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


1

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

Science Journals Connector (OSTI)

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

2014-01-01T23:59:59.000Z

2

Characterization of isothermal vapor phase epitaxial (Hg,Cd)Te  

Science Journals Connector (OSTI)

We report on the characterization of mercury cadmium telluride (Hg 1?x Cd x Te) film grown by the isothermal vapor phase epitaxial method (ISOVPE) and on the surface conversion of bulk Hg 1?xCd x Te to larger bandgap material. The crystal perfection is evaluated using defect etching electron beam and electrolyte electroreflectance (EBER and EER) and Rutherford backscattering spectrometry (RBS). Hall measurements are used to measure carrier densities and mobilities. Surface concentrations and concentration profiles are measured for the ISOVPE grown layers by transmission Fourier transform infrared spectroscopy (FTIR) and electron?probe microanalysis (EPMA) to establish quantitative informations about composition control. Metal–insulator?semiconductor (MIS) structures were made and the properties important to device performance such as compositional uniformity storage time and carrier concentration are measured. The ISOVPE layers are compared in quality to films grown by other methods and show promise for MIS devices.

S. B. Lee; L. K. Magel; M. F. S. Tang; D. A. Stevenson; J. H. Tregilgas; M. W. Goodwin; R. L. Strong

1990-01-01T23:59:59.000Z

3

Growth of vertical-cavity surface emitting lasers by metalorganic vapor phase epitaxy  

SciTech Connect

We present growth and characterization of visible and near-infrared vertical-cavity surface emitting lasers (VCSELs) grown by metalorganic vapor phase epitaxy. Discussions on the growth issue of VCSEL materials include growth rate and composition control using an {ital in}{ital situ} normal-incidence reflectometer, comprehensive p- and n-type doping study in AlGaAs by CCl{sub 4} and Si{sub 2}H{sub 6} over the entire composition range, and optimization of ultra-high material uniformity. We also demonstrate our recent achievements of all-AlGaAs VCSELs which include the first room-temperature continuous- wave demonstration of 700-nm red VCSELs and high-efficiency and low- threshold voltage 850-nm VCSELs.

Hou, H.Q.; Hammons, B.E.; Crawford, M.H.; Lear, K.L.; Choquette, K.D.

1996-10-01T23:59:59.000Z

4

FeP precipitates in hydride?vapor phase epitaxially grown InP:Fe  

Science Journals Connector (OSTI)

Fe?doped InP was grown by hydride?vapor phase epitaxy.Doping levels up to 8×1018 cm?3 were determined by secondary ion mass spectrometry. Additionally performed photoluminescence measurements revealed a homogeneous distribution of electrically active Fe atoms. From microstructural investigations by analytical transmission electron microscopy spherical?shaped precipitates were detected in plan?view samples. These precipitates with diameters up to 13 nm are homogeneously arranged in the epilayer. For conglomerates of precipitates a distinct enrichment with Fe and P was measured by a comparative energy dispersive x?ray analysis. The lattice plane distances of the precipitates were deduced from the electron diffraction patterns and from high?resolution electron micrographs. A comparison with calculated values for different Fe–P alloys indicates that the precipitates consist mainly of orthorhombic FeP.

M. Luysberg; R. Göbel; H. Janning

1994-01-01T23:59:59.000Z

5

Hydride vapor phase epitaxy and characterization of high-quality ScN epilayers  

SciTech Connect

The heteroepitaxial growth of ScN films was investigated on various substrates by hydride vapor phase epitaxy (HVPE). Single crystalline mirror-like ScN(100) and ScN(110) layers were successfully deposited on r- and m-plane sapphire substrates, respectively. Homogeneous stoichiometric films (N/Sc ratio 1.01?±?0.10) up to 40??m in thickness were deposited. Their mosaicity drastically improved with increasing the film thickness. The band gap was determined by optical methods to be 2.06?eV. Impurity concentrations including H, C, O, Si, and Cl were investigated through energy dispersive X-ray spectrometry and secondary ion mass spectrometry. As a result, it was found that the presence of impurities was efficiently suppressed in comparison with that of HVPE-grown ScN films reported in the past, which was possible thanks to the home-designed corrosion-free HVPE reactor. Room-temperature Hall measurements indicated that the residual free electron concentrations ranged between 10{sup 18}–10{sup 20}?cm{sup ?3}, which was markedly lower than the reported values. The carrier mobility increased monotonically with the decreasing in carrier concentration, achieving the largest value ever reported, 284?cm{sup 2}?V{sup ?1}?s{sup ?1} at n?=?3.7?×?10{sup 18}?cm{sup ?3}.

Oshima, Yuichi, E-mail: OSHIMA.Yuichi@nims.go.jp; Víllora, Encarnación G.; Shimamura, Kiyoshi [Environment and Energy Materials Research Division, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

2014-04-21T23:59:59.000Z

6

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

SciTech Connect

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

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

2008-01-01T23:59:59.000Z

7

Recent progress in GaInAsSb thermophotovoltaics grown by organometallic vapor phase epitaxy  

SciTech Connect

Studies on the materials development of Ga{sub 1{minus}x}In{sub x}As{sub y}Sb{sub 1{minus}y} alloys for thermophotovoltaic (TPV) devices are reviewed. Ga{sub 1{minus}x}In{sub x}As{sub y}Sb{sub 1{minus}y} epilayers were grown lattice matched to GaSb substrates by organometallic vapor phase epitaxy (OMVPE) using all organometallic precursors including triethylgallium, trimethylindium, tertiarybutylarsine, and trimethylantimony with diethyltellurium and dimethylzinc as the n- and p-type dopants, respectively. The overall material quality of these alloys depends on growth temperature, In content, V/III ratio, substrate misorientation, and to a lesser extent, growth rate. A mirror-like surface morphology and room temperature photoluminescence (PL) are obtained for GaInAsSb layers with peak emission in the wavelength range between 2 and 2.5 {micro}m. The crystal quality improves for growth temperature decreasing from 575 to 525 C, and with decreasing In content, as based on epilayer surface morphology and low temperature PL spectra. A trend of smaller full width at half-maximum for low temperature PL spectra is observed as the growth rate is increased from 1.5 to 2.5 and 5 {micro}m/h. In general, GaInAsSb layers grown on (100) GaSb substrates with a 6{degree} toward (111)B misorientation exhibited overall better material quality than layers grown on the more standard substrate (100)2{degree} toward (110). Consistent growth of high performance lattice-matched GaInAsSb TPV devices is also demonstrated.

Wang, C.A.; Choi, H.K.; Oakley, D.C. [Massachusetts Inst. of Tech., Lexington, MA (United States). Lincoln Lab.; Charache, G.W. [Lockheed Martin, Inc., Schenectady, NY (United States)

1998-06-01T23:59:59.000Z

8

Ion-beam-induced epitaxial vapor-phase growth: A molecular-dynamics study  

Science Journals Connector (OSTI)

Low-energy ions which bombard a vapor-deposited film of low adatom mobility during growth mobilize surface atoms in the vicinity of the ion impact, causing a modification in the evolving microstructure. In a two-dimensional molecular-dynamics simulation where inert-gas ions strike a growing film of Lennard-Jones particles, it is demonstrated that ion bombardment during growth causes the filling of voids quenched in during vapor condensation and induces homoepitaxial growth. The dependence of film density and degree of homoepitaxial growth on the ion-to-vapor arrival rate ratio and ion energy is studied in detail.

Karl-Heinz Müller

1987-05-15T23:59:59.000Z

9

Chemical vapor deposition of epitaxial silicon  

DOE Patents (OSTI)

A single chamber continuous chemical vapor deposition (CVD) reactor is described for depositing continuously on flat substrates, for example, epitaxial layers of semiconductor materials. The single chamber reactor is formed into three separate zones by baffles or tubes carrying chemical source material and a carrier gas in one gas stream and hydrogen gas in the other stream without interaction while the wafers are heated to deposition temperature. Diffusion of the two gas streams on heated wafers effects the epitaxial deposition in the intermediate zone and the wafers are cooled in the final zone by coolant gases. A CVD reactor for batch processing is also described embodying the deposition principles of the continuous reactor.

Berkman, Samuel (Florham Park, NJ)

1984-01-01T23:59:59.000Z

10

X-ray determination of threading dislocation densities in GaN/Al{sub 2}O{sub 3}(0001) films grown by metalorganic vapor phase epitaxy  

SciTech Connect

Densities of a- and a+c-type threading dislocations for a series of GaN films grown in different modes by metalorganic vapor phase epitaxy are determined from the x-ray diffraction profiles in skew geometry. The reciprocal space maps are also studied. Theory of x-ray scattering from crystals with dislocations is extended in order to take into account contribution from both threading and misfit dislocations. The broadening of the reciprocal space maps along the surface normal and the rotation of the intensity distribution ellipse is attributed to misfit dislocations at the interface. We find that the presence of a sharp AlN/GaN interface leads to an ordering of misfit dislocations and reduces strain inhomogeneity in GaN films.

Kopp, Viktor S., E-mail: victor.kopp@pdi-berlin.de; Kaganer, Vladimir M. [Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5–7, 10117 Berlin (Germany); Baidakova, Marina V.; Lundin, Wsevolod V.; Nikolaev, Andrey E.; Verkhovtceva, Elena V.; Yagovkina, Maria A. [Ioffe Physical-Technical Institute of the Russian Academy of Sciences, Politekhnicheskaya 26, 194021 St.-Petersburg (Russian Federation); Cherkashin, Nikolay [CEMES-CNRS and Université de Toulouse, 29 rue J. Marvig, 31055 Toulouse (France)

2014-02-21T23:59:59.000Z

11

Organometallic Vapor Phase Epitaxy of n-GaSb and n-GaInAsSb for Low Resistance Ohmic Contacts  

SciTech Connect

A comparison of n-GaSb and n-GaInAsSb epilayers for ohmic contacts in GaSb-based devices is studied. The epilayers were grown by organometallic vapor phase epitaxy and doped with Te. At similar electron concentrations, the atomic Te concentration, as determined by secondary ion mass spectroscopy, is more than 2 times higher in n-GaSb compared to n-GaInAsSb. In addition, the electron mobility is lower in n-GaSb than n-GaInAsSb at similar electron concentrations. The electron concentration saturates at about 1.3 x 10{sup 18} cm{sup -3} for n-GaSb, but linearly increases for n-GaInAsSb. Pd/Ge/Au/Pt/Au metallization was studied for ohmic contacts. A specific contact resistivity of 1 x 10{sup -5}{Omega}-cm{sup 2} for n-GaSb was measured. The specific contact resistivity can be greatly improved by contacting n-GaInAsSb, and a significantly lower specific contact resistivity of 2 x 10{sup -6} {Omega}-cm{sup 2} for n-GaInAsSb was measured.

C.A. Wang; D.A. Shiau; R.K. Huang; C.T. Harris; M.K. Connors

2003-07-10T23:59:59.000Z

12

Observation of photoluminescence from Al1 xInxN heteroepitaxial films grown by metalorganic vapor phase epitaxy  

E-Print Network (OSTI)

Observation of photoluminescence from Al1 xInxN heteroepitaxial films grown by metalorganic vapor have observed photoluminescence of Al1 xInxN films. The films were grown on GaN by atmospheric pressure-temperature deposited AlN buffer layer. Photoluminescence, absorption, and x-ray diffraction measurements have shown

Wetzel, Christian M.

13

Charge transport properties of p-CdTe/n-CdTe/n{sup +}-Si diode-type nuclear radiation detectors based on metalorganic vapor-phase epitaxy-grown epilayers  

SciTech Connect

Charge transport properties of p-CdTe/n-CdTe/n{sup +}-Si diode-type nuclear radiation detectors, fabricated by growing p-and n-type CdTe epilayers on (211) n{sup +}-Si substrates using metalorganic vapor-phase epitaxy (MOVPE), were studied by analyzing current-voltage characteristics measured at various temperatures. The diode fabricated shows good rectification properties, however, both forward and reverse biased currents deviate from their ideal behavior. The forward current exhibits typical feature of multi-step tunneling at lower biases; however, becomes space charge limited type when the bias is increased. On the other hand, the reverse current exhibits thermally activated tunneling-type current. It was found that trapping centers at the p-CdTe/n-CdTe junction, which were formed due to the growth induced defects, determine the currents of this diode, and hence limit the performance of the nuclear radiation detectors developed.

Niraula, M.; Yasuda, K.; Wajima, Y.; Yamashita, H.; Tsukamoto, Y.; Suzuki, Y.; Matsumoto, M.; Takai, N.; Tsukamoto, Y.; Agata, Y. [Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya 466-8555 (Japan)] [Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya 466-8555 (Japan)

2013-10-28T23:59:59.000Z

14

Time-resolved photoluminescence, positron annihilation, and Al0.23Ga0.77N/GaN heterostructure growth studies on low defect density polar and nonpolar freestanding GaN substrates grown by hydride vapor phase epitaxy  

Science Journals Connector (OSTI)

Time-resolved photoluminescence(TRPL) and positron annihilation measurements as well as Al0.23Ga0.77N/GaN heterostructuregrowth by metalorganic vapor phase epitaxy were carried out on very low defect density polar c-plane and nonpolar m-plane freestanding GaN (FS-GaN) substrates grown by hydride vapor phase epitaxy. Room-temperature photoluminescence(PL) lifetime for the near-band-edge (NBE) excitonic emission of the FS-GaN substrates increases with increasing positron diffusion length (L +); i.e. decreasing gross concentration of charged and neutral point defects and complexes. The best undoped c-plane FS-GaN exhibits record-long L + being 116?nm. The fast component of the PL lifetime for its NBE emission increases with temperature rise up to 100?K and levels off at approximately 1.1?ns. The result implies a saturation in thermal activation of nonradiative recombination centers. The surface and interface roughnesses for a Si-doped Al0.23Ga0.77N/GaN/Al0.18Ga0.82N/GaN heterostructure are improved by the use of FS-GaN substrates in comparison with the structure fabricated on a standard GaN template. The emission signals related to the recombination of a two-dimensional electron gas and excited holes are recognized for an Al0.23Ga0.77N/GaN single heterostructuregrown on the c-plane FS-GaN substrate.

S. F. Chichibu; K. Hazu; Y. Ishikawa; M. Tashiro; H. Namita; S. Nagao; K. Fujito; A. Uedono

2012-01-01T23:59:59.000Z

15

Substrate effect on CdTe layers grown by metalorganic vapor phase N. V. Sochinskiia),b)  

E-Print Network (OSTI)

Substrate effect on CdTe layers grown by metalorganic vapor phase epitaxy N. V. Sochinskiia for publication 30 December 1996 CdTe layers were grown by metalorganic vapor phase epitaxy MOVPE on different substrates like sapphire, GaAs, and CdTe wafers. The growth was carried out at the temperature 340 °C

Viña, Luis

16

InGaAs heterostructure formation in catalyst-free GaAs nanopillars by selective-area metal-organic vapor phase epitaxy  

SciTech Connect

We investigate axial GaAs/InGaAs/GaAs heterostructures embedded in GaAs nanopillars via catalyst-free selective-area metal-organic chemical vapor deposition. Structural characterization by transmission electron microscopy with energy dispersive x-ray spectroscopy (EDS) indicates formation of axial In{sub x}Ga{sub 1-x}As (x{approx}0.20) inserts with thicknesses from 36 to 220 nm with {+-}10% variation and graded Ga:In transitions controlled by In segregation. Using the heterointerfaces as markers, the vertical growth rate is determined to increase linearly during growth. Photoluminescence from 77 to 290 K and EDS suggest the presence of strain in the shortest inserts. This capability to control the formation of axial nanopillar heterostructures is crucial for optimized device integration.

Shapiro, J. N.; Lin, A.; Wong, P. S.; Scofield, A. C.; Tu, C.; Senanayake, P. N.; Mariani, G.; Liang, B. L.; Huffaker, D. L. [Department of Electrical Engineering and California Nano-Systems Institute, University of California at Los Angeles, Los Angeles, California 90095 (United States)

2010-12-13T23:59:59.000Z

17

Photoelectric and luminescence properties of GaSb-Based nanoheterostructures with a deep Al(As)Sb/InAsSb/Al(As)Sb quantum well grown by metalorganic vapor-phase epitaxy  

SciTech Connect

The luminescence and photoelectric properties of heterostructures with a deep Al(As)Sb/InAsSb/Al(As)Sb quantum well grown on n-GaSb substrates by metalorganic vapor-phase epitaxy are investigated. Intense superlinear luminescence and increased optical power as a function of the pump current in the photon energy range of 0.6-0.8 eV are observed at temperatures of T = 77 and 300 K. The photoelectric, current-voltage, and capacitance characteristics of these heterostructures are studied in detail. The photosensitivity is examined with photodetectors operating in the photovoltaic mode in the spectral range of 0.9-2.0 {mu}m. The sensitivity maximum at room temperature is observed at a wavelength of 1.55 {mu}m. The quantum efficiency, detectivity, and response time of the photodetectors were estimated. The quantum efficiency and detectivity at the peak of the photosensitivity spectrum are as high as {eta} = 0.6-0.7 and D{sub {lambda}max}{sup *} = (5-7) Multiplication-Sign 10{sup 10} cm Hz{sup 1/2} W{sup -1}, respectively. The photodiode response time determined as the rise time of the photoresponse pulse from 0.1 to the level 0.9 is 100-200 ps. The photodiode transmission bandwidth is 2-3 GHz. Photodetectors with a deep Al(As)Sb/InAsSb/Al(As)Sb quantum well grown on n-GaSb substrates are promising foruse in heterodyne detection systems and in information technologies.

Mikhailova, M. P.; Andreev, I. A., E-mail: igor@iropt9.ioffe.ru; Ivanov, E. V.; Konovalov, G. G.; Grebentshikova, E. A.; Yakovlev, Yu. P. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)] [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Hulicius, E.; Hospodkova, A.; Pangrac, Y. [Academy of Sciences of the Czech Republic, Institute of Physics (Czech Republic)] [Academy of Sciences of the Czech Republic, Institute of Physics (Czech Republic)

2013-08-15T23:59:59.000Z

18

Electronic parameters and interfacial properties of GaAs/AlxGa1-xAs multiquantum wells grown on (111)A GaAs by metalorganic vapor phase epitaxy  

Science Journals Connector (OSTI)

We report a comprehensive study of the optical and interfacial properties of GaAs/AlxGa1-xAs multiquantum wells grown on (111)A GaAs substrates by metalorganic vapor phase epitaxy which allowed the determination of the electronic parameters appropriate for such quantum wells. High-resolution x-ray diffractometry studies indicate an excellent crystal quality and good periodicity for the multiquantum wells and provided their structural parameters accurately. The photoreflectance spectra exhibit all the allowed and almost all the weakly allowed optical transitions between the confined hole and electron states. From an analysis of the photoreflectance spectra it is shown that the quantum well interfaces have an abruptness better than ±1 ML. Photoluminescence spectroscopy was also performed to evaluate independently the roughness of the interfaces and multiquantum well period reproducibility. For a 25-period multiquantum well structure with a well width of 55 Å, a photoluminescence linewidth of 12.5 meV, which corresponds to a combined well-width fluctuation and interface roughness of less than ±1 monolayer over the 25 periods, proves the achievement of heterointerfaces with excellent interfacial quality. From a detailed analysis of the high-order transitions observed in the photoreflectance spectra we determined key quantum well electronic parameters, such as, the heavy-hole valence-band offset Qv=0.33±0.02, the transverse GaAs heavy-hole effective mass mhh=(0.95±0.02)m0, and the light-hole effective mass mlh=0.08m0 in ?111? directions, for ?111?-oriented GaAs/AlxGa1-xAs quantum well structures.

Soohaeng Cho; A. Sanz-Hervás; A. Majerfeld; B. W. Kim

2003-07-10T23:59:59.000Z

19

Vapor phase modifiers for oxidative coupling  

DOE Patents (OSTI)

Volatilized metal compounds retard vapor phase alkane conversion reactions in oxidative coupling processes that convert lower alkanes to higher hydrocarbons.

Warren, Barbara K. (Charleston, WV)

1991-01-01T23:59:59.000Z

20

Vapor phase modifiers for oxidative coupling  

DOE Patents (OSTI)

Volatilized metal compounds are described which are capable of retarding vapor phase alkane conversion reactions in oxidative coupling processes that convert lower alkanes to higher hydrocarbons.

Warren, B.K.

1991-12-17T23:59:59.000Z

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


21

Epitaxial graphene prepared by chemical vapor deposition on single crystal thin iridium films on sapphire  

E-Print Network (OSTI)

Epitaxial graphene prepared by chemical vapor deposition on single crystal thin iridium films Cedex 9, France (Dated: 15 March 2011) Uniform single layer graphene was grown on single-crystal Ir. These graphene layers have a single crystallographic orientation and a very low density of defects, as shown

Boyer, Edmond

22

Nanoscale Phase Separation In Epitaxial Cr-Mo and Cr-V Alloy...  

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

Separation In Epitaxial Cr-Mo and Cr-V Alloy Thin Films Studied Using Atom Probe Tomography: Comparison Of Nanoscale Phase Separation In Epitaxial Cr-Mo and Cr-V Alloy Thin Films...

23

High-efficiency solar cells fabricated from direct-current magnetron sputtered n-indium tin oxide onto p-InP grown by atmospheric pressure metalorganic vapor phase epitaxy  

SciTech Connect

Solar cells based on dc magnetron sputtered indium tin oxide onto epitaxially grown films of p-InP have been fabricated and analyzed. The best cells had a global efficiency of 18.4% and an air mass zero (AMO) efficiency of 16.0%. The principal fabrication variable considered was the constituency of the sputtering gas and both argon/hydrogen and argon/oxygen mixtures have been used. The former cells have the higher efficiencies, are apparently stable, and exhibit almost ideal junction characteristics. The latter cells are relatively unstable and exhibit much higher ideality factors and reverse saturation current densities. The temperature dependence of the reverse saturation current indicates totally different charge transfer mechanisms in the two cases.

Li, X.; Wanlass, M.W.; Gessert, T.A.; Emery, K.A.; Coutts, T.J.

1989-05-01T23:59:59.000Z

24

Vapour-Phase Graphene Epitaxy at Low Temperatures Lianchang Zhang1,2  

E-Print Network (OSTI)

Nano Res 1 Vapour-Phase Graphene Epitaxy at Low Temperatures Lianchang Zhang1,2 , Zhiwen Shi1 2012 ABSTRACT We report an epitaxial growth of graphene, including homo- and hetero-epitaxy on graphite yield large-area high- quality graphene with the desired number of layers over the entire substrate

Zhang, Guangyu

25

Preliminary assessment of halogenated alkanes as vapor-phase tracers  

SciTech Connect

New tracers are needed to evaluate the efficiency of injection strategies in vapor-dominated environments. One group of compounds that seems to meet the requirements for vapor-phase tracing are the halogenated alkanes (HCFCs). HCFCs are generally nontoxic, and extrapolation of tabulated thermodynamic data indicate that they will be thermally stable and nonreactive in a geothermal environment. The solubilities and stabilities of these compounds, which form several homologous series, vary according to the substituent ratios of fluorine, chlorine, and hydrogen. Laboratory and field tests that will further define the suitability of HCFCs as vapor-phase tracers are under way.

Adams, Michael C.; Moore, Joseph N.; Hirtz, Paul

1991-01-01T23:59:59.000Z

26

Ultrahigh growth rate of epitaxial silicon by chemical vapor deposition at low temperature with neopentasilane  

E-Print Network (OSTI)

- iane SiH4 to disilane Si2H6 , to trisilane, Si3H8 2 leads to increased epitaxy growth rates at the same growth rate was 0.6 nm/min, and the disilane growth rate was 8 nm/min. In this work, we explored the use

27

Epitaxial growth of CdTe thin film on cube-textured Ni by metal-organic chemical vapor deposition  

SciTech Connect

CdTe thin film has been grown by metalorganic chemical vapor deposition (MOCVD) on Ni(100) substrate. Using x-ray pole figure measurements we observed the epitaxial relationship of {111}CdTe// {001}Ni with [110]CdTe//[010]Ni and [112] CdTe//[100]Ni. The 12 diffraction peaks in the (111) pole figure of CdTe film and their relative positions with respect to the four peak positions in the (111) pole figure of Ni substrate are consistent with four equivalent orientational domains of CdTe with three to four superlattice match of about 0.7% in the [110] direction of CdTe and the [010] direction of Ni. The electron backscattered diffraction (EBSD) images show that the CdTe domains are 30 degrees orientated from each other.

GIARE, C [Rensselaer Polytechnic Institute (RPI); RAO, S [Rensselaer Polytechnic Institute (RPI); RILEY, M [Rensselaer Polytechnic Institute (RPI); CHEN, L [Rensselaer Polytechnic Institute (RPI); Goyal, Amit [ORNL; BHAT, I [Rensselaer Polytechnic Institute (RPI); LU, T [Rensselaer Polytechnic Institute (RPI); WANG, G [Rensselaer Polytechnic Institute (RPI)

2012-01-01T23:59:59.000Z

28

Structure/processing relationships in vapor-liquid-solid nanowire epitaxy  

E-Print Network (OSTI)

The synthesis of Si and III-V nanowires using the vapor-liquid-solid (VLS) growth mechanism and low-cost Si substrates was investigated. The VLS mechanism allows fabrication of heterostructures which are not readily ...

Boles, Steven Tyler

2010-01-01T23:59:59.000Z

29

Phase effects for electrons in liquid water and water vapor  

SciTech Connect

The objective of these studies is to compare transport, energy loss, and other phenomena for electrons in water in the liquid and vapor phases. Understanding the differences and similarities is an interesting physics problem in its own right. It is also important for applying the relatively large body of experimental data available for the vapor to the liquid, which is of greater relevance in radiobiology. This paper presents a summary of results from a series of collaborative studies carried out by the authors at Oak Ridge National Laboratory (ORNL) and the Gesellschaft fuer Strahlen- und Umweltforschung (GSF). 14 figs.

Turner, J.E.; Paretzke, H.G.; Wright, H.A.; Hamm, R.N.; Ritchie, R.H.

1988-01-01T23:59:59.000Z

30

Growth of manganese filled carbon nanofibers in the vapor phase  

Science Journals Connector (OSTI)

We report the vapor phase growth of partially filled graphitic fibers, 20-30 nm in diameter and up to a micron in length, during a manganese catalyzed carbon electric arc discharge. The fiber morphology resembles that of catalytic chemical vapor deposited carbon filaments but the inside hollow contains intermittent precipitates and continuous filling of Mn that at times occupy >50% of fiber lengths. Transmission electron microscopy and electron energy loss line spectra show that the fillings form as solid cores and may correspond to pure metal.

P. M. Ajayan; C. Colliex; J. M. Lambert; P. Bernier; L. Barbedette; M. Tence; O. Stephan

1994-03-14T23:59:59.000Z

31

Epitaxial growth of aligned AlGalnN nanowires by metal-organic chemical vapor deposition  

DOE Patents (OSTI)

Highly ordered and aligned epitaxy of III-Nitride nanowires is demonstrated in this work. <1010> M-axis is identified as a preferential nanowire growth direction through a detailed study of GaN/AlN trunk/branch nanostructures by transmission electron microscopy. Crystallographic selectivity can be used to achieve spatial and orientational control of nanowire growth. Vertically aligned (Al)GaN nanowires are prepared on M-plane AlN substrates. Horizontally ordered nanowires, extending from the M-plane sidewalls of GaN hexagonal mesas or islands demonstrate new opportunities for self-aligned nanowire devices, interconnects, and networks.

Han, Jung (Woodbridge, CT); Su, Jie (New Haven, CT)

2008-08-05T23:59:59.000Z

32

Epitaxial Pb(Zr, Ti)O3 thin films with coexisting tetragonal and rhombohedral phases  

Science Journals Connector (OSTI)

Epitaxial Pb(Zr, Ti)O3 thin films having coexisting tetragonal and rhombohedral phases have been successfully fabricated with the film compositions that correspond to the Zr-rich region of the morphotropic phase boundary (MPB). The key to the present success is to quantitatively understand the shift of the MPB under a film stress. The present fabrication has been theoretically justified by superimposing the computed temperature-dependent film stress on the theoretical temperature-stress (T-S) phase diagram and by delineating a probable phase-transition path upon cooling the film from the processing temperature.

S. Hoon Oh and Hyun M. Jang

2001-03-12T23:59:59.000Z

33

InAlAs EPITAXIAL GROWTH FOR WIDE BAND GAP SOLAR CELLS Marina S. Leite  

E-Print Network (OSTI)

InAlAs EPITAXIAL GROWTH FOR WIDE BAND GAP SOLAR CELLS Marina S. Leite 1 , Robyn L. Woo 2 , William vapor phase epitaxy and wide band gap solar cell fabrication. X-ray diffraction and transmissionAlAs solar cells lattice-matched to InP were grown and electrically characterized under AM 1.5 global 1-sun

Atwater, Harry

34

Effect of dimensionality on vapor-liquid phase transition  

SciTech Connect

Dimensionality play significant role on ‘phase transitions’. Fluids in macroscopic confinement (bulk or 3-Dimensional, 3D) do not show significant changes in their phase transition properties with extent of confinement, since the number of molecules away from the surrounding surfaces is astronomically higher than the number of molecules in close proximity of the confining surfaces. In microscopic confinement (quasi 3D to quasi-2D), however, the number of molecules away from the close proximity of the surface is not as high as is the case with macroscopic (3D) confinement. Hence, under the same thermodynamic conditions ‘phase transition’ properties at microscopic confinement may not remain the same as the macroscopic or 3D values. Phase transitions at extremely small scale become very sensitive to the dimensions as well as the surface characteristics of the system. In this work our investigations reveal the effect of dimensionality on the phase transition from 3D to quasi-2D to 2D behavior. We have used grand canonical transition matrix Monte Carlo simulation to understand the vapor–liquid phase transitions from 3D to quasi-2D behavior. Such studies can be helpful in understanding and controlling the fluid film behaviour confined between solid surfaces of few molecular diameters, for example, in lubrication applications.

Singh, Sudhir Kumar, E-mail: sksingh@thapar.edu [Department Chemical Engineering, Thapar University, Patiala-147004 Punjab (India)

2014-04-24T23:59:59.000Z

35

Epitaxial growth of Si1 ? xGex alloys and Ge on Si(100) by electron-cyclotron-resonance Ar plasma chemical vapor deposition without substrate heating  

Science Journals Connector (OSTI)

Abstract By using electron-cyclotron-resonance (ECR) Ar-plasma chemical vapor deposition (CVD) without substrate heating, the epitaxial growth process of Si1 ? xGex alloy and Ge films deposited directly on dilute-HF-treated Si(100) was investigated. From the reflection high energy electron diffraction patterns of the deposited Si1 ? xGex alloy (x = 0.50, 0.75) and Ge films on Si(100), it is confirmed that epitaxial growth can be realized without substrate heating, and that crystallinity degradation at larger film thickness is observed. The X-ray diffraction peak of the epitaxial films reveals the existence of large compressive strain, which is induced by lattice matching with the Si(100) substrate at smaller film thicknesses, as well as strain relaxation behavior at larger film thicknesses. The Ge fraction of Si1 ? xGex thin film is in good agreement with the normalized GeH4 partial pressure. The Si1 ? xGex deposition rate increases with an increase of GeH4 partial pressure. The GeH4 partial pressure dependence of partial deposition rates [(Si or Ge fraction) × (Si1 ? xGex thickness) / (deposition time)] shows that the Si partial deposition rate is slightly enhanced by the existence of Ge. From these results, it is proposed that the ECR-plasma CVD process can be utilized for Ge fraction control in highly-strained heterostructure formation of group IV semiconductors.

Naofumi Ueno; Masao Sakuraba; Junichi Murota; Shigeo Sato

2014-01-01T23:59:59.000Z

36

Vapor phase elemental sulfur amendment for sequestering mercury in contaminated soil  

DOE Patents (OSTI)

The process of treating elemental mercury within the soil is provided by introducing into the soil a heated vapor phase of elemental sulfur. As the vapor phase of elemental sulfur cools, sulfur is precipitated within the soil and then reacts with any elemental mercury thereby producing a reaction product that is less hazardous than elemental mercury.

Looney, Brian B.; Denham, Miles E.; Jackson, Dennis G.

2014-07-08T23:59:59.000Z

37

Role of hydrogen desorption in the chemical-vapor deposition of Si(100) epitaxial films using disilane  

Science Journals Connector (OSTI)

A scanning tunneling microscopy and spectroscopy study of the role of hydrogen desorption in epitaxial film growth on the Si(100) surface is presented. Following disilane adsorption, epitaxial growth is shown to be driven by the rebonding of the disilane fragments induced by H2 desorption. This requires the decomposition of only the higher surface hydrides and occurs between 640 and 670 K. The epitaxial layer formed in this manner has a 2×1 monohydride structure. Continuous exposure to disilane at 690 K resulted in multilayer epitaxial growth, the surface of which remains largely H passivated. This latter growth is in part due to a direct reaction between disilane and the monohydride surface.

John J. Boland

1991-07-15T23:59:59.000Z

38

An 8-{mu}m quantum cascade laserproduced by the metalorganic vapour phase epitaxy method  

SciTech Connect

An 8-{mu}m quantum cascade laser is fabricated by the metalorganic vapour phase epitaxy method. A scheme of vertical transitions in a structure consisting of three quantum wells is used. The laser operates in a pulsed regime at temperatures up to 250 K. The threshold current density was about 3 kA cm{sup -2} and increased up to 6 kA cm{sup -2} at 250 K. The 1-{mu}s pulse power in the multimode regime was 45 mW at 77 K.

Zasavitskii, I I; Pashkeev, D A [P N Lebedev Physical Institute, Russian Academy of Sciences, Moscow (Russian Federation); Marmalyuk, Aleksandr A; Ryaboshtan, Yu L [M.F. Stel'makh Polyus Research and Development Institute, Moscow (Russian Federation); Mikaelyan, G T [OJSC Research and Manufacturing Enterprise 'Inject', Saratov (Russian Federation)

2010-02-28T23:59:59.000Z

39

Excess conductivity in 2:2:1:2-phase Bi-Sr-Ca-Cu-O epitaxial thin films  

Science Journals Connector (OSTI)

Measurements of the excess conductivity above the transition temperature on selected, high-quality, superconducting epitaxial films of the 2:2:1:2-phase Bi-Sr-Ca-Cu-O (BSCCO), obtained by liquid-phase epitaxy, are reported. The data confirm the two-dimensional nature of the thermodynamical fluctuations in BSCCO compounds in a wide range of temperature above Tc and very good agreement is found with an extended version of the Aslamazov-Larkin theory [L. Reggiani, R. Vaglio, and A. A. Varlamov, Phys. Rev. B 44, 9541 (1991)].

G. Balestrino; M. Marinelli; E. Milani; Lucia Reggiani; R. Vaglio; A. A. Varlamov

1992-12-01T23:59:59.000Z

40

Phase Transition Enthalpy Measurements of Organic and Organometallic Compounds. Sublimation, Vaporization and Fusion Enthalpies From  

E-Print Network (OSTI)

Phase Transition Enthalpy Measurements of Organic and Organometallic Compounds. Sublimation, Vaporization and Fusion Enthalpies From 1880 to 2010 William Acree, Jr. Department of Chemistry, University of North Texas, Denton, Texas 76203 James S. Chickosa... Department of Chemistry and Biochemistry

Chickos, James S.

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


41

The kinetics of heterogeneous nucleation in vapor-liquid phase transitions in the presence of ions  

Science Journals Connector (OSTI)

A method for calculating the work of nucleus formation in vapor-liquid phase transitions in the presence of ions was suggested. The method took into account ions localized in the boundary surface layer of...

G. V. Anikin; L. S. Podenko

2008-12-01T23:59:59.000Z

42

Growth of GaN on SiC(0001) by Molecular Beam Epitaxy C. D. LEE (a), ASHUTOSH SAGAR (a), R. M. FEENSTRA  

E-Print Network (OSTI)

]. Silicon carbide has a much better lattice match to GaN (3.4%), and has gained in popularity in recent years as a substrate for both molecular beam epitaxy (MBE) and metal-organic vapor phase epitaxy of Ga where a transition between streaky and spotty behavior occurs in the reflection high energy electron

Feenstra, Randall

43

VAPOR-CONDENSED PHASE PROCESSES IN THE EARLY SOLAR SYSTEM. L. Grossman. Department of the  

E-Print Network (OSTI)

VAPOR-CONDENSED PHASE PROCESSES IN THE EARLY SOLAR SYSTEM. L. Grossman. Department@uchicago.edu. Equilibrium thermodynamic calculations of the sequence of condensation of phases from a cooling gas of solar that they underwent melting after condensation, crystallizing into the same phase as- semblage as their precursors

Grossman, Lawrence

44

X-ray-induced phase transformation in congruent and vapor-transport-equilibrated lithium tantalate  

E-Print Network (OSTI)

X-ray-induced phase transformation in congruent and vapor-transport-equilibrated lithium tantalate an effect of a partially reversible x-ray-induced increase of diffuse x-ray scattering in both congruent been attributed to x-ray-induced decay of the ferroelectric phase at room temperature. The x-ray

Byer, Robert L.

