up possibilities for implementation of large area CVD h-BN in spintronic technologies.

  18. Steel bonded dense silicon nitride compositions and method for their fabrication

    DOE Patents [OSTI]

    Landingham, Richard L.; Shell, Thomas E.

    1987-01-01

    A two-stage bonding technique for bonding high density silicon nitride and other ceramic materials to stainless steel and other hard metals, and multilayered ceramic-metal composites prepared by the technique are disclosed. The technique involves initially slurry coating a surface of the ceramic material at about 1500.degree. C. in a vacuum with a refractory material and the stainless steel is then pressure bonded to the metallic coated surface by brazing it with nickel-copper-silver or nickel-copper-manganese alloys at a temperature in the range of about 850.degree. to 950.degree. C. in a vacuum. The two-stage bonding technique minimizes the temperature-expansion mismatch between the dissimilar materials.

  19. Optical Strong Coupling between near-Infrared Metamaterials and Intersubband Transitions in III-Nitride Heterostructures

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

    Benz, Alexander; Campione, Salvatore; Moseley, Michael W.; Wierer, Jonathan J.; Allerman, Andrew A.; Wendt, Joel R.; Brener, Igal

    2014-08-25

    We present the design, realization, and characterization of optical strong light–matter coupling between intersubband transitions within a semiconductor heterostructures and planar metamaterials in the near-infrared spectral range. The strong light–matter coupling entity consists of a III-nitride intersubband superlattice heterostructure, providing a two-level system with a transition energy of ~0.8 eV (λ ~1.55 μm) and a planar “dogbone” metamaterial structure. Furthermore, as the bare metamaterial resonance frequency is varied across the intersubband resonance, a clear anticrossing behavior is observed in the frequency domain. We found that this strongly coupled entity could enable the realization of electrically tunable optical filters, a newmore » class of efficient nonlinear optical materials, or intersubband-based light-emitting diodes.« less

  20. Steel bonded dense silicon nitride compositions and method for their fabrication

    DOE Patents [OSTI]

    Landingham, R.L.; Shell, T.E.

    1985-05-20

    A two-stage bonding technique for bonding high density silicon nitride and other ceramic materials to stainless steel and other hard metals, and multilayered ceramic-metal composites prepared by the technique are disclosed. The technique involves initially slurry coating a surface of the ceramic material at about 1500/sup 0/C in a vacuum with a refractory material and the stainless steel is then pressure bonded to the metallic coated surface by brazing it with nickel-copper-silver or nickel-copper-manganese alloys at a temperature in the range of about 850/sup 0/ to 950/sup 0/C in a vacuum. The two-stage bonding technique minimizes the temperature-expansion mismatch between the dissimilar materials.

  1. Porous Vycor membranes modified by chemical vapor deposition of boron nitride for gas separation

    SciTech Connect (OSTI)

    Levy, R.A.; Ravindranath, C.; Krasnoperov, L.N.; Opyrchal, J.; Ramos, E.S.

    1997-01-01

    This study focuses on the characterization of porous Vycor membranes modified by chemical vapor deposition of boron nitride (B-N-C-H) for gas separation. The B-N-C-H films were deposited on mesoporous Vycor tubes using triethylamine borane complex and ammonia as precursors. The effects of deposition temperature and reactant flow geometry on permselectivity of membranes with respect to various permeant gases were investigated. High selectivities (up to 50,000) were achieved between small molecules (He, H{sub 2}) and large molecules (N{sub 2}, Ar, C{sub 6}H{sub 5}CH{sub 3}). The measured activation energies for the He and H{sub 2} permeability are 9.5 kcal/mol and 12 kcal/mol, respectively. The membranes synthesized at lower temperatures and lower ammonia flow rates showed good mechanical and chemical stability.

  2. Thermal interface conductance across a graphene/hexagonal boron nitride heterojunction

    SciTech Connect (OSTI)

    Chen, Chun-Chung; Li, Zhen; Cronin, Stephen B. [Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089 (United States); Shi, Li [Department of Mechanical Engineering and Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712 (United States)

    2014-02-24

    We measure thermal transport across a graphene/hexagonal boron nitride (h-BN) interface by electrically heating the graphene and measuring the temperature difference between the graphene and BN using Raman spectroscopy. Because the temperature of the graphene and BN are measured optically, this approach enables nanometer resolution in the cross-plane direction. A temperature drop of 60?K can be achieved across this junction at high electrical powers (14 mW). Based on the temperature difference and the applied power data, we determine the thermal interface conductance of this junction to be 7.4??10{sup 6}?Wm{sup ?2}K{sup ?1}, which is below the 10{sup 7}10{sup 8}?Wm{sup ?2}K{sup ?1} values previously reported for graphene/SiO{sub 2} interface.

  3. Graphene on boron-nitride: Moir pattern in the van der Waals energy

    SciTech Connect (OSTI)

    Neek-Amal, M. [Department of Physics, University of Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen (Belgium); Department of Physics, Shahid Rajaee University, Lavizan, Tehran 16788 (Iran, Islamic Republic of); Peeters, F. M. [Department of Physics, University of Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen (Belgium)

    2014-01-27

    The spatial dependence of the van der Waals (vdW) energy between graphene and hexagonal boron-nitride (h-BN) is investigated using atomistic simulations. The van der Waals energy between graphene and h-BN shows a hexagonal superlattice structure identical to the observed Moir pattern in the local density of states, which depends on the lattice mismatch and misorientation angle between graphene and h-BN. Our results provide atomistic features of the weak van der Waals interaction between graphene and BN which are in agreement with experiment and provide an analytical expression for the size of the spatial variation of the weak van der Waals interaction. We also found that the A-B-lattice symmetry of graphene is broken along the armchair direction.

  4. Functionalization of cubic boron nitride films with rhodamine B and their fluorescent properties

    SciTech Connect (OSTI)

    Liu, W. M.; Zhang, H. Y.; Wang, P. F.; Ye, Q.; Yang, Y.; He, B.; Bello, I.; Lee, S. T.; Zhang, W. J.

    2011-08-08

    Fluorophore-functionalized cubic boron nitride (cBN) films grown by chemical vapor deposition were achieved by immobilizing rhodamine B isothiocyanate onto their surfaces. To perform the immobilization, the cBN substrates were modified with amino groups by photochemical reaction between hydrogen-terminated cBN surfaces and allylamine. The surface analysis of hydrogen-terminated cBN films surfaces and after functionalization with x-ray photoelectron spectroscopy verified that rhodamine B was indeed attached to the cBN surfaces with covalent bonding. The rhodamine B-functionalized cBN surfaces showed significant variation in fluorescent spectra and confocal imaging upon the treatment in acidic or basic solutions.

  5. The synthesis and structure of new transition metal lithium calcium nitride compounds

    SciTech Connect (OSTI)

    Hunting, Janet L.; Szymanski, Marta M.; Kowalsick, Amanda L.; Downie, Craig M.; DiSalvo, Francis J.

    2013-01-15

    Three new nitrides, Li{sub 3}Ca{sub 2}V{sub 0.79}Nb{sub 0.21}N{sub 4}, Li{sub 2}Ca{sub 2.67}Nb{sub 0.33}N{sub 3} and Li{sub 12}Ca{sub 9}W{sub 5}N{sub 20}, were synthesized in sealed niobium tubes using lithium nitride as a flux at temperatures ranging from 800 Degree-Sign C to 1050 Degree-Sign C. In all of these compounds, the transition metals are coordinated tetrahedrally by nitrogen; these tetrahedra are isolated from each other. Bullet Li{sub 3}Ca{sub 2}V{sub 0.79}Nb{sub 0.21}N{sub 4}, space group P2{sub 1}/m (no. 11), cell parameters a=5.7669(8) A, b=6.9123(9) A, c=6.0116(12) A, {beta}=90.727(9) Degree-Sign , Z=2, has a shared vanadium/niobium tetrahedral position which shares vertices with the tetrahedrally-coordinated lithium position. Bullet Li{sub 2}Ca{sub 2.67}Nb{sub 0.33}N{sub 3}, space group Req /o(3, Macron )m (no. 166), cell parameters a=3.6311(2) A, c=29.459(3) A, Z=3, contains a disordered tetrahedral calcium/niobium position, an octahedral calcium position and a triangularly coordinated lithium position. Bullet Li{sub 12}Ca{sub 9}W{sub 5}N{sub 20}, space group C2/c (no. 15), cell parameters a=27.7347(19) A, b=8.6652(6) A, c=10.7685(7) A, {beta}=110.314(2) Degree-Sign , Z=4, contains three crystallographically different tungsten positions as well as one disordered lithium position. - Graphical abstract: Crystal structure of Li{sub 3}Ca{sub 2}V{sub 0.79}Nb{sub 0.21}N{sub 4} depicting the chains of edge-sharing LiN{sub 4} (light hatching) and (V/Nb)N{sub 4} (dark hatching) tetrahedra viewed approximately along the [100] direction. Calcium atoms are shown as open circles and nitrogen atoms are colored black. Highlights: Black-Right-Pointing-Pointer Three new lithium calcium nitrides are synthesized. Black-Right-Pointing-Pointer Lithium nitride flux used in synthesis. Black-Right-Pointing-Pointer Structures contain isolated tetrahedrally coordinated transition metals. Black-Right-Pointing-Pointer Li{sub 12}Ca{sub 9}W{sub 5}N{sub 20} contains three crystallographically different W positions.

  6. A cohesive law for interfaces in graphene/hexagonal boron nitride heterostructure

    SciTech Connect (OSTI)

    Zhang, Chenxi; Lou, Jun; Song, Jizhou

    2014-04-14

    Graphene/hexagonal boron nitride (h-BN) heterostructure has showed great potential to improve the performance of graphene device. We have established the cohesive law for interfaces between graphene and monolayer or multi-layer h-BN based on the van der Waals force. The cohesive energy and cohesive strength are given in terms of area density of atoms on corresponding layers, number of layers, and parameters in the van der Waals force. It is found that the cohesive law in the graphene/multi-layer h-BN is dominated by the three h-BN layers which are closest to the graphene. The approximate solution is also obtained to simplify the expression of cohesive law. These results are very useful to study the deformation of graphene/h-BN heterostructure, which may have significant impacts on the performance and reliability of the graphene devices especially in the areas of emerging applications such as stretchable electronics.

  7. Dilute Group III-V nitride intermediate band solar cells with contact blocking layers

    DOE Patents [OSTI]

    Walukiewicz, Wladyslaw; Yu, Kin Man

    2012-07-31

    An intermediate band solar cell (IBSC) is provided including a p-n junction based on dilute III-V nitride materials and a pair of contact blocking layers positioned on opposite surfaces of the p-n junction for electrically isolating the intermediate band of the p-n junction by blocking the charge transport in the intermediate band without affecting the electron and hole collection efficiency of the p-n junction, thereby increasing open circuit voltage (V.sub.OC) of the IBSC and increasing the photocurrent by utilizing the intermediate band to absorb photons with energy below the band gap of the absorber layers of the IBSC. Hence, the overall power conversion efficiency of a IBSC will be much higher than an conventional single junction solar cell. The p-n junction absorber layers of the IBSC may further have compositionally graded nitrogen concentrations to provide an electric field for more efficient charge collection.

  8. Dilute group III-V nitride intermediate band solar cells with contact blocking layers

    DOE Patents [OSTI]

    Walukiewicz, Wladyslaw; Yu, Kin Man

    2015-02-24

    An intermediate band solar cell (IBSC) is provided including a p-n junction based on dilute III-V nitride materials and a pair of contact blocking layers positioned on opposite surfaces of the p-n junction for electrically isolating the intermediate band of the p-n junction by blocking the charge transport in the intermediate band without affecting the electron and hole collection efficiency of the p-n junction, thereby increasing open circuit voltage (V.sub.OC) of the IBSC and increasing the photocurrent by utilizing the intermediate band to absorb photons with energy below the band gap of the absorber layers of the IBSC. Hence, the overall power conversion efficiency of a IBSC will be much higher than an conventional single junction solar cell. The p-n junction absorber layers of the IBSC may further have compositionally graded nitrogen concentrations to provide an electric field for more efficient charge collection.

  9. Polarization doping and the efficiency of III-nitride optoelectronic devices

    SciTech Connect (OSTI)

    Kivisaari, Pyry; Oksanen, Jani; Tulkki, Jukka

    2013-11-18

    The intrinsic polarization is generally considered a nuisance in III-nitride devices, but recent studies have shown that it can be used to enhance p- and n-type conductivity and even to replace impurity doping. We show by numerical simulations that polarization-doped light-emitting diode (LED) structures have a significant performance advantage over conventional impurity-doped LED structures. Our results indicate that polarization doping decreases electric fields inside the active region and potential barriers in the depletion region, as well as the magnitude of the quantum-confined Stark effect. The simulations also predict at least an order of magnitude increase in the current density corresponding to the maximum efficiency (i.e., smaller droop) as compared to impurity-doped structures. The obtained high doping concentrations could also enable, e.g., fabrication of III-N resonant tunneling diodes and improved ohmic contacts.

  10. Transient fission-gas behavior in uranium nitride fuel under proposed space applications. Doctoral thesis

    SciTech Connect (OSTI)

    Deforest, D.L.

    1991-12-01

    In order to investigate whether fission gas swelling and release would be significant factors in a space based nuclear reactor operating under the Strategic Defense Initiative (SDI) program, the finite element program REDSTONE (Routine For Evaluating Dynamic Swelling in Transient Operational Nuclear Environments) was developed to model the 1-D, spherical geometry diffusion equations describing transient fission gas behavior in a single uranium nitride fuel grain. The equations characterized individual bubbles, rather than bubble groupings. This limits calculations to those scenarios where low temperatures, low burnups, or both were present. Instabilities in the bubble radii calculations forced the implementation of additional constraints limiting the bubble sizes to minimum and maximum (equilibrium) radii. The validity of REDSTONE calculations were checked against analytical solutions for internal consistency and against experimental studies for agreement with swelling and release results.

  11. The interaction between hexagonal boron nitride and water from first principles

    SciTech Connect (OSTI)

    Wu, Yanbin; Aluru, Narayana R.; Wagner, Lucas K.

    2015-06-21

    The use of hexagonal boron nitride (h-BN) in microfluidic and nanofluidic applications requires a fundamental understanding of the interaction between water and the h-BN surface. A crucial component of the interaction is the binding energy, which is sensitive to the treatment of electron correlation. In this work, we use state of the art quantum Monte Carlo and quantum chemistry techniques to compute the binding energy. Compared to high-level many-body theory, we found that the second-order Mller-Plesset perturbation theory captures the interaction accurately and can thus be used to develop force field parameters between h-BN and water for use in atomic scale simulations. On the contrary, density functional theory with standard dispersion corrections tends to overestimate the binding energy by approximately 75%.

  12. Novel Electronic and Magnetic Properties of Graphene Nanoflakes in a Boron Nitride Layer

    SciTech Connect (OSTI)

    Zhou, Yungang; Wang, Zhiguo; Yang, Ping; Gao, Fei

    2012-04-05

    Novel electronic and magnetic properties of various-sized graphene nanoflakes (GNFs) embedded in a boron nitride (BN) layer are studied using ab initio methods. The feasibility of synthesizing hybrid GNF-BN structure, a desirable quantum dot structure, is explored. In this structure, photoexcited electrons and holes occupy the same spatial region - the GNF region - which offers an effective way to generate a GNF-based light-emitting device and adjust its emitted optical properties by controlling the size and array of GNF in the BN layer. Based on the important magnetism properties of embedded GNF, we propose a specific configuration to obtain a large spin. Together with the high stability of spin alignment, the proposed configuration can be exploited for spintronic devices.

  13. Pt monolayer shell on nitrided alloy core — A path to highly stable oxygen reduction catalyst

    SciTech Connect (OSTI)

    Hu, Jue; Kuttiyiel, Kurian A.; Sasaki, Kotaro; Su, Dong; Yang, Tae -Hyun; Park, Gu -Gon; Zhang, Chengxu; Chen, Guangyu; Adzic, Radoslav R.

    2015-07-22

    The inadequate activity and stability of Pt as a cathode catalyst under the severe operation conditions are the critical problems facing the application of the proton exchange membrane fuel cell (PEMFC). Here we report on a novel route to synthesize highly active and stable oxygen reduction catalysts by depositing Pt monolayer on a nitrided alloy core. The prepared PtMLPdNiN/C catalyst retains 89% of the initial electrochemical surface area after 50,000 cycles between potentials 0.6 and 1.0 V. By correlating electron energy-loss spectroscopy and X-ray absorption spectroscopy analyses with electrochemical measurements, we found that the significant improvement of stability of the PtMLPdNiN/C catalyst is caused by nitrogen doping while reducing the total precious metal loading.

  14. Silicon nitride swirl lower-chamber for high power turbocharged diesel engines

    SciTech Connect (OSTI)

    Kamiya, S.; Murachi, M.; Kawamoto, H.; Kato, S.; Kawakami, S.; Suzuki, Y.

    1985-01-01

    This paper describes application of sintered silicon nitride to the swirl lower-chamber in order to improve performance of turbocharged diesel engines. Various stress analyses by finite element method and stress measurements have been applied to determine the design specifications for the component, which compromise brittleness of ceramic materials. Material development was conducted to evaluate strength, fracture toughness, and thermal properties for the sintered bodies. Ceramic injection molding has been employed to fabricate components with large quantities. In the present work. Quality assurance for the components can be made by reliability evaluation methods as well as non-destructive and stress loading inspections. It is found that the engine performance with ceramic component has been increased in the power out put of 9ps as compared to that of conventional engines.

  15. Local residual stress monitoring of aluminum nitride MEMS using UV micro-Raman spectroscopy

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

    Choi, Sukwon; Griffin, Benjamin A.

    2016-01-06

    Localized stress variation in aluminum nitride (AlN) sputtered on patterned metallization has been monitored through the use of UV micro-Raman spectroscopy. This technique utilizing 325 nm laser excitation allows detection of the AlN E2(high) phonon mode in the presence of metal electrodes beneath the AlN layer with a high spatial resolution of less than 400 nm. The AlN film stress shifted 400 MPa from regions where AlN was deposited over a bottom metal electrode versus silicon dioxide. Thus, across wafer stress variations were also investigated showing that wafer level stress metrology, for example using wafer curvature measurements, introduces large uncertaintiesmore » for predicting the impact of AlN residual stress on the device performance.« less

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

    SciTech Connect (OSTI)

    Imtiaz, Atif; Wallis, Thomas M.; Brubaker, Matt D.; Blanchard, Paul T.; Bertness, Kris A.; Sanford, Norman A.; Kabos, Pavel; Weber, Joel C.; Coakley, Kevin J.

    2014-06-30

    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.

  17. Liquid sampling system

    DOE Patents [OSTI]

    Larson, Loren L.

    1987-01-01

    A conduit extends from a reservoir through a sampling station and back to the reservoir in a closed loop. A jet ejector in the conduit establishes suction for withdrawing liquid from the reservoir. The conduit has a self-healing septum therein upstream of the jet ejector for receiving one end of a double-ended cannula, the other end of which is received in a serum bottle for sample collection. Gas is introduced into the conduit at a gas bleed between the sample collection bottle and the reservoir. The jet ejector evacuates gas from the conduit and the bottle and aspirates a column of liquid from the reservoir at a high rate. When the withdrawn liquid reaches the jet ejector the rate of flow therethrough reduces substantially and the gas bleed increases the pressure in the conduit for driving liquid into the sample bottle, the gas bleed forming a column of gas behind the withdrawn liquid column and interrupting the withdrawal of liquid from the reservoir. In the case of hazardous and toxic liquids, the sample bottle and the jet ejector may be isolated from the reservoir and may be further isolated from a control station containing remote manipulation means for the sample bottle and control valves for the jet ejector and gas bleed.

  18. Liquid sampling system

    DOE Patents [OSTI]

    Larson, L.L.

    1984-09-17

    A conduit extends from a reservoir through a sampling station and back to the reservoir in a closed loop. A jet ejector in the conduit establishes suction for withdrawing liquid from the reservoir. The conduit has a self-healing septum therein upstream of the jet ejector for receiving one end of a double-ended cannula, the other end of which is received in a serum bottle for sample collection. Gas is introduced into the conduit at a gas bleed between the sample collection bottle and the reservoir. The jet ejector evacuates gas from the conduit and the bottle and aspirates a column of liquid from the reservoir at a high rate. When the withdrawn liquid reaches the jet ejector the rate of flow therethrough reduces substantially and the gas bleed increases the pressure in the conduit for driving liquid into the sample bottle, the gas bleed forming a column of gas behind the withdrawn liquid column and interrupting the withdrawal of liquid from the reservoir. In the case of hazardous and toxic liquids, the sample bottle and the jet ejector may be isolated from the reservoir and may be further isolated from a control station containing remote manipulation means for the sample bottle and control valves for the jet ejector and gas bleed. 5 figs.

  19. The cost of silicon nitride powder: What must it be to compete?

    SciTech Connect (OSTI)

    Das, S.; Curlee, T.R.

    1992-02-01

    The ability of advanced ceramic components to compete with similar metallic parts will depend in part on current and future efforts to reduce the cost of ceramic parts. This paper examines the potential reductions in part cost that could result from the development of less expensive advanced ceramic powders. The analysis focuses specifically on two silicon nitride engine components -- roller followers and turbocharger rotors. The results of the process-cost models developed for this work suggest that reductions in the cost of advanced silicon nitride powder from its current level of about $20 per pound to about $5 per pound will not in itself be sufficient to lower the cost of ceramic parts below the current cost of similar metallic components. This work also examines if combinations of lower-cost powders and further improvements in other key technical parameters to which costs are most sensitive could push the cost of ceramics below the cost of metallics. Although these sensitivity analyses are reflective of technical improvements that are very optimistic, the resulting part costs are estimated to remain higher than similar metallic parts. Our findings call into question the widely-held notion that the cost of ceramic components must not exceed the cost of similar metallic parts if ceramics are to be competitive. Economic viability will ultimately be decided not on the basis of which part is less costly, but on an assessment of the marginal costs and benefits provided by ceramics and metallics. This analysis does not consider the benefits side of the equation. Our findings on the cost side of the equation suggest that the competitiveness of advanced ceramics will ultimately be decided by our ability to evaluate and communicate the higher benefits that advanced ceramic parts may offer.

  20. The cost of silicon nitride powder: What must it be to compete

    SciTech Connect (OSTI)

    Das, S.; Curlee, T.R.

    1992-02-01

    The ability of advanced ceramic components to compete with similar metallic parts will depend in part on current and future efforts to reduce the cost of ceramic parts. This paper examines the potential reductions in part cost that could result from the development of less expensive advanced ceramic powders. The analysis focuses specifically on two silicon nitride engine components -- roller followers and turbocharger rotors. The results of the process-cost models developed for this work suggest that reductions in the cost of advanced silicon nitride powder from its current level of about $20 per pound to about $5 per pound will not in itself be sufficient to lower the cost of ceramic parts below the current cost of similar metallic components. This work also examines if combinations of lower-cost powders and further improvements in other key technical parameters to which costs are most sensitive could push the cost of ceramics below the cost of metallics. Although these sensitivity analyses are reflective of technical improvements that are very optimistic, the resulting part costs are estimated to remain higher than similar metallic parts. Our findings call into question the widely-held notion that the cost of ceramic components must not exceed the cost of similar metallic parts if ceramics are to be competitive. Economic viability will ultimately be decided not on the basis of which part is less costly, but on an assessment of the marginal costs and benefits provided by ceramics and metallics. This analysis does not consider the benefits side of the equation. Our findings on the cost side of the equation suggest that the competitiveness of advanced ceramics will ultimately be decided by our ability to evaluate and communicate the higher benefits that advanced ceramic parts may offer.

  1. Pre-Oxidized and Nitrided Stainless Steel Foil for Proton Exchange Membrane Fuel Cell Bipolar Plates: Part 1 Corrosion, Interfacial Contact Resistance, and Surface Structure

    SciTech Connect (OSTI)

    Brady, Michael P; Wang, Heli; Turner, John; Meyer III, Harry M; More, Karren Leslie; Tortorelli, Peter F; McCarthy, Brian D

    2010-01-01

    Thermal (gas) nitridation of stainless steels can yield low interfacial contact resistance (ICR), electrically-conductive and corrosion-resistant nitride containing surfaces (Cr2N, CrN, TiN, V2N, VN, etc) of interest for fuel cells, batteries, and sensors. This paper presents the results of scale up studies to determine the feasibility of extending the nitridation approach to thin 0.1 mm stainless steel alloy foils for proton exchange membrane fuel cell (PEMFC) bipolar plates. A major emphasis was placed on selection of alloy foil composition and nitidation conditions potentially capable of meeting the stringent cost goals for automotive PEMFC applications. Developmental Fe-20Cr-4V alloy and type 2205 stainless steel foils were treated by pre-oxidation and nitridation to form low-ICR, corrosion-resistant surfaces. Promising behavior was observed under simulated aggressive anode- and cathode- side bipolar plate conditions for both materials. Variation in ICR values were observed for treated 2205 foil, with lower (better) values generally observed for the treated Fe-20Cr-4V. This behavior was linked to the nature of the pre-oxidized and nitrided surface structure, which contained through surface layer thickness V-nitride particles in the case of Fe-20Cr-4V but near continuous chromia in the case of 2205 stainless steel. The implications of these findings for stamped bipolar plate foils are discussed.

  2. Low-temperature CVD of iron, cobalt, and nickel nitride thin films from bis[di(tert-butyl)amido]metal(II) precursors and ammonia

    SciTech Connect (OSTI)

    Cloud, Andrew N.; Abelson, John R., E-mail: abelson@illinois.edu [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 201 Materials Science and Engineering Building, 1304 W. Green St., Urbana, Illinois 61801 (United States); Davis, Luke M.; Girolami, Gregory S., E-mail: girolami@scs.illinois.edu [School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, Illinois 61801 (United States)

    2014-03-15

    Thin films of late transition metal nitrides (where the metal is iron, cobalt, or nickel) are grown by low-pressure metalorganic chemical vapor deposition from bis[di(tert-butyl)amido]metal(II) precursors and ammonia. These metal nitrides are known to have useful mechanical and magnetic properties, but there are few thin film growth techniques to produce them based on a single precursor family. The authors report the deposition of metal nitride thin films below 300?C from three recently synthesized M[N(t-Bu){sub 2}]{sub 2} precursors, where M?=?Fe, Co, and Ni, with growth onset as low as room temperature. Metal-rich phases are obtained with constant nitrogen content from growth onset to 200?C over a range of feedstock partial pressures. Carbon contamination in the films is minimal for iron and cobalt nitride, but similar to the nitrogen concentration for nickel nitride. X-ray photoelectron spectroscopy indicates that the incorporated nitrogen is present as metal nitride, even for films grown at the reaction onset temperature. Deposition rates of up to 18?nm/min are observed. The film morphologies, growth rates, and compositions are consistent with a gas-phase transamination reaction that produces precursor species with high sticking coefficients and low surface mobilities.

  3. Visual Sample Plan

    Energy Science and Technology Software Center (OSTI)

    2007-10-25

    VSP selects the appropriate number and location of environmental samples to ensure that the results of statistical tests performed to provide input to risk decisions have the required confidence and performance. VSP Version 5.0 provides sample-size equations or algorithms needed by specific statistical tests appropriate for specific environmental sampling objectives. It also provides data quality assessment and statistical analysis functions to support evaluation of the data and determine whether the data support decisions regarding sitesmore » suspected of contamination. The easy-to-use program is highly visual and graphic. VSP runs on personal computers with Microsoft Windows operating systems (98, NT, 2000, Millennium Edition, CE, and XP) Designed primarily for project managers and users without expertise in statistics, VSP is applicable to two- and three-dimensional populations to be sampled (e.g., rooms and buildings, surface soil, a defined layer of subsurface soil, water bodies, and other similar applications) for studies of environmental quality. VSP is also applicable for designing sampling plans for assessing chem./rad/bio threat and hazard identification within rooms and buildings, and for designing geophysical surveys for UXO identification.« less

  4. Fluid sampling system

    DOE Patents [OSTI]

    Houck, Edward D.

    1994-01-01

    An fluid sampling system allows sampling of radioactive liquid without spillage. A feed tank is connected to a liquid transfer jet powered by a pumping chamber pressurized by compressed air. The liquid is pumped upwardly into a sampling jet of a venturi design having a lumen with an inlet, an outlet, a constricted middle portion, and a port located above the constricted middle portion. The liquid is passed under pressure through the constricted portion causing its velocity to increase and its pressure to decreased, thereby preventing liquid from escaping. A septum sealing the port can be pierced by a two pointed hollow needle leading into a sample bottle also sealed by a pierceable septum affixed to one end. The bottle is evacuated by flow through the sample jet, cyclic variation in the sampler jet pressure periodically leaves the evacuated bottle with lower pressure than that of the port, thus causing solution to pass into the bottle. The remaining solution in the system is returned to the feed tank via a holding tank.

  5. Fluid sampling system

    DOE Patents [OSTI]

    Houck, E.D.

    1994-10-11

    An fluid sampling system allows sampling of radioactive liquid without spillage. A feed tank is connected to a liquid transfer jet powered by a pumping chamber pressurized by compressed air. The liquid is pumped upwardly into a sampling jet of a venturi design having a lumen with an inlet, an outlet, a constricted middle portion, and a port located above the constricted middle portion. The liquid is passed under pressure through the constricted portion causing its velocity to increase and its pressure to be decreased, thereby preventing liquid from escaping. A septum sealing the port can be pierced by a two pointed hollow needle leading into a sample bottle also sealed by a pierceable septum affixed to one end. The bottle is evacuated by flow through the sample jet, cyclic variation in the sampler jet pressure periodically leaves the evacuated bottle with lower pressure than that of the port, thus causing solution to pass into the bottle. The remaining solution in the system is returned to the feed tank via a holding tank. 4 figs.

  6. Viscous sludge sample collector

    DOE Patents [OSTI]

    Beitel, George A [Richland, WA

    1983-01-01

    A vertical core sample collection system for viscous sludge. A sample tube's upper end has a flange and is attached to a piston. The tube and piston are located in the upper end of a bore in a housing. The bore's lower end leads outside the housing and has an inwardly extending rim. Compressed gas, from a storage cylinder, is quickly introduced into the bore's upper end to rapidly accelerate the piston and tube down the bore. The lower end of the tube has a high sludge entering velocity to obtain a full-length sludge sample without disturbing strata detail. The tube's downward motion is stopped when its upper end flange impacts against the bore's lower end inwardly extending rim.

  7. ANNULAR IMPACTOR SAMPLING DEVICE

    DOE Patents [OSTI]

    Tait, G.W.C.

    1959-03-31

    A high-rate air sampler capable of sampling alphaemitting particles as small as 0.5 microns is described. The device is a cylindrical shaped cup that fits in front of a suction tube and which has sticky grease coating along its base. Suction forces contaminated air against the periodically monitored particle absorbing grease.