45

THz Quantum Cascade Lasers Grown by Low-Pressure Metalorganic Vapor Phase Epitaxy  

Science Journals Connector (OSTI)

A terahertz quantum cascade laser (QCL) has been successfully grown by low-pressure MOVPE. Very high quality semiconductor interfaces are demonstrated as well as very promising lasing...

Sirigu, Lorenzo; Rudra, Alok; Amanti, Maria I; Scalari, Giacomo; Fischer, Milan; Giovannini, Marcella; Faist, Jerome; Kapon, Eli

46

Elastic effects and phase segregation during the growth of thin alloy layers by molecular-beam epitaxy  

Science Journals Connector (OSTI)

We explore the effects of stress and strain on the composition modulations seen during the growth of thin solid films by molecular-beam epitaxy when phase separation is the driving mechanism for the concentration inhomogeneity. A top view of the growing thin film shows lamellar and hexagonal patterns of phase-separated domains, the elastic effects being directly responsible for the appearance of the hexagonal order. We find that in the lamellar regime, elastically deformed lamellae are separated by undeformed interfaces, while in the droplet phase, the soft component is deformed and wraps the hard component. We also discuss the effects of crystal anisotropy in our system.

François Léonard and Rashmi C. Desai

1997-08-15T23:59:59.000Z

47

Arsenic redistribution after solid phase epitaxial regrowth of shallow pre-amorphized silicon layers  

SciTech Connect

The behavior of ultra shallow ion implants of arsenic in Si following solid phase epitaxial re-growth process is reported. A 16 nm amorphous layer was created by ion implantation of Si{sup +} at energy 5 keV and a dose 1 Multiplication-Sign 10{sup 15} at/cm{sup 2}. As ion were implanted at 2 keV using 3 different doses: 1 Multiplication-Sign 10{sup 14}, 5 Multiplication-Sign 10{sup 14} and 1 Multiplication-Sign 10{sup 15} at/cm{sup 2}. The resulting As distributions, confined in the amorphous layer, were thermally treated at 550 Degree-Sign C for 5-300 s in order to electrically activate dopant atoms. Crystal re-growth and As redistribution was investigated by secondary ion mass spectrometry and medium energy ion scattering. A growth rate depending on the As concentration was observed, the rate being slower for higher As content. Arsenic re-distribution to the surface and at the end-of-range defects was observed and a segregation model was developed. Finally, the substitutional fraction of As atoms was related to sheet resistance measurements revealing a higher fraction of electrically active dopant atoms in pre-amorphized samples compared to not pre-amorphized.

Demenev, E.; Giubertoni, D.; Gennaro, S.; Bersani, M.; Hourdakis, E.; Nassiopoulou, A. G.; Reading, M. A.; Berg, J. A. van den [CMM, Fondazione Bruno Kessler, Via Sommarive 18. 38123 Povo - Trento (Italy); NCSR Demokritos, IMEL, Terma Patriarchou Grigoriou, Aghia Paraskevi, Athens (Greece); Centre for Materials and Physics, University of Salford (United Kingdom)

2012-11-06T23:59:59.000Z

48

Condensed phase conversion and growth of nanorods and other materials instead of from vapor  

DOE Patents (OSTI)

Compositions, systems and methods are described for condensed phase conversion and growth of nanorods and other materials. A method includes providing a condensed phase matrix material; and activating the condensed phase matrix material to produce a plurality of nanorods by condensed phase conversion and growth from the condensed phase matrix material instead of from vapor. The compositions are very strong. The compositions and methods provide advantages because they allow (1) formation rates of nanostructures necessary for reasonable production rates, and (2) the near net shaped production of component structures.

Geohegan, David B. (Knoxville, TN); Seals, Roland D. (Oak Ridge, TN); Puretzky, Alex A. (Knoxville, TN); Fan, Xudong (Oak Ridge, TN)

2010-10-19T23:59:59.000Z

49

Sulfur Impregnation on Activated Carbon Fibers through H2S Oxidation for Vapor Phase  

E-Print Network (OSTI)

Sulfur Impregnation on Activated Carbon Fibers through H2S Oxidation for Vapor Phase Mercury: Sulfur was impregnated onto activated carbon fibers ACFs through H2S oxidation catalyzed by the sorbent CE Database subject headings: Activated carbon; Sulfur; Mercury; Hydrogen sulfides; Oxidation

Borguet, Eric

50

Sulfurization of a carbon surface for vapor phase mercury removal II: Sulfur forms and mercury uptake  

E-Print Network (OSTI)

promote the formation of organic sulfur and the presence of H2S during the cooling process increased in the presence of H2S was very effective towards Hg uptake in nitrogen. Corre- lation of mercury uptake capacitySulfurization of a carbon surface for vapor phase mercury removal ­ II: Sulfur forms and mercury

Borguet, Eric

51

Vapor-condensed phase processes in the early solar system Lawrence GROSSMAN*  

E-Print Network (OSTI)

Vapor-condensed phase processes in the early solar system Lawrence GROSSMAN* Department accepted 26 September 2009) Abstract­Equilibrium thermodynamic calculations of the sequence of condensation of condensation, and some may be pristine condensates that escaped later melting. Compact Type A and Type B

Grossman, Lawrence

52

Modelling and Numerical Simulation of Liquid-Vapor Phase Transition  

E-Print Network (OSTI)

of pressurized water reactors in the nuclear industry. Indeed, understanding the triggering of boiling crisis, temperatures and chemical potentials, which enables dynamic generation of two-phase interfaces within a pure is a critical safety issue for the nuclear industry: when the transition occurs from nucleate boiling to film

Faccanoni, Gloria

53

Microsoft Word - Vapor Phase Elemental Sulfur Tech Brief DRAFT bbl 08-24.docx  

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

AT A GLANCE AT A GLANCE  eliminates excavation expense  applicable to large or small sites  straightforward deployment  uses heat to distribute sulfur throughout a soil  mercury reacts with sulfur to form immobile and insoluble minerals  patent applied for TechBrief Vapor Phase Elemental Sulfur Amendment for Sequestering Mercury in Contaminated Soil Scientists at the Savannah River National Laboratory (SRNL) have identified a method of targeting mercury in contaminated soil zone by use of sulfur vapor heated gas. Background Mercury contamination in soil is a common problem in the environment. The most common treatment is excavation - a method that works well for small sites where the

54

Defect mitigation by ion induced amorphousization and solid-phase epitaxy  

SciTech Connect

Ion implantation is a common technique in the semiconductor industry used to modify the electrical properties of materials, usually silicon. Some dopant ions are sufficiently light, such as boron, that they do not create a continuous amorphous layer in silicon over the range of the ions. In the presence of such a layer, most of the ioninduced damage can be removed by solid-phase epitaxy growth (SPEG), which results in recrystallization of the amorphous damage. However, end-of-range defects at the amorphous-crystal interface give rise to threading dislocations during SPEG that degrade the quality of the recrytallized Si. We have studied the end of range defects in silicon with three different implantations. The first was with 80 keV {sup 30}Si with a dose of 3 Multiplication-Sign 10{sup 15} Si/cm{sup 2}, and the second was with 100 keV {sup 72}Ge at a dose of 1 Multiplication-Sign 10{sup 15} Ge/cm{sup 2}, and the third was a double implant of 100 keV {sup 72}Ge at a dose of 1 Multiplication-Sign 10{sup 15} Ge/cm{sup 2} followed by 340 keV {sup 28}Si at a dose of 3 Multiplication-Sign 10{sup 14} Si/cm{sup 2}. SPEG was done at 650 Degree-Sign C to recrystalize the implanted samples, and the end of range defects were studied using channeled Rutherford Backscattering Spectrometry (RBS-c). The effects of photon-assisted hydrogenation on amorphization and recrystallization were also studied.

Phinney, L. C.; Cottier, R. J.; Golding, T. D.; Holland, O. W.; Hossain, K. [Amethyst Research, Inc., 123 Case Circle, Ardmore OK 73401 (United States)

2013-04-19T23:59:59.000Z

55

Reducing dislocations in semiconductors utilizing repeated thermal cycling during multistage epitaxial growth  

DOE Patents (OSTI)

Dislocation densities are reduced in growing semiconductors from the vapor phase by employing a technique of interrupting growth, cooling the layer so far deposited, and then repeating the process until a high quality active top layer is achieved. The method of interrupted growth, coupled with thermal cycling, permits dislocations to be trapped in the initial stages of epitaxial growth.

Fan, John C. C. (Chestnut Hill, MA); Tsaur, Bor-Yeu (Arlington, MA); Gale, Ronald P. (Bedford, MA); Davis, Frances M. (Framingham, MA)

1986-12-30T23:59:59.000Z

56

Reducing dislocations in semiconductors utilizing repeated thermal cycling during multistage epitaxial growth  

DOE Patents (OSTI)

Dislocation densities are reduced in growing semiconductors from the vapor phase by employing a technique of interrupting growth, cooling the layer so far deposited, and then repeating the process until a high quality active top layer is achieved. The method of interrupted growth, coupled with thermal cycling, permits dislocations to be trapped in the initial stages of epitaxial growth.

Fan, John C. C. (Chestnut Hill, MA); Tsaur, Bor-Yeu (Arlington, MA); Gale, Ronald P. (Bedford, MA); Davis, Frances M. (Framingham, MA)

1992-02-25T23:59:59.000Z

57

Metal organic chemical vapor deposition of 111-v compounds on silicon  

DOE Patents (OSTI)

Expitaxial composite comprising thin films of a Group III-V compound semiconductor such as gallium arsenide (GaAs) or gallium aluminum arsenide (GaAlAs) on single crystal silicon substrates are disclosed. Also disclosed is a process for manufacturing, by chemical deposition from the vapor phase, epitaxial composites as above described, and to semiconductor devices based on such epitaxial composites. The composites have particular utility for use in making light sensitive solid state solar cells.

Vernon, Stanley M. (Wellesley, MA)

1986-01-01T23:59:59.000Z

58

In situ, subsurface monitoring of vapor-phase TCE using fiber optics  

SciTech Connect

A vapor-phase, reagent-based, fiber optic trichloroethylene (TCE) sensor developed by Lawrence Livermore National Laboratory (LLNL) was demonstrated at the Savannah River Site (SRS) in two configurations. The first incorporated the sensor into a down-well instrument bounded by two inflatable packers capable of sealing an area for discrete depth analysis. The second involved an integration of the sensor into the probe tip of the Army Corps of Engineers Waterways Experiment Station (WES) cone penetrometry system. Discrete depth measurements of vapor-phase concentrations of TCE in the vadose zone were successfully made using both configurations. These measurements demonstrate the first successful in situ sensing (as opposed to sampling) of TCE at a field site.

Rossabi, J. [Westinghouse Savannah River Co., Aiken, SC (United States); Colston, B. Jr.; Brown, S.; Milanovich, F. [Lawrence Livermore National Lab., CA (United States); Lee, L.T. Jr. [Army Engineer Waterways Experiment Station, Vicksburg, MS (United States). Geotechnical Lab.

1993-03-05T23:59:59.000Z

59

Ice-water and liquid-vapor phase transitions by a Ginzburg–Landau model  

Science Journals Connector (OSTI)

A model for the first order phase transitions as ice-water and liquid-vapor is proposed using the Ginzburg–Landau equation for the order parameter ? . In this model the density ? is composed of two quantities ? 0 and ? 1 such that 1 / ? = 1 / ? 0 + 1 / ? 1 where ? 1 is strictly connected to the order parameter ? . By means of this decomposition we are able to represent the Andrew diagram without the use of the heuristic van der Waals equation.

Mauro Fabrizio

2008-01-01T23:59:59.000Z

60

Molecular Simulation of Henry's Constant at Vapor-Liquid and Liquid-Liquid Phase Richard J. Sadus  

E-Print Network (OSTI)

coexistence. 1. Introduction Henry's constant is a well-known measure of a solute's solubility in a particularMolecular Simulation of Henry's Constant at Vapor-Liquid and Liquid-Liquid Phase Boundaries Richard to determine Henry's constant from the residual chemical potential at infinite dilution at the vapor-liquid

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


61

Liquid phase epitaxial growth and characterization of germanium far infrared blocked impurity band detectors  

SciTech Connect

Germanium Blocked Impurity Band (BIB) detectors require a high purity blocking layer (< 10{sup 13} cm{sup -3}) approximately 1 mm thick grown on a heavily doped active layer ({approx} 10{sup 16} cm{sup -3}) approximately 20 mm thick. Epilayers were grown using liquid phase epitaxy (LPE) of germanium out of lead solution. The effects of the crystallographic orientation of the germanium substrate on LPE growth modes were explored. Growth was studied on substrates oriented by Laue x-ray diffraction between 0.02{sup o} and 10{sup o} from the {l_brace}111{r_brace} toward the {l_brace}100{r_brace}. Terrace growth was observed, with increasing terrace height for larger misorientation angles. It was found that the purity of the blocking layer was limited by the presence of phosphorus in the lead solvent. Unintentionally doped Ge layers contained {approx}10{sup 15} cm{sup -3} phosphorus as determined by Hall effect measurements and Photothermal Ionization Spectroscopy (PTIS). Lead purification by vacuum distillation and dilution reduced the phosphorus concentration in the layers to {approx} 10{sup 14} cm{sup -3} but further reduction was not observed with successive distillation runs. The graphite distillation and growth components as an additional phosphorus source cannot be ruled out. Antimony ({approx}10{sup 16} cm{sup -3}) was used as a dopant for the active BIB layer. A reduction in the donor binding energy due to impurity banding was observed by variable temperature Hall effect measurements. A BIB detector fabricated from an Sb-doped Ge layer grown on a pure substrate showed a low energy photoconductive onset ({approx}6 meV). Spreading resistance measurements on doped layers revealed a nonuniform dopant distribution with Sb pile-up at the layer surface, which must be removed by chemomechanical polishing. Sb diffusion into the pure substrate was observed by Secondary Ion Mass Spectroscopy (SIMS) for epilayers grown at 650 C. The Sb concentration at the interface dropped by an order of magnitude over {approx} 1.5 {micro}m. Layers grown at 550 C did not show significant Sb diffusion. Sn doped In{sub 2}O{sub 3} (ITO) was studied for use in far infrared transparent low temperature contacts for BIB arrays. It was found that {approx}100 nm of ITO deposited on Ge remains electrically conducting at 4 K and is {approx}90% transparent in the far infrared. ITO should be suitable for passivating contacts to Ge BIB arrays.

Bandaru, Jordana

2001-05-12T23:59:59.000Z

62

A description of the vapor phase in the lithium thionyl chloride battery  

E-Print Network (OSTI)

A DESCRIPTION OF TIIE YAPOP, PHASE IN THF. LITHIUM THIONYI. CHLORIDE BATTERY A Thesis by RODOLFO MORALES, JR. Submitted to the Graduate College of Texas AEzM University in partial fulfrHment of the requirement for the degree oi' MASTER... OF SCIENCE August 1988 Major Subject: Chemical Engineering A DESCRIPTION OF THE VAPOR PHASE IN THE LITHIUM THIONYL CHLORIDE BATTERY A Thesis bv RODOLFO 'vIORALES, JR. Approved as to style and content by: Ralph E. White (Chairman of Committee) James...

Morales, Rodolfo

1988-01-01T23:59:59.000Z

63

Au-mediated low-temperature solid phase epitaxial growth of a SixGe1 x alloy on Si(001)  

E-Print Network (OSTI)

a silicide or a germanide of a near noble metal e.g., Pd, Pt , obtained by the reaction of the metal- taxial growth techniques. Metal-mediated solid phase epitaxy SPE has been stud- ied in a variety or Ge is accomplished at low temperatures by using a eutectic-forming metal e.g., Au, Al, Ag, etc

Allen, Leslie H.

64

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

SciTech Connect

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

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

2014-06-16T23:59:59.000Z

65

The growth of vapor bubble and relaxation between two-phase bubble flow  

Science Journals Connector (OSTI)

This paper presents the behavior of the bubble growth and relaxation between vapor and superheated...

S. Mohammadein; Rama Subba Reddy Gorla

2003-01-01T23:59:59.000Z

66

On the existence of vapor-liquid phase transition in dusty plasmas  

SciTech Connect

The phenomenon of phase transition in a dusty-plasma system (DPS) has attracted some attention in the past. Earlier Farouki and Hamaguchi [J. Chem. Phys. 101, 9876 (1994)] have demonstrated the existence of a liquid to solid transition in DPS where the dust particles interact through a Yukawa potential. However, the question of the existence of a vapor-liquid (VL) transition in such a system remains unanswered and relatively unexplored so far. We have investigated this problem by performing extensive molecular dynamics simulations which show that the VL transition does not have a critical curve in the pressure versus volume diagram for a large range of the Yukawa screening parameter ? and the Coulomb coupling parameter ?. Thus, the VL phase transition is found to be super-critical, meaning that this transition is continuous in the dusty plasma model given by Farouki and Hamaguchi. We provide an approximate analytic explanation of this finding by means of a simple model calculation.

Kundu, M.; Sen, A.; Ganesh, R. [Institute for Plasma Research, Bhat, Gandhinagar 382 428, Gujarat (India); Avinash, K. [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

2014-10-15T23:59:59.000Z

67

Vapor-deposited non-crystalline phase vs ordinary glasses and supercooled liquids: evidence for significant thermodynamic and kinetic differences  

E-Print Network (OSTI)

Vapor deposition of molecules on a substrate often results in glassy materials of high kinetic stability and low enthalpy. The extraordinary properties of such glasses are attributed to high rates of surface diffusion during sample deposition, which makes it possible for constituents to find a configuration of much lower energy on a typical laboratory time scale1,2,7. The exact structure of the resulting phase is often assumed to be identical to that obtained by aging of ordinary glass over exceedingly long times. Using Fast Scanning Calorimetry technique, we show that out-of-equilibrium relaxation kinetics and possibly the enthalpy of vapor-deposited films of toluene, an archetypical fragile glass former, are distinct from those of ordinary supercooled phase even when the deposition takes place at temperatures above the glass softening. These observations provide support to the conjecture that the vapor-deposition may result in formation of non-crystalline phase of unique structural, thermodynamic, and kinetic properties.

Deepanjan Bhattacharya; Vlad Sadtchenko

2014-10-31T23:59:59.000Z

68

Gas-phase reaction study of disilane pyrolysis: Applications to low pressure chemical vapor deposition  

SciTech Connect

The gas-phase thermal reactions during disilane decomposition at low pressure chemical vapor deposition conditions were studied from 300 to 1,000 K using resonance enhanced multiphoton ionization (REMPI) and multiphoton ionization (MPI). REMPI of gas-phase Si, mass 28, was detected from 640 to 840 K and 1 to 10 Torr, with a maximum signal intensity between 700 to 720 K. During disilane decomposition, no SiH (427.8 nm), SiH[sub 2] (494-515 nm), or SiH[sub 3] (419.0 nm) was detected. MPI of higher silanes, silenes, and silylenes were detected through mass fragments 2, 32, and 60; these species reached a maximum signal intensity 20 degrees prior to the mass-28 maximum. Modeling studies that included a detailed low pressure gas-phase kinetic scheme predict relative gas-phase partial pressures generated during disilane pyrolysis. The model predicted experimental trends in the Si partial pressure and the higher silane, silene, and silylene partial pressures.

Johannes, J.E.; Ekerdt, J.G. (Univ. of Texas, Austin, TX (United States). Dept. of Chemical Engineering)

1994-08-01T23:59:59.000Z

69

Gas-phase silicon atom densities in the chemical vapor deposition of silicon from silane  

SciTech Connect

Silicon atom number density profiles have been measured using laser-induced fluorescence during the chemical vapor deposition of silicon from silane. Measurements were obtained in a rotating-disk reactor as a function of silane partial pressure and the amount of hydrogen added to the carrier gas. Absolute number densities were obtained using an atomic absorption technique. Results were compared with calculated density profiles from a model of the coupled fluid flow, gas-phase and surface chemistry for an infinite-radius rotating disk. An analysis of the reaction mechanism showed that the unimolecular decomposition of SiH{sub 2} is not the dominant source of Si atoms. Profile shapes and positions, and all experimental trends are well matched by the calculations. However, the calculated number density is up to 100 times smaller than measured.

Coltrin, M.E.; Breiland, W.G.; Ho, P.

1993-12-31T23:59:59.000Z

70

Method for the generation of variable density metal vapors which bypasses the liquidus phase  

DOE Patents (OSTI)

The present invention provides a method for producing a metal vapor that includes the steps of combining a metal and graphite in a vessel to form a mixture; heating the mixture to a first temperature in an argon gas atmosphere to form a metal carbide; maintaining the first temperature for a period of time; heating the metal carbide to a second temperature to form a metal vapor; withdrawing the metal vapor and the argon gas from the vessel; and separating the metal vapor from the argon gas. Metal vapors made using this method can be used to produce uniform powders of the metal oxide that have narrow size distribution and high purity.

Kunnmann, Walter (Stony Brook, NY); Larese, John Z. (Rocky Point, NY)

2001-01-01T23:59:59.000Z

71

On the influence of solution density on the formation of macroscopic defects in the liquid phase epitaxy of GaN  

Science Journals Connector (OSTI)

This paper reports on a new simple method for avoiding particle-induced macroscopic defects using the liquid phase epitaxy (LPE) of GaN as an example. In a series of growth experiments by LPE of GaN it is demonstrated that the number of particle-induced macrodefects in the epitaxial layers correlates strongly and reproducibly with the density of the solution. In solutions with a density higher than that of the deleterious particles, the particles float on the solution and hence are hindered to get into contact with the seed, which is placed at the bottom of the crucible. Consequently, so-called depressions — a typical particle-induced defect in GaN–LPE layers — are avoided. The principle of avoiding the formation of macroscopic defects originating from particles by adapting the density of the solution (density criterion) should be generally applicable to solution growth processes, regardless of the material system.

S. Hussy; P. Berwian; E. Meissner; J. Friedrich; G. Müller

2008-01-01T23:59:59.000Z

72

Prevention of In droplets formation by HCl addition during metal organic vapor phase epitaxy of InN  

E-Print Network (OSTI)

for InN such as solar cells and infrared laser diodes. The growth of InN films must overcome several chal plasma-assisted15,16 and ArF excimer laser assisted MOVPE Ref. 17 has been demonstrated to avoid

Anderson, Timothy J.

73

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

E-Print Network (OSTI)

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

Li, Lian

74

Growth and characterization of liquid phase epitaxial GaP layers  

E-Print Network (OSTI)

Inside a High-vacuum Chamber . . . . . . . . . . . . . . . . . . . . . . . 3 3. Cross Section of Multi-well Sliding Graphite Boat. Solubility Curve of P in Ga Melt 5. Apparatus of LPE Growth by Tipping Method. 10 Dipping System Schematic for LPE... Growth. 10 7. Sliding Boat System Block Diagram for LPE Growth 12 Temperature Profile Along the Graphite Boat. 13 9. Disassembled Graphite Boat for Multi-layer LPE Growth. . . 14 10. Ga-P Phase Diagram 17 Solution Cooling Procedure for Three...

Kao, Yung-Chung

2012-06-07T23:59:59.000Z

75

Epitaxial growth of B-doped Si on Si(100) by electron-cyclotron-resonance Ar plasma chemical vapor deposition in a SiH4–B2H6–H2 gas mixture without substrate heating  

Science Journals Connector (OSTI)

Abstract Characteristics of B-doped Si epitaxial growth on Si(100) by using electron-cyclotron-resonance Ar plasma enhanced chemical vapor deposition without substrate heating in a SiH4–B2H6–H2–Ar gas mixture were investigated. B concentration in the deposited films increases with decreasing microwave power for plasma generation. At the microwave power of 125 W, the B concentration increases up to 5 × 1021 cm? 3. Deposition rate of the B-doped Si tends to be enhanced at the higher B2H6 partial pressure. Resistivity of the B-doped Si film tends to increase with decreasing the microwave power. Referring Irvin curve, in the case of 200 W, the carrier concentration is estimated to be at least about 1017 cm? 3 at the B concentration of 1021 cm? 3. After heat treatment in N2 atmosphere at 200 °C and 300 °C for 2 h, the resistivity drastically decreases to the value which corresponds to carrier concentration of around 1019 cm? 3. From Fourier transform infrared spectroscopy measurement, it is found that hydrogen incorporated in the as-deposited film desorbed by the heat treatment.

Yusuke Abe; Masao Sakuraba; Junichi Murota

2014-01-01T23:59:59.000Z

76

Desalination-of water by vapor-phase transport through hydrophobic nanopores  

E-Print Network (OSTI)

We propose a new approach to desalination of water whereby a pressure difference across a vapor-trapping nanopore induces selective transport of water by isothermal evaporation and condensation across the pore. Transport ...

Lee, Jongho

77

A series of layered intergrowth phases grown by molecular beam epitaxy: Sr{sub m}TiO{sub 2+m}(m=1-5)  

SciTech Connect

Sr{sub m}TiO{sub 2+m} phases having one TiO{sub 2} layer sandwiched between m SrO layers were grown using molecular beam epitaxy. The out-of-plane (in-plane) lattice parameters determined by x-ray diffraction were c(a)=9.14 A (3.78 A), 23.55 A (3.75 A), and 14.60 A (3.75 A) for Sr{sub 3}TiO{sub 5}, Sr{sub 4}TiO{sub 6}, and Sr{sub 5}TiO{sub 7}, respectively. Both lattice parameters change abruptly on going from the m=2 Ruddlesden-Popper phase to m=3 phase, indicating a significant change in the bond lengths (or strain states) on transitioning from the known members to the higher order members of this structural family. Electron microscopy confirmed the artificially layered structures.

Fisher, P.; Wang, S.; Skowronski, M.; Salvador, P. A.; Snyder, M.; Maksimov, O. [Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Electro-Optics Center, Pennsylvania State University, Freeport, Pennsylvania 16229 (United States)

2007-12-17T23:59:59.000Z

78

Treatment of Produced Waters Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System  

SciTech Connect

This report summarizes work performed on this project from October 2004 through March 2005. In previous work, a surfactant modified zeolite (SMZ) was shown to be an effective system for removing BTEX contaminants from produced water. Additional work on this project demonstrated that a compost-based biofilter could biodegrade the BTEX contaminants found in the SMZ regeneration waste gas stream. However, it was also determined that the BTEX concentrations in the waste gas stream varied significantly during the regeneration period and the initial BTEX concentrations were too high for the biofilter to handle effectively. A series of experiments were conducted to determine the feasibility of using a passive adsorption column placed upstream of the biofilter to attenuate the peak gas-phase VOC concentrations delivered to the biofilter during the SMZ regeneration process. In preparation for the field test of the SMZ/VPB treatment system in New Mexico, a pilot-scale SMZ system was also designed and constructed during this reporting period. Finally, a cost and feasibility analysis was also completed. To investigate the merits of the passive buffering system during SMZ regeneration, two adsorbents, SMZ and granular activated carbon (GAC) were investigated in flow-through laboratory-scale columns to determine their capacity to handle steady and unsteady VOC feed conditions. When subjected to a toluene-contaminated air stream, the column containing SMZ reduced the peak inlet 1000 ppmv toluene concentration to 630 ppmv at a 10 second contact time. This level of buffering was insufficient to ensure complete removal in the downstream biofilter and the contact time was longer than desired. For this reason, using SMZ as a passive buffering system for the gas phase contaminants was not pursued further. In contrast to the SMZ results, GAC was found to be an effective adsorbent to handle the peak contaminant concentrations that occur early during the SMZ regeneration process. At a one second residence time, the GAC bed reduced peak contaminant concentrations by 97%. After the initial peak, the inlet VOC concentration in the SMZ regeneration gas stream drops exponentially with time. During this period, the contaminants on the GAC subsequently desorbed at a nearly steady rate over the next 45 hours resulting in a relatively steady effluent concentration of approximately 25 ppm{sub v}. This lower concentration is readily degradable by a downstream vapor phase biofilter (VPB) and the steady nature of the feed stream will prevent the biomass in the VPB from enduring starvation conditions between SMZ regeneration cycles. Repetitive sorption and desorption cycles that would be expected in the field were also investigated. It was determined that although the GAC initially lost some VOC sorption capacity, the adsorption and desorption profiles stabilized after approximately 6 cycles indicating that a GAC bed should be suitable for continuous operation. In preparation for the pilot field testing of the SMZ/VPB system, design, ''in-house'' construction and testing of the field system were completed during this project period. The design of the SMZ system for the pilot test was based on previous investigations by the PI's in Wyoming, 2002 and on analyses of the produced water at the field site in New Mexico. The field tests are scheduled for summer, 2005. A cost survey, feasibility of application and cost analyses were completed to investigate the long term effectiveness of the SMZ/VPB system as a method of treating produced water for re-use. Several factors were investigated, including: current costs to treat and dispose of produced water, end-use water quality requirements, and state and federal permitting requirements.

Soondong Kwon; Elaine B. Darby; Li-Jung Chen; Lynn E. Katz; Kerry A. Kinney; R. S. Bowman; E. J. Sullivan

2005-03-11T23:59:59.000Z

79

Identification of vapor-phase chemical warfare agent simulants and rocket fuels using laser-induced breakdown spectroscopy  

SciTech Connect

Application of laser-induced breakdown spectroscopy (LIBS) to the identification of security threats is a growing area of research. This work presents LIBS spectra of vapor-phase chemical warfare agent simulants and typical rocket fuels. A large dataset of spectra was acquired using a variety of gas mixtures and background pressures and processed using partial least squares analysis. The five compounds studied were identified with a 99% success rate by the best method. The temporal behavior of the emission lines as a function of chamber pressure and gas mixture was also investigated, revealing some interesting trends that merit further study.

Stearns, Jaime A.; McElman, Sarah E.; Dodd, James A.

2010-05-01T23:59:59.000Z

80

Chemical beam epitaxy for high efficiency photovoltaic devices  

SciTech Connect

InP-based multijunction tandem solar cells show great promise for the conversion efficiency (eta) and high radiation resistance. InP and its related ternary and quanternary compound semiconductors such as InGaAs and InGaAsP offer desirable combinations for energy bandgap values which are very suitable for multijunction tandem solar cell applications. The monolithically integrated InP/In(0.53)Ga(0.47)As tandem solar cells are expected to reach efficiencies above 30 percent. Wanlass, et.al., have reported AMO efficiencies as high as 20.1% for two terminal cells fabricated using atmospheric-pressure metalorganic vapor phase epitaxy (APMOVPE). The main limitations in their technique are first related to the degradation of the intercell ohmic contact (IOC), in this case the In(0.53)Ga(0.47)As tunnel junction during the growth of the top InP subcell structure, and second to the current matching, often limited by the In(0.53)Ga(0.47)As bottom subcell. Chemical beam epitaxy (CBE) has been shown to allow the growth of high quality materials with reproducible complex compositional and doping profiles. The main advantage of CBE compared to metalorganic chemical vapor deposition (MOCVD), the most popular technique for InP-based photovoltaic device fabrication, is the ability to grow high purity epilayers at much lower temperatures (450 C - 530 C). In a recent report it was shown that cost-wise CBE is a breakthrough technology for photovoltaic (PV) solar energy progress in the energy conversion efficiency of InP-based solar cells fabricated using chemical beam epitaxy. This communication summarizes recent results on PV devices and demonstrates the strength of this new technology.

Bensaoula, A.; Freundlich, A.; Vilela, M. F.; Medelci, N.; Renaud, P.

1994-09-01T23:59:59.000Z

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


81

Lattice-matched epitaxial GaInAsSb/GaSb thermophotovoltaic devices  

SciTech Connect

The materials development of Ga{sub 1{minus}x}In{sub x}As{sub y}Sb{sub 1{minus}y} alloys for lattice-matched thermophotovoltaic (TPV) devices is reported. Epilayers with cutoff wavelength 2--2.4 {micro}m at room temperature and lattice-matched to GaSb substrates were grown by both low-pressure organometallic vapor phase epitaxy and molecular beam epitaxy. These layers exhibit high optical and structural quality. For demonstrating lattice-matched thermophotovoltaic devices, p- and n-type doping studies were performed. Several TPV device structures were investigated, with variations in the base/emitter thicknesses and the incorporation of a high bandgap GaSb or AlGaAsSb window layer. Significant improvement in the external quantum efficiency is observed for devices with an AlGaAsSb window layer compared to those without one.

Wang, C.A.; Choi, H.K.; Turner, G.W.; Spears, D.L.; Manfra, M.J. [Massachusetts Inst. of Tech., Lexington, MA (United States). Lincoln Lab.; Charache, G.W. [Lockheed Martin, Inc., Schenectady, NY (United States)

1997-05-01T23:59:59.000Z

82

Enhanced quality thin film Cu(In,Ga)Se.sub.2 for semiconductor device applications by vapor-phase recrystallization  

DOE Patents (OSTI)

Enhanced quality thin films of Cu.sub.w (In,Ga.sub.y)Se.sub.z for semiconductor device applications are fabricated by initially forming a Cu-rich, phase-separated compound mixture comprising Cu(In,Ga):Cu.sub.x Se on a substrate to form a large-grain precursor and then converting the excess Cu.sub.x Se to Cu(In,Ga)Se.sub.2 by exposing it to an activity of In and/or Ga, either in vapor In and/or Ga form or in solid (In,Ga).sub.y Se.sub.z. Alternatively, the conversion can be made by sequential deposition of In and/or Ga and Se onto the phase-separated precursor. The conversion process is preferably performed in the temperature range of about 300.degree.-600.degree. C., where the Cu(In,Ga)Se.sub.2 remains solid, while the excess Cu.sub.x Se is in a liquid flux. The characteristic of the resulting Cu.sub.w (In,Ga).sub.y Se.sub.z can be controlled by the temperature. Higher temperatures, such as 500.degree.-600.degree. C., result in a nearly stoichiometric Cu(In,Ga)Se.sub.2, whereas lower temperatures, such as 300.degree.-400.degree. C., result in a more Cu-poor compound, such as the Cu.sub.z (In,Ga).sub.4 Se.sub.7 phase.

Tuttle, John R. (Denver, CO); Contreras, Miguel A. (Golden, CO); Noufi, Rommel (Golden, CO); Albin, David S. (Denver, CO)

1994-01-01T23:59:59.000Z

83

Enhanced quality thin film Cu(In,Ga)Se[sub 2] for semiconductor device applications by vapor-phase recrystallization  

DOE Patents (OSTI)

Enhanced quality thin films of Cu[sub w](In,Ga[sub y])Se[sub z] for semiconductor device applications are fabricated by initially forming a Cu-rich, phase-separated compound mixture comprising Cu(In,Ga):Cu[sub x]Se on a substrate to form a large-grain precursor and then converting the excess Cu[sub x]Se to Cu(In,Ga)Se[sub 2] by exposing it to an activity of In and/or Ga, either in vapor In and/or Ga form or in solid (In,Ga)[sub y]Se[sub z]. Alternatively, the conversion can be made by sequential deposition of In and/or Ga and Se onto the phase-separated precursor. The conversion process is preferably performed in the temperature range of about 300--600 C, where the Cu(In,Ga)Se[sub 2] remains solid, while the excess Cu[sub x]Se is in a liquid flux. The characteristic of the resulting Cu[sub w](In,Ga)[sub y]Se[sub z] can be controlled by the temperature. Higher temperatures, such as 500--600 C, result in a nearly stoichiometric Cu(In,Ga)Se[sub 2], whereas lower temperatures, such as 300--400 C, result in a more Cu-poor compound, such as the Cu[sub z](In,Ga)[sub 4]Se[sub 7] phase. 7 figs.

Tuttle, J.R.; Contreras, M.A.; Noufi, R.; Albin, D.S.

1994-10-18T23:59:59.000Z

84

Surface tension and vapor-liquid phase coexistence of confined square-well fluid  

E-Print Network (OSTI)

,4 Gibbs-Duhem integration GDI ,5 and N-P-T +test particle.6­8 Panagiotopoulos used GEMC to obtain, Sarkisov and Monson used GDI to get the phase behavior in a disordered porous structure,10 and Forsman

Singh, Jayant K.