  8. Preparation and properties of antiperovskite-type nitrides: InNNi{sub 3} and InNCo{sub 3}

    SciTech Connect (OSTI)

    Cao, W.H.; He, B.; Liao, C.Z.; Yang, L.H.; Zeng, L.M.; Dong, C.

    2009-12-15

    Two antiperovskite-type ternary nitrides of InNM{sub 3} (M=Ni, Co) have been synthesized from In{sub 2}O{sub 3} and Ni or Co powders under NH{sub 3} atmosphere at 600 deg. C. InNCo{sub 3} is a new ternary nitride whereas InNNi{sub 3} was previously reported as InN{sub 0.5}Ni{sub 3} with different nitrogen content. The lattice parameters refined by Rietveld method are 3.8445(1) A for InNNi{sub 3} and 3.8541(7) A for InNCo{sub 3}, respectively. Both nitrides show metallic behaviors and below 70 K the T{sup 2} temperature dependence of resistivity was observed indicative of a Fermi liquid behavior. The temperature dependence of the field-cooling (FC) and zero-field-cooling (ZFC) magnetization and time decay of thermoremanent magnetization indicate the spin-glass-like behavior in InNM{sub 3} (M=Ni, Co). The freezing temperatures for this behavior, T{sub f}, are about 300 K for InNNi{sub 3} and 10 K for InNCo{sub 3}, respectively. - Graphical abstract: Two ternary nitrides InNM{sub 3} (M=Ni, Co) were synthesized by solid-gas reactions of metal powders with NH{sub 3}. Both InNNi{sub 3} and InNCo{sub 3} adopt the antiperovskite crystal structure, and measurements of magnetization indicate that they have spin-glass-like properties.

  9. Field Sampling | Open Energy Information

    Open Energy Info (EERE)

    Field Mapping Hand-held X-Ray Fluorescence (XRF) Macrophotography Portable X-Ray Diffraction (XRD) Field Sampling Gas Sampling Gas Flux Sampling Soil Gas Sampling Surface Gas...

  10. Process for producing high purity silicon nitride by the direct reaction between elemental silicon and nitrogen-hydrogen liquid reactants

    DOE Patents [OSTI]

    Pugar, Eloise A.; Morgan, Peter E. D.

    1990-01-01

    A process is disclosed for producing, at a low temperature, a high purity reaction product consisting essentially of silicon, nitrogen, and hydrogen which can then be heated to produce a high purity alpha silicon nitride. The process comprises: reacting together a particulate elemental high purity silicon with a high purity nitrogen-hydrogen reactant in its liquid state (such as ammonia or hydrazine) having the formula: N.sub.n H.sub.(n+m) wherein: n=1-4 and m=2 when the nitrogen-hydrogen reactant is straight chain, and 0 when the nitrogen-hydrogen reactant is cyclic. High purity silicon nitride can be formed from this intermediate product by heating the intermediate product at a temperature of from about 1200.degree.-1700.degree. C. for a period from about 15 minutes up to about 2 hours to form a high purity alpha silicon nitride product. The discovery of the existence of a soluble Si-N-H intermediate enables chemical pathways to be explored previously unavailable in conventional solid state approaches to silicon-nitrogen ceramics.

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

    SciTech Connect (OSTI)

    Russell D. Dupuis

    2004-09-30

    We report research activities and technical progress on the development of high-efficiency long wavelength ({lambda} {approx} 540nm) green light emitting diodes which covers the first year of the three-year program ''Novel approaches to high-efficiency III-V nitride heterostructure emitters for next-generation lighting applications''. The first year activities were focused on the installation, set-up, and use of advanced equipment for the metalorganic chemical vapor deposition growth of III-nitride films and the characterization of these materials (Task 1) and the design, fabrication, testing of nitride LEDs (Task 4). As a progress highlight, we obtained improved quality of {approx} 2 {micro}m-thick GaN layers (as measured by the full width at half maximum of the asymmetric (102) X-ray diffraction peak of less than 350 arc-s) and higher p-GaN:Mg doping level (free hole carrier higher than 1E18 cm{sup -3}). Also in this year, we have developed the growth of InGaN/GaN active layers for long-wavelength green light emitting diodes, specifically, for emission at {lambda} {approx} 540nm. The effect of the Column III precursor (for Ga) and the post-growth thermal annealing effect were also studied. Our LED device fabrication process was developed and initially optimized, especially for low-resistance ohmic contacts for p-GaN:Mg layers, and blue-green light emitting diode structures were processed and characterized.

  12. Process for producing high purity silicon nitride by the direct reaction between elemental silicon and nitrogen-hydrogen liquid reactants

    DOE Patents [OSTI]

    Pugar, E.A.; Morgan, P.E.D.

    1987-09-15

    A process is disclosed for producing, at a low temperature, a high purity reaction product consisting essentially of silicon, nitrogen, and hydrogen which can then be heated to produce a high purity alpha silicon nitride. The process comprises: reacting together a particulate elemental high purity silicon with a high purity nitrogen-hydrogen reactant in its liquid state (such as ammonia or hydrazine) having the formula: N/sub n/H/sub (n+m)/ wherein: n = 1--4 and m = 2 when the nitrogen-hydrogen reactant is straight chain, and 0 when the nitrogen-hydrogen reactant is cyclic. High purity silicon nitride can be formed from this intermediate product by heating the intermediate product at a temperature of from about 1200--1700/degree/C for a period from about 15 minutes up to about 2 hours to form a high purity alpha silicon nitride product. The discovery of the existence of a soluble Si/endash/N/endash/H intermediate enables chemical pathways to be explored previously unavailable in conventional solid-state approaches to silicon-nitrogen ceramics

  13. NID Copper Sample Analysis

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Zhu, Zihua

    2011-09-12

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0???). This experiment requires the use of germanium isotopically enriched in 76Ge. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology, possibly one under development at Nonlinear Ion Dynamics (NID), will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL in January 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are reported here. A second sample of isotopically separated copper was provided by NID to PNNL in August 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are also reported here.

  14. Germanium-76 Sample Analysis

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Engelhard, Mark H.; Zhu, Zihua

    2011-04-01

    The MAJORANA DEMONSTRATOR is a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0???). The DEMONSTRATOR will utilize 76Ge from Russia, and the first one gram sample was received from the supplier for analysis on April 24, 2011. The Environmental Molecular Sciences facility, a DOE user facility at PNNL, was used to make the required isotopic and chemical purity measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR. The results of this first analysis are reported here.

  15. Pulsed field sample neutralization

    DOE Patents [OSTI]

    Appelhans, Anthony D.; Dahl, David A.; Delmore, James E.

    1990-01-01

    An apparatus and method for alternating voltage and for varying the rate of extraction during the extraction of secondary particles, resulting in periods when either positive ions, or negative ions and electrons are extracted at varying rates. Using voltage with alternating charge during successive periods to extract particles from materials which accumulate charge opposite that being extracted causes accumulation of surface charge of opposite sign. Charge accumulation can then be adjusted to a ratio which maintains a balance of positive and negative charge emission, thus maintaining the charge neutrality of the sample.

  16. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Water Sampling at the Salmon, Mississippi, Site March 2014 Approved for public release; further dissemination unlimited LMS/SAL/S00413 Available for sale to the public from: U.S. Department of Commerce National Technical Information Service 5301 Shawnee Road Alexandria, VA 22312 Telephone: 800.553.6847 Fax: 703.605.6900 E-mail: orders@ntis.gov Online Ordering: http://www.ntis.gov/help/ordermethods.aspx Available electronically at http://www.osti.gov/bridge Available for a processing fee to U.S.

  17. September 2004 Water Sampling

    Office of Legacy Management (LM)

    4 Groundwater Sampling at the Central Nevada Test Area February 2015 LMS/CNT/S01214 Available for sale to the public from: U.S. Department of Commerce National Technical Information Service 5301 Shawnee Road Alexandria, VA 22312 Telephone: 800.553.6847 Fax: 703.605.6900 E-mail: orders@ntis.gov Online Ordering: http://www.ntis.gov/help/ordermethods.aspx Available electronically at http://www.osti.gov/scitech/ Available for a processing fee to U.S. Department of Energy and its contractors, in

  18. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Groundwater, Surface Water, Produced Water, and Natural Gas Sampling at the Gasbuggy, New Mexico, Site October 2014 LMS/GSB/S00614 Available for sale to the public from: U.S. Department of Commerce National Technical Information Service 5301 Shawnee Road Alexandria, VA 22312 Telephone: 800.553.6847 Fax: 703.605.6900 E-mail: orders@ntis.gov Online Ordering: http://www.ntis.gov/help/ordermethods.aspx Available electronically at http://www.osti.gov/scitech/ Available for a processing fee to U.S.

  19. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and Surface Water Sampling at the Rio Blanco, Colorado, Site October 2014 LMS/RBL/S00514 Available for sale to the public from: U.S. Department of Commerce National Technical Information Service 5301 Shawnee Road Alexandria, VA 22312 Telephone: 800.553.6847 Fax: 703.605.6900 E-mail: orders@ntis.gov Online Ordering: http://www.ntis.gov/help/ordermethods.aspx Available electronically at http://www.osti.gov/scitech/ Available for a processing fee to U.S. Department of Energy and its contractors, in

  20. September 2004 Water Sampling

    Office of Legacy Management (LM)

    and Surface Water Sampling at the Rio Blanco, Colorado, Site October 2015 LMS/RBL/S00515 Available for sale to the public from: U.S. Department of Commerce National Technical Information Service 5301 Shawnee Road Alexandria, VA 22312 Telephone: 800.553.6847 Fax: 703.605.6900 E-mail: orders@ntis.gov Online Ordering: http://www.ntis.gov/help/ordermethods.aspx Available electronically at http://www.osti.gov/scitech/ Available for a processing fee to U.S. Department of Energy and its contractors, in

  1. September 2004 Water Sampling

    Office of Legacy Management (LM)

    5 Produced Water Sampling at the Rulison, Colorado, Site May 2015 LMS/RUL/S00115 Available for sale to the public from: U.S. Department of Commerce National Technical Information Service 5301 Shawnee Road Alexandria, VA 22312 Telephone: 800.553.6847 Fax: 703.605.6900 E-mail: orders@ntis.gov Online Ordering: http://www.ntis.gov/help/ordermethods.aspx Available electronically at http://www.osti.gov/scitech/ Available for a processing fee to U.S. Department of Energy and its contractors, in paper,

  2. September 2004 Water Sampling

    Office of Legacy Management (LM)

    5 Groundwater and Surface Water Sampling at the Rulison, Colorado, Site October 2015 LMS/RUL/S00515 Available for sale to the public from: U.S. Department of Commerce National Technical Information Service 5301 Shawnee Road Alexandria, VA 22312 Telephone: 800.553.6847 Fax: 703.605.6900 E-mail: orders@ntis.gov Online Ordering: http://www.ntis.gov/help/ordermethods.aspx Available electronically at http://www.osti.gov/scitech/ Available for a processing fee to U.S. Department of Energy and its

  3. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Natural Gas and Produced Water Sampling at the Rulison, Colorado, Site November 2014 LMS/RUL/S00714 Available for sale to the public from: U.S. Department of Commerce National Technical Information Service 5301 Shawnee Road Alexandria, VA 22312 Telephone: 800.553.6847 Fax: 703.605.6900 E-mail: orders@ntis.gov Online Ordering: http://www.ntis.gov/help/ordermethods.aspx Available electronically at http://www.osti.gov/scitech/ Available for a processing fee to U.S. Department of Energy and its

  4. September 2004 Water Sampling

    Office of Legacy Management (LM)

    Produced Water Sampling at the Rulison, Colorado, Site January 2016 LMS/RUL/S00915 Available for sale to the public from: U.S. Department of Commerce National Technical Information Service 5301 Shawnee Road Alexandria, VA 22312 Telephone: 800.553.6847 Fax: 703.605.6900 E-mail: orders@ntis.gov Online Ordering: http://www.ntis.gov/help/ordermethods.aspx Available electronically at http://www.osti.gov/scitech/ Available for a processing fee to U.S. Department of Energy and its contractors, in

  5. Stack sampling apparatus

    DOE Patents [OSTI]

    Lind, Randall F; Lloyd, Peter D; Love, Lonnie J; Noakes, Mark W; Pin, Francois G; Richardson, Bradley S; Rowe, John C

    2014-09-16

    An apparatus for obtaining samples from a structure includes a support member, at least one stabilizing member, and at least one moveable member. The stabilizing member has a first portion coupled to the support member and a second portion configured to engage with the structure to restrict relative movement between the support member and the structure. The stabilizing member is radially expandable from a first configuration where the second portion does not engage with a surface of the structure to a second configuration where the second portion engages with the surface of the structure.

  6. Post-Award Deliverables Sample (Part 2 of Sample Deliverables...

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

    J-4) Post-Award Deliverables Sample (Part 2 of Sample Deliverables for Task Orders, IDIQ Attachment. J-4) Document offers a post-award deliverables sample for an energy savings ...

  7. Methods for and products of processing nanostructure nitride, carbonitride and oxycarbonitride electrode power materials by utilizing sol gel technology for supercapacitor applications

    DOE Patents [OSTI]

    Huang, Yuhong; Wei, Oiang; Chu, Chung-tse; Zheng, Haixing

    2001-01-01

    Metal nitride, carbonitride, and oxycarbonitride powder with high surface area (up to 150 m.sup.2 /g) is prepared by using sol-gel process. The metal organic precursor, alkoxides or amides, is synthesized firstly. The metal organic precursor is modified by using unhydrolyzable organic ligands or templates. A wet gel is formed then by hydrolysis and condensation process. The solvent in the wet gel is then be removed supercritically to form porous amorphous hydroxide. This porous hydroxide materials is sintered to 725.degree. C. under the ammonia flow and porous nitride powder is formed. The other way to obtain high surface area nitride, carbonitride, and oxycarbonitride powder is to pyrolyze polymerized templated metal amides aerogel in an inert atmosphere. The electrochemical capacitors are prepared by using sol-gel prepared nitride, carbonitride, and oxycarbonitride powder. Two methods are used to assemble the capacitors. Electrode is formed either by pressing the mixture of nitride powder and binder to a foil, or by depositing electrode coating onto metal current collector. The binder or coating is converted into a continuous network of electrode material after thermal treatment to provide enhanced energy and power density. Liquid electrolyte is soaked into porous electrode. The electrochemical capacitor assembly further has a porous separator layer between two electrodes/electrolyte and forming a unit cell.

  8. Fluid sampling tool

    DOE Patents [OSTI]

    Garcia, Anthony R.; Johnston, Roger G.; Martinez, Ronald K.

    1999-05-25

    A fluid sampling tool for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall.

  9. Fluid sampling tool

    DOE Patents [OSTI]

    Garcia, A.R.; Johnston, R.G.; Martinez, R.K.

    1999-05-25

    A fluid sampling tool is described for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall. 6 figs.

  10. NID Copper Sample Analysis

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Zhu, Zihua

    2011-02-01

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0???). This experiment requires the use of germanium isotopically enriched in 76Ge. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology under development at Nonlinear Ion Dynamics (NID) will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making these isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL for isotopic analysis as a test of the NID technology. The results of that analysis are reported here.

  11. Exploration of LOCOS-type isolation limit using SUPERSILO isolation by rapid thermal nitridation of silicon

    SciTech Connect (OSTI)

    Deleonibus, S.; Martin, F.; Pontcharra, J. du Port de; Tedesco, S. . Dept. de Microelectronique)

    1993-10-01

    The limits for overcoming shrinking localized oxidation of silicon type isolation in the subhalfmicron design rules area are considered: geometric limitations and field implant defect generation are investigated. A super sealed interface local oxidation (SUPERSILO) field isolation process using rapid thermal nitridation of silicon is characterized in terms of morphology, defect density, and electrical performance, With this isolation an encroachment lower than 100 nm is obtained in a large field area of 400 nm finished field oxide. Field oxide thinning and corner encroachment are minimized compared to other conventional isolations and make this process and better candidate for scaling down to 0.7 [mu]m active area pitch design rules. The compatibility with low gate oxide defect density for a thickness as low as 7 nm is demonstrated. Several boron p[sup +] field channel stop implant processes are investigated by characterizing three different scenarios: implanting before field oxidation (classical), through field oxide after the oxidation mask removal (field-retro), and through the poly gate material (poly-retro). In order to avoid defect generation, the retrograde scenarios will be the solution in the future. The poly-retro scenario is the one that reduces boron segregation by a factor of about 10 with respect to the classical scenario and allows high performance without affecting the sustaining voltage. The use of a 0[degree] tilt boron implant at 350 keV through the field oxide and poly gate material stack is shown to be practicable and reproducible.

  12. Silicon surface and bulk defect passivation by low temperature PECVD oxides and nitrides

    SciTech Connect (OSTI)

    Chen, Z.; Rohatgi, A.; Ruby, D.

    1995-01-01

    The effectiveness of PECVD passivation of surface and bulk defects in Si, as well as phosphorous diffused emitters, Is investigated and quantified. Significant hydrogen incorporation coupled with high positive charge density in the PECVD SiN layer is found to play an important role in bulk and surface passivation. It is shown that photo-assisted anneal in a forming gas ambient after PECVD depositions significantly improves the passivation of emitter and bulk defects. PECVD passivation of phosphorous doped emitters and boron doped bare Si surfaces is found to be a strong function of doping concentration. Surface recombination velocity of less than 200 cm/s for 0.2 Ohm-cm and less than 1 cm/s for high resistivity substrates ({approximately} Ohm-cm) were achieved. PECVD passivation improved bulk lifetime in the range of 30% to 70% in multicrystalline Si materials. However, the degree of the passivation was found to be highly material specific. Depending upon the passivation scheme, emitter saturation current density (J{sub oe}) can be reduced by a factor of 3 to 9. Finally, the stability of PECVD oxide/nitride passivation under prolonged UV exposure is established.

  13. Microwave induced plasma (MIP) brazing of silicon nitride to stainless steel

    SciTech Connect (OSTI)

    Samandi, M.; Bate, M.; Donnan, R.; Miyake, S.

    1996-12-31

    In an attempt to accelerate the process of joining of metals to ceramics, a new rapid brazing technology has been developed. In this process, referred to as Microwave Induced Plasma (MIP) brazing, a microwave plasma is used to rapidly heat the ceramic and metal to the melting temperature of the reactive braze material. The heating rate obtained by MIP could be many times faster than those achieved by conventional resistive heating in a tube furnace. The fast heating rate has no detrimental effect on the joint quality and in fact results in the formation of a thick interfacial film suggesting significant interdiffusion between the braze and ceramic, possibly stimulated by the microwave radiation. In this paper the experimental arrangement of the MIP system is described. The unique capability of the MIP heating is demonstrated by successful joining of hot pressed nitride to stainless steel using reactive metal brazing. The results of microstructural characterization of the joints carried out by SEM and EDS will also be presented.

  14. Antifuse with a single silicon-rich silicon nitride insulating layer

    DOE Patents [OSTI]

    Habermehl, Scott D.; Apodaca, Roger T.

    2013-01-22

    An antifuse is disclosed which has an electrically-insulating region sandwiched between two electrodes. The electrically-insulating region has a single layer of a non-hydrogenated silicon-rich (i.e. non-stoichiometric) silicon nitride SiN.sub.X with a nitrogen content X which is generally in the range of 0

  15. Interlayer coupling enhancement in graphene/hexagonal boron nitride heterostructures by intercalated defects or vacancies

    SciTech Connect (OSTI)

    Park, Sohee [Department of Materials Science and Engineering, Seoul National University, Seoul 151-747 (Korea, Republic of)] [Department of Materials Science and Engineering, Seoul National University, Seoul 151-747 (Korea, Republic of); Park, Changwon [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Kim, Gunn, E-mail: gunnkim@sejong.ac.kr [Department of Physics and Graphene Research Institute, Sejong University, Seoul 143-747 (Korea, Republic of)] [Department of Physics and Graphene Research Institute, Sejong University, Seoul 143-747 (Korea, Republic of)

    2014-04-07

    Hexagonal boron nitride (hBN), a remarkable material with a two-dimensional atomic crystal structure, has the potential to fabricate heterostructures with unusual properties. We perform first-principles calculations to determine whether intercalated metal atoms and vacancies can mediate interfacial coupling and influence the structural and electronic properties of the graphene/hBN heterostructure. Metal impurity atoms (Li, K, Cr, Mn, Co, and Cu), acting as extrinsic defects between the graphene and hBN sheets, produce n-doped graphene. We also consider intrinsic vacancy defects and find that a boron monovacancy in hBN acts as a magnetic dopant for graphene, whereas a nitrogen monovacancy in hBN serves as a nonmagnetic dopant for graphene. In contrast, the smallest triangular vacancy defects in hBN are unlikely to result in significant changes in the electronic transport of graphene. Our findings reveal that a hBN layer with some vacancies or metal impurities enhances the interlayer coupling in the graphene/hBN heterostructure with respect to charge doping and electron scattering.

  16. P-doping-free III-nitride high electron mobility light-emitting diodes and transistors

    SciTech Connect (OSTI)

    Li, Baikui; Tang, Xi; Chen, Kevin J.; Wang, Jiannong

    2014-07-21

    We report that a simple metal-AlGaN/GaN Schottky diode is capable of producing GaN band-edge ultraviolet emission at 3.4?eV at a small forward bias larger than ?2?V at room temperature. Based on the surface states distribution of AlGaN, a mature impact-ionization-induced Fermi-level de-pinning model is proposed to explain the underlying mechanism of the electroluminescence (EL) process. By experimenting with different Schottky metals, Ni/Au and Pt/Au, we demonstrated that this EL phenomenon is a universal property of metal-AlGaN/GaN Schottky diodes. Since this light-emitting Schottky diode shares the same active structure and fabrication processes as the AlGaN/GaN high electron mobility transistors, straight-forward and seamless integration of photonic and electronic functional devices has been demonstrated on doping-free III-nitride heterostructures. Using a semitransparent Schottky drain electrode, an AlGaN/GaN high electron mobility light-emitting transistor is demonstrated.

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

    SciTech Connect (OSTI)

    Shanmugam, Mariyappan; Jain, Nikhil; Jacobs-Gedrim, Robin; Yu, Bin; Xu, Yang

    2013-12-09

    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.

  18. Resistive switching phenomena of tungsten nitride thin films with excellent CMOS compatibility

    SciTech Connect (OSTI)

    Hong, Seok Man; Kim, Hee-Dong; An, Ho-Myoung; Kim, Tae Geun

    2013-12-15

    Graphical abstract: - Highlights: The resistive switching characteristics of WN{sub x} thin films. Excellent CMOS compatibility WN{sub x} films as a resistive switching material. Resistive switching mechanism revealed trap-controlled space charge limited conduction. Good endurance and retention properties over 10{sup 5} cycles, and 10{sup 5} s, respectively - Abstract: We report the resistive switching (RS) characteristics of tungsten nitride (WN{sub x}) thin films with excellent complementary metal-oxide-semiconductor (CMOS) compatibility. A Ti/WN{sub x}/Pt memory cell clearly shows bipolar RS behaviors at a low voltage of approximately 2.2 V. The dominant conduction mechanisms at low and high resistance states were verified by Ohmic behavior and trap-controlled space-charge-limited conduction, respectively. A conducting filament model by a redox reaction explains the RS behavior in WN{sub x} films. We also demonstrate the memory characteristics during pulse operation, including a high endurance over >10{sup 5} cycles and a long retention time of >10{sup 5} s.

  19. Direct growth of nanocrystalline hexagonal boron nitride films on dielectric substrates

    SciTech Connect (OSTI)

    Tay, Roland Yingjie; Tsang, Siu Hon; Loeblein, Manuela; Chow, Wai Leong; Loh, Guan Chee; Toh, Joo Wah; Ang, Soon Loong; Teo, Edwin Hang Tong

    2015-03-09

    Atomically thin hexagonal-boron nitride (h-BN) films are primarily synthesized through chemical vapor deposition (CVD) on various catalytic transition metal substrates. In this work, a single-step metal-catalyst-free approach to obtain few- to multi-layer nanocrystalline h-BN (NCBN) directly on amorphous SiO{sub 2}/Si and quartz substrates is demonstrated. The as-grown thin films are continuous and smooth with no observable pinholes or wrinkles across the entire deposited substrate as inspected using optical and atomic force microscopy. The starting layers of NCBN orient itself parallel to the substrate, initiating the growth of the textured thin film. Formation of NCBN is due to the random and uncontrolled nucleation of h-BN on the dielectric substrate surface with no epitaxial relation, unlike on metal surfaces. The crystallite size is ?25?nm as determined by Raman spectroscopy. Transmission electron microscopy shows that the NCBN formed sheets of multi-stacked layers with controllable thickness from ?2 to 25?nm. The absence of transfer process in this technique avoids any additional degradation, such as wrinkles, tears or folding and residues on the film which are detrimental to device performance. This work provides a wider perspective of CVD-grown h-BN and presents a viable route towards large-scale manufacturing of h-BN substrates and for coating applications.

  20. Carbide/nitride grain refined rare earth-iron-boron permanent magnet and method of making

    DOE Patents [OSTI]

    McCallum, R. William; Branagan, Daniel J.

    1996-01-23

    A method of making a permanent magnet wherein 1) a melt is formed having a base alloy composition comprising RE, Fe and/or Co, and B (where RE is one or more rare earth elements) and 2) TR (where TR is a transition metal selected from at least one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Al) and at least one of C and N are provided in the base alloy composition melt in substantially stoichiometric amounts to form a thermodynamically stable compound (e.g. TR carbide, nitride or carbonitride). The melt is rapidly solidified in a manner to form particulates having a substantially amorphous (metallic glass) structure and a dispersion of primary TRC, TRN and/or TRC/N precipitates. The amorphous particulates are heated above the crystallization temperature of the base alloy composition to nucleate and grow a hard magnetic phase to an optimum grain size and to form secondary TRC, TRN and/or TRC/N precipitates dispersed at grain boundaries. The crystallized particulates are consolidated at an elevated temperature to form a shape. During elevated temperature consolidation, the primary and secondary precipitates act to pin the grain boundaries and minimize deleterious grain growth that is harmful to magnetic properties.

  1. Carbide/nitride grain refined rare earth-iron-boron permanent magnet and method of making

    DOE Patents [OSTI]

    McCallum, R.W.; Branagan, D.J.

    1996-01-23

    A method of making a permanent magnet is disclosed wherein (1) a melt is formed having a base alloy composition comprising RE, Fe and/or Co, and B (where RE is one or more rare earth elements) and (2) TR (where TR is a transition metal selected from at least one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Al) and at least one of C and N are provided in the base alloy composition melt in substantially stoichiometric amounts to form a thermodynamically stable compound (e.g. TR carbide, nitride or carbonitride). The melt is rapidly solidified in a manner to form particulates having a substantially amorphous (metallic glass) structure and a dispersion of primary TRC, TRN and/or TRC/N precipitates. The amorphous particulates are heated above the crystallization temperature of the base alloy composition to nucleate and grow a hard magnetic phase to an optimum grain size and to form secondary TRC, TRN and/or TRC/N precipitates dispersed at grain boundaries. The crystallized particulates are consolidated at an elevated temperature to form a shape. During elevated temperature consolidation, the primary and secondary precipitates act to pin the grain boundaries and minimize deleterious grain growth that is harmful to magnetic properties. 33 figs.

  2. Design of defect spins in piezoelectric aluminum nitride for solid-state hybrid quantum technologies

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

    Seo, Hosung; Govoni, Marco; Galli, Giulia

    2016-02-15

    Spin defects in wide-band gap semiconductors are promising systems for the realization of quantum bits, or qubits, in solid-state environments. To date, defect qubits have only been realized in materials with strong covalent bonds. Here, we introduce a strain-driven scheme to rationally design defect spins in functional ionic crystals, which may operate as potential qubits. In particular, using a combination of state-of-the-art ab-initio calculations based on hybrid density functional and many-body perturbation theory, we predicted that the negatively charged nitrogen vacancy center in piezoelectric aluminum nitride exhibits spin-triplet ground states under realistic uni- and bi-axial strain conditions; such states maymore » be harnessed for the realization of qubits. As a result, the strain-driven strategy adopted here can be readily extended to a wide range of point defects in other wide-band gap semiconductors, paving the way to controlling the spin properties of defects in ionic systems for potential spintronic technologies.« less

  3. Sample introducing apparatus and sample modules for mass spectrometer

    DOE Patents [OSTI]

    Thompson, Cyril V.; Wise, Marcus B.

    1993-01-01

    An apparatus for introducing gaseous samples from a wide range of environmental matrices into a mass spectrometer for analysis of the samples is described. Several sample preparing modules including a real-time air monitoring module, a soil/liquid purge module, and a thermal desorption module are individually and rapidly attachable to the sample introducing apparatus for supplying gaseous samples to the mass spectrometer. The sample-introducing apparatus uses a capillary column for conveying the gaseous samples into the mass spectrometer and is provided with an open/split interface in communication with the capillary and a sample archiving port through which at least about 90 percent of the gaseous sample in a mixture with an inert gas that was introduced into the sample introducing apparatus is separated from a minor portion of the mixture entering the capillary discharged from the sample introducing apparatus.

  4. Sample introducing apparatus and sample modules for mass spectrometer

    DOE Patents [OSTI]

    Thompson, C.V.; Wise, M.B.

    1993-12-21

    An apparatus for introducing gaseous samples from a wide range of environmental matrices into a mass spectrometer for analysis of the samples is described. Several sample preparing modules including a real-time air monitoring module, a soil/liquid purge module, and a thermal desorption module are individually and rapidly attachable to the sample introducing apparatus for supplying gaseous samples to the mass spectrometer. The sample-introducing apparatus uses a capillary column for conveying the gaseous samples into the mass spectrometer and is provided with an open/split interface in communication with the capillary and a sample archiving port through which at least about 90 percent of the gaseous sample in a mixture with an inert gas that was introduced into the sample introducing apparatus is separated from a minor portion of the mixture entering the capillary discharged from the sample introducing apparatus. 5 figures.

  5. Soil sampling kit and a method of sampling therewith

    DOE Patents [OSTI]

    Thompson, C.V.

    1991-02-05

    A soil sampling device and a sample containment device for containing a soil sample is disclosed. In addition, a method for taking a soil sample using the soil sampling device and soil sample containment device to minimize the loss of any volatile organic compounds contained in the soil sample prior to analysis is disclosed. The soil sampling device comprises two close fitting, longitudinal tubular members of suitable length, the inner tube having the outward end closed. With the inner closed tube withdrawn a selected distance, the outer tube can be inserted into the ground or other similar soft material to withdraw a sample of material for examination. The inner closed end tube controls the volume of the sample taken and also serves to eject the sample. The soil sample containment device has a sealing member which is adapted to attach to an analytical apparatus which analyzes the volatile organic compounds contained in the sample. The soil sampling device in combination with the soil sample containment device allows an operator to obtain a soil sample containing volatile organic compounds and minimizing the loss of the volatile organic compounds prior to analysis of the soil sample for the volatile organic compounds. 11 figures.

  6. Soil sampling kit and a method of sampling therewith

    DOE Patents [OSTI]

    Thompson, Cyril V.