85

Epitaxial growth of europium monoxide on diamond  

SciTech Connect

We report the epitaxial integration of phase-pure EuO on both single-crystal diamond and on epitaxial diamond films grown on silicon utilizing reactive molecular-beam epitaxy. The epitaxial orientation relationship is (001) EuO ? (001) diamond and [110] EuO ?[100] diamond. The EuO layer is nominally unstrained and ferromagnetic with a transition temperature of 68 ± 2 K and a saturation magnetization of 5.5 ± 0.1 Bohr magnetons per europium ion on the single-crystal diamond, and a transition temperature of 67 ± 2 K and a saturation magnetization of 2.1 ± 0.1 Bohr magnetons per europium ion on the epitaxial diamond film.

Melville, A.; Heeg, T. [Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853 (United States)] [Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853 (United States); Mairoser, T.; Schmehl, A. [Zentrum für elektronische Korrelationen und Magnetismus, Universität Augsburg, Universitätsstraße 1, 86159 Augsburg (Germany)] [Zentrum für elektronische Korrelationen und Magnetismus, Universität Augsburg, Universitätsstraße 1, 86159 Augsburg (Germany); Fischer, M.; Gsell, S.; Schreck, M. [Institut für Physik, Universität Augsburg, D-86135 Augsburg (Germany)] [Institut für Physik, Universität Augsburg, D-86135 Augsburg (Germany); Awschalom, D. D. [Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637 (United States)] [Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637 (United States); Holländer, B.; Schubert, J. [Peter Grünberg Institute, PGI9-IT, JARA-FIT, Research Centre Jülich, D-52425 Jülich (Germany)] [Peter Grünberg Institute, PGI9-IT, JARA-FIT, Research Centre Jülich, D-52425 Jülich (Germany); Schlom, D. G. [Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853 (United States) [Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853 (United States); Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853 (United States)

2013-11-25T23:59:59.000Z

86

A lattice Boltzmann study of phase separation in liquid-vapor systems with gravity  

E-Print Network (OSTI)

Phase separation of a two-dimensional van der Waals fluid subject to a gravitational force is studied by numerical simulations based on lattice Boltzmann methods (LBM) implemented with a finite difference scheme. A growth exponent $\\alpha=1$ is measured in the direction of the external force.

A. Cristea; G. Gonnella; A. Lamura; V. Sofonea

2009-07-16T23:59:59.000Z

87

Phase-Controlled Growth of Metastable Fe5Si3 Nanowires by a Vapor Transport Method  

E-Print Network (OSTI)

to produce other metal-rich silicide nanostructures for future spintronic devices. Introduction Iron. Depending on the concentration ratio of FeI2(g) to SiI4(g), different phases of iron silicides are formed. The growth of nanowires is facilitated by the initial nucleation of silicide particles on the substrate

Kim, Bongsoo

88

Doping of gallium nitride using disilane  

Science Journals Connector (OSTI)

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

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

1995-11-01T23:59:59.000Z

89

Controlled Vapor Phase Growth of Single Crystalline, Two-Dimensional GaSe Crystals with High Photoresponse  

SciTech Connect

Abstract Compared with their bulk counterparts, atomically thin two-dimensional (2D) crystals exhibit new physical properties, and have the potential to enable next-generation electronic and optoelectronic devices. However, controlled synthesis of large uniform monolayer and multi-layer 2D crystals is still challenging. Here, we report the controlled synthesis of 2D GaSe crystals on SiO2/Si substrates using a vapor phase deposition method. For the first time, uniform, large (up to ~60 m in lateral size), single-crystalline, triangular monolayer GaSe crystals were obtained and their atomic resolution structure were characterized. The size, density, shape, thickness, and uniformity of the 2D GaSe crystals were shown to be controllable by growth duration, growth region, growth temperature, and argon carrier gas flow rate. The theoretical modeling of the electronic structure and Raman spectroscopy demonstrate a direct-to-indirect bandgap transition and progressive confinement-induced bandgap shifts for 2D GaSe crystals. The 2D GaSe crystals show p-type semiconductor characteristics and high photoresponsivity (~1.7 A/W under white light illumination) comparable to exfoliated GaSe nanosheets. These 2D GaSe crystals are potentially useful for next-generation electronic and optoelectronic devices such as photodetectors and field-effect transistors.

Li, Xufan [ORNL; Lin, Ming-Wei [ORNL; Zhang, Huidong [University of Tennessee, Knoxville (UTK); Puretzky, Alexander A [ORNL; Idrobo Tapia, Juan C [ORNL; Ma, Cheng [ORNL; Chi, Miaofang [ORNL; Yoon, Mina [ORNL; Rouleau, Christopher M [ORNL; Kravchenko, Ivan I [ORNL; Geohegan, David B [ORNL; Xiao, Kai [ORNL

2014-01-01T23:59:59.000Z

90

Structural and Magnetic Properties of Epitaxial MnSi(111) Thin Films.  

E-Print Network (OSTI)

??MnSi(111) films were grown on Si(111) substrates by solid phase epitaxy (SPE) and molecular beam epitaxy (MBE) to determine their magnetic structures. A lattice mismatch… (more)

Karhu, Eric

2012-01-01T23:59:59.000Z

91

Characteristics of PCDD/F distributions in vapor and solid phases and emissions from the Waelz process  

SciTech Connect

The Waelz process is a classic method used for recovering zinc from electric arc furnace (EAF) dusts containing relatively high concentrations of PCDD/Fs (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans) as well as volatile metals, such as Zn, Pb, and Cu, and chlorine. The EAF dust is mixed with coke (30%) and sand (20%) then fed into a rotary kiln. Significant PCDD/Fs are formed in the typical Waelz process, causing public concerns regarding PCDD/F emissions. In this study, flue gas and ash samplings are simultaneously conducted at different sampling points to evaluate the removal efficiency and the partitioning of PCDD/Fs between the vapor and solid phases in the Waelz plant investigated. With the environment (temperature window, sufficient retention time, chlorine, and catalysts available) conducive to PCDD/F formation in the dust settling chamber (DSC), a significantly high PCDD/F concentration (1223 ng TEQ/Nm{sup 3}) is measured in flue gas downstream from the DSC of the Waelz plant investigated. In addition, the cyclone and bag filter adopted in this facility can only remove 51.3% and 69.4%, respectively, of the PCDD/Fs in the flue gas, resulting in a high PCDD/F concentration (145 ng TEQ/Nm{sup 3}) measured in the stack gas of the Waelz plant investigated. On the basis of treating 1 ton of EAF dust, the total PCDD/F discharge (stack gas emission + ash discharge) is 840 ng TEQ/kg EAF dust of the Waelz plant investigated. Because of the lack of effective air pollutant control devices for PCDD/Fs, about 560 ng TEQ/kg EAF dust are discharged via stack gas in this facility. 16 refs., 7 figs., 2 tabs.

Kai Hsien Chi; Shu Hao Chang; Moo Been Chang [National Central University, Chungli (Taiwan). Graduate Institute of Environmental Engineering

2006-03-15T23:59:59.000Z

92

GaAs/AIGaAs quantum well and modulation-doped heterostructures grown by organometallic vapor phase epitaxy using trimethylamine alane  

E-Print Network (OSTI)

describedpreviously.6 The carrier gaswashydrogenand the sourcereagentswere arsine,TEGa, andTMAA. Disilane wasutilized

Florida, University of

93

Metalorganic vapor phase epitaxy and characterizations of nearly-lattice-matched AlInN alloys on GaN/sapphire templates and  

E-Print Network (OSTI)

InN material lattice-matched to GaN will also be useful as cladding layer in laser structure. Specifically, Al) for solid state light- ing [1­19], visible diode lasers for both display and biosensing [20GaN and AlGaN in III-nitride based applications for LEDs [40­42] and laser diode (LD) [20­26], solar

Gilchrist, James F.

94

Epitaxial Graphene - Energy Innovation Portal  

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

Epitaxial Graphene Brookhaven National Laboratory Contact BNL About This Technology

Scanning electron micrographs of epitaxial graphene grown on ruthenium films atop patterned...

95

Role of gas phase reactions in subatmospheric chemical-vapor deposition ozone/TEOS processes for oxide deposition  

E-Print Network (OSTI)

-vapor deposition. Our results for oxide deposition show optimum process window around 200 Torr for producing films a po- tentially optimum process window in which film properties, deposition rates, film uniformity requires high quality dielectric films that can be deposited rapidly and conformally on high aspect ratio

Rubloff, Gary W.

96

Stress induced phase transition in Gd2O3 films by ion beam assisted reactive electron beam-physical vapor deposition (EB-PVD)  

Science Journals Connector (OSTI)

Abstract The structural evolution of thick polycrystalline gadolinium oxide (Gd2O3) films deposited by reactive electron beam-physical vapor deposition (EB-PVD) is investigated. High deposition rates (> 5 Å/s) lead to the growth of mixed phase films which are of the cubic phase near the film/substrate interface before forming monoclinic phase as distance from the interface increases. By decreasing the deposition rate to phase. The growth of the thermodynamically stable cubic phase under these conditions is attributed to both higher surface mobility of the adatoms during growth and to increased tensile stress within the film. Ion beam assisted deposition (IBAD) was then performed to introduce compressive stress into the film resulting in the formation of the monoclinic phase. Wafer curvature, X-ray diffraction, confocal Raman spectroscopy, and scanning electron microscopy are utilized to characterize the film and present evidence for the existence of a stress-induced phase transition in the Gd2O3 films.

Daniel A. Grave; Michael P. Schmitt; Joshua A. Robinson; Douglas E. Wolfe

2014-01-01T23:59:59.000Z

97

Ferromagnetism in Mn-Implanted Epitaxially Grown Ge on Si(100)  

SciTech Connect

We have studied ferromagnetism of Mn-implanted epitaxial Ge films on silicon. The Ge films were grown by ultrahigh vacuum chemical vapor deposition using a mixture of germane (GeH{sub 4}) and methylgermane (CH{sub 3}GeH{sub 3}) gases with a carbon concentration of less than 1 at. %, and observed surface rms roughness of 0.5 nm, as measured by atomic force microscopy. Manganese ions were implanted in epitaxial Ge films grown on Si (100) wafers to an effective concentration of 16, 12, 6, and 2 at. %. Superconducting quantum interference device measurements showed that only the three highest Mn concentration samples are ferromagnetic, while the fourth sample, with [Mn] = 2 at. %, is paramagnetic. X-ray absorption spectroscopy and x-ray magnetic circular dichroism measurements indicate that localized Mn moments are ferromagnetically coupled below the Curie temperature. Isothermal annealing of Mn-implanted Ge films with [Mn] = 16 at. % at 300 C for up to 1200 s decreases the magnetization but does not change the Curie temperature, suggesting that the amount of the magnetic phase slowly decreases with time at this anneal temperature. Furthermore, transmission electron microscopy and synchrotron grazing incidence x-ray diffraction experiments show that the Mn-implanted region is amorphous, and we believe that it is this phase that is responsible for the ferromagnetism. This is supported by our observation that high-temperature annealing leads to recrystallization and transformation of the material into a paramagnetic phase.

Guchhait, S.; Jamil, M.; Ohldag, H.; Mehta, A.; Arenholz, E.; Lian, G.; Li Fatou, A.; Ferrer, D. A.; Markert, J. T.; Colombo, L.; Banerjee, S. K.

2011-01-05T23:59:59.000Z

98

Quantitative Infrared Intensity Studies of Vapor-Phase Glyoxal, Methylglyoxal, and 2,3-Butanedione (Diacetyl) with Vibrational Assignments  

SciTech Connect

Glyoxal, methylglyoxal and 2,3-butanedione (diacetyl) are all known biomass burning effluents and suspected aerosol precursors. Pressure-broadened quantitative infrared spectra of glyoxal, methylglyoxal and diacetyl vapors covering the 520–6500 cm?1 range are reported at 0.11 cm?1 resolution, each with a composite spectrum derived from a minimum of ten different sample pressures for the compound, representing some of the first quantitative data for these analytes. The ordinate corresponds to a 1 meter optical pathlength and a mixing ratio of 1ppmv at 296 K. Many vibrational assignments for methylglyoxal are reported for the first time, as are some near-IR and far-IR bands of glyoxal and diacetyl. To complete the vibrational assignments, the quantitative far-infrared spectra (25 to 600 cm-1) of all three vapors are also reported, methylglyoxal for the first time. Density functional theory and ab initio MP2 theory are used to help assign vibrational modes. Potential bands useful for atmospheric monitoring are discussed.

Profeta, Luisa T.; Sams, Robert L.; Johnson, Timothy J.; Williams, Stephen D.

2011-09-08T23:59:59.000Z

99

Experimental and Modeling Study of the Flammability of Fuel Tank Headspace Vapors from Ethanol/Gasoline Fuels, Phase 2: Evaluations of Field Samples and Laboratory Blends  

SciTech Connect

Study to measure the flammability of gasoline/ethanol fuel vapors at low ambient temperatures and develop a mathematical model to predict temperatures at which flammable vapors were likely to form.

Gardiner, D. P.; Bardon, M. F.; LaViolette, M.

2010-04-01T23:59:59.000Z

100

Synchroton X-Ray Studies of Liquid-Vapor Interfaces  

Science Journals Connector (OSTI)

The variation of density across the liquid-vapor interface from essentially zero density far out in the vapor phase to a homogeneous density deep in the liquid phase can be determined by X-ray reflectivity mea...

J. Als-Nielsen

1988-01-01T23:59:59.000Z

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


101

Selective deposition of silicon and silicon-germanium alloys by rapid thermal chemical vapor deposition  

SciTech Connect

Selective deposition of SiGe alloys by rapid thermal deposition has been studied using a commercially available Rapid Thermal Chemical Vapor Deposition (RTCVD) cluster tool. The precursors used in this work were dichlorosilane and germane diluted in either hydrogen or argon. An initial characterization was performed to find the appropriate temperature and GeH{sub 4} flow ranges to deposit epitaxial layers with low surface roughness. For layers with higher germanium concentration lower deposition temperatures are required to minimize surface roughness. The effects of the dilutant gas on the deposition were examined. An H{sub 2} dilutant affects the deposition by consuming chlorine released by the SiCl{sub 2}H{sub 2} and forming HCl. When Ar is used as the dilutant, more chlorine is available for other reactions that can result in etching of the silicon surface. Finally, the effects of pre-deposition treatment were determined. When compared to a wet HF dip, a gas/vapor phase HF/methanol native oxide removal treatment appears to increase the initiation time for the epitaxial deposition reaction. This is most likely due to increased fluorine termination of the surface. When a wet HF or HF/methanol native oxide removal is followed by a UV-Cl{sub 2} process, the deposition reaction initiation time is reduced. The UV-Cl{sub 2} process was also found to etch silicon through the native oxide.

Grant, J.M.; Ang, M.; Allen, L.R. [Sharp Microelectronics Technology, Inc., Camas, WA (United States)

1996-12-01T23:59:59.000Z

102

Veeco Develops a Tool to Reduce Epitaxy Costs and Increase LED Brightness  

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

With the help of DOE funding, Veeco is working on reducing epitaxy costs and increasing LED efficiency by developing a physical vapor deposition (PVD) tool for depositing aluminum nitride buffer layers on LED substrates. PVD, also known as "sputtering," is an alternative to metal-organic chemical vapor deposition (MOCVD). PVD is a purely physical process that involves plasma sputter bombardment rather than a chemical reaction at the surface to be coated, as in MOCVD.

103

Molecular Beam Epitaxy, Multi-source | EMSL  

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

beam epitaxy, is examined using a combination... Self-corrected Sensors Based On Atomic Absorption Spectroscopy For Atom Flux Measurements In Molecular Beam Epitaxy. A...

104

Three-Phase Vapor?Liquid?Liquid Equilibria for Methane + n-Octane + Monoethylene Glycol + Water at Pressures from (3.1 to 15.0) MPa and Temperatures from (281 to 363) K  

Science Journals Connector (OSTI)

There are several commercial processes available for the dehydration of gas, such as the use of liquid or solid desiccants and expansion refrigeration. ... The gaseous part of the liquid samples, and the gas phase samples direct from the equilibrium cell, were expanded into a series of evacuated vessels of known volume from which the total amount of substance was determined from the perfect gas equation using the measured low-pressure PVT data. ... To predict the losses of MEG in processes for the dehydration of natural gas, the concentrations of MEG in the vapor phase are of interest to the gas industry. ...

Stanley J. Ashcroft; Gerd Brunner; Hansjörg Vollmer; Christopher W. Sweeney

2009-03-06T23:59:59.000Z

105

Long Term Field Development of a Surfactant Modified Zeolite/Vapor Phase Bioreactor System for Treatment of Produced Waters for Power Generation  

SciTech Connect

The main goal of this research was to investigate the feasibility of using a combined physicochemical/biological treatment system to remove the organic constituents present in saline produced water. In order to meet this objective, a physical/chemical adsorption process was developed and two separate biological treatment techniques were investigated. Two previous research projects focused on the development of the surfactant modified zeolite adsorption process (DE-AC26-99BC15221) and development of a vapor phase biofilter (VPB) to treat the regeneration off-gas from the surfactant modified zeolite (SMZ) adsorption system (DE-FC26-02NT15461). In this research, the SMZ/VPB was modified to more effectively attenuate peak loads and to maintain stable biodegradation of the BTEX constituents from the produced water. Specifically, a load equalization system was incorporated into the regeneration flow stream. In addition, a membrane bioreactor (MBR) system was tested for its ability to simultaneously remove the aromatic hydrocarbon and carboxylate components from produced water. The specific objectives related to these efforts included the following: (1) Optimize the performance VPBs treating the transient loading expected during SMZ regeneration: (a) Evaluate the impact of biofilter operating parameters on process performance under stable operating conditions. (b) Investigate how transient loads affect biofilter performance, and identify an appropriate technology to improve biological treatment performance during the transient regeneration period of an SMZ adsorption system. (c) Examine the merits of a load equalization technology to attenuate peak VOC loads prior to a VPB system. (d) Evaluate the capability of an SMZ/VPB to remove BTEX from produced water in a field trial. (2) Investigate the feasibility of MBR treatment of produced water: (a) Evaluate the biodegradation of carboxylates and BTEX constituents from synthetic produced water in a laboratory-scale MBR. (b) Evaluate the capability of an SMZ/MBR system to remove carboxylates and BTEX from produced water in a field trial. Laboratory experiments were conducted to provide a better understanding of each component of the SMZ/VPB and SMZ/MBR process. Laboratory VPB studies were designed to address the issue of influent variability and periodic operation (see DE-FC26-02NT15461). These experiments examined multiple influent loading cycles and variable concentration loadings that simulate air sparging as the regeneration option for the SMZ system. Two pilot studies were conducted at a produced water processing facility near Farmington, New Mexico. The first field test evaluated SMZ adsorption, SMZ regeneration, VPB buffering, and VPB performance, and the second test focused on MBR and SMZ/MBR operation. The design of the field studies were based on the results from the previous field tests and laboratory studies. Both of the biological treatment systems were capable of removing the BTEX constituents in the laboratory and in the field over a range of operating conditions. For the VPB, separation of the BTEX constituents from the saline aqueous phase yielded high removal efficiencies. However, carboxylates remained in the aqueous phase and were not removed in the combined VPB/SMZ system. In contrast, the MBR was capable of directly treating the saline produced water and simultaneously removing the BTEX and carboxylate constituents. The major limitation of the MBR system is the potential for membrane fouling, particularly when the system is treating produced water under field conditions. The combined process was able to effectively pretreat water for reverse osmosis treatment and subsequent downstream reuse options including utilization in power generation facilities. The specific conclusions that can be drawn from this study are summarized.

Lynn Katz; Kerry Kinney; Robert Bowman; Enid Sullivan; Soondong Kwon; Elaine Darby; Li-Jung Chen; Craig Altare

2007-12-31T23:59:59.000Z

106

Calibrated vapor generator source  

DOE Patents (OSTI)

A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet. 10 figs.

Davies, J.P.; Larson, R.A.; Goodrich, L.D.; Hall, H.J.; Stoddard, B.D.; Davis, S.G.; Kaser, T.G.; Conrad, F.J.

1995-09-26T23:59:59.000Z

107

Spray structures and vaporizing characteristics of a GDI fuel spray  

Science Journals Connector (OSTI)

The spray structures and distribution characteristics of liquid and vapor phases in non-evaporating and evaporating Gasoline Direct Injection (GDI) fuel sprays were investigated using Laser Induced...

Dong-Seok Choi; Gyung-Min Choi; Duck-Jool Kim

2002-07-01T23:59:59.000Z

108

Mechanism of compensation of the donor impurity in the near-surface layer of gap during heat treatment in phosphorus vapors  

SciTech Connect

The secondary ion mass spectrometry and capacitance-voltage measurements have been used to study the mechanism of formation of the near-surface layer with a low concentration of uncompensated donors in n-GaP grown by vapor-phase epitaxy and subjected to heat treatment at different pressures of phosphorus vapors. The dependence of the thickness of the mentioned layer on the pressure of phosphorus vapors has a minimum at a pressure of (1.5 {+-} 0.5) x 10{sup 3} Pa. It is shown that at vapor pressures above the mentioned value, the interstitial P, which forms a deep electron trap, is a suitable candidate for the role of compensating acceptor. At low pressures, the probable compensating center is the P vacancy giving rise to a deep level with the energy Ec-(0.21 {+-} 0.01) eV. At 700 deg. C, the effective diffusivity of interstitial P is {approx}(3 {+-} 1) s- 10{sup -15} cm{sup 2}/s, while that of the P vacancy is {approx}(3 {+-} 1) x 10{sup -14} cm{sup 2}/s.

Krutogolov, Yu. K., E-mail: krutogolov@mail.ru [Research Institute for Materials of Electronic Engineering (Russian Federation)

2010-06-15T23:59:59.000Z

109

Nanostructures produced by phase-separation during growth of (III-V).sub.1-x(IV.sub.2).sub.x alloys  

DOE Patents (OSTI)

Nanostructures (18) and methods for production thereof by phase separation during metal organic vapor-phase epitaxy (MOVPE). An embodiment of one of the methods may comprise providing a growth surface in a reaction chamber and introducing a first mixture of precursor materials into the reaction chamber to form a buffer layer (12) thereon. A second mixture of precursor materials may be provided into the reaction chamber to form an active region (14) on the buffer layer (12), wherein the nanostructure (18) is embedded in a matrix (16) in the active region (14). Additional steps are also disclosed for preparing the nanostructure (18) product for various applications.

Norman, Andrew G. (Evergreen, CO); Olson, Jerry M. (Lakewood, CO)

2007-06-12T23:59:59.000Z

110

Optical characterization of epitaxial Ga{sub x}In{sub 1{minus}x}As suitable for thermophotovoltaic (TPV) converters  

SciTech Connect

A preliminary investigation of the optical characteristics of Ga{sub x}In{sub 1{minus}x}As epilayers is presented. Ga{sub x}In{sub 1{minus}x}As epilayers with x = 0.465, 0.400, and 0.277 were prepared by metalorganic vapor-phase epitaxy (MOVPE) to represent a wide spectrum of TPV converter applications. Ellipsometric measurements, combined with various characterization techniques and multi-layer modeling, are used to extract n({lambda}) and k({lambda}) for these epilayers. The validity of the results was checked by using the experimentally determined optical constants to calculate expected reflectance, and then comparing this result against measured reflectance. Good agreement was obtained in all cases; larger differences were observed for samples having greater surface roughness. Suggestions for improving the optical constant determination procedure are given.

Wangensteen, T.L.; Wanlass, M.W.; Carapella, J.J.; Moutinho, H.R.; Mason, A.R.; Webb, J.D.; Abulfotuh, F.A. [National Renewable Energy Lab., Golden, CO (United States)

1997-12-31T23:59:59.000Z

111

ARM Water Vapor IOP  

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

ARM Water Vapor IOP The SGP CART site will host the third ARM water vapor IOP on September 18-October 8, 2000. The CART site is home to a powerful array of instruments capable of...

112

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

DOE Patents (OSTI)

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

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

2010-03-02T23:59:59.000Z

113

Epitaxial Graphene on Cu(111)  

Science Journals Connector (OSTI)

Epitaxial Graphene on Cu(111) ... The growth of graphene on single crystal Cu(111) has been achieved by thermal decomposition of ethylene in an ultrahigh vacuum chamber for the first time. ... The structural and electronic properties of graphene on Cu(111) have been investigated by scanning tunneling microscopy and spectroscopy. ...

Li Gao; Jeffrey R. Guest; Nathan P. Guisinger

2010-08-02T23:59:59.000Z

114

Vapor spill monitoring method  

DOE Patents (OSTI)

Method for continuous sampling of liquified natural gas effluent from a spill pipe, vaporizing the cold liquified natural gas, and feeding the vaporized gas into an infrared detector to measure the gas composition. The apparatus utilizes a probe having an inner channel for receiving samples of liquified natural gas and a surrounding water jacket through which warm water is flowed to flash vaporize the liquified natural gas.

Bianchini, Gregory M. (Livermore, CA); McRae, Thomas G. (Livermore, CA)

1985-01-01T23:59:59.000Z

115

ARM - Water Vapor  

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

Water Vapor Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global...

116

Aerogel composites using chemical vapor infiltration  

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

Aerogel composites using chemical vapor infiltration Aerogel composites using chemical vapor infiltration Title Aerogel composites using chemical vapor infiltration Publication Type Journal Article Year of Publication 1995 Authors Hunt, Arlon J., Michael R. Ayers, and Wanqing Cao Journal Journal of Non-Crystalline Solids Volume 185 Pagination 227-232 Abstract A new method to produce novel composite materials based on the use of aerogels as a starting material is described. Using chemical vapor infiltration, a variety of solid materials were thermally deposited into the open pore structure of aerogel. The resulting materials possess new and unusual properties including photoluminescence, magnetism and altered optical properties. An important characteristic of this preparation process is the very small size of the deposits that gives rise to new behaviors. Silicon deposits exhibit photoluminescence, indicating quantum confinement. Two or more phases may be deposited simultaneously and one or both chemically or thermally reacted to produce new structures.

117

Thermal Stability and Substitutional Carbon Incorporation far above Solid-Solubility in Si1-xCx and Si1-x-yGexCy Layers Grown by Chemical Vapor Deposition  

E-Print Network (OSTI)

Cx and Si1-x-yGexCy Layers Grown by Chemical Vapor Deposition using Disilane M. S. Carroll*, J. C. Sturm on (100) silicon substrates by rapid thermal chemical vapor deposition (RTCVD) with disilane source gas and disilane is known to produce higher silicon epitaxial growth rates for similar partial

118

Epitaxial growth of VO{sub 2} by periodic annealing  

SciTech Connect

We report the growth of ultrathin VO{sub 2} films on rutile TiO{sub 2} (001) substrates via reactive molecular-beam epitaxy. The films were formed by the cyclical deposition of amorphous vanadium and its subsequent oxidation and transformation to VO{sub 2} via solid-phase epitaxy. Significant metal-insulator transitions were observed in films as thin as 2.3?nm, where a resistance change ?R/R of 25 was measured. Low angle annular dark field scanning transmission electron microscopy was used in conjunction with electron energy loss spectroscopy to study the film/substrate interface and revealed the vanadium to be tetravalent and the titanium interdiffusion to be limited to 1.6?nm.

Tashman, J. W.; Paik, H.; Merz, T. A. [Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853-1501 (United States); Lee, J. H. [Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853-1501 (United States); Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Moyer, J. A.; Schiffer, P. [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Misra, R. [Department of Physics and Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Mundy, J. A. [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853 (United States); Spila, T. [Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Schubert, J. [Peter Grünberg Institute, PGI 9-IT, JARA-FIT, Research Centre Jülich, D-52425 Jülich (Germany); Muller, D. A. [School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853 (United States); Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853 (United States); Schlom, D. G., E-mail: schlom@cornell.edu [Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853-1501 (United States); Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853 (United States)

2014-02-10T23:59:59.000Z

119

Epitaxial Single Crystal Nanostructures for Batteries & PVs ...  

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

Electrode Channel Flow DEMS Cell Sulfur@Carbon Cathodes for Lithium Sulfur Batteries Better Ham & Cheese: Enhanced Anodes and Cathodes for Fuel Cells Epitaxial Single...

120

Molecular Beam Epitaxy, Multi-source | EMSL  

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

fundamental insight into water splitting for hydrogen... Self-corrected Sensors Based On Atomic Absorption Spectroscopy For Atom Flux Measurements In Molecular Beam Epitaxy. A...

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


121

THz Carrier Dynamics in Epitaxial Graphene  

Science Journals Connector (OSTI)

Ultrafast optical pump/THz-probe spectroscopy is used to measure the conductivity recovery dynamics in epitaxial graphene. The observed dynamics are insensitive to probe frequency,...

Divin, Charles J; Sun, Dong; Berger, Claire; de Heer, Walt; First, P N; Norris, Theodore B

122

1. Roller J. , Arellano-Jimneza J., Yu H. , Carter C.B., and Maric R., "Catalyst nanoscale assembly from the vapor phase on corrosion resistant supports",  

E-Print Network (OSTI)

and reactive spray deposition technology for low temperature solid oxide fuel cell", Journal of Thermal Spray Temperature Solid Oxide Fuel Cell (LTSOFC) by Reactive Spray Deposition Technology, RSDT, ECS Trans., 35.-P., Stöver, D., "Gas phase deposition of diffusion barriers for metal substrates in solid oxide fuel cells

Alpay, S. Pamir

123

Chemical vapor deposition sciences  

SciTech Connect

Chemical vapor deposition (CVD) is a widely used method for depositing thin films of a variety of materials. Applications of CVD range from the fabrication of microelectronic devices to the deposition of protective coatings. New CVD processes are increasingly complex, with stringent requirements that make it more difficult to commercialize them in a timely fashion. However, a clear understanding of the fundamental science underlying a CVD process, as expressed through computer models, can substantially shorten the time required for reactor and process development. Research scientists at Sandia use a wide range of experimental and theoretical techniques for investigating the science of CVD. Experimental tools include optical probes for gas-phase and surface processes, a range of surface analytic techniques, molecular beam methods for gas/surface kinetics, flow visualization techniques and state-of-the-art crystal growth reactors. The theoretical strategy uses a structured approach to describe the coupled gas-phase and gas-surface chemistry, fluid dynamics, heat and mass transfer of a CVD process. The software used to describe chemical reaction mechanisms is easily adapted to codes that model a variety of reactor geometries. Carefully chosen experiments provide critical information on the chemical species, gas temperatures and flows that are necessary for model development and validation. This brochure provides basic information on Sandia`s capabilities in the physical and chemical sciences of CVD and related materials processing technologies. It contains a brief description of the major scientific and technical capabilities of the CVD staff and facilities, and a brief discussion of the approach that the staff uses to advance the scientific understanding of CVD processes.

NONE

1992-12-31T23:59:59.000Z

124

Characterization of particle- and vapor-phase organic fraction emissions from a heavy-duty diesel engine equipped with a particle trap and regeneration controls  

SciTech Connect

The effects of a ceramic particle trap on the chemical and biological character of the exhaust from a heavy-duty diesel engine have been studied during steady-state operation and during periods of trap regeneration. Phase I of this project involved developing and refining the methods using a Caterpillar 3208 engine, and Phase II involved more detailed experiments with a Cummins LTA10-300 engine, which met Federal 1988 particulate matter standards, and a ceramic particle trap with built-in regeneration controls. During the Phase I experiments, samples wee collected at the Environmental Protection Agency (EPA)* steady-state mode 4 (50% load at intermediate speed). Varying the dilution ratio to obtain a constant filter-face temperature resulted in less variability in total particulate matter (TPM), particle-associated soluble organic fraction (SOF), solids (SOL), and polynuclear aromatic hydrocarbon (PAH) levels than sampling with a constant dilution ratio and allowing filter-face temperature to vary. A modified microsuspension Ames assay detected mutagenicity in the SOF samples, and in the semivolatile organic fraction extracted from XAD-2 resin (XAD-2 resin organic component, XOC) with at least 10 times less sample mass than the standard plate incorporation assay. Measurement techniques for PAH and nitro-PAH in the SOF and XOC also were developed during this portion of the project. For the Phase II work, two EPA steady-state rated speed modes were selected: mode 11 (25% load) and mode 9 (75% load). With or without the trap, filter-face temperatures were kept at 45 degrees +/- 2 degrees C, nitrogen dioxide (NO2) levels less than 5 parts per million (ppm), and sampling times less than 60 minutes. Particle sizes were determined using an electrical aerosol analyzer. Similar sampling methods were used when the trap was regenerated, except that a separate dilution tunnel and sampling system was designed and built to collect all of the regeneration emissions.

Bagley, S.T.; Gratz, L.D.; Leddy, D.G.; Johnson, J.H. (Michigan Technological Univ., Houghton, MI (United States))

1993-07-01T23:59:59.000Z

125

Chemistry, phase formation, and catalytic activity of thin palladium-containing oxide films synthesized by plasma-assisted physical vapor deposition  

SciTech Connect

The chemistry, microstructure, and catalytic activity of thin films incorporating palladium were studied using scanning and transmission electron microscopies, X-ray diffraction, spectrophotometry, 4-point probe and catalytic tests. The films were synthesized using pulsed filtered cathodic arc and magnetron sputter deposition, i.e. techniques far from thermodynamic equilibrium. Catalytic particles were formed by thermally cycling thin films of the Pd-Pt-O system. The evolution and phase formation in such films as a function of temperature were discussed in terms of the stability of PdO and PtO2 in air. The catalytic efficiency was found to be strongly affected by the chemical composition, with oxidized palladium definitely playing a major role in the combustion of methane. Reactive sputter deposition of thin films in the Pd-Zr-Y-O system allowed us forming microstructures ranging from nanocrystalline zirconia to palladium nanoparticles embedded in a (Zr,Y)4Pd2O matrix. The sequence of phase formation is put in relation to simple thermodynamic considerations.

Anders, Andre

2010-11-26T23:59:59.000Z

126

Measurements of atmospheric water vapor above Mauna Kea using an infrared radiometer  

E-Print Network (OSTI)

Measurements of atmospheric water vapor above Mauna Kea using an infrared radiometer David A in atmospheric water vapor that distort the phase coherence of incoming celestial signals. The signal received water vapor, this paper presents results obtained with a second generation IRMA operating at the James

Naylor, David A.

127

Characterization of recombination processes in epitaxial thin films and substrates for antimonide based thermophotovoltaic devices  

SciTech Connect

Recombination processes in antimonide-based materials for thermophotovoltaic (TPV) devices have been investigated using a radio-frequency (RF) photoreflectance technique, in which a Nd-YAG pulsed laser is used to excite excess carriers, and the short-pulse response and photoconductivity decay are monitored with an inductively-coupled non-contacting RF probe. Double-capped lattice-matched GaInAsSb organometallic vapor phase epitaxy (OMVPE)--grown layers on GaSb substrates have been used to evaluate bulk lifetime and surface recombination velocity with different layer thicknesses. With an active layer doping of 2 {times} 10{sup 17} cm{sup {minus}3}, effective bulk lifetimes of 95 ns and surface recombination velocities of 1,900 cm/s have been obtained. As the laser intensity is increased the lifetime decreases, which may be indicative of radiative recombination under these high level injection conditions. Similar measurements have been taken on both commercially available GaSb boules as well as in-house grown quaternary GaInAsSb boules. A two-step decay is observed with the quaternary boules, an initial decay of nominally 15 ns which is relatively independent of laser intensity and a second decay of 30--60 ns which increases with decreasing laser intensity. This behavior may be indicative of free charge separation as a result of short-range ordering in the quaternary crystals. GaSb boules, both commercially available and those grown in-house, exhibit more classical characteristics.

Saroop, S.; Borrego, J.; Gutmann, R.; Dutta, P.; Ostrogorsky, A. [Rensselaer Polytechnic Inst., Troy, NY (United States). Center for Integrated Electronics and Electronics Manufacturing; Charache, G. [Lockheed Martin Inc., Schenectady, NY (United States); Wang, C. [Massachusetts Inst. of Tech., Lexington, MA (United States). Lincoln Lab.

1998-06-01T23:59:59.000Z

128

Gasoline vapor recovery  

SciTech Connect

In a gasoline distribution network wherein gasoline is drawn from a gasoline storage tank and pumped into individual vehicles and wherein the gasoline storage tank is refilled periodically from a gasoline tanker truck, a method of recovering liquid gasoline from gasoline vapor that collects in the headspace of the gasoline storage tank as the liquid gasoline is drawn therefrom, said method comprising the steps of: (a) providing a source of inert gas; (b) introducing inert gas into the gasoline storage tank as liquid gasoline is drawn therefrom so that liquid gasoline drawn from the tank is displaced by inert gas and gasoline vapor mixes with the inert gas in the headspace of the tank; (c) collecting the inert gas/gasoline vapor mixture from the headspace of the gasoline storage tank as the tank is refilled from a gasoline tanker truck; (d) cooling the inert gas/gasoline vapor mixture to a temperature sufficient to condense the gasoline vapor in the mixture to liquid gasoline but not sufficient to liquify the inert gas in the mixture; (e) separating the condensed liquid gasoline from the inert gas; and delivering the condensed liquid gasoline to a remote location for subsequent use.