    1991-01-01

    A soil sampling device and a sample containment device for containing a soil sample is disclosed. In addition, a method for taking a soil sample using the soil sampling device and soil sample containment device to minimize the loss of any volatile organic compounds contained in the soil sample prior to analysis is disclosed. The soil sampling device comprises two close fitting, longitudinal tubular members of suitable length, the inner tube having the outward end closed. With the inner closed tube withdrawn a selected distance, the outer tube can be inserted into the ground or other similar soft material to withdraw a sample of material for examination. The inner closed end tube controls the volume of the sample taken and also serves to eject the sample. The soil sample containment device has a sealing member which is adapted to attach to an analytical apparatus which analyzes the volatile organic compounds contained in the sample. The soil sampling device in combination with the soil sample containment device allow an operator to obtain a soil sample containing volatile organic compounds and minimizing the loss of the volatile organic compounds prior to analysis of the soil sample for the volatile organic compounds.

  7. Fluid sampling apparatus and method

    DOE Patents [OSTI]

    Yeamans, David R.

    1998-01-01

    Incorporation of a bellows in a sampling syringe eliminates ingress of contaminants, permits replication of amounts and compression of multiple sample injections, and enables remote sampling for off-site analysis.

  8. Fluid sampling apparatus and method

    DOE Patents [OSTI]

    Yeamans, D.R.

    1998-02-03

    Incorporation of a bellows in a sampling syringe eliminates ingress of contaminants, permits replication of amounts and compression of multiple sample injections, and enables remote sampling for off-site analysis. 3 figs.

  9. Fluid sampling tool

    DOE Patents [OSTI]

    Johnston, Roger G.; Garcia, Anthony R. E.; Martinez, Ronald K.

    2001-09-25

    The invention includes a rotatable tool for collecting fluid through the wall of a container. The tool includes a fluid collection section with a cylindrical shank having an end portion for drilling a hole in the container wall when the tool is rotated, and a threaded portion for tapping the hole in the container wall. A passageway in the shank in communication with at least one radial inlet hole in the drilling end and an opening at the end of the shank is adapted to receive fluid from the container. The tool also includes a cylindrical chamber affixed to the end of the shank opposite to the drilling portion thereof for receiving and storing fluid passing through the passageway. The tool also includes a flexible, deformable gasket that provides a fluid-tight chamber to confine kerf generated during the drilling and tapping of the hole. The invention also includes a fluid extractor section for extracting fluid samples from the fluid collecting section.

  10. Rock Sampling | Open Energy Information

    Open Energy Info (EERE)

    resource at depth. These hand samples can be collected using a rock hammer or sledge. Data Access and Acquisition Under a detailed investigation, a systematic sampling procedure...

  11. Water Sampling | Open Energy Information

    Open Energy Info (EERE)

    Water Sampling Details Activities (63) Areas (51) Regions (5) NEPA(2) Exploration Technique Information Exploration Group: Field Techniques Exploration Sub Group: Field Sampling...

  12. Electronic properties of III-nitride semiconductors: A first-principles investigation using the Tran-Blaha modified Becke-Johnson potential

    SciTech Connect (OSTI)

    Araujo, Rafael B. Almeida, J. S. de Ferreira da Silva, A.

    2013-11-14

    In this work, we use density functional theory to investigate the influence of semilocal exchange and correlation effects on the electronic properties of III-nitride semiconductors considering zinc-blende and wurtzite crystal structures. We find that the inclusion of such effects through the use of the Tran-Blaha modified Becke-Johnson potential yields an excellent description of the electronic structures of these materials giving energy band gaps which are systematically larger than the ones obtained with standard functionals such as the generalized gradient approximation. The discrepancy between the experimental and theoretical band gaps is then significantly reduced with semilocal exchange and correlation effects. However, the effective masses are overestimated in the zinc-blende nitrides, but no systematic trend is found in the wurtzite compounds. New results for energy band gaps and effective masses of zinc-blende and wurtzite indium nitrides are presented.

  13. Sample holder with optical features

    DOE Patents [OSTI]

    Milas, Mirko; Zhu, Yimei; Rameau, Jonathan David

    2013-07-30

    A sample holder for holding a sample to be observed for research purposes, particularly in a transmission electron microscope (TEM), generally includes an external alignment part for directing a light beam in a predetermined beam direction, a sample holder body in optical communication with the external alignment part and a sample support member disposed at a distal end of the sample holder body opposite the external alignment part for holding a sample to be analyzed. The sample holder body defines an internal conduit for the light beam and the sample support member includes a light beam positioner for directing the light beam between the sample holder body and the sample held by the sample support member.

  14. Compact cold stage for micro-computerized tomography imaging of chilled or frozen samples

    SciTech Connect (OSTI)

    Hullar, Ted; Anastasio, Cort; Paige, David F.; Rowland, Douglas J.

    2014-04-15

    High resolution X-ray microCT (computerized tomography) can be used to image a variety of objects, including temperature-sensitive materials. In cases where the sample must be chilled or frozen to maintain sample integrity, either the microCT machine itself must be placed in a refrigerated chamber, or a relatively expensive commercial cold stage must be purchased. We describe here the design and construction of a low-cost custom cold stage suitable for use in a microCT imaging system. Our device uses a boron nitride sample holder, two-stage Peltier cooler, fan-cooled heat sink, and electronic controller to maintain sample temperatures as low as ?25?C 0.2?C for the duration of a tomography acquisition. The design does not require modification to the microCT machine, and is easily installed and removed. Our custom cold stage represents a cost-effective solution for refrigerating CT samples for imaging, and is especially useful for shared equipment or machines unsuitable for cold room use.

  15. Precipitation of aluminum nitride in a high strength maraging steel with low nitrogen content

    SciTech Connect (OSTI)

    Jeanmaire, G.; Dehmas, M.; Redjamia, A.; Puech, S.; Fribourg, G.

    2014-12-15

    In the present work, aluminum nitride (AlN) precipitation was investigated in a X23NiCoCrMoAl13-6-3 maraging steel with low nitrogen content (wt.% N = 5.5 ppm). A reliable and robust automatic method by scanning electron microscopy observations coupled with energy dispersive X-ray spectroscopy was developed for the quantification of AlN precipitates. The first stage was to identify the solvus temperature and to develop a heat treatment able to dissolve the AlN precipitates. The experimental determination of equilibrium conditions and solvus temperature show good agreement with ThermoCalc simulation. Then, from this AlN-free state, the cooling rate, isothermal holding time and temperature were the subject of an intensive investigation in the austenite region of this maraging steel. In spite of the high temperatures used during heat treatments, the growth kinetic of the largest AlN precipitates (> 1 ?m) is slow. The cooling rate has a major effect on the size and the number density of AlN due to a higher driving force for nucleation at low temperatures. At last, quenching prior to isothermal annealing at high temperatures leads to fine and dense AlN precipitation, resulting from the martensite to austenite transformation. Experimental results will be discussed and compared with kinetic data obtained with the mobility database MobFe2 implemented in Dictra software. - Highlights: Slow dissolution kinetic of AlN precipitates due to both their large size and small chemical driving force Significant effects of cooling rate prior isothermal heat treatment, holding time and temperature on AlN precipitation Size of AlN precipitates can be reduced by quenching prior isothermal holding. Fine precipitation of AlN related to the ? ? ? transformation.

  16. Group-III nitride based high electron mobility transistor (HEMT) with barrier/spacer layer

    DOE Patents [OSTI]

    Chavarkar, Prashant; Smorchkova, Ioulia P.; Keller, Stacia; Mishra, Umesh; Walukiewicz, Wladyslaw; Wu, Yifeng

    2005-02-01

    A Group III nitride based high electron mobility transistors (HEMT) is disclosed that provides improved high frequency performance. One embodiment of the HEMT comprises a GaN buffer layer, with an Al.sub.y Ga.sub.1-y N (y=1 or y 1) layer on the GaN buffer layer. An Al.sub.x Ga.sub.1-x N (0.ltoreq.x.ltoreq.0.5) barrier layer on to the Al.sub.y Ga.sub.1-y N layer, opposite the GaN buffer layer, Al.sub.y Ga.sub.1-y N layer having a higher Al concentration than that of the Al.sub.x Ga.sub.1-x N barrier layer. A preferred Al.sub.y Ga.sub.1-y N layer has y=1 or y.about.1 and a preferred Al.sub.x Ga.sub.1-x N barrier layer has 0.ltoreq.x.ltoreq.0.5. A 2DEG forms at the interface between the GaN buffer layer and the Al.sub.y Ga.sub.1-y N layer. Respective source, drain and gate contacts are formed on the Al.sub.x Ga.sub.1-x N barrier layer. The HEMT can also comprising a substrate adjacent to the buffer layer, opposite the Al.sub.y Ga.sub.1-y N layer and a nucleation layer between the Al.sub.x Ga.sub.1-x N buffer layer and the substrate.

  17. Sampling Report for May-June, 2014 WIPP Samples

    Office of Environmental Management (EM)

    UNCLASSIFIED iii Table of Contents WIPP Panel 7 Sampling May-June, 2014 ... 15 LLNL-TR-667001 Section 1 WIPP Panel 7 Sampling May-June, 2014 1. Summary of ...

  18. Specified assurance level sampling procedure

    SciTech Connect (OSTI)

    Willner, O.

    1980-11-01

    In the nuclear industry design specifications for certain quality characteristics require that the final product be inspected by a sampling plan which can demonstrate product conformance to stated assurance levels. The Specified Assurance Level (SAL) Sampling Procedure has been developed to permit the direct selection of attribute sampling plans which can meet commonly used assurance levels. The SAL procedure contains sampling plans which yield the minimum sample size at stated assurance levels. The SAL procedure also provides sampling plans with acceptance numbers ranging from 0 to 10, thus, making available to the user a wide choice of plans all designed to comply with a stated assurance level.

  19. Preliminary design study of small long life boiling water reactor (BWR) with tight lattice thorium nitride fuel

    SciTech Connect (OSTI)

    Trianti, Nuri E-mail: szaki@fi.itba.c.id; Su'ud, Zaki E-mail: szaki@fi.itba.c.id; Arif, Idam E-mail: szaki@fi.itba.c.id; Riyana, EkaSapta

    2014-09-30

    Neutronic performance of small long-life boiling water reactors (BWR) with thorium nitride based fuel has been performed. A recent study conducted on BWR in tight lattice environments (with a lower moderator percentage) produces small power reactor which has some specifications, i.e. 10 years operation time, power density of 19.1 watt/cc and maximum excess reactivity of about 4%. This excess reactivity value is smaller than standard reactivity of conventional BWR. The use of hexagonal geometry on the fuel cell of BWR provides a substantial effect on the criticality of the reactor to obtain a longer operating time. Supported by a tight concept lattice where the volume fraction of the fuel is greater than the moderator and fuel, Thorium Nitride give good results for fuel cell design on small long life BWR. The excess reactivity of the reactor can be reduced with the addition of gadolinium as burnable poisons. Therefore the hexagonal tight lattice fuel cell design of small long life BWR that has a criticality more than 20 years of operating time has been obtained.

  20. Groundwater Sampling | Open Energy Information

    Open Energy Info (EERE)

    500 mL), whereas analysis for stable isotopes that are present in greater abundance in natural samples requires less water to be sampled by a full order of magnitude (approximately...

  1. Geoscience Laboratory | Sample Preparation Laboratories

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

    preparation and other relatively straight-forward laboratory manipulations. These include buffer preparations, solid sample grinding, solution concentration, filtration, and...

  2. Combinatorial Insights into Doping Control and Transport Properties of Zinc Tin Nitride

    SciTech Connect (OSTI)

    Fioretti, Angela N.; Zakutayev, Andriy; Moutinho, Helio; Melamed, Celeste; Perkins, John D.; Norman, Andrew G.; Al-Jassim, Mowafak; Toberer, Eric S.; Tamboli, Adele C.

    2015-09-21

    ZnSnN2 is an Earth-abundant semiconductor analogous to the III–nitrides with potential as a solar absorber due to its direct bandgap, steep absorption onset, and disorder-driven bandgap tunability. Despite these desirable properties, discrepancies in the fundamental bandgap and degenerate n-type carrier density have been prevalent issues in the limited amount of literature available on this material. We we use a combinatorial RF co-sputtering approach, we explored a growth-temperature-composition space for Zn1+xSn1-xN2 over the ranges 35–340 °C and 0.30–0.75 Zn/(Zn + Sn). In this way, we identified an optimal set of deposition parameters for obtaining as-deposited films with wurtzite crystal structure and carrier density as low as 1.8 × 1018 cm-3. Films grown at 230 °C with Zn/(Zn + Sn) = 0.60 were found to have the largest grain size overall (70 nm diameter on average) while also exhibiting low carrier density (3 × 1018 cm-3) and high mobility (8.3 cm2 V-1 s-1). Using this approach, we establish the direct bandgap of cation-disordered ZnSnN2 at 1.0 eV. Moreover, we report tunable carrier density as a function of cation composition, in which lower carrier density is observed for higher Zn content. Consequently, this relationship manifests as a Burstein–Moss shift widening the apparent bandgap as cation composition moves away from Zn-rich. Collectively, these findings provide important insight into the fundamental properties of the Zn–Sn–N material system and highlight the potential to utilize ZnSnN2 for photovoltaics.

  3. Hetero-junctions of Boron Nitride and Carbon Nanotubes: Synthesis and Characterization

    SciTech Connect (OSTI)

    Yap, Yoke Khin

    2013-03-14

    Hetero-junctions of boron nitride nanotubes (BNNTs) and carbon nanotubes (CNTs) are expected to have appealing new properties that are not available from pure BNNTs and CNTs. Theoretical studies indicate that BNNT/CNT junctions could be multifunctional and applicable as memory, spintronic, electronic, and photonics devices with tunable band structures. This will lead to energy and material efficient multifunctional devices that will be beneficial to the society. However, experimental realization of BNNT/CNT junctions was hindered by the absent of a common growth technique for BNNTs and CNTs. In fact, the synthesis of BNNTs was very challenging and may involve high temperatures (up to 3000 degree Celsius by laser ablation) and explosive chemicals. During the award period, we have successfully developed a simple chemical vapor deposition (CVD) technique to grow BNNTs at 1100-1200 degree Celsius without using dangerous chemicals. A series of common catalyst have then been identified for the synthesis of BNNTs and CNTs. Both of these breakthroughs have led to our preliminary success in growing two types of BNNT/CNT junctions and two additional new nanostructures: 1) branching BNNT/CNT junctions and 2) co-axial BNNT/CNT junctions, 3) quantum dots functionalized BNNTs (QDs-BNNTs), 4) BNNT/graphene junctions. We have started to understand their structural, compositional, and electronic properties. Latest results indicate that the branching BNNT/CNT junctions and QDs-BNNTs are functional as room-temperature tunneling devices. We have submitted the application of a renewal grant to continue the study of these new energy efficient materials. Finally, this project has also strengthened our collaborations with multiple Department of Energy’s Nanoscale Science Research Centers (NSRCs), including the Center for Nanophase Materials Sciences (CNMS) at Oak Ridge National Laboratory, and the Center for Integrated Nanotechnologies (CINTs) at Sandia National Laboratories and Los Alamos National Laboratory. Results obtained during the current funding period have led to the publication of twelve peer reviewed articles, three review papers, two book and one encyclopedia chapters, and thirty eight conference/seminar presentation. One US provisional patent and one international patent have also been filed.

  4. Dual mechanical behaviour of hydrogen in stressed silicon nitride thin films

    SciTech Connect (OSTI)

    Volpi, F. Braccini, M.; Pasturel, A.; Devos, A.; Raymond, G.; Morin, P.