Lievens, G.; Tiberi, T.P.

1993-06-22T23:59:59.000Z

129

Study of structural properties of cubic InN films on GaAs(001) substrates by molecular beam epitaxy and migration enhanced epitaxy  

SciTech Connect

InN epitaxial films with cubic phase were grown by rf-plasma-assisted molecular beam epitaxy (RF-MBE) on GaAs(001) substrates employing two methods: migration-enhanced epitaxy (MEE) and conventional MBE technique. The films were synthesized at different growth temperatures ranging from 490 to 550 Degree-Sign C, and different In beam fluxes (BEP{sub In}) ranging from 5.9 Multiplication-Sign 10{sup -7} to 9.7 Multiplication-Sign 10{sup -7} Torr. We found the optimum conditions for the nucleation of the cubic phase of the InN using a buffer composed of several thin layers, according to reflection high-energy electron diffraction (RHEED) patterns. Crystallographic analysis by high resolution X-ray diffraction (HR-XRD) and RHEED confirmed the growth of c-InN by the two methods. We achieved with the MEE method a higher crystal quality and higher cubic phase purity. The ratio of cubic to hexagonal components in InN films was estimated from the ratio of the integrated X-ray diffraction intensities of the cubic (002) and hexagonal (1011) planes measured by X-ray reciprocal space mapping (RSM). For MEE samples, the cubic phase of InN increases employing higher In beam fluxes and higher growth temperatures. We have obtained a cubic purity phase of 96.4% for a film grown at 510 Degree-Sign C by MEE.

Casallas-Moreno, Y. L.; Perez-Caro, M.; Gallardo-Hernandez, S.; Ramirez-Lopez, M.; Martinez-Velis, I.; Lopez-Lopez, M. [Physics Department, Centro de Investigacion y de Estudios Avanzados del IPN, Apartado Postal 14-740, 07000 Mexico D.F. (Mexico)] [Physics Department, Centro de Investigacion y de Estudios Avanzados del IPN, Apartado Postal 14-740, 07000 Mexico D.F. (Mexico); Escobosa-Echavarria, A. [Electric Engineering Department, Centro de Investigacion y de Estudios Avanzados del IPN, Apartado Postal 14-740, 07000 Mexico D.F. (Mexico)] [Electric Engineering Department, Centro de Investigacion y de Estudios Avanzados del IPN, Apartado Postal 14-740, 07000 Mexico D.F. (Mexico)

2013-06-07T23:59:59.000Z

130

Growth and characterisation of epitaxially ordered zinc aluminate domains on c-sapphire  

Science Journals Connector (OSTI)

Epitaxially ordered zinc aluminate domains with sub-micron dimensions are formed on bare c-sapphire substrates using a vapour phase method (with vapour generated by carbothermal reduction of ZnO) at various temperatures and growth durations. A zinc aluminate (ZnAl2O4) layer is formed by reaction of the source materials (Zn and O) with the substrate. We observe crystallites with a well-defined epitaxial relationship on the sapphire substrate in addition to polycrystalline material. The epitaxially oriented deposit displays the form of characteristically twinned (singly or multiply) grains of sub-micron dimensions with three variants, consistent with the c-sapphire substrate symmetry. Scanning electron microscopy and transmission electron microscopy studies show that the formation of these grains is associated with the presence of extended defects in the sapphire substrate. Epitaxially ordered grains formed at higher temperatures show a change in the nature of the twin boundaries and epitaxial relations as a function of growth time, attributed to the effects of annealing during growth.

J. Grabowska; R.T. Rajendra Kumar; E. McGlynn; K.K. Nanda; S.B. Newcomb; P.J. McNally; L. O'Reilly; J.-P. Mosnier; M.O. Henry

2008-01-01T23:59:59.000Z

131

Electrolyte vapor condenser  

DOE Patents (OSTI)

A system is disclosed for removing electrolyte from a fuel cell gas stream. The gas stream containing electrolyte vapor is supercooled utilizing conventional heat exchangers and the thus supercooled gas stream is passed over high surface area passive condensers. The condensed electrolyte is then drained from the condenser and the remainder of the gas stream passed on. The system is particularly useful for electrolytes such as phosphoric acid and molten carbonate, but can be used for other electrolyte cells and simple vapor separation as well. 3 figs.

Sederquist, R.A.; Szydlowski, D.F.; Sawyer, R.D.

1983-02-08T23:59:59.000Z

132

Electrolyte vapor condenser  

DOE Patents (OSTI)

A system is disclosed for removing electrolyte from a fuel cell gas stream. The gas stream containing electrolyte vapor is supercooled utilizing conventional heat exchangers and the thus supercooled gas stream is passed over high surface area passive condensers. The condensed electrolyte is then drained from the condenser and the remainder of the gas stream passed on. The system is particularly useful for electrolytes such as phosphoric acid and molten carbonate, but can be used for other electrolyte cells and simple vapor separation as well.

Sederquist, Richard A. (Newington, CT); Szydlowski, Donald F. (East Hartford, CT); Sawyer, Richard D. (Canton, CT)

1983-01-01T23:59:59.000Z

133

Epitaxial \\{MCrAlY\\} coating on a Ni-base superalloy produced by electrospark deposition  

Science Journals Connector (OSTI)

Abstract A novel electrospark deposition technique has been successfully developed to deposit epitaxially \\{MCrAlY\\} coating onto a directionally solidified nickel base superalloy. The coating is featured by cellular directionally solidified microstructure with primary ? phase. Its formation mechanism may be attributed to the facts that the alloy solidifies primarily with ? phase and solidification conditions of the tiny thin melt close to the limit of constitutional undercooling under the electrospark treatment condition.

Yu-jiang Xie; Mao-cai Wang

2006-01-01T23:59:59.000Z

134

Experimental and Modeling Study of the Flammability of Fuel Tank Headspace Vapors from Ethanol/Gasoline Fuels; Phase 3: Effects of Winter Gasoline Volatility and Ethanol Content on Blend Flammability; Flammability Limits of Denatured Ethanol  

SciTech Connect

This study assessed differences in headspace flammability for summertime gasolines and new high-ethanol content fuel blends. The results apply to vehicle fuel tanks and underground storage tanks. Ambient temperature and fuel formulation effects on headspace vapor flammability of ethanol/gasoline blends were evaluated. Depending on the degree of tank filling, fuel type, and ambient temperature, fuel vapors in a tank can be flammable or non-flammable. Pure gasoline vapors in tanks generally are too rich to be flammable unless ambient temperatures are extremely low. High percentages of ethanol blended with gasoline can be less volatile than pure gasoline and can produce flammable headspace vapors at common ambient temperatures. The study supports refinements of fuel ethanol volatility specifications and shows potential consequences of using noncompliant fuels. E85 is flammable at low temperatures; denatured ethanol is flammable at warmer temperatures. If both are stored at the same location, one or both of the tanks' headspace vapors will be flammable over a wide range of ambient temperatures. This is relevant to allowing consumers to splash -blend ethanol and gasoline at fueling stations. Fuels compliant with ASTM volatility specifications are relatively safe, but the E85 samples tested indicate that some ethanol fuels may produce flammable vapors.

Gardiner, D. P.; Bardon, M. F.; Clark, W.

2011-07-01T23:59:59.000Z

135

Organic vapor jet printing system  

SciTech Connect

An organic vapor jet printing system includes a pump for increasing the pressure of an organic flux.

Forrest, Stephen R

2012-10-23T23:59:59.000Z

136

A Bibliography of Vapor Phase Thermal Fragmentation  

Science Journals Connector (OSTI)

......inert gas on hexa- decane pyrolysis", Can. J. Chem. 47, 3477...General Review of Ether Pyrolysis," Chapt. 4 of "The Chemistry...Chralovsky, "Phenyl Dimethyl Silane," Coll. Czech. Chem. Commun...Tebben and M. A. Ring, "Disilane and Trisilane," Inorg. Chem......

Stanley F. Sarner

1972-02-01T23:59:59.000Z

137

Vapor phase transport at a hillside landfill  

Science Journals Connector (OSTI)

...ambient density gradients. Post-landfill gas input reverses the direction of...landfill may explain observations of landfill gas found at depth. Post-landfill...of gas generation. Transport of landfill gas is shown to be dominated by diffusion...

P. H. Stauffer; N. D. Rosenberg

138

A Bibliography of Vapor Phase Thermal Fragmentation  

Science Journals Connector (OSTI)

......Catalysis 7, 386 (1967). S. J. Price, "Toluene," Can. J. Chem...Green, and L. P. Hallee, "Ethylene," Oil Gas J. 65, 192 (1967...1962). M. Krech and S. J. Price, "Dimethyl Mercury," Can...1963). M. Krech and S. J. Price, "Dimethyl Cadmium," Can......

Stanley F. Sarner

1972-02-01T23:59:59.000Z

139

E-Print Network 3.0 - acid vapor pressures Sample Search Results  

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

Sciences and Ecology 22 3b. Thermodynamics of moist air Water phase, water latent heat of vaporization Lv Summary: 3b. Thermodynamics of moist air Water phase, water latent...

140

Mercury Vapor | Open Energy Information  

Open Energy Info (EERE)

Mercury Vapor Mercury Vapor Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Mercury Vapor Details Activities (23) Areas (23) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Lab Analysis Techniques Exploration Sub Group: Fluid Lab Analysis Parent Exploration Technique: Fluid Lab Analysis Information Provided by Technique Lithology: Stratigraphic/Structural: Anomalously high concentrations can indicate high permeability or conduit for fluid flow Hydrological: Field wide soil sampling can generate a geometrical approximation of fluid circulation Thermal: High concentration in soils can be indicative of active hydrothermal activity Dictionary.png Mercury Vapor: Mercury is discharged as a highly volatile vapor during hydrothermal

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


141

Substrate-Induced Band-Gap Opening in Epitaxial Graphene  

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

Substrate-Induced Band-Gap Opening in Epitaxial Graphene Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Wednesday, 26 March 2008 00:00 Prospective challengers to...

142

Structure, Magnetism and Conductivity in Epitaxial Ti-doped ...  

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

Magnetism and Conductivity in Epitaxial Ti-doped -Fe2O3 Hematite: Experiment and density functional theory Structure, Magnetism and Conductivity in Epitaxial Ti-doped -Fe2O3...

143

Stratified vapor generator  

DOE Patents (OSTI)

A stratified vapor generator (110) comprises a first heating section (H.sub.1) and a second heating section (H.sub.2). The first and second heating sections (H.sub.1, H.sub.2) are arranged so that the inlet of the second heating section (H.sub.2) is operatively associated with the outlet of the first heating section (H.sub.1). A moisture separator (126) having a vapor outlet (164) and a liquid outlet (144) is operatively associated with the outlet (124) of the second heating section (H.sub.2). A cooling section (C.sub.1) is operatively associated with the liquid outlet (144) of the moisture separator (126) and includes an outlet that is operatively associated with the inlet of the second heating section (H.sub.2).

Bharathan, Desikan (Lakewood, CO); Hassani, Vahab (Golden, CO)

2008-05-20T23:59:59.000Z

144

Storing images in warm atomic vapor  

E-Print Network (OSTI)

Reversible and coherent storage of light in atomic medium is a key-stone of future quantum information applications. In this work, arbitrary two-dimensional images are slowed and stored in warm atomic vapor for up to 30 $\\mu$s, utilizing electromagnetically induced transparency. Both the intensity and the phase patterns of the optical field are maintained. The main limitation on the storage resolution and duration is found to be the diffusion of atoms. A techniqueanalogous to phase-shift lithography is employed to diminish the effect of diffusion on the visibility of the reconstructed image.

M. Shuker; O. Firstenberg; R. Pugatch; A. Ron; N. Davidson

2008-06-17T23:59:59.000Z

145

Epitaxial graphene on silicon carbide: Introduction to structured graphene  

E-Print Network (OSTI)

Epitaxial graphene on silicon carbide: Introduction to structured graphene Ming Ruan 1 , Yike Hu 1, France Abstract We present an introduction to the rapidly growing field of epitaxial graphene on silicon present, highly evolved state. The potential of epitaxial graphene as a new electronic material is now

Paris-Sud XI, Université de

146

I n s i t u thermal oxidation for surface cleaning and mask generation prior to selective area epitaxy  

Science Journals Connector (OSTI)

Dry thermal oxidation of GaAs and AlAs has been carried out in an organometallic chemical vapor deposition system. This i n s i t u process performed either before or after an epitaxialgrowth serves the purposes of surface cleaning and mask generation for selective area epitaxy of various III?V semiconductors.AlAsoxidized immediately after growth and patterned for the next regrowth provides better oxide?semiconductor interfaces and minimizes wafer handling. Pre?epitaxy oxidation at 435?°C on a patterned wafer with AlAs/GaAs areas resulted in a selective oxide mask. Since thermal oxides of GaAssublime at temperatures >600?°C a 700?°C pregrowth annealing thus thermally cleans the oxidizedGaAs areas while the oxides of AlAs remain as a mask for the following regrowth. Photoluminescence results indicate that high quality regrown interfaces have been obtained.

Stephen H. Jones; Kei May Lau

1988-01-01T23:59:59.000Z

147

Vapor Barriers or Vapor Diffusion Retarders | Department of Energy  

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

Home Air Sealing for New Home Construction Insulation Types of Insulation Insulation and Air Sealing Products and Services External Resources Find a Local AirVapor Barrier...

148

Production of higher quality bio-oils by in-line esterification of pyrolysis vapor  

DOE Patents (OSTI)

The disclosure encompasses in-line reactive condensation processes via vapor phase esterification of bio-oil to decease reactive species concentration and water content in the oily phase of a two-phase oil, thereby increasing storage stability and heating value. Esterification of the bio-oil vapor occurs via the vapor phase contact and subsequent reaction of organic acids with ethanol during condensation results in the production of water and esters. The pyrolysis oil product can have an increased ester content and an increased stability when compared to a condensed pyrolysis oil product not treated with an atomized alcohol.

Hilten, Roger Norris; Das, Keshav; Kastner, James R; Bibens, Brian P

2014-12-02T23:59:59.000Z

149

Comprehensive study of the metal-insulator transition in pulsed laser deposited epitaxial VO2 thin films  

E-Print Network (OSTI)

Comprehensive study of the metal-insulator transition in pulsed laser deposited epitaxial VO2 thin properties of high-quality VO2 thin films across its metal-insulator phase transition. Detailed x-ray deposition,9 sol-gel deriving,10 sputtering,11 and pulsed laser deposition,12 the study of VO2 is reviving

Wu, Junqiao

150

Vapor spill pipe monitor  

DOE Patents (OSTI)

The invention is a method and apparatus for continually monitoring the composition of liquefied natural gas flowing from a spill pipe during a spill test by continually removing a sample of the LNG by means of a probe, gasifying the LNG in the probe, and sending the vaporized LNG to a remote ir gas detector for analysis. The probe comprises three spaced concentric tubes surrounded by a water jacket which communicates with a flow channel defined between the inner and middle, and middle and outer tubes. The inner tube is connected to a pump for providing suction, and the probe is positioned in the LNG flow below the spill pipe with the tip oriented partly downward so that LNG is continuously drawn into the inner tube through a small orifice. The probe is made of a high thermal conductivity metal. Hot water is flowed through the water jacket and through the flow channel between the three tubes to provide the necessary heat transfer to flash vaporize the LNG passing through the inner channel of the probe. The gasified LNG is transported through a connected hose or tubing extending from the probe to a remote ir sensor which measures the gas composition.

Bianchini, G.M.; McRae, T.G.

1983-06-23T23:59:59.000Z

151

Electrostatic transfer of epitaxial graphene to glass.  

SciTech Connect

We report on a scalable electrostatic process to transfer epitaxial graphene to arbitrary glass substrates, including Pyrex and Zerodur. This transfer process could enable wafer-level integration of graphene with structured and electronically-active substrates such as MEMS and CMOS. We will describe the electrostatic transfer method and will compare the properties of the transferred graphene with nominally-equivalent 'as-grown' epitaxial graphene on SiC. The electronic properties of the graphene will be measured using magnetoresistive, four-probe, and graphene field effect transistor geometries [1]. To begin, high-quality epitaxial graphene (mobility 14,000 cm2/Vs and domains >100 {micro}m2) is grown on SiC in an argon-mediated environment [2,3]. The electrostatic transfer then takes place through the application of a large electric field between the donor graphene sample (anode) and the heated acceptor glass substrate (cathode). Using this electrostatic technique, both patterned few-layer graphene from SiC(000-1) and chip-scale monolayer graphene from SiC(0001) are transferred to Pyrex and Zerodur substrates. Subsequent examination of the transferred graphene by Raman spectroscopy confirms that the graphene can be transferred without inducing defects. Furthermore, the strain inherent in epitaxial graphene on SiC(0001) is found to be partially relaxed after the transfer to the glass substrates.

Ohta, Taisuke; Pan, Wei; Howell, Stephen Wayne; Biedermann, Laura Butler; Beechem Iii, Thomas Edwin; Ross, Anthony Joseph, III

2010-12-01T23:59:59.000Z

152

New High Performance Water Vapor Membranes to Improve Fuel Cell Balance of Plant Efficiency and Lower Costs (SBIR Phase I) - DOE Hydrogen and Fuel Cells Program FY 2012 Annual Progress Report  

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

0 0 DOE Hydrogen and Fuel Cells Program FY 2012 Annual Progress Report Earl H. Wagener (Primary Contact), Brad P. Morgan, Jeffrey R. DiMaio Tetramer Technologies L.L.C. 657 S. Mechanic St. Pendleton, SC 29670 Phone: (864) 646-6282 Email: earl.wagener@tetramertechnologies.com DOE Manager HQ: Nancy Garland Phone: (202) 586-5673 Email: Nancy.Garland@ee.doe.gov Contract Number: DE-SC0006172 Project Start Date: June 17, 2011 Project End Date: March 16, 2012 Fiscal Year (FY) 2012 Objectives Demonstrate water vapor transport membrane with * >18,000 gas permeation units (GPU) Water vapor membrane with less than 20% loss in * performance after stress tests Crossover leak rate: <150 GPU * Temperature Durability of 90°C with excursions to * 100°C Cost of <$10/m

153

Relaxation of crystal lattice parameters and structural ordering in In{sub x}Ga{sub 1-x}As epitaxial alloys  

SciTech Connect

Epitaxial In{sub x}Ga{sub 1-x}As/GaAs(100) heterostructures grown by the MOC-hydride method with a considerable lattice mismatch are studied by X-ray diffraction and scanning electron microscopy. The relaxation coefficient of the crystal lattice of the epitaxial alloy is calculated and the deformation energy is evaluated. It is shown that, at a concentration of the In atoms in metal sublattice close to x = 0.5, the superstructural phase formed on the surface of the epitaxial In{sub x}Ga{sub 1-x}As alloy is the InGaAs{sub 2} compound with a layered tetragonal crystal lattice and ordered arrangement of the atoms of the metal sublattice in the growth plane of the epitaxial film.

Seredin, P. V., E-mail: paul@phys.vsu.ru; Glotov, A. V.; Domashevskaya, E. P. [Voronezh State University (Russian Federation); Arsentyev, I. N., E-mail: arsentyev@mail.ioffe.ru; Vinokurov, D. A. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Stankevich, A. L.; Tarasov, I. S. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation)

2010-08-15T23:59:59.000Z

154

Hydrogen Cars and Water Vapor  

E-Print Network (OSTI)

. This cycle is currently under way with hydrogen fuel cells. As fuel cell cars are suggested as a solutionHydrogen Cars and Water Vapor D.W.KEITHANDA.E.FARRELL'S POLICY FORUM "Rethinking hydrogen cars" (18 misidentified as "zero-emissions vehicles." Fuel cell vehicles emit water vapor. A global fleet could have

Colorado at Boulder, University of

155

Fuel vapor control device  

SciTech Connect

A fuel vapor control device is described having a valve opening and closing a passage connecting a carburetor and a charcoal canister according to a predetermined temperature. A first coil spring formed by a ''shape memory effect'' alloy is provided to urge the valve to open the passage when the temperature is high. A second coil spring urges the valve to close the passage. A solenoid is provided to urge an armature against the valve to close the passage against the force of the first coil spring when the engine is running. The solenoid heats the first coil spring to generate a spring force therein when the engine is running. When the engine is turned off, the solenoid is deactivated, and the force of the first spring overcomes the force of the second spring to open the passage until such time as the temperature of the first spring drops below the predetermined temperature.

Ota, I.; Nishimura, Y.; Nishio, S.; Yogo, K.

1987-10-20T23:59:59.000Z

156

The Dust Settles on Water Vapor Feedback  

Science Journals Connector (OSTI)

...To understand water vapor feedback...shifts in the atmospheric circulation...caused a positive water vapor feedback...temperature. Condensation, evaporation...shifts in the atmospheric circulation...caused a positive water vapor feedback...temperature. Condensation, evaporation...

Anthony D. Del Genio

2002-04-26T23:59:59.000Z

157

E-Print Network 3.0 - amorphous phase separation Sample Search...  

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

University Collection: Physics 74 Atomistic examinations of the solid-phase epitaxial growth of silicon B.A. Gillespie , H.N.G. Wadley Summary: of the crystalline phase into an...

158

E-Print Network 3.0 - amorphous-crystal phase change Sample Search...  

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

method using the Tersoff (C) potential. With the solid phase... Phase Epitaxy (SPE) growth (111direction at 2100K). 12;3. 3.1 001, 111 Fig. 3 Fig. 3 -4.25eV 111...

159

Indium and tellurium doping of CdS crystals in cadmium vapor and their luminescent properties  

Science Journals Connector (OSTI)

A technique is devised for vapor-phase doping of CdS in the quaternary system Cd-In-Te-S. CdS crystals are doped with In and Te via four-zone ... InTe vapors. The luminescence spectra of the CdS?In,Te?[Cd] crysta...

I. N. Odin; M. V. Chukichev; M. E. Rubina

160

Indium and tellurium doping of CdS crystals in cadmium vapor and their luminescent properties  

Science Journals Connector (OSTI)

—A technique is devised for vapor-phase doping of CdS in the quaternary system Cd—In—Te—S. CdS crystals are doped with In and Te via four-zone ... InTe vapors. The luminescence spectra of the CdS?In,Te?[Cd] cryst...

I. N. Odin; M. V. Chukichev; M. E. Rubina

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


161

Optimization of the chemical vapor deposition process for carbon nanotubes fabrication  

E-Print Network (OSTI)

Optimization of the chemical vapor deposition process for carbon nanotubes fabrication M. Grujicica-phase chemistry and surface chemistry model is developed to analyze, at the reactor length scale, chemical vapor (carrier gas) in the presence of cobalt catalytic particles in a cylindrical reactor. The model allows

Grujicic, Mica

162

Category:Mercury Vapor | Open Energy Information  

Open Energy Info (EERE)

search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Mercury Vapor page? For detailed information on Mercury Vapor as exploration techniques,...

163

Chemical Vapor Deposition Epitaxy of Silicon-based Materials using Neopentasilane  

E-Print Network (OSTI)

of dichlorosilane, silane, disilane, and neopentasilane vs. inverse temperature observed in our lab on Si(100 dichlorosilane is not observable, and that for silane and disilane were 0.6 and 8 ECS Transactions, 16 (10) 799 sources of dichlorosilane (DCS), silane, disilane and neopentasilane (NPS) precursor on (100) silicon

164

Junction Transport in Epitaxial Film Silicon Heterojunction Solar Cells: Preprint  

SciTech Connect

We report our progress toward low-temperature HWCVD epitaxial film silicon solar cells on inexpensive seed layers, with a focus on the junction transport physics exhibited by our devices. Heterojunctions of i/p hydrogenated amorphous Si (a-Si) on our n-type epitaxial crystal Si on n++ Si wafers show space-charge-region recombination, tunneling or diffusive transport depending on both epitaxial Si quality and the applied forward voltage.

Young, D. L.; Li, J. V.; Teplin, C. W.; Stradins, P.; Branz, H. M.

2011-07-01T23:59:59.000Z

165

Method of physical vapor deposition of metal oxides on semiconductors  

DOE Patents (OSTI)

A process for growing a metal oxide thin film upon a semiconductor surface with a physical vapor deposition technique in a high-vacuum environment and a structure formed with the process involves the steps of heating the semiconductor surface and introducing hydrogen gas into the high-vacuum environment to develop conditions at the semiconductor surface which are favorable for growing the desired metal oxide upon the semiconductor surface yet is unfavorable for the formation of any native oxides upon the semiconductor. More specifically, the temperature of the semiconductor surface and the ratio of hydrogen partial pressure to water pressure within the vacuum environment are high enough to render the formation of native oxides on the semiconductor surface thermodynamically unstable yet are not so high that the formation of the desired metal oxide on the semiconductor surface is thermodynamically unstable. Having established these conditions, constituent atoms of the metal oxide to be deposited upon the semiconductor surface are directed toward the surface of the semiconductor by a physical vapor deposition technique so that the atoms come to rest upon the semiconductor surface as a thin film of metal oxide with no native oxide at the semiconductor surface/thin film interface. An example of a structure formed by this method includes an epitaxial thin film of (001)-oriented CeO.sub.2 overlying a substrate of (001) Ge.

Norton, David P. (Knoxville, TN)

2001-01-01T23:59:59.000Z

166

Wafer bonded epitaxial templates for silicon heterostructures  

DOE Patents (OSTI)

A heterostructure device layer is epitaxially grown on a virtual substrate, such as an InP/InGaAs/InP double heterostructure. A device substrate and a handle substrate form the virtual substrate. The device substrate is bonded to the handle substrate and is composed of a material suitable for fabrication of optoelectronic devices. The handle substrate is composed of a material suitable for providing mechanical support. The mechanical strength of the device and handle substrates is improved and the device substrate is thinned to leave a single-crystal film on the virtual substrate such as by exfoliation of a device film from the device substrate. An upper portion of the device film exfoliated from the device substrate is removed to provide a smoother and less defect prone surface for an optoelectronic device. A heterostructure is epitaxially grown on the smoothed surface in which an optoelectronic device may be fabricated.

Atwater, Jr., Harry A. (So. Pasadena, CA); Zahler, James M. (Pasadena, CA); Morral, Anna Fontcubera I (Paris, FR)

2008-03-11T23:59:59.000Z

167

Epitaxial growth and ferrimagnetic properties of Mn film on GaSb(100)  

SciTech Connect

We report on the epitaxial stabilization and magnetic properties of Mn films on GaSb(100) using molecular beam epitaxy, a follow-up to our previous work on the growth of Mn films on GaAs(100) [Phys. Rev. B 79, 045309 (2009)]. A strong ferrimagnetic ordering was observed which was attributed to the largely expanded lattice parameter resulting from the lattice mismatch with substrate and the enhanced thermal energy with increasing growth temperature. The observed magnetic moment of 1.16{mu}{sub B}/Mn atom was several times larger than that observed in the Mn/GaAs(100) films due to the lattice constant difference of substrates. The in-plane magnetoresistance behavior demonstrated the magnetic anisotropy that might result from the slightly distorted cubic structure of {alpha}-Mn phase under low-dimensional growth.

Feng Wuwei; Dung, Dang Duc; Shin, Yooleemi; Cho, Sunglae [Department of Physics, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Choi, Jeongyong [IT Convergence Technology Research Laboratory, Electronics and Telecommunications Research Institute, Daejeon 305-700 (Korea, Republic of)

2010-05-15T23:59:59.000Z

168

Substrate-Induced Band-Gap Opening in Epitaxial Graphene  

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

Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic...

169

ORIGINAL PAPER Epitaxial Stabilization of Face Selective Catalysts  

E-Print Network (OSTI)

with changes in catalytic performance (activity and selec- tivity), using the hydrogenation of acrolein combinations. Keywords Epitaxy Á Perovskite Á Platinum Á Heterogeneous catalysis Á Hydrogenation Á Acrolein

Marks, Laurence D.

170

Ultrafast THz Studies of Few-Layer Epitaxial Graphene  

Science Journals Connector (OSTI)

We report the broadband optical conductivity and ultrafast THz dynamics of few-layer epitaxial graphene, revealing electrodynamics consistent with a dense Dirac electron plasma and a...

Choi, Hyunyong; Borondics, Ferenc; Siegel, David A; Zhou, Shuyun; Martin, Michael C; Lanzara, Alessandra; Kaindl, Robert A

171

Ultra-low contact resistance at an epitaxial metal/oxide heterojunctio...  

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

Ultra-low contact resistance at an epitaxial metaloxide heterojunction through interstitial site doping. Ultra-low contact resistance at an epitaxial metaloxide heterojunction...

172

Vapor deposition of hardened niobium  

DOE Patents (OSTI)

A method of coating ceramic nuclear fuel particles containing a major amount of an actinide ceramic in which the particles are placed in a fluidized bed maintained at ca. 800.degree. to ca. 900.degree. C., and niobium pentachloride vapor and carbon tetrachloride vapor are led into the bed, whereby niobium metal is deposited on the particles and carbon is deposited interstitially within the niobium. Coating apparatus used in the method is also disclosed.

Blocher, Jr., John M. (Columbus, OH); Veigel, Neil D. (Columbus, OH); Landrigan, Richard B. (Columbus, OH)

1983-04-19T23:59:59.000Z

173

Liquid phase epitaxial growth of GaAs  

SciTech Connect

Research into new semiconductor materials for measurement of electromagnetic radiation over a wide range of energies has been an active field for several decades. There is a strong desire to identify and develop new materials which can lead to improved detectors. Such devices are expected to solve problems that cannot be solved using the semiconductor materials and device structures which have been traditionally used for radiation detection. In order for a detector which is subjected to some type of irradiation to respond, the radiation must undergo an interaction with the detector. The net result of the radiation interaction in a broad category of detectors is the generation of mobile electric charge carriers (electrons and/or holes) within the detector active volume. This charge is collected at the detector contacts and it forms the basic electrical signal. Typically, the collection of the charge is accomplished through the imposition of an electric field within the detector which causes the positive and/or negative charges created by the radiation to flow in opposite directions to the contacts. For the material to serve as a good radiation detector, a large fraction (preferably 100%) of all carriers created by the interacting incident radiation must be collected. Charge trapping by deep level impurities and structural defects can seriously degrade detector performance. The focus of this thesis is on far infrared and X-ray detection. In X-ray detector applications of p-I-n diodes, the object is to measure accurately the energy distribution of the incident radiation quanta. One important property of such detectors is their ability to measure the energy of individual incident photons with high energy resolution.

Wynne, D.I. [Univ. of California, Berkeley, CA (United States). Materials Science and Mineral Engineering; [Lawrence Berkeley National Lab., CA (United States)

1997-10-01T23:59:59.000Z

174

New plasma source of hydrides for epitaxial growth. Final subcontract report, 15 April 1991--3 September 1993  

SciTech Connect

This report describes a novel plasma-activated selenium source that was developed during the course of this subcontract and which is significantly different than any other heretofore reported in the scientific literature. It involves microwave excited, magnetically confined plasma sources that are intended to operate under electron cyclotron resonance (ECR) conditions at 2.455 GHz. This source is designed to excite and dissociate the molecular vapor evaporating or subliming from a heated solid or liquid reservoir. It can combine an effusion cell vapor flux with a stream of hydrogen or helium gas, enabling the in-situ generation of hydrides for use in low-pressure growth techniques where long mean free paths are desirable. Experiments were conducted to demonstrate a stable discharge within the source, and measures were identified to improve its operational characteristics. Application of this novel source is anticipated to enable a low-temperature, safe process for the growth of high-quality epitaxial compound semiconductor films. This reduction of epitaxial growth temperatures may enable the fabrication of novel photovoltaic devices that have heretofore been impossible due to the deleterious effects of interdiffusion at heterointerfaces resulting from the high temperatures required to grow adequate quality material using conventional processes.

Stanbery, B.J. [Boeing Defense & Space Group, Seattle, WA (United States)

1994-05-01T23:59:59.000Z

175

Processing of CuInSe{sub 2}-based solar cells: Characterization of deposition processes in terms of chemical reaction analyses. Phase 2 Annual Report, 6 May 1996--5 May 1997  

SciTech Connect

This report describes research performed by the University of Florida during Phase 2 of this subcontract. First, to study CIGS, researchers adapted a contactless, nondestructive technique previously developed for measuring photogenerated excess carrier lifetimes in SOI wafers. This dual-beam optical modulation (DBOM) technique was used to investigate the differences between three alternative methods of depositing CdS (conventional chemical-bath deposition [CBD], metal-organic chemical vapor deposition [MOCVD], and sputtering). Second, a critical assessment of the Cu-In-Se thermochemical and phase diagram data using standard CALPHAD procedures is being performed. The outcome of this research will produce useful information on equilibrium vapor compositions (required annealing ambients, Sex fluxes from effusion cells), phase diagrams (conditions for melt-assisted growth), chemical potentials (driving forces for diffusion and chemical reactions), and consistent solution models (extents of solid solutions and extending phase diagrams). Third, an integrated facility to fabricate CIS PV devices was established that includes migration-enhanced epitaxy (MEE) for deposition of CIS, a rapid thermal processing furnace for absorber film formation, sputtering of ZnO, CBD or MOCVD of CdS, metallization, and pattern definition.

Anderson, T.

1999-10-20T23:59:59.000Z

176

Growth of cubic SiC thin films on Si,,001... by high vacuum chemical vapor deposition using 1,3-disilabutane and an investigation of the effect of  

E-Print Network (OSTI)

Department of Chemistry, Sungkyunkwan University, Suwon 440-746, Korea K.-W. Lee, M. M. Sung, and Y. Kim Thin by sublimation and liquid phase epitaxial growth is not commer- cially available in sizes above 2 in. Moreover

Boo, Jin-Hyo

177

The Vaporization Enthalpies and Vapor Pressures of Some Primary Amines of Pharmaceutical Importance by Correlation Gas  

E-Print Network (OSTI)

by Correlation Gas Chromatography Chase Gobble, Nigam Rath, and James Chickos* Department of Chemistry Information ABSTRACT: Vapor pressures, vaporization, and sublimation enthalpies of several pharmaceuticals and boiling temperatures when available. Sublimation enthalpies and vapor pressures are also evaluated for 1

Chickos, James S.

178

Mercury Source Zone Identification using Soil Vapor Sampling and Analysis  

SciTech Connect

Development and demonstration of reliable measurement techniqes that can detect and help quantify the nature and extent of elemental mercury (Hg(0)) in the subsurface are needed to reduce certainties in the decision making process and increase the effectiveness of remedial actions. We conducted field tests at the Y-12 National Security Complex (NSC) in Oak Ridge, TN, to determine if sampling and analysis of Hg(0) vapors in the shallow subsurface (<0.3 m depth) can be used to as an indicator of the location and extent of Hg(0) releases in the subsurface. We constructed a rigid PVC pushprobe assembly, which was driven into the ground. Soil gas samples were collected through a sealed inner tube of the assembly and analyzed immediately in the field with a Lumex and/or Jerome Hg(0) analyzer. Time-series sampling showed that Hg vapor concentrations were fairly stable over time suggesting that the vapor phase Hg(0) was not being depleted and that sampling results were not dependent on the soil gas purge volume. Hg(0) vapor data collected at over 200 pushprobe locations at 3 different release sites correlated well to areas of known Hg(0) contamination. Vertical profiling of Hg(0) vapor concentrations conducted at 2 locations provided information on the vertical distribution of Hg(0) contamination in the subsurface. We concluded from our studies that soil gas sampling and analysis can be conducted rapidly and inexpensively at a large scale to help identify areas contaminated with Hg(0).

Watson, David B [ORNL] [ORNL; Miller, Carrie L [ORNL] [ORNL; Lester, Brian P [ORNL] [ORNL; Lowe, Kenneth Alan [ORNL] [ORNL; Southworth, George R [ORNL] [ORNL; Bogle, Mary Anna [ORNL] [ORNL; Liang, Liyuan [ORNL] [ORNL; Pierce, Eric M [ORNL] [ORNL

2014-01-01T23:59:59.000Z

179

van der Waals Epitaxy of MoS2 Layers Using Graphene As Growth Templates  

SciTech Connect

We present a method for synthesizing MoS{sub 2}/Graphene hybrid heterostructures with a growth template of graphene-covered Cu foil. Compared to other recent reports, a much lower growth temperature of 400 C is required for this procedure. The chemical vapor deposition of MoS{sub 2} on the graphene surface gives rise to single crystalline hexagonal flakes with a typical lateral size ranging from several hundred nanometers to several micrometers. The precursor (ammonium thiomolybdate) together with solvent was transported to graphene surface by a carrier gas at room temperature, which was then followed by post annealing. At an elevated temperature, the precursor self-assembles to form MoS{sub 2} flakes epitaxially on the graphene surface via thermal decomposition. With higher amount of precursor delivered onto the graphene surface, a continuous MoS{sub 2} film on graphene can be obtained. This simple chemical vapor deposition method provides a unique approach for the synthesis of graphene heterostructures and surface functionalization of graphene. The synthesized two-dimensional MoS{sub 2}/Graphene hybrids possess great potential toward the development of new optical and electronic devices as well as a wide variety of newly synthesizable compounds for catalysts.

Shi, Yumeng [Massachusetts Institute of Technology (MIT); Zhou, Wu [Vanderbilt University; Lu, Ang-Yu [Academia Sinica, Hefei, China; Fang, Wenjing [Massachusetts Institute of Technology (MIT); Lee, Yi-Hsien [Massachusetts Institute of Technology (MIT); Hsu, Allen Long [Massachusetts Institute of Technology (MIT); Kim, Soo Min [Massachusetts Institute of Technology (MIT); Kim, Ki Kang [Massachusetts Institute of Technology (MIT); Yang, Hui Ying [Singapore University of Technology and Design; Liang, Lain-Jong [Academia Sinica, Hefei, China; Idrobo Tapia, Juan C [ORNL; Kong, Jing [Massachusetts Institute of Technology (MIT)

2012-01-01T23:59:59.000Z

180

Interface structure and thermal stability of epitaxial SrTiO{sub 3} thin films on Si (001)  

SciTech Connect

We have used medium energy ion scattering, temperature programmed desorption, and atomic force microscopy to study the interface composition and thermal stability of epitaxial strontium titanate thin films grown by molecular-beam epitaxy on Si (001). The composition of the interface between the film and the substrate was found to be very sensitive to the recrystallization temperature used during growth, varying from a strontium silicate phase when the recrystallization temperature is low to a Ti-rich phase for a higher recrystallization temperature. The films are stable towards annealing in vacuum up to {approx}550 deg.C, where SrO desorption begins and the initially flat film starts to roughen. Significant film disintegration occurs at 850 deg.C, and is accompanied by SiO and SrO desorption, pinhole formation, and finally titanium diffusion into the silicon bulk.

Goncharova, L. V.; Starodub, D. G.; Garfunkel, E.; Gustafsson, T.; Vaithyanathan, V.; Lettieri, J.; Schlom, D. G. [Department of Physics and Astronomy, and Laboratory for Surface Modification, Rutgers University, Piscataway, New Jersey 08854 (United States); Department of Chemistry and Chemical Biology, and Laboratory for Surface Modification, Rutgers University, Piscataway, New Jersey 08854 (United States); Department of Physics and Astronomy, and Laboratory for Surface Modification, Rutgers University, Piscataway, New Jersey 08854 (United States); Department of Material Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

2006-07-01T23:59:59.000Z

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


181

VAPORIZATION THERMODYNAMICS OF KCl. COMBINING VAPOR PRESSURE AND GRAVIMETRIC DATA  

E-Print Network (OSTI)

.B. Department of Chemistry, Moscow State University, Moscow, 119899, Russia Bonnell D.W., Hastie J.W. National temperature chemistry situations, vapor pressures are typically less than 100 kPa. The molar volume is p = 101325 Pa). The subscript trs denotes that the changeisfor a transition, typically sublimation

Rudnyi, Evgenii B.

182

E-Print Network 3.0 - arsenide thin films Sample Search Results  

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

Engineering 14 Formation of etch pits during carbon doping of gallium arsenide with carbon tetrachloride by metalorganic vapor-phase epitaxy Summary: :jap.aip.orgjap...

183

Vacuum vapor deposition gun assembly  

DOE Patents (OSTI)

A vapor deposition gun assembly includes a hollow body having a cylindrical outer surface and an end plate for holding an adjustable heat sink, a hot hollow cathode gun, two magnets for steering the plasma from the gun into a crucible on the heat sink, and a shutter for selectively covering and uncovering the crucible.

Zeren, Joseph D. (Boulder, CO)

1985-01-01T23:59:59.000Z

184

LNG Vaporizer Utilizing Vacuum Steam Condensing  

Science Journals Connector (OSTI)

This report concerns the field test results of a new type of peak-shaving LNG vaporizer (VSV) whose heat source is ... heat of vacuum steam to vaporize and superheat LNG within heat transfer tubes. Prior to the.....

Y. Miyata; M. Hanamure; H. Kujirai; Y. Sato…

1991-01-01T23:59:59.000Z

185

Running-Film Vaporizer for LNG  

Science Journals Connector (OSTI)

Advances in welding technology and steel fabrication techniques have permitted the development of a new concept in cryogenic vaporizers—the running-film plate vaporizer. Although similar in heat transfer philosop...

H. H. West; G. L. Puckett

1975-01-01T23:59:59.000Z

186

Vapor Retarder Classification- Building America Top Innovation  

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

This Building America Innovations profile describes research in vapor retarders. Since 2006 the IRC has permitted Class III vapor retarders like latex paint (see list above) in all climate zones under certain conditions thanks to research by Building America teams.

187

Epitaxial oxygen sponges as low temperature catalysts | ornl.gov  

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

Functional Materials for Energy Functional Materials for Energy Epitaxial oxygen sponges as low temperature catalysts September 10, 2013 Crystal structure of SrCoO2.5 superimposed on a scanning transmission electron microscopy image of an epitaxially stabilized oxygen sponge. Fast and reversible redox reactions at considerably reduced temperatures are achieved by epitaxial stabilization of multivalent transition metal oxides. This illustrates the unprecedented potential of complex oxides for oxide-ionics, where oxidation state changes are used for energy generation, storage and electrochemical sensing. Thermomechanical degradation reduces the overall performance and lifetime of many perovskite oxides undergoing reversible redox reactions, such as those found in solid oxide fuel cells, rechargeable batteries,

188

Epitaxial-Graphene/Graphene-Oxide Junction: An Essential Step towards Epitaxial Graphene Electronics  

Science Journals Connector (OSTI)

Graphene-oxide (GO) flakes have been deposited to bridge the gap between two epitaxial-graphene electrodes to produce all-graphene devices. Electrical measurements indicate the presence of Schottky barriers at the graphene/graphene-oxide junctions, as a consequence of the band gap in GO. The barrier height is found to be about 0.7 eV, and is reduced after annealing at 180?°C, implying that the gap can be tuned by changing the degree of oxidation. A lower limit of the GO mobility was found to be 850??cm2/V?s, rivaling silicon. In situ local oxidation of patterned epitaxial graphene has been achieved.

Xiaosong Wu; Mike Sprinkle; Xuebin Li; Fan Ming; Claire Berger; Walt A. de Heer

2008-07-07T23:59:59.000Z

189

Improving chemical vapor deposition graphene conductivity using molybdenum trioxide: An in-situ field effect transistor study  

SciTech Connect

By using in situ field effect transistor characterization integrated with molecular beam epitaxy technique, we demonstrate the strong surface transfer p-type doping effect of single layer chemical vapor deposition (CVD) graphene, through the surface functionalization of molybdenum trioxide (MoO{sub 3}) layer. After doping, both the hole and electron mobility of CVD graphene are nearly retained, resulting in significant enhancement of graphene conductivity. With coating of 10 nm MoO{sub 3}, the conductivity of CVD graphene can be increased by about 7 times, showing promising application for graphene based electronics and transparent, conducting, and flexible electrodes.

Han, Cheng [Department of Physics and Institute for Advanced Study, Nanchang University, 999 Xue Fu Da Dao, Nanchang (China) [Department of Physics and Institute for Advanced Study, Nanchang University, 999 Xue Fu Da Dao, Nanchang (China); Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Lin, Jiadan; Xiang, Du [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore)] [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Wang, Chaocheng; Wang, Li [Department of Physics and Institute for Advanced Study, Nanchang University, 999 Xue Fu Da Dao, Nanchang (China)] [Department of Physics and Institute for Advanced Study, Nanchang University, 999 Xue Fu Da Dao, Nanchang (China); Chen, Wei [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore) [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 and Graphene Research Centre, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore)

2013-12-23T23:59:59.000Z

190

Vapor Pressures and Heats of Vaporization of Primary Coal Tars  

Office of Scientific and Technical Information (OSTI)

/ PC92544-18 / PC92544-18 VAPOR PRESSURES AND HEATS OF VAPORIZATION OF PRIMARY COAL TARS FINAL REPORT Grant Dates: August, 1992 - November, 1996 Principal Authors: Eric M. Suuberg (PI) and Vahur Oja Report Submitted: April, 1997 Revised: July, 1997 Grant Number: DE-FG22-92PC92544 Report Submitted by: ERIC M. SUUBERG DIVISION OF ENGINEERING BROWN UNIVERSITY PROVIDENCE, RI 02912 TEL. (401) 863-1420 Prepared For: U. S. DEPT. OF ENERGY FEDERAL ENERGY TECHNOLOGY CENTER P.O. BOX 10940 PITTSBURGH, PA 15236 DR. KAMALENDU DAS, FETC, MORGANTOWN , WV TECHNICAL PROJECT OFFICER "US/DOE Patent Clearance is not required prior to the publication of this document" ii United States Government Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any

191

Self-doping effects in epitaxially grown graphene  

E-Print Network (OSTI)

The electronic properties of graphene, Rev. Mod. Phys. (inE?ects in Epitaxially-Grown Graphene D.A. Siegel, 1, 2 S.Y.2009) Abstract Self-doping in graphene has been studied by

Siegel, David A.

2009-01-01T23:59:59.000Z

192

Desorption efficiencies of toluene and n-butanol in an organic vapor monitor  

E-Print Network (OSTI)

&jards has become one of the most important industrial hygiene f unct i one e The levei of exposure to many organic vapor;=, is det r- mined by co' lecting the chemical on some type o solid sor- bent. Of the various adsorbents available {silica gel... two of these paramet rs) ~ The objective of this re, . earch wa, . to investigate the effe ts of chemical phase (liquid or vapor) on the desorp- tion efficiencies of toluene and n-buta?ol adsorbed on acti- vated charcoal in organic vapor monitors...

Heaney, Mary Ann

2012-06-07T23:59:59.000Z

193

III-V Nanowire Array Growth by Selective Area Epitaxy  

SciTech Connect

III-V semiconductor nanowires are unique material phase due to their high aspect ratio, large surface area, and strong quantum confinement. This affords the opportunity to control charge transport and optical properties for electrical and photonic applications. Nanoscale selective area metalorganic chemical vapor deposition growth (NS-SAG) is a promising technique to maximize control of nanowire diameter and position, which are essential for device application. In this work, InP and GaAs nanowire arrays are grown by NS-SAG. We observe enhanced sidewall growth and array uniformity disorder in high growth rate condition. Disorder in surface morphology and array uniformity of InP nanowire array is explained by enhanced growth on the sidewall and stacking faults. We also find that AsH{sub 3} decomposition on the sidewall affects the growth behavior of GaAs nanowire arrays.

Chu, Hyung-Joon; Stewart, Lawrence [Ming Hsieh Department of Electrical Engineering, University of Southern California (United States); Yeh, Tingwei [Mork Family Department of Chemical Engineering and Material Science, University of Southern California 3651 Watt Way, VHE-314, Los Angeles, CA90089 (United States); Dapkus, P. Daniel [Ming Hsieh Department of Electrical Engineering, University of Southern California (United States); Mork Family Department of Chemical Engineering and Material Science, University of Southern California 3651 Watt Way, VHE-314, Los Angeles, CA90089 (United States)

2011-12-23T23:59:59.000Z

194

Vapor deposition of tantalum and tantalum compounds  

SciTech Connect

Tantalum, and many of its compounds, can be deposited as coatings with techniques ranging from pure, thermal chemical vapor deposition to pure physical vapor deposition. This review concentrates on chemical vapor deposition techniques. The paper takes a historical approach. The authors review classical, metal halide-based techniques and current techniques for tantalum chemical vapor deposition. The advantages and limitations of the techniques will be compared. The need for new lower temperature processes and hence new precursor chemicals will be examined and explained. In the last section, they add some speculation as to possible new, low-temperature precursors for tantalum chemical vapor deposition.

Trkula, M. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.

1996-04-01T23:59:59.000Z

195

Means and method for vapor generation  

DOE Patents (OSTI)

A liquid, in heat transfer contact with a surface heated to a temperature well above the vaporization temperature of the liquid, will undergo a multiphase (liquid-vapor) transformation from 0% vapor to 100% vapor. During this transition, the temperature driving force or heat flux and the coefficients of heat transfer across the fluid-solid interface, and the vapor percentage influence the type of heating of the fluid--starting as "feedwater" heating where no vapors are present, progressing to "nucleate" heating where vaporization begins and some vapors are present, and concluding with "film" heating where only vapors are present. Unstable heating between nucleate and film heating can occur, accompanied by possibly large and rapid temperature shifts in the structures. This invention provides for injecting into the region of potential unstable heating and proximate the heated surface superheated vapors in sufficient quantities operable to rapidly increase the vapor percentage of the multiphase mixture by perhaps 10-30% and thereby effectively shift the multiphase mixture beyond the unstable heating region and up to the stable film heating region.

Carlson, Larry W. (Oswego, IL)

1984-01-01T23:59:59.000Z

196

Results of Soil Vapor Extraction of a Chlorinated Solvent Dnapl Waste Site at the Rocky Flats Superfund Site  

Science Journals Connector (OSTI)

A full scale Soil Vapor Extraction (SVE) system was evaluated for remediation of subsurface contamination of the chlorinated Dense Non-Aqueous Phase Liquids (DNAPL) at a waste site at the Rocky Flats Environmenta...

S. Grace; E. Dille

1995-01-01T23:59:59.000Z

197

Shock formation in the collapse of a vapor nano-bubble  

E-Print Network (OSTI)

In this paper a diffuse-interface model featuring phase change, transition to supercritical conditions, thermal conduction, compressibility effects and shock wave propagation is exploited to deal with the dynamics of a cavitation bubble. At variance with previous descriptions, the model is uniformly valid for all phases (liquid, vapor and supercritical) and phase transitions involved, allowing to describe the non-equilibrium processes ongoing during the collapse. As consequence of this unitary description, rather unexpectedly for pure vapor bubbles, the numerical experiments show that the collapse is accompanied by the emission of a strong shock wave in the liquid and by the oscillation of the bubble that periodically disappears and reappears, due to transition to super/sub critical conditions. The mechanism of shock wave formation is strongly related to the transition of the vapor to supercritical state, with a progressive steepening of the compression wave to form the shock which is eventually reflected as ...

Magaletti, Francesco; Casciola, Carlo Massimo

2014-01-01T23:59:59.000Z

198

Growth of Epitaxial Thin Pd(111) Films on Pt(111) and Oxygen...  

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

Growth of Epitaxial Thin Pd(111) Films on Pt(111) and Oxygen-Terminated FeO(111) Surfaces . Growth of Epitaxial Thin Pd(111) Films on Pt(111) and Oxygen-Terminated FeO(111)...

199

Wick for metal vapor laser  

DOE Patents (OSTI)

An improved wick for a metal vapor laser is made of a refractory metal cylinder, preferably molybdenum or tungsten for a copper laser, which provides the wicking surface. Alternately, the inside surface of the ceramic laser tube can be metalized to form the wicking surface. Capillary action is enhanced by using wire screen, porous foam metal, or grooved surfaces. Graphite or carbon, in the form of chunks, strips, fibers or particles, is placed on the inside surface of the wick to reduce water, reduce metal oxides and form metal carbides.

Duncan, David B. (Livermore, CA)

1992-01-01T23:59:59.000Z

200

Non-Vapor Compression HVAC Technologies Report  

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

While vapor-compression technologies have served heating, ventilation, and air-conditioning (HVAC) needs very effectively, and have been the dominant HVAC technology for close to 100 years, the conventional refrigerants used in vapor-compression equipment contribute to global climate change when released to the atmosphere. The Building Technologies Office is evaluating low-global warming potential (GWP) alternatives to vapor-compression technologies.

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


201

Mercury Vapor (Kooten, 1987) | Open Energy Information  

Open Energy Info (EERE)

Mercury Vapor (Kooten, 1987) Mercury Vapor (Kooten, 1987) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Mercury Vapor (Kooten, 1987) Exploration Activity Details Location Unspecified Exploration Technique Mercury Vapor Activity Date Usefulness useful DOE-funding Unknown Notes Surface soil-mercury surveys are an inexpensive and useful exploration tool for geothermal resources. ---- Surface geochemical surveys for mercury were conducted in 16 areas in 1979-1981 by ARCO Oil and Gas Company as part of its geothermal evaluation program. Three techniques used together have proved satisfactory in evaluating surface mercury data. These are contouring, histograms and cumulative frequency plots of the data. Contouring geochemical data and constructing histograms are standard

202

Thin crystalline silicon solar cells based on epitaxial films grown at 165C by RF PECVD  

E-Print Network (OSTI)

1 Thin crystalline silicon solar cells based on epitaxial films grown at 165°C by RF PECVD Romain temperatures. Keywords : Low temperature, epitaxy, PECVD, Si thin film, Solar cell hal-00749873,version1-25Nov shortage until 2010. Research on epitaxial growth for thin film crystalline silicon solar cells has gained

203

Near real time vapor detection and enhancement using aerosol adsorption  

SciTech Connect

A vapor sample detection method where the vapor sample contains vapor and ambient air and surrounding natural background particles. The vapor sample detection method includes the steps of generating a supply of aerosol that have a particular effective median particle size, mixing the aerosol with the vapor sample forming aerosol and adsorbed vapor suspended in an air stream, impacting the suspended aerosol and adsorbed vapor upon a reflecting element, alternatively directing infrared light to the impacted aerosol and adsorbed vapor, detecting and analyzing the alternatively directed infrared light in essentially real time using a spectrometer and a microcomputer and identifying the vapor sample.

Novick, Vincent J.; Johnson, Stanley A.

1997-12-01T23:59:59.000Z

204

Near real time vapor detection and enhancement using aerosol adsorption  

DOE Patents (OSTI)

A vapor sample detection method is described where the vapor sample contains vapor and ambient air and surrounding natural background particles. The vapor sample detection method includes the steps of generating a supply of aerosol that have a particular effective median particle size, mixing the aerosol with the vapor sample forming aerosol and adsorbed vapor suspended in an air stream, impacting the suspended aerosol and adsorbed vapor upon a reflecting element, alternatively directing infrared light to the impacted aerosol and adsorbed vapor, detecting and analyzing the alternatively directed infrared light in essentially real time using a spectrometer and a microcomputer and identifying the vapor sample. 13 figs.

Novick, V.J.; Johnson, S.A.

1999-08-03T23:59:59.000Z

205

Near real time vapor detection and enhancement using aerosol adsorption  

DOE Patents (OSTI)

A vapor sample detection method where the vapor sample contains vapor and ambient air and surrounding natural background particles. The vapor sample detection method includes the steps of generating a supply of aerosol that have a particular effective median particle size, mixing the aerosol with the vapor sample forming aerosol and adsorbed vapor suspended in an air stream, impacting the suspended aerosol and adsorbed vapor upon a reflecting element, alternatively directing infrared light to the impacted aerosol and adsorbed vapor, detecting and analyzing the alternatively directed infrared light in essentially real time using a spectrometer and a microcomputer and identifying the vapor sample.

Novick, Vincent J. (Downers Grove, IL); Johnson, Stanley A. (Countryside, IL)

1999-01-01T23:59:59.000Z

206

G-Band Vapor Radiometer Precipitable Water Vapor (GVRPWV) Value-Added Product  

SciTech Connect

The G-Band Vapor Radiometer Precipitable Water Vapor (GVRPWV) value-added product (VAP) computes precipitable water vapor using neural network techniques from data measured by the GVR. The GVR reports time-series measurements of brightness temperatures for four channels located at 183.3 ± 1, 3, 7, and 14 GHz.

Koontz, A; Cadeddu, M

2012-12-05T23:59:59.000Z

207

Substrate-Induced Band-Gap Opening in Epitaxial Graphene  

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

Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic devices, have to overcome silicon's superb collection of materials properties as well as sophisticated fabrication technologies refined by six decades of effort by materials scientists and engineers. Graphene, one of the latest contenders, has a rather impressive list of features of its own but has lacked a key characteristic of all semiconductors, an energy gap (band gap) in its electronic band structure. A multi-institutional collaboration under the leadership of researchers with Berkeley Lab and the University of California, Berkeley, have now demonstrated that growing an epitaxial film of graphene on a silicon carbide substrate results in a significant band gap, 0.26 electron volts (eV), an important step toward making graphene useful as a semiconductor.

208

Substrate-Induced Band-Gap Opening in Epitaxial Graphene  

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

Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic devices, have to overcome silicon's superb collection of materials properties as well as sophisticated fabrication technologies refined by six decades of effort by materials scientists and engineers. Graphene, one of the latest contenders, has a rather impressive list of features of its own but has lacked a key characteristic of all semiconductors, an energy gap (band gap) in its electronic band structure. A multi-institutional collaboration under the leadership of researchers with Berkeley Lab and the University of California, Berkeley, have now demonstrated that growing an epitaxial film of graphene on a silicon carbide substrate results in a significant band gap, 0.26 electron volts (eV), an important step toward making graphene useful as a semiconductor.

209

Structure and features of the surface morphology of A{sup 4}B{sup 6} chalcogenide epitaxial films  

SciTech Connect

The structure and features of the surface morphology of Pb{sub 1-x}Mn{sub x}Se (x = 0.03) epitaxial films grown on freshly cleaved BaF{sub 2}(111) faces and PbSe{sub 1-x}S{sub x}(100) (x = 0.12) single-crystal wafers were investigated by molecular beam condensation and the hot-wall method. It is shown that the epitaxial films, in accordance with the data in the literature for other chalcogenides, grow in the (111) and (100) planes, repeating the substrate orientation. Black aggregates are observed on the film surface of the films grown. The results obtained are compared with the data in the literature and generalized for other chalcogenides: A{sup 4}B{sup 6}:Pb (S, Se, Te); Pb{sub 1-x}Sn{sub x} (S, Se, Te); and Pb{sub 1-x}Mn (Se, Te). It is established that the formation of black aggregates, which are second-phase inclusions on the surface of epitaxial films obtained by vacuum thermal deposition, is characteristic of narrow-gap A{sup 4}B{sup 6} chalcogenides.

Nuriyev, I. R., E-mail: afinnazarov@yahoo.com [Azerbaijan National Academy of Sciences, Institute of Physics (Azerbaijan)

2009-12-15T23:59:59.000Z

210

Phase transitions of helium in aerogel  

Science Journals Connector (OSTI)

The effect of dilute quenched impurities on the liquid-vapor critical point, superfluid and He3?He4 phase separation transitions were studied by introducing liquid helium into aerogel. Aerogel is a highly porous ...

M. H. W. Chan

1996-01-01T23:59:59.000Z

211

A molecular beam epitaxy facility for in situ neutron scattering  

SciTech Connect

A molecular beam epitaxy (MBE) facility has been built to enable in situ neutron scattering measurements during growth of epitaxial layers. While retaining the full capabilities of a research MBE chamber, this facility has been optimized for polarized neutron reflectometry measurements. Optimization includes a compact lightweight portable design, a neutron window, controllable magnetic field, deposition across a large 76 mm diameter sample with exceptional flux uniformity, and sample temperatures continuously controllable from 38 to 1375 K. A load lock chamber allows for sample insertion, storage of up to 4 samples, and docking with other facilities. The design and performance of this chamber are described here.

Dura, J. A.; LaRock, J. [NIST Center for Neutron Research, 100 Bureau Dr. MS 6102, Gaithersburg, Maryland 20899 6102 (United States)

2009-07-15T23:59:59.000Z

212

Quantitative organic vapor-particle sampler  

DOE Patents (OSTI)

A quantitative organic vapor-particle sampler for sampling semi-volatile organic gases and particulate components. A semi-volatile organic reversible gas sorbent macroreticular resin agglomerates of randomly packed microspheres with the continuous porous structure of particles ranging in size between 0.05-10 .mu.m for use in an integrated diffusion vapor-particle sampler.

Gundel, Lara (Berkeley, CA); Daisey, Joan M. (Walnut Creek, CA); Stevens, Robert K. (Cary, NC)

1998-01-01T23:59:59.000Z

213

LNG fire and vapor control system technologies  

SciTech Connect

This report provides a review of fire and vapor control practices used in the liquefied natural gas (LNG) industry. Specific objectives of this effort were to summarize the state-of-the-art of LNG fire and vapor control; define representative LNG facilities and their associated fire and vapor control systems; and develop an approach for a quantitative effectiveness evaluation of LNG fire and vapor control systems. In this report a brief summary of LNG physical properties is given. This is followed by a discussion of basic fire and vapor control design philosophy and detailed reviews of fire and vapor control practices. The operating characteristics and typical applications and application limitations of leak detectors, fire detectors, dikes, coatings, closed circuit television, communication systems, dry chemicals, water, high expansion foam, carbon dioxide and halogenated hydrocarbons are described. Summary descriptions of a representative LNG peakshaving facility and import terminal are included in this report together with typical fire and vapor control systems and their locations in these types of facilities. This state-of-the-art review identifies large differences in the application of fire and vapor control systems throughout the LNG industry.

Konzek, G.J.; Yasutake, K.M.; Franklin, A.L.

1982-06-01T23:59:59.000Z

214

ARM - Field Campaign - Water Vapor IOP  

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

govCampaignsWater Vapor IOP govCampaignsWater Vapor IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Water Vapor IOP 2000.09.18 - 2000.10.08 Lead Scientist : Henry Revercomb Data Availability Yes For data sets, see below. Description Scientific hypothesis: 1. Microwave radiometer (MWR) observations of the 22 GHz water vapor line can accurately constrain the total column amount of water vapor (assuming a calibration accuracy of 0.5 degC or better, which translates into 0.35 mm PWV). 2. Continuous profiling by Raman lidar provides a stable reference for handling sampling problems and observes a fixed column directly above the site only requiring a single height- independent calibration factor. 3. Agreement between the salt-bath calibrated in-situ probes, chilled

215

Energy balance in laser-irradiated vaporizing droplets  

Science Journals Connector (OSTI)

The interactions of vaporizing aerosols with a high energy laser beam are analyzed in the diffusive vaporization regime. This is the regime in which diffusive mass transport and...

Zardecki, Andrew; Armstrong, Robert L

1988-01-01T23:59:59.000Z

216

Ground Gravity Survey At Cove Fort Area - Vapor (Warpinski, Et...  

Open Energy Info (EERE)

Vapor (Warpinski, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Ground Gravity Survey At Cove Fort Area - Vapor (Warpinski, Et...

217

Hydrogen-Bond Acidic Polymers for Chemical Vapor Sensing. | EMSL  

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

Acidic Polymers for Chemical Vapor Sensing. Hydrogen-Bond Acidic Polymers for Chemical Vapor Sensing. Abstract: A review with 171 references. Hydrogen-bond acidic polymers for...

218

Reduced gravity rankine cycle design and optimization with passive vortex phase separation  

E-Print Network (OSTI)

. Potential drawbacks to the technology in a reduced gravity environment include two-phase fluid management processes such as liquid-vapor phase separation. The most critical location for phase separation is at the boiler exit where only vapor must be sent...

Supak, Kevin Robert

2009-05-15T23:59:59.000Z

219

Multiperiod quantum-cascade nanoheterostructures: Epitaxy and diagnostics  

SciTech Connect

Advances in the production technology of multiperiod nanoheterostructures of quantum-cascade lasers with 60 cascades by molecular-beam epitaxy (MBE) on an industrial multiple-substrate MBE machine are discussed. The results obtained in studying the nanoheterostructures of quantum-cascade lasers by transmission electron microscopy, high-resolution X-ray diffraction analysis, and photoluminescence mapping are presented.

Egorov, A. Yu., E-mail: Anton@beam.ioffe.ru; Brunkov, P. N.; Nikitina, E. V.; Pirogov, E. V.; Sobolev, M. S.; Lazarenko, A. A. [Russian Academy of Sciences, St. Petersburg Academic University, Nanotechnology Research and Education Center (Russian Federation); Baidakova, M. V.; Kirilenko, D. A.; Konnikov, S. G. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

2014-12-15T23:59:59.000Z

220

Epitaxial silicide formation on recoil-implanted substrates  

SciTech Connect

An epitaxy-on-recoil-implanted-substrate (ERIS) technique is presented. A disordered surface layer, generated by forward recoil implantation of {approx}0.7-3x10{sup 15} cm{sup -2} of oxygen during Ar plasma etching of surface oxide, is shown to facilitate the subsequent epitaxial growth of {approx}25-35-nm-thick CoSi{sub 2} layers on Si(100). The dependence of the epitaxial fraction of the silicide on the recoil-implantation parameters is studied in detail. A reduction in the silicide reaction rate due to recoil-implanted oxygen is shown to be responsible for the observed epitaxial formation, similar to mechanisms previously observed for interlayer-mediated growth techniques. Oxygen is found to remain inside the fully reacted CoSi{sub 2} layer, likely in the form of oxide precipitates. The presence of these oxide precipitates, with only a minor effect on the sheet resistance of the silicide layer, has a surprisingly beneficial effect on the thermal stability of the silicide layers. The agglomeration of ERIS-grown silicide layers on polycrystalline Si is significantly suppressed, likely from a reduced diffusivity due to oxygen in the grain boundaries. The implications of the present technique for the processing of deep submicron devices are discussed.

Hashimoto, Shin; Egashira, Kyoko; Tanaka, Tomoya; Etoh, Ryuji; Hata, Yoshifumi; Tung, R. T. [Corporate Manufacturing and Development Division, Semiconductor Company, Matsushita Electric Industrial Co., Ltd., Kyoto 617-8520 (Japan); Department of Physics, Brooklyn College, City University of New York, Brooklyn, New York 11210 (United States)

2005-01-15T23:59:59.000Z

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


221

Cantilever Epitaxy Process Wins R&D 100 Award  

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

Sandia National Laboratories received an R&D 100 Award from R&D Magazine for development of a new process for growing gallium nitride on an etched sapphire substrate. The process, called cantilever epitaxy, promises to make brighter and more efficient green, blue, and white LEDs.

222

MODELLING AND SIMULATION OF LIQUID-VAPOR PHASE TRANSITION  

E-Print Network (OSTI)

Generator Turbine Generator Cooling Tower Condenser Cooling Water Pump Reactor Core Reactor Vessel Control and Steam (secondary loop) Water (cooling loop) Pump Steam Generator Turbine Generator Cooling Tower Water pressurized (primary loop) Water and Steam (secondary loop) Water (cooling loop) Pump Steam

Faccanoni, Gloria

223

Materials basis for a six-level epitaxial HTS digital circuit process  

SciTech Connect

We have developed a process for fabrication of HTS single-flux-quantum logic circuits based on edge SNS junctions which requires six epitaxial film layers and six mask levels. The process was successfully applied to fabrication of small-scale circuits ({le} 10 junctions). This paper examines the materials properties affecting the reproducibility of YBCO-based SNS junctions, the low inductance provided by an integrated YBCO ground plane, and electrical isolation by SrTiO{sub 3} or SrAlTaO{sub 6} ground-plane and junction insulator layers. Some of the critical processing parameters identified by electrical measurements, TEM, SEM, and AFM were control of second-phase precipitates in YBCO, oxygen diffusion, Ar ion milling parameters, and preparation of surfaces for subsequent high-temperature depositions.

Talvacchio, J.; Forrester, M.G.; Hunt, B.D. [Northrop Grumman Science and Technology Center, Pittsburgh, PA (United States)] [and others

1996-12-31T23:59:59.000Z

224

Selective adsorption and electronic interaction of F16CuPc on epitaxial graphene  

Science Journals Connector (OSTI)

We investigate the electronic coupling between copper hexadecafluoro-phthalocyanine (F16CuPc) and epitaxial graphene (EG) on 6H-SiC(0001) using a combined approach of low-temperature scanning tunneling spectroscopy and electronic structure calculations. The molecules are preferentially adsorbed on monolayer EG than bilayer EG. Competing molecule-surface and intermolecular van der Waals interactions result in two well-ordered incommensurate phases. We show that the amount of charge transfer from EG to F16CuPc can be tuned by applied voltage or the thickness of graphene layers. A characteristic feature at ?0.4?eV above the Dirac point is identified in bilayer EG, which indicates its electronic structure is modified via introducing extra unoccupied states upon adsorption.

Yi-Lin Wang; Jun Ren; Can-Li Song; Ye-Ping Jiang; Li-Li Wang; Ke He; Xi Chen; Jin-Feng Jia; Sheng Meng; Efthimios Kaxiras; Qi-Kun Xue; Xu-Cun Ma

2010-12-14T23:59:59.000Z

225

Engineering coercivity in epitaxially grown (110) films of DyFe 2 –YFe 2 superlattices  

Science Journals Connector (OSTI)

Molecular beam epitaxial methods have been used to growsingle crystal Laves phase DyFe 2 –YFe 2 superlattice samples with a (110) growth direction. It is shown that it is possible in principle to engineer a desired coercivity between the limits K DyFe 2 ?K??. This can be achieved by adjusting the relative thickness of the individual DyFe 2 and YFe 2 layers in multilayerfilms This novel feature is illustrated using the superlatticefilms [x?Å? DyFe 2 /(100-x)?Å? YFe 2 ]×40 with x=80 60 50 and 45. It is found that the measured coercivity is in semiquantitative agreement with a simple theoretical expression for the nucleation fields in both bilayer and multilayer compounds. However in practice exchange spring penetration into the DyFe 2 layers can set a limit to the maximum coercivity that can be achieved.

M. Sawicki; G. J. Bowden; P. A. J. de Groot; B. D. Rainford; J. M. L. Beaujour; R. C. C. Ward; M. R. Wells

2000-01-01T23:59:59.000Z

226

Luminescent Properties of CdS Crystals Doped with Gallium and Tellurium in Cadmium Vapor  

Science Journals Connector (OSTI)

A technique is devised for vapor-phase doping CdS in the quaternary system Cd–Ga–Te–S. CdS crystals are doped with Ga and Te via four-zone ... and Cd (the more volatile component of CdS). The luminescence spectra...

I. N. Odin; M. V. Chukichev; M. E. Rubina

2003-07-01T23:59:59.000Z

227

Water Vapor Radiometry : Outline of Goals and Tasks for the Spring Semester 2001  

E-Print Network (OSTI)

that can accu­ rately measure the spectrum of the water vapor emis­ sion. The current receivers follow, as in a conventional re­ ceiver, the correlation receiver splits the rf signal into two with a splitter that follows the feed horn. Both branches are mixed with a carefully controlled ther­ mal load. A 180 ffi phase shift

Backer, Don

228

Capillary waves and the inherent density profile for the liquid-vapor interface  

E-Print Network (OSTI)

. This approach in turn allows: (1) identification of an "outermost layer" of particles on the liquid. (2). is a nonmonotonic function of normal distance through the interface. and is expected to reflect the diverging bulk distribution for the system in a state of liquid-vapor phase coexistence. This leads to identification

Stillinger, Frank

229

Recovering hydrocarbons from hydrocarbon-containing vapors  

DOE Patents (OSTI)

Values are recovered from a hydrocarbon-containing vapor by contacting the vapor with quench liquid consisting essentially of hydrocarbons to form a condensate and a vapor residue, the condensate and quench fluid forming a combined liquid stream. The combined liquid stream is mixed with a viscosity-lowering liquid to form a mixed liquid having a viscosity lower than the viscosity of the combined liquid stream to permit easy handling of the combined liquid stream. The quench liquid is a cooled portion of the mixed liquid. Viscosity-lowering liquid is separated from a portion of the mixed liquid and cycled to form additional mixed liquid.

Mirza, Zia I. (La Verne, CA); Knell, Everett W. (Los Alamitos, CA); Winter, Bruce L. (Danville, CA)

1980-09-30T23:59:59.000Z

230

Chemical vapor detection using nanomechanical platform  

Science Journals Connector (OSTI)

For high sensitive and multiplexed chemical analysis, an opto-mechanical detection platform has been built. To check the performance of the platform, we performed water vapor response measurements for ... sensors...

S. H. Lim

2007-11-01T23:59:59.000Z

231

Chemical vapor deposition of functionalized isobenzofuran polymers  

E-Print Network (OSTI)

This thesis develops a platform for deposition of polymer thin films that can be further tailored by chemical surface modification. First, we explore chemical vapor deposition of functionalized isobenzofuran films using ...