    2014-07-28

    In the present article, we report a study on the mechanical behaviour displayed by hydrogen atoms and pores in silicon nitride (SiN) films. A simple three-phase model is proposed to relate the physical properties (stiffness, film stress, mass density, etc.) of hydrogenated nanoporous SiN thin films to the volume fractions of hydrogen and pores. This model is then applied to experimental data extracted from films deposited by plasma enhanced chemical vapour deposition, where hydrogen content, stress, and mass densities range widely from 11% to 30%, ?2.8 to 1.5?GPa, and 2.0 to 2.8?g/cm{sup 3}, respectively. Starting from the conventional plotting of film's Young's modulus against film porosity, we first propose to correct the conventional calculation of porosity volume fraction with the hydrogen content, thus taking into account both hydrogen mass and concentration. The weight of this hydrogen-correction is found to evolve linearly with hydrogen concentration in tensile films (in accordance with a simple mass correction of the film density calculation), but a clear discontinuity is observed toward compressive stresses. Then, the effective volume occupied by hydrogen atoms is calculated taking account of the bond type (N-H or Si-H bonds), thus allowing a precise extraction of the hydrogen volume fraction. These calculations applied to tensile films show that both volume fractions of hydrogen and porosity are similar in magnitude and randomly distributed against Young's modulus. However, the expected linear dependence of the Young's modulus is clearly observed when both volume fractions are added. Finally, we show that the stiffer behaviour of compressive films cannot be only explained on the basis of this (hydrogen?+?porosity) volume fraction. Indeed this stiffness difference relies on a dual mechanical behaviour displayed by hydrogen atoms against the film stress state: while they participate to the stiffness in compressive films, hydrogen atoms mainly behave like pores in tensile films where they do not participate to the film stiffness.

  5. Sampling Report for August 15, 2014 WIPP Samples

    Office of Environmental Management (EM)

    UNCLASSIFIED iii Table of Contents WIPP Panel 7 Sampling August 15, 2014 ... 3. Photograph of current configuration of Panel 7 from the 50 ft. boom ...

  6. Sampling Report for May-June, 2014 WIPP Samples

    Office of Environmental Management (EM)

    1 L L N L - X X X X - X X X X X Sampling Report for May- June, 2014 WIPP Samples UNCLASSIFIED Forensic Science Center January 8, 2015 Sampling Report for May-June, 2014 WIPP Samples Lawrence Livermore National Laboratory UNCLASSIFIED ii Disclaimer This document was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor Lawrence Livermore National Security, LLC, nor any of their employees makes any warranty, expressed or

  7. Acceptance sampling using judgmental and randomly selected samples

    SciTech Connect (OSTI)

    Sego, Landon H.; Shulman, Stanley A.; Anderson, Kevin K.; Wilson, John E.; Pulsipher, Brent A.; Sieber, W. Karl

    2010-09-01

    We present a Bayesian model for acceptance sampling where the population consists of two groups, each with different levels of risk of containing unacceptable items. Expert opinion, or judgment, may be required to distinguish between the high and low-risk groups. Hence, high-risk items are likely to be identifed (and sampled) using expert judgment, while the remaining low-risk items are sampled randomly. We focus on the situation where all observed samples must be acceptable. Consequently, the objective of the statistical inference is to quantify the probability that a large percentage of the unsampled items in the population are also acceptable. We demonstrate that traditional (frequentist) acceptance sampling and simpler Bayesian formulations of the problem are essentially special cases of the proposed model. We explore the properties of the model in detail, and discuss the conditions necessary to ensure that required samples sizes are non-decreasing function of the population size. The method is applicable to a variety of acceptance sampling problems, and, in particular, to environmental sampling where the objective is to demonstrate the safety of reoccupying a remediated facility that has been contaminated with a lethal agent.

  8. Sample Retention Incentive Service Agreement

    Energy Savers [EERE]

    Department of Energy Sample Contract Language for Construction Using Energy-Efficient Products Sample Contract Language for Construction Using Energy-Efficient Products Document covers sample language that federal agencies can use in contracts specifying or purchasing energy-efficient products in construction projects. This includes the following products qualified by ENERGY STAR or designated by the Federal Energy Management Program: Air conditioners Ballasts Boilers Chillers Doors Electric

  9. Gas Sampling | Open Energy Information

    Open Energy Info (EERE)

    of geothermometric calculations and geochemical modeling of the data. In the case of gas flux sampling, different measurement techniques and devices may disrupt or alter the...

  10. Sample page | Open Energy Information

    Open Energy Info (EERE)

    Sample pages; Help pages; References Francis C. Monastero. 2002. An overview of industry-military cooperation in the development of power operations at the Coso...

  11. Sample Residential Program Term Sheet

    Broader source: Energy.gov [DOE]

    A sample for defining and elaborating on the specifics of a clean energy loan program. Author: U.S. Department of Energy

  12. Environmental surveillance master sampling schedule

    SciTech Connect (OSTI)

    Bisping, L.E.

    1995-02-01

    Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest Laboratory (PNL) for the U.S. Department of Energy (DOE). This document contains the planned 1994 schedules for routine collection of samples for the Surface Environmental Surveillance Project (SESP), Drinking Water Project, and Ground-Water Surveillance Project. Samples are routinely collected for the SESP and analyzed to determine the quality of air, surface water, soil, sediment, wildlife, vegetation, foodstuffs, and farm products at Hanford Site and surrounding communities. The responsibility for monitoring onsite drinking water falls outside the scope of the SESP. PNL conducts the drinking water monitoring project concurrent with the SESP to promote efficiency and consistency, utilize expertise developed over the years, and reduce costs associated with management, procedure development, data management, quality control, and reporting. The ground-water sampling schedule identifies ground-water sampling .events used by PNL for environmental surveillance of the Hanford Site. Sampling is indicated as annual, semi-annual, quarterly, or monthly in the sampling schedule. Some samples are collected and analyzed as part of ground-water monitoring and characterization programs at Hanford (e.g. Resources Conservation and Recovery Act (RCRA), Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), or Operational). The number of samples planned by other programs are identified in the sampling schedule by a number in the analysis column and a project designation in the Cosample column. Well sampling events may be merged to avoid redundancy in cases where sampling is planned by both-environmental surveillance and another program.

  13. Excitation wavelength dependence of water-window line emissions from boron-nitride laser-produced plasmas

    SciTech Connect (OSTI)

    Crank, M.; Harilal, S. S.; Hassan, S. M.; Hassanein, A.

    2012-02-01

    We investigated the effects of laser excitation wavelength on water-window emission lines of laser-produced boron-nitride plasmas. Plasmas are produced by focusing 1064 nm and harmonically generated 532 and 266 nm radiation from a Nd:YAG laser on BN target in vacuum. Soft x-ray emission lines in the water-window region are recorded using a grazing-incidence spectrograph. Filtered photodiodes are used to obtain complementary data for water-window emission intensity and angular dependence. Spectral emission intensity changes in nitrogen Ly-{alpha} and He-{alpha} are used to show how laser wavelength affects emission. Our results show that the relative intensity of spectral lines is laser wavelength dependent, with the ratio of Ly-{alpha} to He-{alpha} emission intensity decreasing as laser wavelength is shortened. Filtered photodiode measurements of angular dependence showed that 266 and 532 nm laser wavelengths produce uniform emission.

  14. Compact, Interactive Electric Vehicle Charger: Gallium-Nitride Switch Technology for Bi-directional Battery-to-Grid Charger Applications

    SciTech Connect (OSTI)

    2010-10-01

    ADEPT Project: HRL Laboratories is using gallium nitride (GaN) semiconductors to create battery chargers for electric vehicles (EVs) that are more compact and efficient than traditional EV chargers. Reducing the size and weight of the battery charger is important because it would help improve the overall performance of the EV. GaN semiconductors process electricity faster than the silicon semiconductors used in most conventional EV battery chargers. These high-speed semiconductors can be paired with lighter-weight electrical circuit components, which helps decrease the overall weight of the EV battery charger. HRL Laboratories is combining the performance advantages of GaN semiconductors with an innovative, interactive battery-to-grid energy distribution design. This design would support 2-way power flow, enabling EV battery chargers to not only draw energy from the power grid, but also store and feed energy back into it.

  15. Effects of boron-nitride substrates on Stone-Wales defect formation in graphene: An ab initio molecular dynamics study

    SciTech Connect (OSTI)

    Jin, K.; Xiao, H. Y. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Zhang, Y. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Weber, W. J., E-mail: wjweber@utk.edu [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2014-05-19

    Ab initio molecular dynamics simulations are performed to investigate the effects of a boron nitride (BN) substrate on Stone-Wales (SW) defect formation and recovery in graphene. It is found that SW defects can be created by an off-plane recoil atom that interacts with the BN substrate. A mechanism with complete bond breakage for formation of SW defects in suspended graphene is also revealed for recoils at large displacement angles. In addition, further irradiation can result in recovery of the SW defects through a bond rotation mechanism in both graphene and graphene/BN, and the substrate has little effect on the recovery process. This study indicates that the BN substrate enhances the irradiation resistance of graphene.

  16. Thickness determination of few-layer hexagonal boron nitride films by scanning electron microscopy and Auger electron spectroscopy

    SciTech Connect (OSTI)

    Sutter, P. Sutter, E.

    2014-09-01

    We assess scanning electron microscopy (SEM) and Auger electron spectroscopy (AES) for thickness measurements on few-layer hexagonal boron nitride (h-BN), the layered dielectric of choice for integration with graphene and other two-dimensional materials. Observations on h-BN islands with large, atomically flat terraces show that the secondary electron intensity in SEM reflects monolayer height changes in films up to least 10 atomic layers thickness. From a quantitative analysis of AES data, the energy-dependent electron escape depth in h-BN films is deduced. The results show that AES is suitable for absolute thickness measurements of few-layer h-BN of 1 to 6 layers.

  17. Looking for Auger signatures in III-nitride light emitters: A full-band Monte Carlo perspective

    SciTech Connect (OSTI)

    Bertazzi, Francesco Goano, Michele; Zhou, Xiangyu; Calciati, Marco; Ghione, Giovanni; Matsubara, Masahiko; Bellotti, Enrico

    2015-02-09

    Recent experiments of electron emission spectroscopy (EES) on III-nitride light-emitting diodes (LEDs) have shown a correlation between droop onset and hot electron emission at the cesiated surface of the LED p-cap. The observed hot electrons have been interpreted as a direct signature of Auger recombination in the LED active region, as highly energetic Auger-excited electrons would be collected in long-lived satellite valleys of the conduction band so that they would not decay on their journey to the surface across the highly doped p-contact layer. We discuss this interpretation by using a full-band Monte Carlo model based on first-principles electronic structure and lattice dynamics calculations. The results of our analysis suggest that Auger-excited electrons cannot be unambiguously detected in the LED structures used in the EES experiments. Additional experimental and simulative work are necessary to unravel the complex physics of GaN cesiated surfaces.

  18. 200 area TEDF sample schedule

    SciTech Connect (OSTI)

    Brown, M.J.

    1995-03-22

    This document summarizes the sampling criteria associated with the 200 Area Treatment Effluent Facility (TEDF) that are needed to comply with the requirements of the Washington State Discharge Permit No. WA ST 4502 and good engineering practices at the generator streams that feed into TEDF. In addition, this document Identifies the responsible parties for both sampling and data transference.

  19. Sample push-out fixture

    DOE Patents [OSTI]

    Biernat, John L.

    2002-11-05

    This invention generally relates to the remote removal of pelletized samples from cylindrical containment capsules. V-blocks are used to receive the samples and provide guidance to push out rods. Stainless steel liners fit into the v-channels on the v-blocks which permits them to be remotely removed and replaced or cleaned to prevent cross contamination between capsules and samples. A capsule holder securely holds the capsule while allowing manual up/down and in/out movement to align each sample hole with the v-blocks. Both end sections contain identical v-blocks; one that guides the drive out screw and rods or manual push out rods and the other to receive the samples as they are driven out of the capsule.

  20. Environmental surveillance master sampling schedule

    SciTech Connect (OSTI)

    Bisping, L.E.

    1991-01-01

    Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE). This document contains the planned schedule for routine sample collection for the Surface Environmental Surveillance Project (SESP) and Ground-Water Monitoring Project. The routine sampling plan for the SESP has been revised this year to reflect changing site operations and priorities. Some sampling previously performed at least annually has been reduced in frequency, and some new sampling to be performed at a less than annual frequency has been added. Therefore, the SESP schedule reflects sampling to be conducted in calendar year 1991 as well as future years. The ground-water sampling schedule is for 1991. This schedule is subject to modification during the year in response to changes in Site operation, program requirements, and the nature of the observed results. Operational limitations such as weather, mechanical failures, sample availability, etc., may also require schedule modifications. Changes will be documented in the respective project files, but this plan will not be reissued. The purpose of these monitoring projects is to evaluate levels of radioactive and nonradioactive pollutants in the Hanford evirons.

  1. Duplex sampling apparatus and method

    DOE Patents [OSTI]

    Brown, Paul E. (Pittsburgh, PA); Lloyd, Robert (West Mifflin, PA)

    1992-01-01

    An improved apparatus is provided for sampling a gaseous mixture and for measuring mixture components. The apparatus includes two sampling containers connected in series serving as a duplex sampling apparatus. The apparatus is adapted to independently determine the amounts of condensable and noncondensable gases in admixture from a single sample. More specifically, a first container includes a first port capable of selectively connecting to and disconnecting from a sample source and a second port capable of selectively connecting to and disconnecting from a second container. A second container also includes a first port capable of selectively connecting to and disconnecting from the second port of the first container and a second port capable of either selectively connecting to and disconnecting from a differential pressure source. By cooling a mixture sample in the first container, the condensable vapors form a liquid, leaving noncondensable gases either as free gases or dissolved in the liquid. The condensed liquid is heated to drive out dissolved noncondensable gases, and all the noncondensable gases are transferred to the second container. Then the first and second containers are separated from one another in order to separately determine the amount of noncondensable gases and the amount of condensable gases in the sample.

  2. Defining And Characterizing Sample Representativeness For DWPF Melter Feed Samples

    SciTech Connect (OSTI)

    Shine, E. P.; Poirier, M. R.