Olsson, Ylva Kristina

2007-01-01T23:59:59.000Z

232

Chemical Vapor Deposition Epitaxy of Silicon and Silicon-Carbon Alloys at High Rates and Low Temperatures using Neopentasilane  

E-Print Network (OSTI)

dichlorosilane (slowest) to silane (SiH4) to disilane (Si2H6) (data from our lab) to trisilane (Si3H8) (Ref 2

233

High Growth Rate of Epitaxial Silicon-Carbon Alloys by High-Order Silane Precursor and Chemical Vapor Deposition  

E-Print Network (OSTI)

rates typically achieved by disilane and silane, respectively, at 575o C. The rate at present is limited precursor HOS than disilane in CVD, even at lower temperatures. Our current growth rates of Si1-yCy alloys

234

Vapor Power Systems MAE 4263 Final Exam  

E-Print Network (OSTI)

Vapor Power Systems MAE 4263 Final Exam Wednesday, May 5, 2004 Prof. P.M. Moretti Key Instructions, then think, then write! 1. What is the dewpoint of the exhaust of your car, if the gasoline consists2 so that the mole fraction of water vapor is yH2 O = 9 9 + 8 + 47 = 0:14063 pH2 O = 0:14063 14

235

Optical monitor for water vapor concentration  

DOE Patents (OSTI)

A system for measuring and monitoring water vapor concentration in a sample uses as a light source an argon discharge lamp, which inherently emits light with a spectral line that is close to a water vapor absorption line. In a preferred embodiment, the argon line is split by a magnetic field parallel to the direction of light propagation from the lamp into sets of components of downshifted and upshifted frequencies of approximately 1575 Gauss. The downshifted components are centered on a water vapor absorption line and are thus readily absorbed by water vapor in the sample; the upshifted components are moved away from that absorption line and are minimally absorbed. A polarization modulator alternately selects the upshifted components or downshifted components and passes the selected components to the sample. After transmission through the sample, the transmitted intensity of a component of the argon line varies as a result of absorption by the water vapor. The system then determines the concentration of water vapor in the sample based on differences in the transmitted intensity between the two sets of components. In alternative embodiments alternate selection of sets of components is achieved by selectively reversing the polarity of the magnetic field or by selectively supplying the magnetic field to the emitting plasma. 5 figs.

Kebabian, P.

1998-06-02T23:59:59.000Z

236

Optical monitor for water vapor concentration  

DOE Patents (OSTI)

A system for measuring and monitoring water vapor concentration in a sample uses as a light source an argon discharge lamp, which inherently emits light with a spectral line that is close to a water vapor absorption line. In a preferred embodiment, the argon line is split by a magnetic field parallel to the direction of light propagation from the lamp into sets of components of downshifted and upshifted frequencies of approximately 1575 Gauss. The downshifted components are centered on a water vapor absorption line and are thus readily absorbed by water vapor in the sample; the upshifted components are moved away from that absorption line and are minimally absorbed. A polarization modulator alternately selects the upshifted components or downshifted components and passes the selected components to the sample. After transmission through the sample, the transmitted intensity of a component of the argon line varies as a result of absorption by the water vapor. The system then determines the concentration of water vapor in the sample based on differences in the transmitted intensity between the two sets of components. In alternative embodiments alternate selection of sets of components is achieved by selectively reversing the polarity of the magnetic field or by selectively supplying the magnetic field to the emitting plasma.

Kebabian, Paul (Acton, MA)

1998-01-01T23:59:59.000Z

237

Synthetic IIuid inclusions in natural quartz. III. Determination of phase equilibrium properties in the system H,O-NaCI to 1000C and 1500 bars  

E-Print Network (OSTI)

and a lower salinity vapor phase and produce coexisting halite-bearing and vapor-rich fluid inclusions with shallow intrusions. particularly the porphyry copper deposits, in which halite-bearing and coexisting

Bodnar, Robert J.

238

CORRELATIONS BETWEEN VAPOR SATURATION, FLUID COMPOSITION, AND WELL DECLINE IN LARDERELLO  

SciTech Connect

A large body of field data from Larderello shows striking temporal correlations between decline of well flow-rate, produced gas/steam ratio, chloride concentration and produced vapor fraction. The latter is inferred from measured concentrations of non-condensible gases in samples of well fluid, using chemical phase equilibrium principles. Observed temporal changes in the vapor fractions can be interpreted in term of a ''multiple source'' model, as suggested by D'Amore and Truesdell (1979). This provides clues to the dynamics of reservoir depletion, and to the evaluation of well productivity and longevity.

D'Amore, F.; Pruess, K.

1985-01-22T23:59:59.000Z

239

Faceted ceramic fibers, tapes or ribbons and epitaxial devices therefrom  

DOE Patents (OSTI)

A crystalline article includes a single-crystal ceramic fiber, tape or ribbon. The fiber, tape or ribbon has at least one crystallographic facet along its length, which is generally at least one meter long. In the case of sapphire, the facets are R-plane, M-plane, C-plane or A-plane facets. Epitaxial articles, including superconducting articles, can be formed on the fiber, tape or ribbon.

Goyal, Amit

2013-07-09T23:59:59.000Z

240

Microwave studies of weak localization and antilocalization in epitaxial graphene  

SciTech Connect

A microwave detection method was applied to study weak localization and antilocalization in epitaxial graphene sheets grown on both polarities of SiC substrates. Both coherence and scattering length values were obtained. The scattering lengths were found to be smaller for graphene grown on C-face of SiC. The decoherence rate was found to depend linearly on temperature, showing the electron-electron scattering mechanism.

Drabi?ska, Aneta; Kami?ska, Maria [Faculty of Physics, University of Warsaw, ul. Ho?a 69, 00-681 Warsaw (Poland); Wo?o?, Agnieszka [Faculty of Physics, University of Warsaw, ul. Ho?a 69, 00-681 Warsaw, Poland and Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Strupinski, Wlodek [Institute of Electronic Materials Technology, ul. Wólczyñska 133, 01-919 Warsaw (Poland); Baranowski, J. M. [Faculty of Physics, University of Warsaw, ul. Ho?a 69, 00-681 Warsaw, Poland and Institute of Electronic Materials Technology, ul. Wólczyñska 133, 01-919 Warsaw (Poland)

2013-12-04T23:59:59.000Z

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


241

Faceted ceramic fibers, tapes or ribbons and epitaxial devices therefrom  

DOE Patents (OSTI)

A crystalline article includes a single-crystal ceramic fiber, tape or ribbon. The fiber, tape or ribbon has at least one crystallographic facet along its length, which is generally at least one meter long. In the case of sapphire, the facets are R-plane, M-plane, C-plane or A-plane facets. Epitaxial articles, including superconducting articles, can be formed on the fiber, tape or ribbon.

Goyal, Amit (Knoxville, TN)

2012-07-24T23:59:59.000Z

242

Vapor Pressures and Vaporization, Sublimation, and Fusion Enthalpies of Some Fatty Acids  

E-Print Network (OSTI)

Vapor Pressures and Vaporization, Sublimation, and Fusion Enthalpies of Some Fatty Acids Joe A. Wilson and James S. Chickos* Department of Chemistry and Biochemistry, University of MissouriSt. Louis, St. Louis, Missouri 63121, United States *S Supporting Information ABSTRACT: Sublimation enthalpies

Chickos, James S.

243

Vapor Pressures and Vaporization Enthalpies of a Series of Dialkyl Phthalates by Correlation Gas Chromatography  

E-Print Network (OSTI)

Chromatography Chase Gobble and James Chickos* Department of Chemistry and Biochemistry University of Missouri-St. Louis, St. Louis Missouri 63121, United States Sergey P. Verevkin Department of Physical Chemistry: Experimental vapor pressures, vaporization, fusion and sublimation enthalpies of a number of dialkyl

Chickos, James S.

244

Epitaxial HTS bolometers on silicon for IR detection  

SciTech Connect

Silicon wafers have shown promise for the fabrication of photothermal IR detectors (i.e., bolometers) from epitaxial HTS thin films of YBa{sub 2}Cu{sub 3}O{sub (7{minus}{delta})} (YBCO). Conventional IC-grade wafers, ultrathin wafers, and micromachined-silicon membrane windows in conventional wafers, are all suitable, but the latter provides considerable advantage for bolometer performance. The high thermal conductivity and strength of silicon make it ideal for submicron-thick window designs. Epitaxy in the HTS film is advantageous, since it reduces granular disorder, the primary cause of dark noise (resistance-fluctuations) in the detector. Mid-to-far-IR transparency of Si at 90 K is unique among those substrates that support high-quality epitaxial YBCO films. This Si transparency to IR can be used for various improvements in the optical design of these devices. The authors review the thermal and optical advantages of silicon substrates, device fabrication issues, and bolometer modeling. Thermal modeling of membrane bolometers indicates that the steady-state temperature-rise profile is nonuniform, but that this does not degrade the response linearity of the bolometer. Certain size limits and trade-offs in the design, will be important in the final device performance. They also discuss applications to FTIR instruments, and extensions of this technology to arrays including a novel on-chip transform spectrometer design.

Fenner, D.B.; Li, Q.; Hamblen, W.D.; Luo, J.; Hamblen, D.G. [AFR, Inc., East Hartford, CT (United States). Superconductivity Group; Budnick, J.I. [Univ. of Connecticut, Storrs, CT (United States). Dept. of Physics

1994-12-31T23:59:59.000Z

245

Magneto-transport properties of InAs nanowires laterally-grown by selective area molecular beam epitaxy on GaAs (110) masked substrates  

SciTech Connect

We prepared InAs nanowires (NWs) by lateral growth on GaAs (110) masked substrates in molecular beam epitaxy. We measured magneto-transport properties of the InAs NWs. In spite of parallel-NW multi-channels, we observed fluctuating magneto-conductance. From the fluctuation, we evaluated phase coherence length as a function of measurement temperature, and found decrease in the length with increase in the temperature. We also evaluate phase coherence length as a function of gate voltage.

Akabori, M.; Yamada, S. [Center for Nano-Materials and Technology, Japan Advanced Institute of Science and Technology, 1-1, Asahidai, Nomi, Ishikawa 923-1292 (Japan)

2013-12-04T23:59:59.000Z

246

The influence of ice nucleation mode and ice vapor growth on simulation of  

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

The influence of ice nucleation mode and ice vapor growth on simulation of The influence of ice nucleation mode and ice vapor growth on simulation of arctic mixed-phase clouds Avramov, Alexander The Pennsylvania State University Category: Modeling Mixed-phase arctic stratus clouds are the predominant cloud type in the Arctic . Perhaps one of the most intriguing of their features is that they tend to have liquid tops that precipitate ice. Despite the fact that this situation is colloidally unstable, these cloud systems are quite long lived - from a few days to over a couple of weeks. Previous studies have suggested that this longevity may be due to a paucity of ice nucleating aerosols (ice nuclei, or IN) in the Arctic. Such studies have shown that small changes in IN concentrations can cause large changes in the amount of liquid water within a mixed-phase stratus deck. We use the Regional

247

Giant magnetoresistive structures based on CrO{sub 2} with epitaxial RuO{sub 2} as the spacer layer  

SciTech Connect

Epitaxial ruthenium dioxide (RuO{sub 2})/chromium dioxide(CrO{sub 2}) thin film heterostructures have been grown on (100)-TiO{sub 2} substrates by chemical vapor deposition. Both current-in-plane (CIP) and current-perpendicular-to-plane (CPP) giant magnetoresistive stacks were fabricated with either Co or another epitaxial CrO{sub 2} layer as the top electrode. The Cr{sub 2}O{sub 3} barrier, which forms naturally on CrO{sub 2} surfaces, is no longer present after the RuO{sub 2} deposition, resulting in a highly conductive interface that has a resistance at least four orders of magnitude lower. However, only very limited magnetoresistance (MR) was observed. Such low MR is due to the appearance of a chemically and magnetically disordered layer at the CrO{sub 2} and RuO{sub 2} interfaces when Cr{sub 2}O{sub 3} is transformed into rutile structures during its intermixing with RuO{sub 2}.

Miao, G.X.; Gupta, A.; Sims, H.; Butler, W.H.; Ghosh, S.; Xiao Gang [Physics Department, Brown University, Providence, Rhode Island 02912 (United States); Center for Materials for Information Technology, University of Alabama, Tuscaloosa, Alabama 35487 (United States); Department of Electrical and Computer Engineering, University of Illinois, Chicago, Illinois 60607 (United States); Physics Department, Brown University, Providence, Rhode Island 02912 (United States)

2005-05-15T23:59:59.000Z

248

Atomic-level investigation of the growth of Si/Ge by ultrahigh vacuum chemical vapor deposition  

SciTech Connect

Si and Ge films can be prepared under ultrahigh vacuum conditions by chemical vapor deposition using disilane and digermane as source gases. These gases offer a high sticking probability, and are suitable for atomic layer epitaxy. Using synchrotron radiation photoemission spectroscopy and scanning tunneling microscopy, we have examined the surface processes associated with the heteroepitaxial growth of Ge/Si. The measured surface-induced shifts and chemical shifts of the Si 2p and Ge 3d core levels allow us to identify the surface species and to determine the surface chemical composition, and this information is correlated with the atomic features observed by scanning tunneling microscopy. Issues related to precursor dissociation, attachment to dangling bonds, diffusion, surface segregation, growth morphology, and pyrolytic reaction pathways will be discussed. {copyright} {ital 1997 American Vacuum Society.}

Lin, D. [Institute of Physics, National Chiao-Tung University, Hsinchu, Taiwan, Republic of (China)] [Institute of Physics, National Chiao-Tung University, Hsinchu, Taiwan, Republic of (China); Miller, T.; Chiang, T. [Department of Physics and Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States)] [Department of Physics and Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States)

1997-05-01T23:59:59.000Z

249

Demonstration of a vapor density monitoring system using UV radiation generated from quasi-phasematched SHG waveguide devices  

SciTech Connect

Many industrial applications require non-intrusive diagnostics for process monitoring and control. One example is the physical vapor deposition of titanium alloys. In this paper we present a system based on laser absorption spectroscopy for monitoring titanium vapor. Appropriate transitions for monitoring high rate vaporization of titanium require extension of available IR diode technology to the UV. The heart of this vapor density monitoring system is the 390nm radiation generated from quasi-phase matched interactions within periodically poled waveguides. In this paper, key system components of a UV laser absorption spectroscopy based system specific for titanium density monitoring are described. Analysis is presented showing the minimum power levels necessary from the ultraviolet laser source. Performance data for prototype systems using second harmonic generation (SHG) waveguide technology is presented. Application of this technology to other alloy density monitoring systems is discussed.

Galanti, S.A.; Berzins, L.V.; Brown, J.B.; Tamosaitis, R.S.; Bortz, M.L.; Day, T.; Fejer, M.M.; Wang, W.

1996-01-29T23:59:59.000Z

250

ARM - Field Campaign - Water Vapor IOP  

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

govCampaignsWater Vapor IOP govCampaignsWater Vapor IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Water Vapor IOP 1996.09.10 - 1996.09.30 Lead Scientist : Henry Revercomb For data sets, see below. Summary SCHEDULE This IOP will be conducted from September 10 - 30, 1996 (coincident with the Fall ARM-UAV IOP). Instruments that do not require supervision will be operated continuously during this period. Instruments that do require supervision are presently planned to be operated for 8-hour periods each day. Because it is necessary to cover as broad a range of environmental conditions as possible, the daily 8-hour period will be shifted across the diurnal cycle as deemed appropriate during the IOP (but will be maintained as a contiguous 8-hour block).

251

atmospheric water vapor | OpenEI  

Open Energy Info (EERE)

atmospheric water vapor atmospheric water vapor Dataset Summary Description (Abstract): Monthly Average Solar Resource for 2-axis tracking concentrating collectors for Mexico, Central America, and the Caribbean Islands. (Purpose): Provide information on the solar resource potential for the data domain. The insolation values represent the average solar energy available to a concentrating collector, such as a dish collector, which tracks the sun continuously. Source NREL Date Released July 31st, 2006 (8 years ago) Date Updated October 30th, 2007 (7 years ago) Keywords atmospheric water vapor Carribean Islands Central America DNI GIS Mexico NREL GEF solar SWERA UNEP Data application/zip icon Download Shapefile (zip, 247.8 KiB) text/csv icon Download Data (csv, 370.6 KiB) Quality Metrics Level of Review Some Review

252

atmoshperic water vapor | OpenEI  

Open Energy Info (EERE)

atmoshperic water vapor atmoshperic water vapor Dataset Summary Description (Abstract): Monthly Average Solar Resource for flat-plate collectors tilted at latitude for China. Source NREL Date Released April 12th, 2005 (9 years ago) Date Updated October 30th, 2007 (7 years ago) Keywords atmoshperic water vapor China GEF GIS NREL solar SWERA TILT UNEP Data application/zip icon Download Shapefile (zip, 625.6 KiB) text/csv icon Download Data (csv, 704.1 KiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Time Period 01/01/1985 - 12/31/1991 License License Open Data Commons Public Domain Dedication and Licence (PDDL) Comment Rate this dataset Usefulness of the metadata Average vote Your vote Usefulness of the dataset Average vote Your vote Ease of access

253

Band Offsets at the Epitaxial Anatase TiO2/n-SrTiO3(001) Interface...  

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

to measure valence band offsets at the epitaxial anatase TiO2(002)n-SrTiO3(001) heterojunction prepared by molecular beam epitaxy, Within experimental error, the valance band...

254

X-ray Microdiffraction from ?-Ti0.04Fe1.96O3 (0001) Epitaxial...  

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

(0001) Epitaxial Film Grown Over ?-Cr2O3 Buffer Layer Boundary. X-ray Microdiffraction from ?-Ti0.04Fe1.96O3 (0001) Epitaxial Film Grown Over...

255

Vapor characterization of Tank 241-C-103  

SciTech Connect

The Westinghouse Hanford Company Tank Vapor Issue Resolution Program has developed, in cooperation with Northwest Instrument Systems, Inc., Oak Ridge National Laboratory, Oregon Graduate Institute of Science and Technology, Pacific Northwest Laboratory, and Sandia National Laboratory, the equipment and expertise to characterize gases and vapors in the high-level radioactive waste storage tanks at the Hanford Site in south central Washington State. This capability has been demonstrated by the characterization of the tank 241-C-103 headspace. This tank headspace is the first, and for many reasons is expected to be the most problematic, that will be characterized (Osborne 1992). Results from the most recent and comprehensive sampling event, sample job 7B, are presented for the purpose of providing scientific bases for resolution of vapor issues associated with tank 241-C-103. This report is based on the work of Clauss et al. 1994, Jenkins et al. 1994, Ligotke et al. 1994, Mahon et al. 1994, and Rasmussen and Einfeld 1994. No attempt has been made in this report to evaluate the implications of the data presented, such as the potential impact of headspace gases and vapors to tank farm workers health. That and other issues will be addressed elsewhere. Key to the resolution of worker health issues is the quantitation of compounds of toxicological concern. The Toxicology Review Panel, a panel of Pacific Northwest Laboratory experts in various areas, of toxicology, has chosen 19 previously identified compounds as being of potential toxicological concern. During sample job 7B, the sampling and analytical methodology was validated for this preliminary list of compounds of toxicological concern. Validation was performed according to guidance provided by the Tank Vapor Conference Committee, a group of analytical chemists from academic institutions and national laboratories assembled and commissioned by the Tank Vapor Issue Resolution Program.

Huckaby, J.L. [Westinghouse Hanford Co., Richland, WA (United States); Story, M.S. [Northwest Instrument Systems, Inc. Richland, WA (United States)

1994-06-01T23:59:59.000Z

256

Thermal electric vapor trap arrangement and method  

DOE Patents (OSTI)

A technique for trapping vapor within a section of a tube is disclosed herein. This technique utilizes a conventional, readily providable thermal electric device having a hot side and a cold side and means for powering the device to accomplish this. The cold side of this device is positioned sufficiently close to a predetermined section of the tube and is made sufficiently cold so that any condensable vapor passing through the predetermined tube section is condensed and trapped, preferably within the predetermined tube section itself. 4 figs.

Alger, T.

1988-03-15T23:59:59.000Z

257

Diode pumped alkali vapor fiber laser  

DOE Patents (OSTI)

A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

Payne, Stephen A. (Castro Valley, CA); Beach, Raymond J. (Livermore, CA); Dawson, Jay W. (Livermore, CA); Krupke, William F. (Pleasanton, CA)

2006-07-26T23:59:59.000Z

258

Diode pumped alkali vapor fiber laser  

DOE Patents (OSTI)

A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

Payne, Stephen A. (Castro Valley, CA); Beach, Raymond J. (Livermore, CA); Dawson, Jay W. (Livermore, CA); Krupke, William F. (Pleasanton, CA)

2007-10-23T23:59:59.000Z

259

Lattice-registered growth of GaSb on Si (211) with molecular beam epitaxy  

SciTech Connect

A GaSb film was grown on a Si(211) substrate using molecular beam epitaxy indicating full lattice relaxation as well as full lattice registration and dislocation-free growth in the plane perpendicular to the [01 - 1]-direction. Heteroepitaxy of GaSb on a Si(211) substrate is dominated by numerous first order and multiple higher order micro-twins. The atomic-resolved structural study of GaSb films by high-angle annular dark-field scanning transmission electron microscopy reveals that slight tilt, along with twinning, favors the lattice registry to Si(211) substrates. Preferential bonding of impinging Ga and Sb atoms at the interface due to two distinctive bonding sites on the Si(211) surface enables growth that is sublattice-ordered and free of anti-phase boundaries. The role of the substrate orientation on the strain distribution of GaSb epilayers is further elucidated by investigating the local change in the lattice parameter using the geometric phase analysis method and hence effectiveness of the lattice tilting in reducing the interfacial strain was confirmed further.

Hosseini Vajargah, S.; Botton, G. A. [Department of Materials Science and Engineering, McMaster University, Hamilton, Ontario L8S 4L7 (Canada); Brockhouse Institute for Materials Research, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Canadian Centre for Electron Microscopy, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Ghanad-Tavakoli, S. [Centre for Emerging Device Technologies, McMaster University, Hamilton, Ontario L8S 4L7 (Canada); Preston, J. S.; Kleiman, R. N. [Brockhouse Institute for Materials Research, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Centre for Emerging Device Technologies, McMaster University, Hamilton, Ontario L8S 4L7 (Canada); Department of Engineering Physics, McMaster University, Hamilton, Ontario L8S 4L7 (Canada)

2012-11-01T23:59:59.000Z

260

Small epitaxial graphene devices for magnetosensing applications V. Panchal, K. Cedergren, R. Yakimova, A. Tzalenchuk, S. Kubatkin et al.  

E-Print Network (OSTI)

Small epitaxial graphene devices for magnetosensing applications V. Panchal, K. Cedergren, R://jap.aip.org/about/rights_and_permissions #12;Small epitaxial graphene devices for magnetosensing applications V. Panchal,1,2 K. Cedergren,3 R from 0.5 to 20.0 lm have been fabricated out of a monolayer graphene epitaxially grown on Si

Sheldon, Nathan D.

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


261

Epitaxial growth of lead zirconium titanate thin films on Ag buffered Si substrates using rf sputtering  

E-Print Network (OSTI)

substrates such as SrTiO3, MgO, and LaAlO3 using different deposition methods sputtering, pubed laser with good dif- fusion barrier properties and epitaxy with Si need to be used. In this work, we investigated grown epitaxially on HF-etched Si 001 with cube-on-cube orientation relationship, though the lattice

Laughlin, David E.

262

Exploring the Potential for High-Quality Epitaxial CdTe Solar Cells , Ana Kanevce2  

E-Print Network (OSTI)

Exploring the Potential for High-Quality Epitaxial CdTe Solar Cells Tao Song1 , Ana Kanevce2 National Renewable Energy Laboratory, Golden, CO, 80401, USA Abstract -- Traditional polycrystalline CdTeV and ~ 20%. Epitaxial CdTe with high-quality, low defect-density, and high carrier density, could yield

Sites, James R.

263

Self-assembly of silicide quantum dot arrays on stepped silicon surfaces by reactive epitaxy  

E-Print Network (OSTI)

investigated on the epitaxy and self- organization of laterally nanostructured transition metal TM silicideSelf-assembly of silicide quantum dot arrays on stepped silicon surfaces by reactive epitaxy L to be a flexible and a convenient method for the preparation of dense arrays of Co silicide quantum dots

Ortega, Enrique

264

Thin crystalline silicon solar cells based on epitaxial films grown at 165C by RF PECVD  

E-Print Network (OSTI)

1 Thin crystalline silicon solar cells based on epitaxial films grown at 165°C by RF PECVD Romain temperatures. Keywords : Low temperature, epitaxy, PECVD, Si thin film, Solar cell #12;2 1. Introduction: martin.labrune@polytechnique.edu ABSTRACT We report on heterojunction solar cells whose thin intrinsic

265

Free-Standing Epitaxial Graphene Shriram Shivaraman,* Robert A. Barton, Xun Yu, Jonathan Alden,  

E-Print Network (OSTI)

Free-Standing Epitaxial Graphene Shriram Shivaraman,* Robert A. Barton, Xun Yu, Jonathan Alden to produce free-standing graphene sheets from epitaxial graphene on silicon carbide (SiC) substrate. Doubly for beams under no tension. Raman spectroscopy suggests that the graphene is not chemically modified during

McEuen, Paul L.

266

Effect of functionalization on the electrostatic charging, tunneling, and Raman spectroscopy of epitaxial graphene  

E-Print Network (OSTI)

of epitaxial graphene Jeongmin Hong, Sandip Niyogi, Elena Bekyarova, Mikhail E. Itkis, Palanisamy Ramesh graphene Appl. Phys. Lett. 101, 111602 (2012); 10.1063/1.4752443 Evidences of electrochemical graphene (2012); 10.1063/1.4725489 Pinned and unpinned epitaxial graphene layers on SiC studied by Raman

267

Controlled oxygen doping of GaN using plasma assisted molecular-beam epitaxy  

E-Print Network (OSTI)

Controlled oxygen doping of GaN using plasma assisted molecular-beam epitaxy A. J. Ptak, L. J-assisted molecular-beam epitaxy to study the dependence of oxygen incorporation on polarity and oxygen partial pressure. Oxygen incorporates at a rate ten times faster on nitrogen-polar GaN than on the Ga polarity

Myers, Tom

268

Optimization of the tunability of barium strontium titanate films via epitaxial stresses  

E-Print Network (OSTI)

Optimization of the tunability of barium strontium titanate films via epitaxial stresses Z.-G. Ban The tunability of epitaxial barium strontium titanate films is analyzed theoretically using a phenomenological.1063/1.1524310 I. INTRODUCTION Thin films of barium strontium titanate (BaxSr1 xTiO3, BST have long been recognized

Alpay, S. Pamir

269

Graphene growth with giant domains using chemical vapor deposition  

E-Print Network (OSTI)

N. Martensson, Controlling graphene corrugation on lattice-in patterned epitaxial graphene, Science, 2006, 312(5777), 92009, 4(6), 17 A. K. Geim, Graphene: Status and Prospects,

Yong, Virginia; Hahn, H. Thomas

2011-01-01T23:59:59.000Z

270

Micro and nanostructured surfaces for enhanced phase change heat transfer  

E-Print Network (OSTI)

Two-phase microchannel heat sinks are of significant interest for thermal management applications, where the latent heat of vaporization offers an efficient method to dissipate large heat fluxes in a compact device. However, ...

Chu, Kuang-Han, Ph. D. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

271

Design of a microbreather for two-phase microchannel devices  

E-Print Network (OSTI)

Multiphase flows in microchannels are encountered in a variety of microfluidic applications. Two-phase microchannel heat sinks leverage the latent heat of vaporization to offer an efficient method of dissipating large heat ...

Alexander, Brentan R

2008-01-01T23:59:59.000Z

272

Phase-Transfer Catalysis Displacement Reactions with Simple Anions  

Science Journals Connector (OSTI)

Phase-transfer catalysis (PTC) is an excellent technique both in liquid—liquid and liquid—solid (and sometimes in liquid—vapor) modes for conducting displacement reactions with anions.

Charles M. Starks; Charles L. Liotta; Marc E. Halpern

1994-01-01T23:59:59.000Z

273

Gas phase 129Xe NMR imaging and spectroscopy  

E-Print Network (OSTI)

5 l l Dynamic NMR microscopy of gas phase Poiseuille flowmetal vapors and noble gases can be used to efficientlypolarize the nuclei ofthe noble-gas atoms. As a result, the

Kaiser, Lana G.

2010-01-01T23:59:59.000Z

274

Phase relations in the system NaCl-KCl-H/sub 2/O. III. Solubilities of halite in vapor-saturated liquids above 445/sup 0/C and redetermination of phase equilibrium properties in the system NaCl-H/sub 2/O to 1000/sup 0/C and 1500 bars  

SciTech Connect

Halite solubilities along the three-phase curve in the binary system NaCl-H/sub 2/O determined by differential thermal analysis (DTA) experiment can be represented by the discussed equation where 447 less than or equal to T less than or equal to 800/sup 0/C. Even though these halite solubilities are up to approx. 7 wt.% higher than those reported in literature, extrapolated values at temperatures below 447/sup 0/C merge with the literature values. It is considered that the equation adequately describes halite solubilities between 382 and 800/sup 0/C. The newly established solubility data are believed to be more reliable because they are compatible with data obtained by using synthetic fluid inclusions and with the observed DTA signals and also because they were measured in a relatively corrosion-free system. In an earlier publication the authors were puzzled greatly by multiple and rather unreproducible DTA peaks appearing during isobaric cooling at pressures below about 500 bars. These DTA signals apparently suggested that the halite liquidus swung sharply upward in temperature as pressure decreased from about 500 bars to that of the halite-saturated boiling curve. Further analysis of the data and helpful discussions with several individuals have revealed that the behavior is a consequence of the initial separation of the fluid into NaCl-poor gas and NaCl-rich liquid that failed to homogenize in the short time encompassed by the DTA experiments. The present analysis is based on extrapolations of the dP/dT slopes from pressures above 500 bars.

Chou, I.

1987-07-01T23:59:59.000Z

275

Feasibility of UV lasing without inversion in mercury vapor  

E-Print Network (OSTI)

We investigate the feasibility of UV lasing without inversion at a wavelength of $253.7$ nm utilizing interacting dark resonances in mercury vapor. Our theoretical analysis starts with radiation damped optical Bloch equations for all relevant 13 atomic levels. These master equations are generalized by considering technical phase noise of the driving lasers. From the Doppler broadened complex susceptibility we obtain the stationary output power from semiclassical laser theory. The finite overlap of the driving Gaussian laser beams defines an ellipsoidal inhomogeneous gain distribution. Therefore, we evaluate the intra-cavity field inside a ring laser self-consistently with Fourier optics. This analysis confirms the feasibility of UV lasing and reveals its dependence on experimental parameters.

Martin R. Sturm; Benjamin Rein; Thomas Walther; Reinhold Walser

2014-06-27T23:59:59.000Z

276

Chemical vapor deposition of hydrogenated amorphous silicon from disilane  

SciTech Connect

The authors describe hydrogenated amorphous silicon (a-Si:H) thin films deposited at growth rates of 1 to 30 A/s by chemical vapor deposition (CVD) from disilane source gas at 24 torr total pressure in a tubular reactor. The effects of substrate temperature and gas holding time (flow rate) on film growth rate and effluent gas composition were measured at temperatures ranging from 360{sup 0} to 485{sup 0}C and gas holding times from 3 to 62s. Effluent gases determined by gas chromatography included silane, disilane and other higher order silanes. A chemical reaction engineering model, based on a silylene (SiH/sub 2/) insertion gas phase reaction network and film growth from both SiH/sub 2/ and high molecular weight silicon species, Si/sub n/H/sub 2n/, was developed. The model predictions were in good agreement with experimentally determined growth rates and effluent gas compositions.

Bogaert, R.J.; Russell, T.W.F.; Klein, M.T. (Delaware Univ., Newark, DE (USA). Dept. of Chemical Engineering); Rocheleau, R.E.; Baron, B.N. (Delaware Univ., Newark, DE (USA). Inst. of Energy Conversion)

1989-10-01T23:59:59.000Z

277

Environmental Chemistry at Vapor/Water Interfaces  

E-Print Network (OSTI)

Environmental Chemistry at Vapor/Water Interfaces: Insights from Vibrational Sum Frequency Generation Spectroscopy Aaron M. Jubb, Wei Hua, and Heather C. Allen Department of Chemistry, The Ohio State/0505-0107$20.00 Keywords salts, lipids, atmospheric chemistry, ion binding, oxidation Abstract The chemistry that occurs

278

Advancing Explosives Detection Capabilities: Vapor Detection  

ScienceCinema (OSTI)

A new, PNNL-developed method provides direct, real-time detection of trace amounts of explosives such as RDX, PETN and C-4. The method selectively ionizes a sample before passing the sample through a mass spectrometer to detect explosive vapors. The method could be used at airports to improve aviation security.

Atkinson, David

2014-07-24T23:59:59.000Z

279

Program performs vapor-liquid equilibrium calculations  

SciTech Connect

A program designed for the Hewlett-Packard HP-41CV or 41C calculators solves basic vapor-liquid equilibrium problems, including figuring the dewpoint, bubblepoint, and equilibrium flash. The algorithm uses W.C. Edmister's method for predicting ideal-solution K values.

Rice, V.L.

1982-06-28T23:59:59.000Z

280

Vapor intrusion modeling : limitations, improvements, and value of information analyses  

E-Print Network (OSTI)

Vapor intrusion is the migration of volatile organic compounds (VOCs) from a subsurface source into the indoor air of an overlying building. Vapor intrusion models, including the Johnson and Ettinger (J&E) model, can be ...

Friscia, Jessica M. (Jessica Marie)

2014-01-01T23:59:59.000Z

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


281

Estimating the Atmospheric Water Vapor Content from Sun Photometer Measurements  

Science Journals Connector (OSTI)

The differential absorption technique for estimating columnar water vapor values from the analysis of sunphotometric measurements with wide- and narrowband interferential filters centered near 0.94 ?m is discussed and adapted. Water vapor line ...

Artemio Plana-Fattori; Michel Legrand; Didier Tanré; Claude Devaux; Anne Vermeulen; Philippe Dubuisson

1998-08-01T23:59:59.000Z

282

OPTIMIZATION OF INJECTION INTO VAPOR-DOMINATED GEOTHERMAL  

E-Print Network (OSTI)

given by U.S. Department of Energy, Geothermal Division. #12;vii Table of Contents ABSTRACTOPTIMIZATION OF INJECTION INTO VAPOR-DOMINATED GEOTHERMAL RESERVOIRS CONSIDERING ADSORPTION governing the behavior of vapor- dominated geothermal reservoirs. These mechanisms affect both

Stanford University

283

Strong circular photogalvanic effect in ZnO epitaxial films  

SciTech Connect

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

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

2011-12-23T23:59:59.000Z

284

Electronic states in epitaxial graphene fabricated on silicon carbide  

SciTech Connect

An analytical expression for the density of states of a graphene monolayer interacting with a silicon carbide surface (epitaxial graphene) is derived. The density of states of silicon carbide is described within the Haldane-Anderson model. It is shown that the graphene-substrate interaction results in a narrow gap of {approx}0.01-0.06 eV in the density of states of graphene. The graphene atom charge is estimated; it is shown that the charge transfer from the substrate is {approx}10{sup -3}-10{sup -2}e per graphene atom.

Davydov, S. Yu., E-mail: Sergei_Davydov@mail.ru [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation)

2011-08-15T23:59:59.000Z

285

Investigation of the relaxation behavior of Si1?xCx alloys during epitaxial UHV-CVD growth  

Science Journals Connector (OSTI)

In this work, the epitaxial growth of Si1?xCx alloys using an Ultra High Vacuum Chemical Vapor Deposition (UHV-CVD) system was studied. Si1?xCx layers were grown in a temperature range of 550–650 °C and characterized using rocking curve X-ray diffraction (XRD), atomic force microscopy (AFM) as well as Fourier transform infrared spectroscopy (FT-IR). It was found that with increasing carbon precursor flow (Methylsilane) the amount of substitutional carbon rises up to a critical value. After a maximum in substitutional carbon content is reached, a further increase of carbon fraction leads to a reduction of the strain. By FT-IR, the non-substitutional carbon was determined to form 3C-SiC precipitates already during growth. A strong correlation between the increase of Methylsilane flow and the formation of coherent precipitates even at low carbon fractions was observed. A low deposition temperature was found to promote the precipitation of 3C-SiC.

I. Ostermay; T. Kammler; A. Naumann; J.W. Bartha; P. Kücher

2008-01-01T23:59:59.000Z

286

Microstructure and Mechanics of Superconductor Epitaxy via the Chemical Solution Deposition Method  

SciTech Connect

Executive Summary: Initially the funds were sufficient funds were awarded to support one graduate student and one post-doc. Lange, though other funds, also supported a graduate intern from ETH Zurich, Switzerland for a period of 6 months. The initial direction was to study the chemical solution deposition method to understand the microstructural and mechanical phenomena that currently limit the production of thick film, reliable superconductor wires. The study was focused on producing thicker buffer layer(s) on Ni-alloy substrates produced by the RABiTS method. It focused on the development of the microstructure during epitaxy, and the mechanical phenomena that produce cracks during dip-coating, pyrolysis (decomposition of precursors during heating), crystallization and epitaxy. The initial direction of producing thicker layers of a know buffer layer material was redirected by co-workers at ORNL, in an attempt to epitaxially synthesize a potential buffer layer material, LaMnO3, via the solution route. After a more than a period of 6 months that showed that the LaMnO3 reacted with the Ni-W substrate at temperatures that could produce epitaxy, reviewers at the annual program review strongly recommended that the research was not yielding positive results. The only positive result presented at the meeting was that much thicker films could be produce by incorporating a polymer into the precursor that appeared to increase the precursor’s resistance to crack growth. Thus, to continue the program, the objectives were changed to find compositions with the perovskite structure that would be a) chemically compatible with either the Ni-W RABiTS or the MgO IBAD Ni-alloy substrates, and produce a better lattice parameter fit between either of the two substrates. At the start of the second year, the funding was reduced to 2/3’s of the first year level, which required the termination of the post-doc after approximately 5 months into the second year. From then on, further funding was intermittent to say the least, and funding to support the student and the research expenses has to be supplemented by Lange’s gift funds. During the first part of the second year, strontium zirconate was identified as an alternative to lanthanum manganite as a buffer layer for use on the IBAD MgO superconducting wire. A lattice parameter of 4.101 Angstroms offers a reduced lattice mismatch between the MgO and SrZrO3. Studies were focused on investigating hybrid precursor routes, combining Sr acetate with a number of different Zr alkoxides. Initial results from heat treating precursors to form powders are positive with the formation of orthorhombic SrZrO3 at temperatures between 800°C and 1100°C under a reducing atmosphere of Ar – 5% H2. Buffer layer research on RABiTS substrates were centered on GdAlO3 (3.71 Å) and YAlO3 (3.68 Å) buffer layer materials. Powder experiments in YAlO3 have shown the perovskite phase to be metastable at processing temperatures below 1500 °C. Experiments involving spin coating of YAlO3 precursors have found significant problems involved with wettability of the YAlO3 precursor (Yttrium acetate, Aluminum tri-sec butoxide, DI water and Formic Acid) on RABiTS substrates; this, and the demise of the funds precluded further research using YAlO3. The diminished funds for the second year, and the small, tricked funds during the third year lead to a redirection of the student to another research area., and a stop to any experimental achievements that were much too ambition relative to the available funds. The only positive results obtained during this latter period was the understanding why two dissimilar structures could result in an epitaxial relation. It was shown that two rules of crystal chemistry, cation/anion coordination and charge balance, could be applied to understand the epitaxy of SrTiO3 on Ni c(2 X 2)S, TiO2 (anatase) on LaAlO3, TiO2 (rutile) on r-plane Al2O3, and Zr1-x(Yx)O2 on (0001) Al2O3. This new understanding of the interface between two dissimilar structures has important implications that include the buff

Frederick F. Lange

2006-11-30T23:59:59.000Z

287

Apparent Temperature Dependence on Localized Atmospheric Water Vapor  

E-Print Network (OSTI)

Apparent Temperature Dependence on Localized Atmospheric Water Vapor Matthew Montanaroa, Carl), hence water vapor is the primary constituent of concern. The tower generates a localized water vapor, Office B108, Aiken, SC, USA ABSTRACT The atmosphere is a critical factor in remote sensing. Radiance from

Salvaggio, Carl

288

Advanced Membrane Systems: Recovering Wasteful and Hazardous Fuel Vapors at the Gasoline Tank  

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

Case study covering Compact Membrane Systems, Inc. and its membrane vapor processor that recovers fuel vapors from gasoline refueling.

289

Modification of epitaxial oxide films with ion implantation  

SciTech Connect

Ion implantation is used to modify the properties of oxide (YBCO and YSZ) thin films. Both superconducting and dielectric epitaxial oxide films, grown by laser ablation, are studied. The properties of the implanted oxide films are characterized by SIMS, XPS, DC resistivity and AC susceptibility measurements. By introducing reactive ions into superconducting oxide films, the conductivity of the material is inhibited possibly due to the interaction of the implanted ions with oxygen originally bound to the copper atoms. Al, Si, Ag and Ca ions are implanted into epitaxial YBCO films with injection energies ranging from 50--100 KeV and doses ranging from 1 {times} 10{sup 15}--1 {times} 10{sup 16}/cm{sup 2}. XPS analysis shows that the implanted Si ions form SiO{sub x}. The inhibition method has been applied to the fabrication of superconducting electronic devices, such as SQUIDs. Dielectric oxide films are doped by the implantation of conductive and nonconductive ions. YSZ films are doped with Ag and Si ions and the ions are found to increase the conductivity.

Hong, S.H.; Miller, J.R.; Ma, Q.Y.; Yang, E.S. [Columbia Univ., New York, NY (United States). Dept. of Electrical Engineering; Fenner, D.B. [AFR Inc., East Hartford, CT (United States); Yang, C.Y. [Santa Clara Univ., CA (United States). Microelectronics Lab.; Budnick, J.I. [Univ. of Connecticut, Storrs, CT (United States). Dept. of Physics

1996-11-01T23:59:59.000Z

290

Chemical Kinetics for Modeling Silicon Epitaxy from Chlorosilanes  

SciTech Connect

A reaction mechanism has been developed that describes the gas-phas 0971 and surface reactions involved in the chemical vapor deposition of Si from chlorosilanes. Good agreement with deposition rate data from a single wafer reactor with no wafer rotation has been attained over a range of gas mixtures, total flow rates, and reactor temperatures.

Balakrishna, A.; Chacin, J.M.; Comita, P.B.; Haas, B.; Ho, P.; Thilderkvist, A.

1998-11-24T23:59:59.000Z

291

Delta-doping of boron atoms by photoexcited chemical vapor deposition  

SciTech Connect

Boron delta-doped structures in Si crystals were fabricated by means of photoexcited chemical vapor deposition (CVD). Core electronic excitation with high-energy photons ranging from vacuum ultraviolet to soft x rays decomposes B{sub 2}H{sub 6} molecules into fragments. Combined with in situ monitoring by spectroscopic ellipsometry, limited number of boron hydrides can be delivered onto a Si(100) surface by using the incubation period before the formation of a solid boron film. The boron-covered surface is subsequently embedded in a Si cap layer by Si{sub 2}H{sub 6} photo-excited CVD. The crystallinity of the Si cap layer depended on its thickness and the substrate temperature. The evaluation of the boron depth profile by secondary ion mass spectroscopy revealed that boron atoms were confined within the delta-doped layer at a concentration of 2.5 x 10{sup 20} cm{sup -3} with a full width at half maximum of less than 9 nm, while the epitaxial growth of a 130-nm-thick Si cap layer was sustained at 420 deg. C.

Akazawa, Housei [NTT Microsystem Integration Laboratories, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198 (Japan)

2012-03-15T23:59:59.000Z

292

Precision micro drilling with copper vapor lasers  

SciTech Connect

The authors have developed a copper vapor laser based micro machining system using advanced beam quality control and precision wavefront tilting technologies. Micro drilling has been demonstrated through percussion drilling and trepanning using this system. With a 30 W copper vapor laser running at multi-kHz pulse repetition frequency, straight parallel holes with size varying from 500 microns to less than 25 microns and with aspect ratio up to 1:40 have been consistently drilled on a variety of metals with good quality. For precision trepanned holes, the hole-to-hole size variation is typically within 1% of its diameter. Hole entrance and exit are both well defined with dimension error less than a few microns. Materialography of sectioned holes shows little (sub-micron scale) recast layer and heat affected zone with surface roughness within 1--2 microns.

Chang, J.J.; Martinez, M.W.; Warner, B.E.; Dragon, E.P.; Huete, G.; Solarski, M.E.

1994-09-02T23:59:59.000Z

293

Copper vapor laser modular packaging assembly  

DOE Patents (OSTI)

A modularized packaging arrangement for one or more copper vapor lasers and associated equipment is disclosed herein. This arrangement includes a single housing which contains the laser or lasers and all their associated equipment except power, water and neon, and means for bringing power, water, and neon which are necessary to the operation of the lasers into the container for use by the laser or lasers and their associated equipment.

Alger, Terry W. (Tracy, CA); Ault, Earl R. (Dublin, CA); Moses, Edward I. (Castro Valley, CA)

1992-01-01T23:59:59.000Z

294

Epitaxial integration of ferromagnetic correlated oxide LaCoO{sub 3} with Si (100)  

SciTech Connect

We have grown epitaxial strained LaCoO{sub 3} on (100)-oriented silicon by molecular beam epitaxy using a relaxed epitaxial SrTiO{sub 3} buffer layer. Superconducting quantum interference device magnetization measurements show that, unlike the bulk material, the ground state of the strained LaCoO{sub 3} on silicon is ferromagnetic with a T{sub C} of 85 K. First principles calculations suggest that a ferromagnetic ground state can be stabilized in LaCoO{sub 3} by a sufficiently large biaxial tensile strain with the transition accompanied by a partial untilting of the CoO{sub 6} octahedra.

Posadas, A.; Berg, M.; Seo, H.; Lozanne, A. de; Demkov, A. A. [Department of Physics, University of Texas at Austin, Austin, Texas 78712 (United States); Smith, D. J. [Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States); Kirk, A. P.; Zhernokletov, D.; Wallace, R. M. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States)

2011-01-31T23:59:59.000Z

295

Developmental of a Vapor Cloud Explosion Risk Analysis Tool Using Exceedance Methodology  

E-Print Network (OSTI)

cloud explosions [4]. Lenoir and Davenport [5] have presented a review of many major incidents involving vapor cloud explosions worldwide from 1921 to 1991. Hydrocarbon materials such as ethane, ethylene, propane, and butane, which have been involved... are typically either in the form of gas, liquid, or two-phase. Examples of hydrocarbon gas releases are methane through butane, while liquid releases could be crude oil, diesel, jet fuel, or others. An example of a two-phase leak is condensate since it is a...

Alghamdi, Salem

2012-10-19T23:59:59.000Z

296

Heat storage system utilizing phase change materials government rights  

DOE Patents (OSTI)

A thermal energy transport and storage system is provided which includes an evaporator containing a mixture of a first phase change material and a silica powder, and a condenser containing a second phase change material. The silica powder/PCM mixture absorbs heat energy from a source such as a solar collector such that the phase change material forms a vapor which is transported from the evaporator to the condenser, where the second phase change material melts and stores the heat energy, then releases the energy to an environmental space via a heat exchanger. The vapor is condensed to a liquid which is transported back to the evaporator. The system allows the repeated transfer of thermal energy using the heat of vaporization and condensation of the phase change material.

Salyer, Ival O. (Dayton, OH)

2000-09-12T23:59:59.000Z

297

Chemical beam epitaxy growth of III–V semiconductor nanowires  

SciTech Connect

Indium- Arsenide (InAs) nanowires were grown in a high vacuum chemical beam epitaxy (CBE) unit on InAs(111) wafers substrates at 425–454°C. Two types of nanogold were used as orientation catalyst, 40nm and 80nm. The measurements were performed using scanning electron microscopy showed that uniform nanowires. The nanowires orient vertically in the InAs nanowire scanning electron microscopy of an array 80nm diameter InAs nanowire with length is in the range 0.5–1 ?m and of an array 40nm diameter with length is in the range 0.3–0.7?m. The nanowire length with growth time shows that the linear increase of nanowires start to grow as soon as TMIn is available. The growth rate with temperature was studied.

Mohummed Noori, Farah T. [University of Baghdad , College of science, Physics department , Jadiriya ,Baghdad (Iraq)

2013-12-16T23:59:59.000Z

298

Photoconductivity of germanium tin alloys grown by molecular beam epitaxy  

SciTech Connect

Photocurrent spectroscopy was used to measure the infrared absorption of germanium-tin alloys grown by molecular beam epitaxy. To study dependence on Sn composition, the photocurrent was measured at 100 K on alloys of Ge{sub 1-x}Sn{sub x} with atomic percentages of Sn up to 9.8%. The optical absorption coefficient was calculated from the photocurrent, and it was found that the absorption edge and extracted bandgap energy decreased with increasing Sn content. For all Ge{sub 1-x}Sn{sub x} samples, a fundamental bandgap below that of bulk Ge was observed, and a bandgap energy as low as 0.624 eV was found for a Sn percentage of 9.8% at 100 K.

Coppinger, Matthew; Hart, John; Bhargava, Nupur; Kim, Sangcheol; Kolodzey, James [Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716 (United States)] [Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716 (United States)

2013-04-08T23:59:59.000Z

299

Dielectric tunability of ,,110... oriented barium strontium titanate epitaxial films on ,,100... orthorhombic substrates  

E-Print Network (OSTI)

Dielectric tunability of ,,110... oriented barium strontium titanate epitaxial films on ,,100 materials such as barium strontium titanate Ba1-xSrxTiO3 BST have emerged as leading candidates

Alpay, S. Pamir

300

Structure, magnetic properties and magnetoelastic anisotropy in epitaxial Sr(Ti???Co?)O? films  

E-Print Network (OSTI)

We report the structure, magnetic properties and magnetoelastic anisotropy of epitaxial Sr(Ti???Co?)O? films grown on LaAlO? (001) and SrTiO? (001) substrates by pulsed laser deposition. Room temperature ferromagnetism was ...

Bi, Lei

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


301

Applied Materials Develops an Advanced Epitaxial Growth System to Bring Down LED Costs  

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

With the help of DOE funding, Applied Materials has developed an advanced epitaxial growth system for gallium nitride (GaN) LED devices that decreases operating costs, increases internal quantum efficiency, and improves binning yields.

302

E-Print Network 3.0 - atomic layer epitaxy Sample Search Results  

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

the surface of the grown MnSi layer. On the atomic scale, scanning... Epitaxial growth of silicide layers on Si substrates has attracted much attention due to their...

303

Enhanced Magnetism in Epitaxial SrRuO3 Thin Films  

E-Print Network (OSTI)

Enhanced Magnetism in Epitaxial SrRuO 3 A. J. Grutter, 1, 2and their e?ects on magnetism. In this paper we demonstrateXMCD con?rmed that the magnetism originates from the Ru 4+

Grutter, A.J.

2010-01-01T23:59:59.000Z

304

Epitaxial Growth and Microstructure of Cu2O Nanoparticle/thin...  

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

Microstructure of Cu2O Nanoparticlethin Films on SrTiO3(100). Epitaxial Growth and Microstructure of Cu2O Nanoparticlethin Films on SrTiO3(100). Abstract: Cuprous oxide (Cu2O)...

305

Electrocaloric properties of epitaxial strontium titanate films I. B. Misirlioglu,2  

E-Print Network (OSTI)

Electrocaloric properties of epitaxial strontium titanate films J. Zhang,1 I. B. Misirlioglu,2 S. P; published online 1 June 2012) The electrocaloric (EC) response of strontium titanate thin films is computed

Alpay, S. Pamir

306

White Light Generating Nonradiative Energy Transfer Directly from Epitaxial Quantum Wells to Colloidal Nanocrystal Quantum Dots  

Science Journals Connector (OSTI)

We present white light generating nonradiative Förster resonance energy transfer at a rate of (2ns)-1directly from epitaxial InGaN/GaN quantum wells to CdSe/ZnS...

Nizamoglu, Sedat; Sari, Emre; Baek, Jong-Hyeob; Lee, In-Hwan; Demir, Hilmi Volkan

307

Molecular-beam epitaxy growth and characterization of mid-infrared quantum cascade laser structures  

Science Journals Connector (OSTI)

The development of molecular-beam epitaxy (MBE) of GaAs/AlGaAs heterostructures, used for fabrication of ~9?m quantum cascade lasers (QCLs), is reported. The X-ray diffractometry (XRD) structural characterization, as an integral part of this process, ... Keywords: GaAs/AlGaAs lasers, Intersubband transitions, Mid-infrared, Molecular-beam epitaxy, Quantum cascade laser, Unipolar devices

Kamil Kosiel; Justyna Kubacka-Traczyk; Piotr Karbownik; Anna Szerling; Jan Muszalski; Maciej Bugajski; Przemek Romanowski; Jaros?aw Gaca; Marek Wójcik

2009-03-01T23:59:59.000Z

308

ARM - Field Campaign - Fall 1997 Water Vapor IOP  

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

Water Vapor IOP Water Vapor IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Fall 1997 Water Vapor IOP 1997.09.15 - 1997.10.05 Lead Scientist : Henry Revercomb For data sets, see below. Summary The Water Vapor IOP was conducted as a follow-up to a predecessor IOP on water vapor held in September 1996. This IOP relied heavily on both ground-based guest and CART instrumentation and in-situ aircraft and tethered sonde/kite measurements. Primary operational hours were from 6 p.m. Central until at least midnight, with aircraft support normally from about 9 p.m. until midnight when available. However, many daytime measurements were made to support this IOP. The first Water Vapor IOP primarily concentrated on the atmosphere's lowest

309

G-Band Vapor Radiometer Profiler (GVRP) Handbook  

SciTech Connect

The G-Band Vapor Radiometer Profiler (GVRP) provides time-series measurements of brightness temperatures from 15 channels between 170 and 183.310 GHz. Atmospheric emission in this spectral region is primarily due to water vapor, with some influence from liquid water. Channels between 170.0 and 176.0 GHz are particularly sensitive to the presence of liquid water. The sensitivity to water vapor of the 183.31-GHz line is approximately 30 times higher than at the frequencies of the two-channel microwave radiometer (MWR) for a precipitable water vapor (PWV) amount of less than 2.5 mm. Measurements from the GVRP instrument are therefore especially useful during low-humidity conditions (PWV < 5 mm). In addition to integrated water vapor and liquid water, the GVRP can provide low-resolution vertical profiles of water vapor in very dry conditions.

Caddeau, MP

2010-06-23T23:59:59.000Z

310

The Impact of Thermal Conductivity and Diffusion Rates on Water Vapor Transport through Gas Diffusion Layers  

E-Print Network (OSTI)

Water management in a hydrogen polymer electrolyte membrane (PEM) fuel cell is critical for performance. The impact of thermal conductivity and water vapor diffusion coefficients in a gas diffusion layer (GDL) has been studied by a mathematical model. The fraction of product water that is removed in the vapour phase through the GDL as a function of GDL properties and operating conditions has been calculated and discussed. Furthermore, the current model enables identification of conditions when condensation occurs in each GDL component and calculation of temperature gradient across the interface between different layers, providing insight into the overall mechanism of water transport in a given cell design. Water transport mode and condensation conditions in the GDL components depend on the combination of water vapor diffusion coefficients and thermal conductivities of the GDL components. Different types of GDL and water removal scenarios have been identified and related to experimentally-determined GDL proper...

Burlatsky, S F; Gummallaa, M; Condita, D; Liua, F

2013-01-01T23:59:59.000Z

311

Vapor port and groundwater sampling well  

DOE Patents (OSTI)

A method and apparatus has been developed for combining groundwater monitoring wells with unsaturated-zone vapor sampling ports. The apparatus allows concurrent monitoring of both the unsaturated and the saturated zone from the same well at contaminated areas. The innovative well design allows for concurrent sampling of groundwater and volatile organic compounds (VOCs) in the vadose (unsaturated) zone from a single well, saving considerable time and money. The sample tubes are banded to the outer well casing during installation of the well casing.

Hubbell, Joel M. (Idaho Falls, ID); Wylie, Allan H. (Idaho Falls, ID)

1996-01-01T23:59:59.000Z

312

Recovery of benzene in an organic vapor monitor  

E-Print Network (OSTI)

solid adsorbents available (silica gel, activated alumina, etc. ), activated charcoal is most frequently utilized. Activated charcoal has retentivity for sorbed vapors several times that of silica gel and it displays a selectivity for organic vapors... (diffusion rate) of the vapor molecules to the sur- face of the adsorbent. The adsorption process determine how effective the adsorbent collects and holds the contam- inant on the surface of the activated charcoal. Recovery of the contaminant from...

Krenek, Gregory Joel

2012-06-07T23:59:59.000Z

313

Growth of epitaxial PrO sub 2 thin films on hydrogen terminated Si (111) by pulsed laser deposition  

SciTech Connect

A new epitaxial oxide, PrO{sub 2}, has been grown on Si (111) by pulsed laser deposition. X-ray diffraction shows that films are oriented with the PrO{sub 2}(111) direction parallel to the substrate (111). The full width at half maximum for the omega rocking curve on the PrO{sub 2} (222) peak is as low as 0.75{degree}, while phi scans indicate {ital in}-{ital plane} epitaxial alignment to better than one degree. In the best quality films, epitaxy is almost pure type-{ital b} epitaxy which is characteristic of epitaxial CaF{sub 2} on Si. To achieve epitaxy, it is essential to remove the native silicon oxide from the substrate prior to film growth. This is done at room temperature using a wet-chemical hydrogen-termination procedure.

Fork, D.K. (Xerox Palo Alto Research Center, Palo Alto, CA (USA) Department of Applied Physics, Stanford University, Stanford, CA (USA)); Fenner, D.B. (Xerox Palo Alto Research Center, Palo Alto, CA (USA) Santa Clara University, Physics Department, Santa Clara, CA (USA)); Geballe, T.H. (Department of Applied Physics, Stanford University, Stanford, CA (USA))

1990-10-15T23:59:59.000Z

314

Mercury Vapor At Haleakala Volcano Area (Thomas, 1986) | Open Energy  

Open Energy Info (EERE)

Mercury Vapor At Haleakala Volcano Area (Thomas, 1986) Mercury Vapor At Haleakala Volcano Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Mercury Vapor At Haleakala Volcano Area (Thomas, 1986) Exploration Activity Details Location Haleakala Volcano Area Exploration Technique Mercury Vapor Activity Date Usefulness not indicated DOE-funding Unknown Notes The field survey program on the northwest rift zone consisted of soil mercury and radon emanometry surveys, groundwater temperature and chemistry studies, Schlumberger resistivity soundings and self-potential profiles. Geophysical and geochemical surveys along this rift (southwest) were limited by difficult field conditions and access limitations. The geophysical program consisted of one Schlumberger sounding, one

315

Mercury Vapor At Vale Hot Springs Area (Varekamp & Buseck, 1983...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Mercury Vapor At Vale Hot Springs Area (Varekamp & Buseck, 1983) Exploration Activity Details...

316

Mercury Vapor At Breitenbush Hot Springs Area (Varekamp & Buseck...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Mercury Vapor At Breitenbush Hot Springs Area (Varekamp & Buseck, 1983) Exploration Activity...

317

Mercury Vapor At Mickey Hot Springs Area (Varekamp & Buseck,...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Mercury Vapor At Mickey Hot Springs Area (Varekamp & Buseck, 1983) Exploration Activity...

318

Mercury Vapor At Desert Peak Area (Varekamp & Buseck, 1983) ...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Mercury Vapor At Desert Peak Area (Varekamp & Buseck, 1983) Exploration Activity Details...

319

Mercury Vapor At Socorro Mountain Area (Kooten, 1987) | Open...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Mercury Vapor At Socorro Mountain Area (Kooten, 1987) Exploration Activity Details Location...

320

Mercury Vapor At Lassen Volcanic National Park Area (Varekamp...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Mercury Vapor At Lassen Volcanic National Park Area (Varekamp & Buseck, 1983) Exploration...

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


321

Thermal Performance of a Double-Tube Type Lng Vaporizer  

Science Journals Connector (OSTI)

This report concerns the confirmed test results and method of analysis of the thermal performance of a double-tube type LNG vaporizer (DTV). The DTV is a...

Y. Miyata; T. Miura; S. Kasahara; H. Shohtani…

1994-01-01T23:59:59.000Z

322

Optimal Control of Vapor Extraction of Heavy Oil.  

E-Print Network (OSTI)

??Vapor extraction (Vapex) process is an emerging technology for viscous oil recovery that has gained much attention in the oil industry. However, the oil production… (more)

Muhamad, Hameed (Author)

2012-01-01T23:59:59.000Z

323

Geographic Information System At Cove Fort Area - Vapor (Nash...  

Open Energy Info (EERE)

navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Geographic Information System At Cove Fort Area - Vapor (Nash, Et Al., 2002) Exploration Activity Details...

324

Raman Lidar Measurements of Aerosols and Water Vapor During the...  

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

modifications reduced but could not eliminate these adverse effects. The Raman lidar water vapor (aerosol extinction) measurements produced by these modified algorithms were,...

325

Thermal Gradient Holes At Cove Fort Area - Vapor (Warpinski,...  

Open Energy Info (EERE)

Warpinski, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Cove Fort Area - Vapor (Warpinski, Et Al.,...

326

Ground Magnetics At Cove Fort Area - Vapor (Warpinski, Et Al...  

Open Energy Info (EERE)

Vapor (Warpinski, Et Al., 2004) Exploration Activity Details Location Cove Fort Geothermal Area Exploration Technique Ground Magnetics Activity Date Usefulness useful DOE-funding...

327

Manufacturing Cost Analysis Relevant to Single-and Dual-Junction Photovoltaic Cells Fabricated with III-Vs and III-Vs Grown on Czochralski Silicon (Presentation)  

SciTech Connect

In this analysis we examine the current, mid-term, and long-term manufacturing costs for III-Vs deposited by traditional Metal Organic Vapor Phase Epitaxy (MOVPE).

Woodhouse, M.; Goodrich, A.

2014-05-01T23:59:59.000Z

328

Sandia National Laboratories: Light Creation Materials  

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

from AlGaN LEDs could also be used to pump RGB phosphors, as mentioned above. Nitride materials are usually grown by Metal Organic Vapor Phase Epitaxy (MOVPE)-also referred to as...

329

Substrate-dependent post-annealing effects on the strain state and electrical transport of epitaxial La{sub 5/8-y}Pr{sub y}Ca{sub 3/8}MnO{sub 3} films  

SciTech Connect

Large scale electronic phase separation (EPS) between ferromagnetic metallic and charge-ordered insulating phases in La{sub 5/8-y}Pr{sub y}Ca{sub 3/8}MnO{sub 3} (y = 0.3) (LPCMO) is very sensitive to the structural changes. This work investigates the effects of post-annealing on the strain states and electrical transport properties of LPCMO films epitaxially grown on (001){sub pc} SrTiO{sub 3} (tensile strain), LaAlO{sub 3} (compressive strain) and NdGaO{sub 3} (near-zero strain) substrates. Before annealing, all the films are coherent-epitaxial and insulating through the measured temperature range. Obvious change of film lattice is observed during the post-annealing: the in-plane strain in LPCMO/LAO varies from ?1.5% to ?0.1% while that in LPCMO/STO changes from 1.6% to 1.3%, and the lattice of LPCMO/NGO keeps constant because of the good lattice-match between LPCMO and NGO. Consequently, the varied film strain leads to the emergence of metal-insulator transitions (MIT) and shift of the critical transition temperature in the electrical transport. These results demonstrate that lattice-mismatch combined with post-annealing is an effective approach to tune strain in epitaxial LPCMO films, and thus to control the EPS and MIT in the films.

Hu, Sixia; Wang, Haibo; Dong, Yongqi; Hong, Bing; He, Hao; Bao, Jun [National Synchrotron Radiation Laboratory and School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China); Huang, Haoliang [CAS Key Laboratory of Materials for Energy Conversion and Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230026 (China); Yang, Yuanjun; Luo, Zhenlin, E-mail: zlluo@ustc.edu.cn; Yang, Mengmeng; Gao, Chen, E-mail: cgao@ustc.edu.cn [National Synchrotron Radiation Laboratory and School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China); CAS Key Laboratory of Materials for Energy Conversion and Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2014-06-15T23:59:59.000Z

330

Synthesis of alloys with controlled phase structure  

DOE Patents (OSTI)

A method for preparing controlled phase alloys useful for engineering and hydrogen storage applications. This novel method avoids melting the constituents by employing vapor transport, in a hydrogen atmosphere, of an active metal constituent, having a high vapor pressure at temperatures .apprxeq.300 C. and its subsequent condensation on and reaction with the other constituent (substrate) of an alloy thereby forming a controlled phase alloy and preferably a single phase alloy. It is preferred that the substrate material be a metal powder such that diffusion of the active metal constituent, preferably magnesium, and reaction therewith can be completed within a reasonable time and at temperatures .apprxeq.300 C. thereby avoiding undesirable effects such as sintering, local compositional inhomogeneities, segregation, and formation of unwanted second phases such as intermetallic compounds.

Guthrie, Stephen Everett (Livermore, CA); Thomas, George John (Livermore, CA); Bauer, Walter (Livermore, CA); Yang, Nancy Yuan Chi (Lafayette, CA)

1999-04-20T23:59:59.000Z

331

Synthesis of alloys with controlled phase structure  

DOE Patents (OSTI)

A method is described for preparing controlled phase alloys useful for engineering and hydrogen storage applications. This novel method avoids melting the constituents by employing vapor transport, in a hydrogen atmosphere, of an active metal constituent, having a high vapor pressure at temperatures {approx_equal}300 C and its subsequent condensation on and reaction with the other constituent (substrate) of an alloy thereby forming a controlled phase alloy and preferably a single phase alloy. It is preferred that the substrate material be a metal powder such that diffusion of the active metal constituent, preferably magnesium, and reaction therewith can be completed within a reasonable time and at temperatures {approx_equal}300 C thereby avoiding undesirable effects such as sintering, local compositional inhomogeneities, segregation, and formation of unwanted second phases such as intermetallic compounds. 4 figs.

Guthrie, S.E.; Thomas, G.J.; Bauer, W.; Yang, N.Y.C.

1999-04-20T23:59:59.000Z

332

Si(001):B gas-source molecular-beam epitaxy: Boron surface segregation and its effect on film growth kinetics  

E-Print Network (OSTI)

The use of disilane (Si2H6) rather than silane (SiH4) for Si 001 gas-source molecular-beam epitaxy GS

Spila, Timothy P.

333

Integration of Global Positioning System and Scanning Water Vapor Radiometers for Precipitable Water Vapor and Cloud Liquid Path Estimates  

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

Integration of Global Positioning System and Scanning Integration of Global Positioning System and Scanning Water Vapor Radiometers for Precipitable Water Vapor and Cloud Liquid Path Estimates V. Mattioli and P. Basili Department of Electronic and Information Engineering University of Perugia Perugia, Italy E. R. Westwater Cooperative Institute for Research in Environmental Sciences University of Colorado National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado Introduction In recent years the Global Positioning System (GPS) has proved to be a reliable instrument for measuring precipitable water vapor (PWV) (Bevis et al. 1992), offering an independent source of information on water vapor when compared with microwave radiometers (MWRs), and/or radiosonde

334

Vapor and gas sampling of Single-Shell Tank 241-T-111 using the vapor sampling system  

SciTech Connect

This document presents sampling data resulting from the January 20, 1995, sampling of SST 241-T-111 using the vapor sampling system.

Caprio, G.S.

1995-09-01T23:59:59.000Z

335

Vapor and gas sampling of single-shell tank 241-BY-112 using the vapor sampling system  

SciTech Connect

This document presents sampling data from the November 18, 1994, sampling of SST 241-BY-112 using the vapor sampling system.

Caprio, G.S.

1995-09-20T23:59:59.000Z

336

Development of a Water Based, Critical Flow, Non-Vapor Compression cooling Cycle  

SciTech Connect

Expansion of a high-pressure liquid refrigerant through the use of a thermostatic expansion valve or other device is commonplace in vapor-compression cycles to regulate the quality and flow rate of the refrigerant entering the evaporator. In vapor-compression systems, as the condensed refrigerant undergoes this expansion, its pressure and temperature drop, and part of the liquid evaporates. We (researchers at Kansas State University) are developing a cooling cycle that instead pumps a high-pressure refrigerant through a supersonic converging-diverging nozzle. As the liquid refrigerant passes through the nozzle, its velocity reaches supersonic (or critical-flow) conditions, substantially decreasing the refrigerant’s pressure. This sharp pressure change vaporizes some of the refrigerant and absorbs heat from the surrounding conditions during this phase change. Due to the design of the nozzle, a shockwave trips the supersonic two-phase refrigerant back to the starting conditions, condensing the remaining vapor. The critical-flow refrigeration cycle would provide space cooling, similar to a chiller, by running a secondary fluid such as water or glycol over one or more nozzles. Rather than utilizing a compressor to raise the pressure of the refrigerant, as in a vapor-cycle system, the critical-flow cycle utilizes a high-pressure pump to drive refrigerant liquid through the cooling cycle. Additionally, the design of the nozzle can be tailored for a given refrigerant, such that environmentally benign substances can act as the working fluid. This refrigeration cycle is still in early-stage development with prototype development several years away. The complex multi-phase flow at supersonic conditions presents numerous challenges to fully understanding and modeling the cycle. With the support of DOE and venture-capital investors, initial research was conducted at PAX Streamline, and later, at Caitin. We (researchers at Kansas State University) have continued development of the cycle and have gained an in-depth understanding of the governing fundamental knowledge, based on the laws of physics and thermodynamics and verified with our testing results. Through this research, we are identifying optimal working fluid and operating conditions to eventually demonstrate the core technology for space cooling or other applications.

Hosni, Mohammad H.

2014-03-30T23:59:59.000Z

337

The Hall mobility measurement of Liquid Phase Epitaxy grown aluminum gallium arsenide  

E-Print Network (OSTI)

allows lasing action at or above room temperature. The utility of AI?Ga& ?As is based on the close latti&e match to GaAs over a range of Al mole fraction between zero and one(Fig. 1)IS). This is significant since heterojunctions between s...-type by occupying the site normally orc?pi& d by th& gro?p V element, ar?l acting as a donor. For the p-type of AI?Ga& ?As. %1g was used as an i&np?ri&y. Fig. 10 and Fig. 11 show I he r&'lal ionship bet wc?n th& in&p?r&I& & o???& r?t ?&n??&l t he alorr&i& weight...

Choi, Young-Shig

2012-06-07T23:59:59.000Z

338

Chemical vapor deposition of amorphous silicon films from disilane  

SciTech Connect

Amorphous silicon films for fabrication of solar cells have been deposited by thermal chemical vapor deposition (CVD) from disilane (Si/sub 2/H/sub 6/) using a tubular flow reactor. A mathematical description for the CVD reactor was developed and solved by a numerical procedure. The proposed chemical reaction network for the model is based on silylene (SiH/sub 2/) insertion in the gas phase and film growth from SiH/sub 2/ and silicon polymers (Si/sub n/N/sub 2n/, n approx. 10). Estimates of the rate constants have been obtained for trisilane decomposition, silicon polymer formation, and polymer dehydrogenation. The silane unimolecular decomposition rate constants were corrected for pressure effects. The model behavior is compared to the experimental results over the range of conditions: reactor temperature (360 to 485/sup 0/C), pressures (2 to 48 torr), and gas holding time (1 to 70 s). Within the above range of conditions, film growth rate varies from 0.01 to 30 A/s. Results indicate that silicon polymers are the main film precursors for gas holding times greater than 3 s. Film growth by silylene only becomes important at short holding times, large inert gas dilution, and positions near the beginning of the reactor hot zone.

Bogaert, R.J.

1986-01-01T23:59:59.000Z

339

Informal Report . VAPOR DETECTION OF TRAFFICKING OF CONTRABAND MONEY-  

E-Print Network (OSTI)

I BNL- 62834 Informal Report . VAPOR DETECTION OF TRAFFICKING OF CONTRABAND MONEY-· [D VAPOR DETECTION OF TRAFFICKING OF CONTRABAND MONEY- A DISCUSSION OF TECHNICAL FEASIBILITY Concept MONEY --A DISCUSSION OF TECHNICAL FEASffiILITY Russell N. Dietz, Head Tracer Technology Center

340

RESONANT FARADAY ROTATION IN A HOT LITHIUM VAPOR  

E-Print Network (OSTI)

RESONANT FARADAY ROTATION IN A HOT LITHIUM VAPOR By SCOTT RUSSELL WAITUKAITIS A Thesis Submitted: #12;Abstract I describe a study of Faraday rotation in a hot lithium vapor. I begin by dis- cussing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.3 The Lithium Oven and Solenoid . . . . . . . . . . . . . . . . . 7 3 Theoretical Framework

Cronin, Alex D.