    2013-10-29

    Representative sampling is important throughout the Defense Waste Processing Facility (DWPF) process, and the demonstrated success of the DWPF process to achieve glass product quality over the past two decades is a direct result of the quality of information obtained from the process. The objective of this report was to present sampling methods that the Savannah River Site (SRS) used to qualify waste being dispositioned at the DWPF. The goal was to emphasize the methodology, not a list of outcomes from those studies. This methodology includes proven methods for taking representative samples, the use of controlled analytical methods, and data interpretation and reporting that considers the uncertainty of all error sources. Numerous sampling studies were conducted during the development of the DWPF process and still continue to be performed in order to evaluate options for process improvement. Study designs were based on use of statistical tools applicable to the determination of uncertainties associated with the data needs. Successful designs are apt to be repeated, so this report chose only to include prototypic case studies that typify the characteristics of frequently used designs. Case studies have been presented for studying in-tank homogeneity, evaluating the suitability of sampler systems, determining factors that affect mixing and sampling, comparing the final waste glass product chemical composition and durability to that of the glass pour stream sample and other samples from process vessels, and assessing the uniformity of the chemical composition in the waste glass product. Many of these studies efficiently addressed more than one of these areas of concern associated with demonstrating sample representativeness and provide examples of statistical tools in use for DWPF. The time when many of these designs were implemented was in an age when the sampling ideas of Pierre Gy were not as widespread as they are today. Nonetheless, the engineers and statisticians used carefully thought out designs that systematically and economically provided plans for data collection from the DWPF process. Key shared features of the sampling designs used at DWPF and the Gy sampling methodology were the specification of a standard for sample representativeness, an investigation that produced data from the process to study the sampling function, and a decision framework used to assess whether the specification was met based on the data. Without going into detail with regard to the seven errors identified by Pierre Gy, as excellent summaries are readily available such as Pitard [1989] and Smith [2001], SRS engineers understood, for example, that samplers can be biased (Gy�s extraction error), and developed plans to mitigate those biases. Experiments that compared installed samplers with more representative samples obtained directly from the tank may not have resulted in systematically partitioning sampling errors into the now well-known error categories of Gy, but did provide overall information on the suitability of sampling systems. Most of the designs in this report are related to the DWPF vessels, not the large SRS Tank Farm tanks. Samples from the DWPF Slurry Mix Evaporator (SME), which contains the feed to the DWPF melter, are characterized using standardized analytical methods with known uncertainty. The analytical error is combined with the established error from sampling and processing in DWPF to determine the melter feed composition. This composition is used with the known uncertainty of the models in the Product Composition Control System (PCCS) to ensure that the wasteform that is produced is comfortably within the acceptable processing and product performance region. Having the advantage of many years of processing that meets the waste glass product acceptance criteria, the DWPF process has provided a considerable amount of data about itself in addition to the data from many special studies. Demonstrating representative sampling directly from the large Tank Farm tanks is a difficult, if not unsolvable enterprise due to limited accessibility. However, the consistency and the adequacy of sampling and mixing at SRS could at least be studied under the controlled process conditions based on samples discussed by Ray and others [2012a] in Waste Form Qualification Report (WQR) Volume 2 and the transfers from Tanks 40H and 51H to the Sludge Receipt and Adjustment Tank (SRAT) within DWPF. It is important to realize that the need for sample representativeness becomes more stringent as the material gets closer to the melter, and the tanks within DWPF have been studied extensively to meet those needs.

  3. Sample Business Plan Framework 5

    Broader source: Energy.gov [DOE]

    U.S. Department of Energy Better Buildings Neighborhood Program: Sample Business Plan Framework 5: A program that establishes itself as a government entity, then operates using a fee-based structure.

  4. Sample Business Plan Framework 4

    Broader source: Energy.gov [DOE]

    U.S. Department of Energy Better Buildings Neighborhood Program: Sample Business Plan Framework 4: A program seeking to continue in the post-grant period as a marketing contractor to a utility.

  5. Sample Business Plan Framework 1

    Broader source: Energy.gov [DOE]

    U.S. Department of Energy Better Buildings Neighborhood Program: Sample Business Plan Framework 1: A program seeking to continue operations in the post-grant period as a not-for-profit (NGO) entity.

  6. Sample Business Plan Framework 3

    Broader source: Energy.gov [DOE]

    U.S. Department of Energy Better Buildings Neighborhood Program: Sample Business Plan Framework 3: A government entity running a Commercial PACE program in the post-grant period.

  7. Air Sampling System Evaluation Template

    Energy Science and Technology Software Center (OSTI)

    2000-05-09

    The ASSET1.0 software provides a template with which a user can evaluate an Air Sampling System against the latest version of ANSI N13.1 "Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stacks and Ducts of Nuclear Facilities". The software uses the ANSI N13.1 PIC levels to establish basic design criteria for the existing or proposed sampling system. The software looks at such criteria as PIC level, type of radionuclide emissions, physical state ofmore » the radionuclide, nozzle entrance effects, particulate transmission effects, system and component accuracy and precision evaluations, and basic system operations to provide a detailed look at the subsystems of a monitoring and sampling system/program. A GAP evaluation can then be completed which leads to identification of design and operational flaws in the proposed systems. Corrective measures can then be limited to the GAPs.« less

  8. Sample Business Plan Framework 2

    Broader source: Energy.gov [DOE]

    U.S. Department of Energy Better Buildings Neighborhood Program: Sample Business Plan Framework 1: A program seeking to continue operations in the post-grant period as a not-for-profit (NGO) entity.

  9. Equipment Inventory | Sample Preparation Laboratories

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

    21KBr Centrifuge Centrifuge SSRL BioChemMat Prep Lab 2 131 209 Saint Gobain K-104 Sanyo MIR-154 Cooled Incubator Temperature Control LCLS Sample Prep Lab 999 109 Sanyo MPR-215F...

  10. Depth-discrete sampling port

    DOE Patents [OSTI]

    Pemberton, Bradley E.; May, Christopher P.; Rossabi, Joseph; Riha, Brian D.; Nichols, Ralph L.

    1999-01-01

    A sampling port is provided which has threaded ends for incorporating the port into a length of subsurface pipe. The port defines an internal receptacle which is in communication with subsurface fluids through a series of fine filtering slits. The receptacle is in further communication through a bore with a fitting carrying a length of tubing there which samples are transported to the surface. Each port further defines an additional bore through which tubing, cables, or similar components of adjacent ports may pass.

  11. Depth-discrete sampling port

    DOE Patents [OSTI]

    Pemberton, Bradley E.; May, Christopher P.; Rossabi, Joseph; Riha, Brian D.; Nichols, Ralph L.

    1998-07-07

    A sampling port is provided which has threaded ends for incorporating the port into a length of subsurface pipe. The port defines an internal receptacle which is in communication with subsurface fluids through a series of fine filtering slits. The receptacle is in further communication through a bore with a fitting carrying a length of tubing there which samples are transported to the surface. Each port further defines an additional bore through which tubing, cables, or similar components of adjacent ports may pass.

  12. Selective layer disordering in intersubband Al0.028Ga0.972 N/AlN superlattices with silicon nitride capping layer

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

    Wierer, Jonathan J.; Allerman, Andrew A.; Skogen, Erik J.; Tauke-Pedretti, Anna; Vawter, Gregory A.; Montaño, Ines

    2015-06-01

    We demonstrate the selective layer disordering in intersubband Al0.028Ga0.972 N/AlN superlattices using a silicon nitride (SiNx) capping layer. The (SiNx) capped superlattice exhibits suppressed layer disordering under high-temperature annealing. In addition, the rate of layer disordering is reduced with increased SiNx thickness. The layer disordering is caused by Si diffusion, and the SiNx layer inhibits vacancy formation at the crystal surface and ultimately, the movement of Al and Ga atoms across the heterointerfaces. In conclusion, patterning of the SiNx layer results in selective layer disordering, an attractive method to integrate active and passive III–nitride-based intersubband devices.

  13. Ball assisted device for analytical surface sampling

    DOE Patents [OSTI]

    ElNaggar, Mariam S; Van Berkel, Gary J; Covey, Thomas R

    2015-11-03

    A system for sampling a surface includes a sampling probe having a housing and a socket, and a rolling sampling sphere within the socket. The housing has a sampling fluid supply conduit and a sampling fluid exhaust conduit. The sampling fluid supply conduit supplies sampling fluid to the sampling sphere. The sampling fluid exhaust conduit has an inlet opening for receiving sampling fluid carried from the surface by the sampling sphere. A surface sampling probe and a method for sampling a surface are also disclosed.

  14. Tank characterization technical sampling basis

    SciTech Connect (OSTI)

    Brown, T.M.

    1998-04-28

    Tank Characterization Technical Sampling Basis (this document) is the first step of an in place working process to plan characterization activities in an optimal manner. This document will be used to develop the revision of the Waste Information Requirements Document (WIRD) (Winkelman et al. 1997) and ultimately, to create sampling schedules. The revised WIRD will define all Characterization Project activities over the course of subsequent fiscal years 1999 through 2002. This document establishes priorities for sampling and characterization activities conducted under the Tank Waste Remediation System (TWRS) Tank Waste Characterization Project. The Tank Waste Characterization Project is designed to provide all TWRS programs with information describing the physical, chemical, and radiological properties of the contents of waste storage tanks at the Hanford Site. These tanks contain radioactive waste generated from the production of nuclear weapons materials at the Hanford Site. The waste composition varies from tank to tank because of the large number of chemical processes that were used when producing nuclear weapons materials over the years and because the wastes were mixed during efforts to better use tank storage space. The Tank Waste Characterization Project mission is to provide information and waste sample material necessary for TWRS to define and maintain safe interim storage and to process waste fractions into stable forms for ultimate disposal. This document integrates the information needed to address safety issues, regulatory requirements, and retrieval, treatment, and immobilization requirements. Characterization sampling to support tank farm operational needs is also discussed.

  15. Sample Results from Routine Salt Batch 7 Samples

    SciTech Connect (OSTI)

    Peters, T.

    2015-05-13

    Strip Effluent Hold Tank (SEHT) and Decontaminated Salt Solution Hold Tank (DSSHT) samples from several of the microbatches of Integrated Salt Disposition Project (ISDP) Salt Batch (Macrobatch) 7B have been analyzed for 238Pu, 90Sr, 137Cs, Inductively Coupled Plasma Emission Spectroscopy (ICPES), and Ion Chromatography Anions (IC-A). The results from the current microbatch samples are similar to those from earlier samples from this and previous macrobatches. The Actinide Removal Process (ARP) and the Modular Caustic-Side Solvent Extraction Unit (MCU) continue to show more than adequate Pu and Sr removal, and there is a distinct positive trend in Cs removal, due to the use of the Next Generation Solvent (NGS). The Savannah River National Laboratory (SRNL) notes that historically, most measured Concentration Factor (CF) values during salt processing have been in the 12-14 range. However, recent processing gives CF values closer to 11. This observation does not indicate that the solvent performance is suffering, as the Decontamination Factor (DF) has still maintained consistently high values. Nevertheless, SRNL will continue to monitor for indications of process upsets. The bulk chemistry of the DSSHT and SEHT samples do not show any signs of unusual behavior.

  16. Model-Based Sampling and Inference

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

    Model-Based Sampling, Inference and Imputation James R. Knaub, Jr., Energy Information Administration, EI-53.1 James.Knaub@eia.doe.gov Key Words: Survey statistics, Randomization, Conditionality, Random sampling, Cutoff sampling Abstract: Picking a sample through some randomization mechanism, such as random sampling within groups (stratified random sampling), or, say, sampling every fifth item (systematic random sampling), may be familiar to a lot of people. These are design-based samples.

  17. Water-Gas Sampling | Open Energy Information

    Open Energy Info (EERE)

    Water-Gas Sampling (Redirected from Water-Gas Samples) Redirect page Jump to: navigation, search REDIRECT Downhole Fluid Sampling Retrieved from "http:en.openei.orgw...

  18. Category:Water Sampling | Open Energy Information

    Open Energy Info (EERE)

    Water Sampling Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Water Sampling page? For detailed information on Water Sampling as...

  19. Inertial impaction air sampling device

    DOE Patents [OSTI]

    Dewhurst, Katharine H.

    1990-01-01

    An inertial impactor to be used in an air sampling device for collection of respirable size particles in ambient air which may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry.

  20. The Ocean Sampling Day Consortium

    SciTech Connect (OSTI)

    Kopf, Anna; Bicak, Mesude; Kottmann, Renzo; Schnetzer, Julia; Kostadinov, Ivaylo; Lehmann, Katja; Fernandez-Guerra, Antonio; Jeanthon, Christian; Rahav, Eyal; Ullrich, Matthias; Wichels, Antje; Gerdts, Gunnar; Polymenakou, Paraskevi; Kotoulas, Giorgos; Siam, Rania; Abdallah, Rehab Z.; Sonnenschein, Eva C.; Cariou, Thierry; O’Gara, Fergal; Jackson, Stephen; Orlic, Sandi; Steinke, Michael; Busch, Julia; Duarte, Bernardo; Caçador, Isabel; Canning-Clode, João; Bobrova, Oleksandra; Marteinsson, Viggo; Reynisson, Eyjolfur; Loureiro, Clara Magalhães; Luna, Gian Marco; Quero, Grazia Marina; Löscher, Carolin R.; Kremp, Anke; DeLorenzo, Marie E.; Øvreås, Lise; Tolman, Jennifer; LaRoche, Julie; Penna, Antonella; Frischer, Marc; Davis, Timothy; Katherine, Barker; Meyer, Christopher P.; Ramos, Sandra; Magalhães, Catarina; Jude-Lemeilleur, Florence; Aguirre-Macedo, Ma Leopoldina; Wang, Shiao; Poulton, Nicole; Jones, Scott; Collin, Rachel; Fuhrman, Jed A.; Conan, Pascal; Alonso, Cecilia; Stambler, Noga; Goodwin, Kelly; Yakimov, Michael M.; Baltar, Federico; Bodrossy, Levente; Van De Kamp, Jodie; Frampton, Dion M. F.; Ostrowski, Martin; Van Ruth, Paul; Malthouse, Paul; Claus, Simon; Deneudt, Klaas; Mortelmans, Jonas; Pitois, Sophie; Wallom, David; Salter, Ian; Costa, Rodrigo; Schroeder, Declan C.; Kandil, Mahrous M.; Amaral, Valentina; Biancalana, Florencia; Santana, Rafael; Pedrotti, Maria Luiza; Yoshida, Takashi; Ogata, Hiroyuki; Ingleton, Tim; Munnik, Kate; Rodriguez-Ezpeleta, Naiara; Berteaux-Lecellier, Veronique; Wecker, Patricia; Cancio, Ibon; Vaulot, Daniel; Bienhold, Christina; Ghazal, Hassan; Chaouni, Bouchra; Essayeh, Soumya; Ettamimi, Sara; Zaid, El Houcine; Boukhatem, Noureddine; Bouali, Abderrahim; Chahboune, Rajaa; Barrijal, Said; Timinouni, Mohammed; El Otmani, Fatima; Bennani, Mohamed; Mea, Marianna; Todorova, Nadezhda; Karamfilov, Ventzislav; ten Hoopen, Petra; Cochrane, Guy; L’Haridon, Stephane; Bizsel, Kemal Can; Vezzi, Alessandro; Lauro, Federico M.; Martin, Patrick; Jensen, Rachelle M.; Hinks, Jamie; Gebbels, Susan; Rosselli, Riccardo; De Pascale, Fabio; Schiavon, Riccardo; dos Santos, Antonina; Villar, Emilie; Pesant, Stéphane; Cataletto, Bruno; Malfatti, Francesca; Edirisinghe, Ranjith; Silveira, Jorge A. Herrera; Barbier, Michele; Turk, Valentina; Tinta, Tinkara; Fuller, Wayne J.; Salihoglu, Ilkay; Serakinci, Nedime; Ergoren, Mahmut Cerkez; Bresnan, Eileen; Iriberri, Juan; Nyhus, Paul Anders Fronth; Bente, Edvardsen; Karlsen, Hans Erik; Golyshin, Peter N.; Gasol, Josep M.; Moncheva, Snejana; Dzhembekova, Nina; Johnson, Zackary; Sinigalliano, Christopher David; Gidley, Maribeth Louise; Zingone, Adriana; Danovaro, Roberto; Tsiamis, George; Clark, Melody S.; Costa, Ana Cristina; El Bour, Monia; Martins, Ana M.; Collins, R. Eric; Ducluzeau, Anne-Lise; Martinez, Jonathan; Costello, Mark J.; Amaral-Zettler, Linda A.; Gilbert, Jack A.; Davies, Neil; Field, Dawn; Glöckner, Frank Oliver

    2015-06-19

    In this study, Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world’s oceans. It is a simultaneous global mega-sequencing campaign aiming to generate the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our vision for a sustainable study of marine microbial communities and their embedded functional traits.

  1. Inertial impaction air sampling device

    DOE Patents [OSTI]

    Dewhurst, K.H.

    1990-05-22

    An inertial impactor is designed which is to be used in an air sampling device for collection of respirable size particles in ambient air. The device may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry. 3 figs.

  2. Inertial impaction air sampling device

    DOE Patents [OSTI]

    Dewhurst, K.H.

    1987-12-10

    An inertial impactor to be used in an air sampling device for collection of respirable size particles in ambient air which may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry. 3 figs.

  3. Sample rotating turntable kit for infrared spectrometers

    DOE Patents [OSTI]

    Eckels, Joel Del (Livermore, CA); Klunder, Gregory L. (Oakland, CA)

    2008-03-04

    An infrared spectrometer sample rotating turntable kit has a rotatable sample cup containing the sample. The infrared spectrometer has an infrared spectrometer probe for analyzing the sample and the rotatable sample cup is adapted to receive the infrared spectrometer probe. A reflectance standard is located in the rotatable sample cup. A sleeve is positioned proximate the sample cup and adapted to receive the probe. A rotator rotates the rotatable sample cup. A battery is connected to the rotator.

  4. Apparatus and method for handheld sampling

    DOE Patents [OSTI]

    Staab, Torsten A.

    2005-09-20

    The present invention includes an apparatus, and corresponding method, for taking a sample. The apparatus is built around a frame designed to be held in at least one hand. A sample media is used to secure the sample. A sample media adapter for securing the sample media is operated by a trigger mechanism connectively attached within the frame to the sample media adapter.

  5. Picosecond ultrasonic study of surface acoustic waves on titanium nitride nanostructures

    SciTech Connect (OSTI)

    Bjornsson, M. M.; Connolly, A. B.; Mahat, S.; Rachmilowitz, B. E.; Daly, B. C.; Antonelli, G. A.; Myers, A.; Singh, K. J.; Yoo, H. J.; King, S. W.

    2015-03-07

    We have measured surface acoustic waves on nanostructured TiN wires overlaid on multiple thin films on a silicon substrate using the ultrafast pump-probe technique known as picosecond ultrasonics. We find a prominent oscillation in the range of 11–54 GHz for samples with varying pitch ranging from 420 nm down to 168 nm. We find that the observed oscillation increases monotonically in frequency with decrease in pitch, but that the increase is not linear. By comparing our data to two-dimensional mechanical simulations of the nanostructures, we find that the type of surface oscillation to which we are sensitive changes depending on the pitch of the sample. Surface waves on substrates that are loaded by thin films can take multiple forms, including Rayleigh-like waves, Sezawa waves, and radiative (leaky) surface waves. We describe evidence for detection of modes that display characteristics of these three surface wave types.

  6. Hard x-ray photoelectron spectroscopy using an environmental cell with silicon nitride membrane windows

    SciTech Connect (OSTI)

    Tsunemi, Eika; Watanabe, Yoshio; Oji, Hiroshi; Cui, Yi-Tao; Son, Jin-Young

    2015-06-21

    We applied hard x-ray photoelectron spectroscopy (HAXPES) to a sample under ambient pressure conditions using an environmental cell with an approximately 24 nm-thick SiN{sub x} membrane window. As a model chemical substance, europium (II) iodide (EuI{sub 2}) sealed in the cell with argon gas was investigated with HAXPES to identify the chemical species present inside the cell. The optical and morphological properties of the sample within the cell were measured with optical and fluorescent microscopy, scanning electron microscopy, cathodoluminescence, and energy dispersive x-ray spectrometry. We confirmed the effectiveness of the gas barrier properties of the cell with the SiN{sub x} window and demonstrated its applicability to various other optical and electron measurements as well as HAXPES.

  7. Environmental surveillance master sampling schedule

    SciTech Connect (OSTI)

    Bisping, L E

    1992-01-01

    Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE). This document contains the planned schedule for routine sample collection for the Surface Environmental Surveillance Project (SESP) and Ground-Water Monitoring Project. Samples for radiological analyses include Air-Particulate Filter, gases and vapor; Water/Columbia River, Onsite Pond, Spring, Irrigation, and Drinking; Foodstuffs/Animal Products including Whole Milk, Poultry and Eggs, and Beef; Foodstuffs/Produce including Leafy Vegetables, Vegetables, and Fruit; Foodstuffs/Farm Products including Wine, Wheat and Alfalfa; Wildlife; Soil; Vegetation; and Sediment. Direct Radiation Measurements include Terrestrial Locations, Columbia River Shoreline Locations, and Onsite Roadway, Railway and Aerial, Radiation Surveys.

  8. The Ocean Sampling Day Consortium

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

    Kopf, Anna; Bicak, Mesude; Kottmann, Renzo; Schnetzer, Julia; Kostadinov, Ivaylo; Lehmann, Katja; Fernandez-Guerra, Antonio; Jeanthon, Christian; Rahav, Eyal; Ullrich, Matthias; et al

    2015-06-19

    In this study, Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world’s oceans. It is a simultaneous global mega-sequencing campaign aiming to generate the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our vision for a sustainable study of marine microbial communities and theirmore » embedded functional traits.« less

  9. Analytical and experimental evaluation of joining silicon nitride to metal and silicon carbide to metal for advanced heat engine applications

    SciTech Connect (OSTI)

    Kang, S.; Selverian, J.H.; Kim, H.; O'Niel, D.; Kim, K. )

    1990-04-01

    This report summarizes the results of Phase I of Analytical and Experimental Evaluation of Joining Silicon Nitride to Metal and Silicon Carbide to Metal and Silicon Carbide to Metal for Advanced Heat Engine Applications. A general methodology was developed to optimize the joint geometry and material systems for 650 and 950{degree}C applications. Failure criteria were derived to predict the fracture of the braze and ceramic. Extensive finite element analyses (FEA), using ABAQUS code, were performed to examine various joint geometries and to evaluate the affect of different interlayers on the residual stress state. Also, material systems composed of coating materials, interlayers, and braze alloys were developed for the program based on the chemical stability and strength of the joints during processing and service. Finally, the FEA results were compared with experiments using an idealized strength relationship. The results showed that the measured strength of the joint reached 30--90% of the strength by predicted by FEA. Overall results demonstrated that FEA is an effective tool for designing the geometries of ceramic-metal joints and that joining by brazing is a relevant method for advanced heat engine applications. 33 refs., 54 figs., 36 tabs.

  10. Effect of substrate temperature on the microstructural properties of titanium nitride nanowires grown by pulsed laser deposition

    SciTech Connect (OSTI)

    Gbordzoe, S. Kotoka, R.; Craven, Eric; Kumar, D.; Wu, F.; Narayan, J.

    2014-08-14

    The current work reports on the growth and microstructural characterization of titanium nitride (TiN) nanowires on single crystal silicon substrates using a pulsed laser deposition method. The physical and microstructural properties of the nanowires were characterized using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The corrosion properties of the TiN nanowires compared to TiN thin film were evaluated using Direct Current potentiodynamic and electrochemical impedance spectroscopy. The nanowires corroded faster than the TiN thin film, because the nanowires have a larger surface area which makes them more reactive in a corrosive environment. It was observed from the FESEM image analyses that as the substrate temperature increases from 600 °C to 800 °C, there was an increase in both diameter (25 nm–50 nm) and length (150 nm–250 nm) of the nanowire growth. There was also an increase in spatial density with an increase of substrate temperature. The TEM results showed that the TiN nanowires grow epitaxially with the silicon substrate via domain matching epitaxy paradigm, despite a large misfit.

  11. Transition metal carbides, nitrides and borides, and their oxygen containing analogs useful as water gas shift catalysts

    DOE Patents [OSTI]

    Thompson, Levi T.; Patt, Jeremy; Moon, Dong Ju; Phillips, Cory

    2003-09-23

    Mono- and bimetallic transition metal carbides, nitrides and borides, and their oxygen containing analogs (e.g. oxycarbides) for use as water gas shift catalysts are described. In a preferred embodiment, the catalysts have the general formula of M1.sub.A M2.sub.B Z.sub.C O.sub.D, wherein M1 is selected from the group consisting of Mo, W, and combinations thereof; M2 is selected from the group consisting of Fe, Ni, Cu, Co, and combinations thereof; Z is selected from the group consisting of carbon, nitrogen, boron, and combinations thereof; A is an integer; B is 0 or an integer greater than 0; C is an integer; O is oxygen; and D is 0 or an integer greater than 0. The catalysts exhibit good reactivity, stability, and sulfur tolerance, as compared to conventional water shift gas catalysts. These catalysts hold promise for use in conjunction with proton exchange membrane fuel cell powered systems.

  12. Performance analysis of boron nitride embedded armchair graphene nanoribbon metaloxidesemiconductor field effect transistor with Stone Wales defects

    SciTech Connect (OSTI)

    Chanana, Anuja; Sengupta, Amretashis; Mahapatra, Santanu

    2014-01-21

    We study the performance of a hybrid Graphene-Boron Nitride armchair nanoribbon (a-GNR-BN) n-MOSFET at its ballistic transport limit. We consider three geometric configurations 3p, 3p + 1, and 3p + 2 of a-GNR-BN with BN atoms embedded on either side (2, 4, and 6 BN) on the GNR. Material properties like band gap, effective mass, and density of states of these H-passivated structures are evaluated using the Density Functional Theory. Using these material parameters, self-consistent Poisson-Schrodinger simulations are carried out under the Non Equilibrium Green's Function formalism to calculate the ballistic n-MOSFET device characteristics. For a hybrid nanoribbon of width ?5?nm, the simulated ON current is found to be in the range of 265??A280??A with an ON/OFF ratio 7.1 10{sup 6}7.4 10{sup 6} for a V{sub DD}?=?0.68?V corresponding to 10?nm technology node. We further study the impact of randomly distributed Stone Wales (SW) defects in these hybrid structures and only 2.5% degradation of ON current is observed for SW defect density of 3.18%.

  13. Correlation of photothermal conversion on the photo-induced deformation of amorphous carbon nitride films prepared by reactive sputtering

    SciTech Connect (OSTI)

    Harata, T.; Aono, M. Kitazawa, N.; Watanabe, Y.

    2014-08-04

    The photo-induced deformation of hydrogen-free amorphous carbon nitride (a-CN{sub x}) films was investigated under visible-light illumination. The films gave rise to photothermal conversion by irradiation. In this study, we investigated the effects of thermal energy generated by irradiation on the deformation of a-CN{sub x}/ultrathin substrate bimorph specimens. The films were prepared on both ultrathin Si and SiO{sub 2} substrates by reactive radio-frequency magnetron sputtering from a graphite target in the presence of pure nitrogen gas. The temperature of the film on the SiO{sub 2} substrate increased as the optical band-gap of the a-CN{sub x} was decreased. For the film on Si, the temperature remained constant. The deformation degree of the films on Si and SiO{sub 2} substrates were approximately the same. Thus, the deformation of a-CN{sub x} films primarily induced by photon energy directly.

  14. Microsoft Word - Ventilation System Sampling Results 1

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

    Ventilation System Sampling Results Air sampling results before and after the High Efficiency Particulate Air (HEPA) filters at WIPP are available here. Station A samples air before the filters and Station B samples air after passing through the filters. These samples were analyzed following the detection of airborne radioactivity on February 14, 2014. They are not environmental samples, and are not representative of the public or worker breathing zone air samples. They do provide assurance that

  15. Offline solid phase microextraction sampling system

    DOE Patents [OSTI]

    Harvey, Chris A.

    2008-12-16

    An offline solid phase microextraction (SPME) sampling apparatus for enabling SPME samples to be taken a number of times from a previously collected fluid sample (e.g. sample atmosphere) stored in a fused silica lined bottle which keeps volatile organics in the fluid sample stable for weeks at a time. The offline SPME sampling apparatus has a hollow body surrounding a sampling chamber, with multiple ports through which a portion of a previously collected fluid sample may be (a) released into the sampling chamber, (b) SPME sampled to collect analytes for subsequent GC analysis, and (c) flushed/purged using a fluidically connected vacuum source and purging fluid source to prepare the sampling chamber for additional SPME samplings of the same original fluid sample, such as may have been collected in situ from a headspace.

  16. CFCNCA Sample Pledge Form | Department of Energy

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

    CFCNCA Sample Pledge Form CFCNCA Sample Pledge Form This file contains a sample pledge form and instructions for completing a paper donation through the CFC. PDF icon CFCNCA Fall 2012 Sample Pledge Form.pdf More Documents & Publications CFCNCA Sample Pledge Form 2012 CFCNCA Catalog of Caring DOE F 3630.1 Rights and Benefits of Reservists Called to Active Duty

  17. Hanford analytical sample projections 1996 - 2000

    SciTech Connect (OSTI)

    Joyce, S.M.

    1996-02-02

    Sample projections are compiled for the Hanford site based on inputs from the major programs for the years 1996 through 2000. Sample projections are categorized by radiation level, protocol, sample matrix and Program. Analyses requirements are also presented.

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

    SciTech Connect (OSTI)

    Russell D. Dupuis

    2006-01-01

    We report research activities and technical progress on the development of high-efficiency long wavelength ({lambda} {approx} 540nm) green light emitting diodes which covers the second year of the three-year program ''Novel approaches to high-efficiency III-V nitride heterostructure emitters for next-generation lighting applications''. The second year activities were focused on the development of p-type layer that has less/no detrimental thermal annealing effect on green LED active region 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 the thermal annealing effect on blue and green LED active region during the p-type layer growth. 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 {lambda} {approx}540nm by electroluminescence. The active region of the green LEDs was found to be much more sensitive to the thermal annealing effect during the p-type layer growth than that of the blue LEDs. We have designed grown, fabricated green LED structures for both 520 nm and 540 nm for the evaluation of second year green LED development.

  19. Synergistic Effect of Nitrogen in Cobalt Nitride and Nitrogen-Doped Hollow Carbon Spheres for Oxygen Reduction Reaction

    SciTech Connect (OSTI)

    Zhong, Xing; Liu, Lin; Jiang, Yu; Wang, Xinde; Wang, Lei; Zhuang, Guilin; Li, Xiaonian; Mei, Donghai; Wang, Jian-guo; Su, Dang S.

    2015-06-15

    The need for inexpensive and high-activity oxygen reduction reaction (ORR) electrocatalysts has attracted considerable research interest over the past years. Here we report a novel hybrid that contains cobalt nitride/nitrogen-rich hollow carbon spheres (CoxN/NHCS) as a high-performance catalyst for ORR. The CoxN nanoparticles were uniformly dispersed and confined in the hollow NHCS shell. The performance of the resulting CoxN/NHCS hybrid was comparable with that of a commercial Pt/C at the same catalyst loading toward ORR, but the mass activity of the former was 5.7 times better than that of the latter. The nitrogen in both CoxN and NHCS, especially CoxN, could weaken the adsorption of reaction intermediates (O and OOH), which follows the favourable reaction pathway on CoxN/NHCS according to the DFT-calculated Gibbs free energy diagrams. Our results demonstrated a new strategy for designing and developing inexpensive, non-precious metal electrocatalysts for next-generation fuels. The authors acknowledge the financial support from the National Basic Research Program (973 program, No. 2013CB733501) and the National Natural Science Foundation of China (No. 21306169, 21101137, 21136001, 21176221 and 91334013). Dr. D. Mei is supported by the US Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle. Computing time was granted by the grand challenge of computational catalysis of the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL). EMSL is a national scientific user facility located at Pacific Northwest National Laboratory (PNNL) and sponsored by DOE’s Office of Biological and Environmental Research.

  20. Category:Gas Sampling | Open Energy Information

    Open Energy Info (EERE)

    Technique Subcategories This category has the following 3 subcategories, out of 3 total. G Gas Flux Sampling 1 pages S Soil Gas Sampling 1 pages Surface Gas...