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


341

Gas: A Neglected Phase in Remediation of Metals and Radionuclides  

SciTech Connect

The gas phase is generally ignored in remediation of metals and radionuclides because it is assumed that there is no efficient way to exploit it. In the literal sense, all remediations involve the gas phase because this phase is linked to the liquid and solid phases by vapor pressure and thermodynamic relationships. Remediation methods that specifically use the gas phase as a central feature have primarily targeted volatile organic contaminants, not metals and radionuclides. Unlike many organic contaminants, the vapor pressure and Henry's Law constants of metals and radionuclides are not generally conducive to direct air stripping of dissolved contaminants. Nevertheless, the gas phase can play an important role in remediation of inorganic contaminants and provide opportunities for efficient, cost effective remediation. The objective here is to explore ways in which manipulation of the gas phase can be used to facilitate remediation of metals and radionuclides.

Denham, Miles E.; Looney, Brian B

2005-09-28T23:59:59.000Z

342

Formation behavior of Be{sub x}Zn{sub 1-x}O alloys grown by plasma-assisted molecular beam epitaxy  

SciTech Connect

We report the phase formation behavior of Be{sub x}Zn{sub 1-x}O alloys grown by plasma-assisted molecular beam epitaxy. We find the alloy with low- and high-Be contents could be obtained by alloying BeO into ZnO films. X-ray diffraction measurements shows the c lattice constant value shrinks, and room temperature absorption shows the energy band-gap widens after Be incorporated. However, the alloy with intermediate Be composition are unstable and segregated into low- and high-Be contents BeZnO alloys. We demonstrate the phase segregation of Be{sub x}Zn{sub 1-x}O alloys with intermediate Be composition resulted from large internal strain induced by large lattice mismatch between BeO and ZnO.

Chen, Mingming; Zhu, Yuan; Su, Longxing; Zhang, Quanlin; Chen, Anqi; Ji, Xu; Xiang, Rong; Gui, Xuchun; Wu, Tianzhun [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China)] [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Pan, Bicai [Department of Physics and Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China)] [Department of Physics and Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Tang, Zikang [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China) [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China)

2013-05-20T23:59:59.000Z

343

The effect of oxygen flow rate and radio frequency plasma power on cubic ZnMgO ultraviolet sensors grown by plasma-enhanced molecular beam epitaxy  

SciTech Connect

Cubic Zn{sub 1-x}Mg{sub x}O thin films were produced by Plasma-Enhanced Molecular Beam Epitaxy. Oxygen flow rate and applied Radio-Frequency (RF) plasma power were varied to investigate the impact on film growth and optoelectronic device performance. Solar-blind and visible-blind detectors were fabricated with metal-semiconductor-metal interdigitated Ni/Mg/Au contacts and responsivity is compared under different growth conditions. Increasing oxygen flow rate and RF plasma power increased Zn incorporation in the film, which leads to phase segregation at relatively high Zn/Mg ratio. Responsivity as high as 61 A/W was measured in phase-segregated ZnMgO visible-blind detectors.

Casey Boutwell, R.; Wei Ming; Schoenfeld, Winston V. [CREOL, College of Optics and Photonics, University of Central Florida, Orlando, Florida 32816-2700 (United States)

2013-07-15T23:59:59.000Z

344

FLAMMABILITY CHARACTERISTICS OF COMBUSTIBLE GASES AND VAPORS  

Office of Scientific and Technical Information (OSTI)

Bulletin 627 Bulletin 627 BUREAU o b MINES FLAMMABILITY CHARACTERISTICS OF COMBUSTIBLE GASES AND VAPORS By Michael G. Zabetakis DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency Thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement,

345

New Regenerative Cycle for Vapor Compression Refrigeration  

Office of Scientific and Technical Information (OSTI)

SCIENTIFIC REPORT SCIENTIFIC REPORT Title Page Project Title: New Regenerative Cycle for Vapor Compression Refrigeration DOE Award Number: DE-FG36-04GO14327 Document Title: Final Scientific Report Period Covered by Report: September 30, 2004 to September 30, 2005 Name and Address of Recipient Organization: Magnetic Development, Inc., 68 Winterhill Road, Madison, CT 06443, phone: 203-214-7247, fax: 203-421-7948, e-mail: mjb1000@aol.com Contact Information: Mark J. Bergander, Ph.D., P.E., Principal Investigator, phone: 203-214-7247, fax: 203-421-7948, e-mail: mjb1000@aol.com Project Objective (as stated in the proposal): The main objective of this project is to confirm on a well-instrumented prototype the theoretically derived claims of higher efficiency and coefficient

346

Chemical vapor deposition of group IIIB metals  

DOE Patents (OSTI)

Coatings of Group IIIB metals and compounds thereof are formed by chemical vapor deposition, in which a heat decomposable organometallic compound of the formula given in the patent where M is a Group IIIB metal, such as lanthanum or yttrium and R is a lower alkyl or alkenyl radical containing from 2 to about 6 carbon atoms, with a heated substrate which is above the decomposition temperature of the organometallic compound. The pure metal is obtained when the compound of the formula 1 is the sole heat decomposable compound present and deposition is carried out under nonoxidizing conditions. Intermetallic compounds such as lanthanum telluride can be deposited from a lanthanum compound of formula 1 and a heat decomposable tellurium compound under nonoxidizing conditions.

Erbil, A.

1989-11-21T23:59:59.000Z

347

Kinetics of wet sodium vapor complex plasma  

SciTech Connect

In this paper, we have investigated the kinetics of wet (partially condensed) Sodium vapor, which comprises of electrons, ions, neutral atoms, and Sodium droplets (i) in thermal equilibrium and (ii) when irradiated by light. The formulation includes the balance of charge over the droplets, number balance of the plasma constituents, and energy balance of the electrons. In order to evaluate the droplet charge, a phenomenon for de-charging of the droplets, viz., evaporation of positive Sodium ions from the surface has been considered in addition to electron emission and electron/ion accretion. The analysis has been utilized to evaluate the steady state parameters of such complex plasmas (i) in thermal equilibrium and (ii) when irradiated; the results have been graphically illustrated. As a significant outcome irradiated, Sodium droplets are seen to acquire large positive potential, with consequent enhancement in the electron density.

Mishra, S. K., E-mail: nishfeb@rediffmail.com [Institute for Plasma Research (IPR), Gandhinagar 382428 (India); Sodha, M. S. [Centre of Energy Studies, Indian Institute of Technology Delhi (IITD), New Delhi 110016 (India)] [Centre of Energy Studies, Indian Institute of Technology Delhi (IITD), New Delhi 110016 (India)

2014-04-15T23:59:59.000Z

348

Epitaxial growth in dislocation-free strained asymmetric alloy films  

Science Journals Connector (OSTI)

Epitaxial growth in strained asymmetric, dislocation-free, coherent, alloy films is explored. Linear-stability analysis is used to theoretically analyze the coupled instability arising jointly from the substrate-film lattice mismatch (morphological instability) and the spinodal decomposition mechanism. Both the static and growing films are considered. Role of various parameters in determining stability regions for a coherent growing alloy film is investigated. In addition to the usual parameters: lattice mismatch ?, solute-expansion coefficient ?, growth velocity V, and growth temperature T, we consider the alloy asymmetry arising from its mean composition. The dependence of elastic moduli on composition fluctuations and the coupling between top surface and underlying bulk of the film also play important roles. The theory is applied to group III-V films such as GaAsN, InGaN, and InGaP and to group IV Si-Ge films at temperatures below the bare critical temperature Tc for strain-free spinodal decomposition. The dependences of various material parameters on mean concentration and temperature lead to significant qualitative changes.

Rashmi C. Desai; HoKwon Kim; Apratim Chatterji; Darryl Ngai; Si Chen; Nan Yang

2010-06-01T23:59:59.000Z

349

Structure and epitaxy studies of cobalt silicide/silicon heterostructures  

SciTech Connect

When considering transition metal silicides for use in integrated circuit technology, CoSi{sub 2} stands out as a silicide possessing an excellent combination of properties. However, the detrimental effects of CoSi{sub 2} pinhole formation seriously restricts the applicability of this silicide system. This study examines the structure/processing/property relationship of thin film cobalt silicide/silicon heterostructures grown on Si(111). The two primary objectives were: (1) identify the basic mechanisms associated with pinhole formation and cobalt silicide thin film growth; and (2) characterization of cobalt silicides grown by Si{sub a}/Co/Si{sub c} multilayer deposition and reaction and the effect this deposition technique has on the microstructure of cobalt silicide thin films. Interfacial pinhole formation was identified at the CoSi/Si interface and involves several active mechanisms. Epitaxial pinhole free CoSi{sub 2} films were grown by single-step annealing Si{sub a}/Co/Si{sub c} multilayer structures. Two step annealing Si{sub a}/Co/Si{sub c} multilayer thin films results in polycrystalline CoSi{sub 2}.

Zaluzec, M.J.

1991-01-01T23:59:59.000Z

350

Maskless lateral epitaxial overgrowth of GaN on sapphire  

SciTech Connect

The authors demonstrate a technique of lateral epitaxial overgrowth (LEO) of GaN, termed maskless LEO, in which no mask is deposited prior to LEO regrowth. Instead, a bulk (> 2 {micro}m) GaN layer on sapphire is selectively dry etched, leaving {approximately} 5 {micro}m-wide stripe mesas oriented in the <10{bar 1}0>{sub GaN} direction, with a 20 {micro}m period. These stripes serve as seeds for LEO GaN growth, which proceeds from the tops of the stripes and expands laterally, resulting in a T, or overhang, morphology. As for LEO over an SiO{sub 2} mask, significant defect reduction (from {approximately} 10{sup 9} cm{sup {minus}2} to {approximately} 10{sup 6} cm{sup {minus}2}) is observed in cross-sectional transmission electron microscopy (TEM). Atomic force microscopy of the top surface of the LEO GaN reveals that no threading dislocations with screw component terminate at the surfaces of laterally overgrown regions. X-ray diffraction measurements reveal that the wings exhibit a crystallographic tilt away from the seed regions in an azimuth perpendicular to the stripe direction; the tilt angle ({approximately} 0.4--0.5{degree}) is relatively independent of growth temperature and wing aspect ratio.

Fini, P.; Marchand, H.; Ibbetson, J.P.; Moran, B.; Zhao, L.; Denbaars, S.P.; Speck, J.S.; Mishra, U.K.

1999-07-01T23:59:59.000Z

351

New frontier in thin film epitaxy and nanostructured materials  

Science Journals Connector (OSTI)

Nanomaterials hold the key to the success of nanotechnology. This review starts with a new paradigm for thin film growth based upon matching of integral multiples of lattice planes across the film-substrate interface. This paradigm of domain matching epitaxy (DME) unifies small as well as large misfit systems utilising the concept of systematic domain variation. By controlling the kinetics of clustering and energetics of interfaces, it is possible to obtain nanoclusters of uniform size and create novel nanostructured materials by design, where relative orientation with respect to matrix can be controlled by DME. In nanostructured materials with unit dimensions 1â??100 nm, science and processing challenges include self-assembly processing, control of interfacial atoms and energetics, quantum confinement issues, nanoscale structure-property correlations. In addition, metastability of interfaces should be controlled for reliability in manufacturing of nanosystems. This paper presents fundamentals of synthesis and processing of nanomaterials, role of interfaces, nanoscale characterisation to establish atomic structure-property correlations and modelling to create novel nanostructured structural, magnetic, photonic and electronic systems with unique and improved properties for next-generation systems with new functionality.

Jagdish Narayan

2009-01-01T23:59:59.000Z

352

Low temperature epitaxial growth of Ge on cube- textured Ni  

SciTech Connect

Quasi- single crystal Ge films were grown on [001]<010> textured Ni substrate at a temperature of 350 oC using an insulating buffer layer of CaF2. A direct deposition of Ge on Ni at 350 oC was shown to alloy with Ni. From x- ray pole figure analysis, it was shown that Ge grew epitaxially with the same orientation as CaF2 and the dispersions in the out- of- plane and in- plane directions were found to be 1.7 0.1o and 6 1o, respectively. In the out- of- plane direction, Ge[111]||CaF2[111]||Ni[001]. In addition, the Ge consisted of four equivalent in- plane oriented domains such that two mutually orthogonal directions: Ge 211 and Ge 011 are parallel to mutually orthogonal directions: Ni 110 and Ni 110 , respectively of the Ni(001) surface. This was shown to be originated from the four equivalent in- plane oriented domains of CaF2 created to minimize the mismatch strain between CaF2 and Ni in those directions.

GIARE, C [Rensselaer Polytechnic Institute (RPI); Palazzo, J [Rensselaer Polytechnic Institute (RPI); Goyal, Amit [ORNL; WANG, G [Rensselaer Polytechnic Institute (RPI); LU, T [Rensselaer Polytechnic Institute (RPI)

2012-01-01T23:59:59.000Z

353

Photo-Electric Ionization of Caesium Vapor  

Science Journals Connector (OSTI)

Measurement of photo-electric ionization in gases.—The current from a filament, normally limited by space change, is increased by the presence of positive ions. As shown by Kingdon this effect may be greatly magnified if a small cathode is practically enclosed by the anode so that the ions are imprisoned. This method was used for the detection of photo-electric ionization. Besides possessing extreme sensitivity it is unaffected by photo-electric emission from the electrodes.Photo-electric effect in caesium vapor.—The change in thermionic current with the unresolved radiation from a mercury arc was measured as functions of the applied voltage, filament temperature, and vapor pressure. Then the photo-electric effect as a function of wave-length was studied using a monochromatic illuminator to disperse light from the arc or a Mazda lamp. The ionization per unit flux was found to increase with increasing wave-length to a sharp maximum at the limit 1s=3184A of the principal series, as is required by the Bohr theory. For longer wave-lengths the ionization decreased to about 10 percent at 3400A. Photo-excitation. The simple theory does not admit of ionization by wave-lengths greater than 3184A but the data are in qualitative agreement with the hypothesis that such radiation produces excited atoms which upon collision with other atoms acquire sufficient additional energy to become ionized. Hence, unlike an x-ray limit, the photo-ionization effect for a valence electron is not sharply discontinuous at the true threshold for direct ionization.Photo-ionization photometer and intensitometer. A tube of the type described, with suitable gases for the range of wave-length involved, may be used as a photometer or may be calibrated to measure intensity of radiation directly.

Paul D. Foote and F. L. Mohler

1925-08-01T23:59:59.000Z

354

Gas Separation Using Organic-Vapor-Resistent Membranes In Conjunctin With Organic-Vapor-Selective Membranes  

DOE Patents (OSTI)

A process for treating a gas mixture containing at least an organic compound gas or vapor and a second gas, such as natural gas, refinery off-gas or air. The process uses two sequential membrane separation steps, one using membrane selective for the organic compound over the second gas, the other selective for the second gas over the organic vapor. The second-gas-selective membranes use a selective layer made from a polymer having repeating units of a fluorinated polymer, and demonstrate good resistance to plasticization by the organic components in the gas mixture under treatment, and good recovery after exposure to liquid aromatic hydrocarbons. The membrane steps can be combined in either order.

Baker, Richard W. (Palo Alto, CA); Pinnau, Ingo (Palo Alto, CA); He, Zhenjie (Fremont, CA); Da Costa, Andre R. (Menlo Park, CA); Daniels, Ramin (San Jose, CA); Amo, Karl D. (Mountain View, CA); Wijmans, Johannes G. (Menlo Park, CA)

2003-06-03T23:59:59.000Z

355

Hybrid Vapor Compression Adsorption System: Thermal Storage Using Hybrid Vapor Compression Adsorption System  

SciTech Connect

HEATS Project: UTRC is developing a new climate-control system for EVs that uses a hybrid vapor compression adsorption system with thermal energy storage. The targeted, closed system will use energy during the battery-charging step to recharge the thermal storage, and it will use minimal power to provide cooling or heating to the cabin during a drive cycle. The team will use a unique approach of absorbing a refrigerant on a metal salt, which will create a lightweight, high-energy-density refrigerant. This unique working pair can operate indefinitely as a traditional vapor compression heat pump using electrical energy, if desired. The project will deliver a hot-and-cold battery that provides comfort to the passengers using minimal power, substantially extending the driving range of EVs.

None

2012-01-04T23:59:59.000Z

356

E-Print Network 3.0 - atomic vapor laser Sample Search Results  

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

with the exception of pagination. IEEE TRANSACTIONS ON PLASMA SCIENCE 1 Summary: vapor, atomic physics and vapor ionization, absorption reflection in a heated plasma layer, and...

357

E-Print Network 3.0 - atom vapor cells Sample Search Results  

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

rotation in the vapor cell due to inten- sity-induced birefringence in the rubidium atomic vapor. While... Super efficient absorption filter for quantum memory using atomic...

358

Electrical properties of scandium nitride epitaxial films grown on (100) magnesium oxide substrates by molecular beam epitaxy  

SciTech Connect

Scandium nitride (ScN) films were grown on (100) MgO single crystals by a molecular beam epitaxy method. The effects of growth conditions, including [Sc]/[N] ratio, growth temperature, and nitrogen radical state, on the electrical properties of the ScN films were studied. The ScN films comprised many small columnar grains. Hall coefficient measurements confirmed that the ScN films were highly degenerate n-type semiconductors and that the carrier concentration of the ScN films was sensitive to the growth temperature and the nitrogen radical states during the film growth. The carrier concentrations of the ScN films ranged from 10{sup 19}–10{sup 21} cm{sup ?3} while the Hall mobilities ranged from 50–130 cm{sup 2}·V{sup ?1}·s{sup ?1} for undoped films. The temperature-dependent Hall coefficient measurements showed that the carrier concentration is nearly independent of temperature, indicating that the change in resistivity with temperature is explained by a change in the Hall mobility. The temperature-dependence of the Hall mobility was strongly affected by the growth conditions.

Ohgaki, Takeshi; Watanabe, Ken; Adachi, Yutaka; Sakaguchi, Isao; Hishita, Shunichi; Ohashi, Naoki; Haneda, Hajime [Environment and Energy Materials Research Division, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)] [Environment and Energy Materials Research Division, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

2013-09-07T23:59:59.000Z

359

Non-adiabatic ab initio molecular dynamics of supersonic beam epitaxy of silicon carbide at room temperature  

E-Print Network (OSTI)

Non-adiabatic ab initio molecular dynamics of supersonic beam epitaxy of silicon carbide at room-adiabatic ab initio molecular dynamics of supersonic beam epitaxy of silicon carbide at room temperature Simone film crystal growth of silicon carbide (SiC), a semiconductor syn- thesized to replace silicon in harsh

Alfè, Dario

360

Electro-oxidized Epitaxial Graphene Channel Field-Effect Transistors with Single-Walled Carbon Nanotube Thin Film  

E-Print Network (OSTI)

Electro-oxidized Epitaxial Graphene Channel Field-Effect Transistors with Single-Walled Carbon on the electronic properties of epitaxial graphene (EG) grown on silicon carbide substrates; we demonstrate the introduction of the reaction medium into the graphene galleries during electro-oxidation. The device

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


361

Epitaxial growth of nickel on Si(100) by dc magnetron sputtering  

SciTech Connect

The influence of the substrate temperature on the growth of highly textured Ni(111) and epitaxial Ni(200) with the relationships Ni[100] parallel Si[110] and Ni(001) parallel Si(001) on hydrogen terminated Si(100) wafer substrates by means of direct current magnetron sputtering is reported. In order to minimize crystal defect formation and to achieve a high quality epitaxial growth of Ni on Si, a two step deposition process was developed whereby different deposition conditions were used for an initial nickel seed layer and the remaining nickel film. The in-plane and out-of-plane structural properties of the films were investigated using x-ray scattering techniques, whereas magneto-optical Kerr effect and neutron reflectometry were used to confirm the magnetic nature of the epitaxially deposited nickel films.

Kreuzpaintner, W.; Stoermer, M.; Lott, D.; Solina, D.; Schreyer, A. [GKSS Forschungszentrum GmbH, Max-Planck-Strasse 1, 21502 Geesthacht (Germany)

2008-12-01T23:59:59.000Z

362

An ultra-thin buffer layer for Ge epitaxial layers on Si  

SciTech Connect

Using an Fe{sub 3}Si insertion layer, we study epitaxial growth of Ge layers on a Si substrate by a low-temperature molecular beam epitaxy technique. When we insert only a 10-nm-thick Fe{sub 3}Si layer in between Si and Ge, epitaxial Ge layers can be obtained on Si. The detailed structural characterizations reveal that a large lattice mismatch of {approx}4% is completely relaxed in the Fe{sub 3}Si layer. This means that the Fe{sub 3}Si layers can become ultra-thin buffer layers for Ge on Si. This method will give a way to realize a universal buffer layer for Ge, GaAs, and related devices on a Si platform.

Kawano, M.; Yamada, S.; Tanikawa, K.; Miyao, M.; Hamaya, K. [Department of Electronics, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan)] [Department of Electronics, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan); Sawano, K. [Advanced Research Laboratories, Tokyo City University, 8-15-1 Todoroki, Tokyo 158-0082 (Japan)] [Advanced Research Laboratories, Tokyo City University, 8-15-1 Todoroki, Tokyo 158-0082 (Japan)

2013-03-25T23:59:59.000Z

363

Molecular beam epitaxial growth and characterization of mixed (Ti,Nb)O{sub 2} rutile films on TiO{sub 2}(100)  

SciTech Connect

Epitaxial films of mixed (Nb,Ti)O{sub 2} rutile have been grown on TiO{sub 2}(100) rutile at 600{degree}C by molecular beam epitaxy. These films grow in a laminar fashion for Nb mole fractions up to {approximately}0.10. In addition, reflection high-energy and low-energy electron diffraction, along with x-ray photoelectron diffraction and Rutherford backscattering reveal that the overlayers possess excellent long- and short-range structure order up to 10 at.{percent}. However, strain-induced disorder becomes prevalent for higher Nb mole fractions, and the surfaces roughen and become defected accordingly. X-ray photoelectron diffraction and Rutherford backscattering reveal that Nb atoms substitutionally incorporate at cation sites in the rutile lattice for all Nb mole fractions investigated, leading to a mixed rutile Nb{sub {ital x}}Ti{sub 1{minus}{ital x}}O{sub 2} phase. Analysis of Nb 3{ital d} and Ti 2{ital p} core-level binding energies reveals that the oxidation state of both Ti and Nb is +4. {copyright} {ital 1996 American Vacuum Society}

Chambers, S.A.; Gao, Y.; Thevuthasan, S.; Liang, Y. [Environmental Molecular Sciences Laboratory, Pacific Northwest Laboratory, Richland, Washington 99352 (United States)] [Environmental Molecular Sciences Laboratory, Pacific Northwest Laboratory, Richland, Washington 99352 (United States); Shivaparan, N.R.; Smith, R.J. [Department of Physics, Montana State University, Bozeman, Montana 59717 (United States)] [Department of Physics, Montana State University, Bozeman, Montana 59717 (United States)

1996-05-01T23:59:59.000Z

364

Mercury Vapor At Medicine Lake Area (Kooten, 1987) | Open Energy  

Open Energy Info (EERE)

Kooten, 1987) Kooten, 1987) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Mercury Vapor At Medicine Lake Area (Kooten, 1987) Exploration Activity Details Location Medicine Lake Area Exploration Technique Mercury Vapor Activity Date Usefulness could be useful with more improvements DOE-funding Unknown References Gerald K. Van Kooten (1987) Geothermal Exploration Using Surface Mercury Geochemistry Retrieved from "http://en.openei.org/w/index.php?title=Mercury_Vapor_At_Medicine_Lake_Area_(Kooten,_1987)&oldid=386431" Category: Exploration Activities What links here Related changes Special pages Printable version Permanent link Browse properties 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation:

365

Effect of substrate temperature on the magnetic properties of epitaxial sputter-grown Co/Pt  

SciTech Connect

Epitaxial Co/Pt films have been deposited by dc-magnetron sputtering onto heated C-plane sapphire substrates. X-ray diffraction, the residual resistivity, and transmission electron microscopy indicate that the Co/Pt films are highly ordered on the atomic scale. The coercive field and the perpendicular magnetic anisotropy increase as the substrate temperature is increased from 100–250?°C during deposition of the Co/Pt. Measurement of the domain wall creep velocity as a function of applied magnetic field yields the domain wall pinning energy, which scales with the coercive field. Evidence for an enhanced creep velocity in highly ordered epitaxial Co/Pt is found.

Mihai, A. P.; Whiteside, A. L.; Canwell, E. J.; Marrows, C. H.; Moore, T. A., E-mail: t.a.moore@leeds.ac.uk [School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom); Benitez, M. J.; McGrouther, D.; McVitie, S.; McFadzean, S. [School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)] [School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

2013-12-23T23:59:59.000Z

366

Magnetism and transport properties of epitaxial Fe-Ga thin films on GaAs(001)  

SciTech Connect

Epitaxial Fe-Ga thin films in disordered bcc {alpha}-Fe crystal structure (A2) have been grown on GaAs(001) by molecular beam epitaxy. The saturated magnetization (M{sub S}) decreased from 1371 to 1105 kA/m with increasing Ga concentration from 10.5 to 24.3 % at room temperature. The lattice parameter increased with the increase in Ga content because of the larger atomic radius of Ga atom than that of Fe. The increase in carrier density with Ga content caused in lower resistivity.

Duong Anh Tuan; Shin, Yooleemi; Cho, Sunglae [Department of Physics, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Dang Duc Dung [Department of Physics, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Department of General Physics, School of Engineering Physics, Ha Noi University of Science and Technology, 1 Dai Co Viet road, Ha Noi (Viet Nam); Vo Thanh Son [Centers for Nanobioenineering and Spintronics, Chungnam National University, Daejon 350-746 (Korea, Republic of)

2012-04-01T23:59:59.000Z

367

Surface photovoltage method for the quality control of silicon epitaxial layers on sapphire  

SciTech Connect

The surface photovoltage method is used to study “silicon-on-sapphire” epitaxial layers with a thickness of 0.3–0.6 ?m, which are used to fabricate p-channel MOS (metal—oxide-semiconductor) transistors with improved radiation hardness. It is shown that the manner in which the photoconductivity of the epitaxial layer decays after the end of a light pulse generated by a light-emitting diode (wavelength ?400 nm) strongly depends on the density of structural defects in the bulk of the structure. This enables control over how a “silicon-on-sapphire” structure is formed to provide the manufacturing of MOS structures with optimal operating characteristics.

Yaremchuk, A. F.; Starkov, A. V.; Zaikin, A. V., E-mail: lynch0000@gmail.com [National Rsearch University MIET (Russian Federation); Alekseev, A. V. [ZAO “Telekom-STV” (Russian Federation); Sokolov, E. M. [ZAO “Epiel” (Russian Federation)

2014-12-15T23:59:59.000Z

368

Step-edge-induced resistance anisotropy in quasi-free-standing bilayer chemical vapor deposition graphene on SiC  

SciTech Connect

The transport properties of quasi-free-standing (QFS) bilayer graphene on SiC depend on a range of scattering mechanisms. Most of them are isotropic in nature. However, the SiC substrate morphology marked by a distinctive pattern of the terraces gives rise to an anisotropy in graphene's sheet resistance, which may be considered an additional scattering mechanism. At a technological level, the growth-preceding in situ etching of the SiC surface promotes step bunching which results in macro steps ?10?nm in height. In this report, we study the qualitative and quantitative effects of SiC steps edges on the resistance of epitaxial graphene grown by chemical vapor deposition. We experimentally determine the value of step edge resistivity in hydrogen-intercalated QFS-bilayer graphene to be ?190???m for step height h{sub S}?=?10?nm and provide proof that it cannot originate from mechanical deformation of graphene but is likely to arise from lowered carrier concentration in the step area. Our results are confronted with the previously reported values of the step edge resistivity in monolayer graphene over SiC atomic steps. In our analysis, we focus on large-scale, statistical properties to foster the scalable technology of industrial graphene for electronics and sensor applications.

Ciuk, Tymoteusz [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Cakmakyapan, Semih; Ozbay, Ekmel [Department of Electrical and Electronics Engineering, Department of Physics, Nanotechnology Research Center, Bilkent University, 06800 Bilkent, Ankara (Turkey); Caban, Piotr; Grodecki, Kacper; Pasternak, Iwona; Strupinski, Wlodek, E-mail: wlodek.strupinski@itme.edu.pl [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Krajewska, Aleksandra [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Institute of Optoelectronics, Military University of Technology, Gen. S. Kaliskiego 2, 00-908 Warsaw (Poland); Szmidt, Jan [Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland)

2014-09-28T23:59:59.000Z

369

Phase equilibrium studies  

SciTech Connect

A phase equilibrium model has been developed for the SRC-I process, as well as the other coal liquefaction processes. It is applicable to both vapor/liquid and liquid/liquid equilibria; it also provides an approximate but adequate description of aqueous mixtures where the volatile electrolyte components dissociate to form ionic species. This report completes the description of the model presented in an earlier report (Mathias and Stein, 1983a). Comparisons of the model to previously published data on coal-fluid mixtures are presented. Further, a preliminary analysis of new data on SRC-I coal fluids is presented. Finally, the current capabilities and deficiencies of the model are discussed. 25 references, 17 figures, 30 tables.

Mathias, P.M.; Stein, F.P.

1983-09-01T23:59:59.000Z

370

Catalytic Reactor For Oxidizing Mercury Vapor  

DOE Patents (OSTI)

A catalytic reactor (10) for oxidizing elemental mercury contained in flue gas is provided. The catalyst reactor (10) comprises within a flue gas conduit a perforated corona discharge plate (30a, b) having a plurality of through openings (33) and a plurality of projecting corona discharge electrodes (31); a perforated electrode plate (40a, b, c) having a plurality of through openings (43) axially aligned with the through openings (33) of the perforated corona discharge plate (30a, b) displaced from and opposing the tips of the corona discharge electrodes (31); and a catalyst member (60a, b, c, d) overlaying that face of the perforated electrode plate (40a, b, c) opposing the tips of the corona discharge electrodes (31). A uniformly distributed corona discharge plasma (1000) is intermittently generated between the plurality of corona discharge electrode tips (31) and the catalyst member (60a, b, c, d) when a stream of flue gas is passed through the conduit. During those periods when corona discharge (1000) is not being generated, the catalyst molecules of the catalyst member (60a, b, c, d) adsorb mercury vapor contained in the passing flue gas. During those periods when corona discharge (1000) is being generated, ions and active radicals contained in the generated corona discharge plasma (1000) desorb the mercury from the catalyst molecules of the catalyst member (60a, b, c, d), oxidizing the mercury in virtually simultaneous manner. The desorption process regenerates and activates the catalyst member molecules.

Helfritch, Dennis J. (Baltimore, MD)

1998-07-28T23:59:59.000Z

371

Laser techniques for studying chemical vapor deposition  

SciTech Connect

Chemical vapor deposition (CVD) is widely used to produce thin films for microelectronics, protective coatings and other materials processing applications. Despite the large number of applications, however, little is known about the fundamental chemistry and physics of most CVD processes. CVD recipes have generally been determined empirically, but as process requirements become more stringent, a more basic understanding will be needed to improve reactor design and speed process optimization. In situ measurements of the reacting gas are important steps toward gaining such an understanding, both from the standpoint of characterizing the reactor and testing models of a CVD process. Our work, a coordinated program of experimental and theoretical research in the fundamental mechanisms of CVD, illustrates the application of laser techniques to the understanding of a CVD system. We have used a number of laser-based techniques to probe CVD systems and have compared our measurements with predictions from computer models, primarily for the silane CVD system. The silane CVD model solves the two-dimensional, steady-state boundary layer equations of fluid flow coupled to 26 elementary chemical reactions describing the thermal decomposition of silane and the subsequent reactions of intermediate species that result in the deposition of a silicon film.

Ho, P.; Breiland, W.G.; Coltrin, M.E.

1990-01-01T23:59:59.000Z

372

Lattice mismatched epitaxy of heterostructures for non-nitride green light emitting devices  

E-Print Network (OSTI)

In this project, we implement modern metal organic chemical vapor deposition (MOCVD) technology to fabricate monolithic platforms which integrate traditionally incompatible materials with the ultimate goal of achieving ...

Mori, Michael James

2008-01-01T23:59:59.000Z

373

Phase five  

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

Phase five Phase five 1663 Los Alamos science and technology magazine Latest Issue:November 2013 All Issues » submit Phase five Los Alamos physicists have conclusively demonstrated the existence of a new phase of matter. November 25, 2013 Phase five Scientists still have more to learn about the exotic physics of specialty materials. What makes the cuprates special? How about a new phase of matter. Ceramic metals known as cuprates have mystified physicists for decades. They exhibit a variety of distinct phases of matter, each with its own specific properties, including a phase bearing an exotic type of magnetism, a high-temperature superconducting phase, an ordinary metal phase, a poorly understood and weird metallic phase simply called a strange metal, and an equally poorly understood metallic phase known as the pseudogap. The

374

ARM - Field Campaign - Arctic Winter Water Vapor IOP  

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

govCampaignsArctic Winter Water Vapor IOP govCampaignsArctic Winter Water Vapor IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Arctic Winter Water Vapor IOP 2004.03.09 - 2004.04.09 Lead Scientist : Ed Westwater Data Availability http://www.etl.noaa.gov/programs/2004/wviop/data will contain quicklooks of all of the data. For data sets, see below. Summary During the IOP, the Ground-based Scanning Radiometer of NOAA/ETL, and the ARM MicroWave Radiometer and Microwave Profiler, yielded excellent data over a range of conditions. In all, angular-scanned and calibrated radiometric data from 22.345 to 380 GHz were taken. The Precipitable Water Vapor varied about an order of magnitude from 1 to 10 mm, and surface temperatures varied from about -10 to -40 deg. Celcius. Vaisala RS90

375

Overview of the ARM/FIRE Water Vapor Experiment (AFWEX)  

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

Overview of the ARM/FIRE Water Vapor Overview of the ARM/FIRE Water Vapor Experiment (AFWEX) D. C. Tobin, H. E. Revercomb, and D. D. Turner University of Wisconsin-Madison Madison, Wisconsin Introduction An overview of the ARM/FIRE Water Vapor Experiment (AFWEX) is given. This field experiment was conducted during November-December 2000 near the central ground-based Atmospheric Radiation Measurement (ARM) site in north central Oklahoma, and was sponsored jointly by the ARM, the National Aeronautics and Space Administration (NASA) First ISCCP Regional Experiment (FIRE), and the National Polar-orbiting Operational Environmental Satellite System (NPOESS) programs. Its primary goal was to collect accurate measurements of upper-level (~8 to 12 km) water vapor near the ground-based ARM site. These data are being used to determine the accuracy of measurements that are

376

Initiated chemical vapor deposition of functional polyacrylic thin films  

E-Print Network (OSTI)

Initiated chemical vapor deposition (iCVD) was explored as a novel method for synthesis of functional polyacrylic thin films. The process introduces a peroxide initiator, which can be decomposed at low temperatures (<200?C) ...

Mao, Yu, 1975-

2005-01-01T23:59:59.000Z

377

Low Level Heat Recovery Through Heat Pumps and Vapor Recompression  

E-Print Network (OSTI)

The intent of this paper is to examine the methods and economics of recovering low level heat through heat pumps and vapor recompression. Actual commercially available equipment is considered to determine the near-term and future economic viability...

Gilbert, J.

1980-01-01T23:59:59.000Z

378

Applications of Mechanical Vapor Recompression to Evaporation and Crystallization  

E-Print Network (OSTI)

there is no boiler plant available or when electrical power is priced competitively in comparison to steam. Vapor recompression is accomplished using centrifugal, axial-flow, or positive displacement compressors and these compressors can be powered by electricity...

Outland, J. S.

379

Enabling integration of vapor-deposited polymer thin films  

E-Print Network (OSTI)

Initiated Chemical Vapor Deposition (iCVD) is a versatile, one-step process for synthesizing conformal and functional polymer thin films on a variety of substrates. This thesis emphasizes the development of tools to further ...

Petruczok, Christy D. (Christy Danielle)

2014-01-01T23:59:59.000Z

380

Hyperfine Studies of Lithium Vapor using Saturated Absorption Spectroscopy  

E-Print Network (OSTI)

the frequency of a laser with respect to an atomic spectral feature.[20] As such, saturated absorptionHyperfine Studies of Lithium Vapor using Saturated Absorption Spectroscopy? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.3 Broadening Mechanisms . . . . . . . . . . . . . . . . . . . . . 15 3.4 Saturated Absorption

Cronin, Alex D.

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


381

All graphene electromechanical switch fabricated by chemical vapor deposition  

E-Print Network (OSTI)

We demonstrate an electromechanical switch comprising two polycrystalline graphene films; each deposited using ambient pressure chemical vapor deposition. The top film is pulled into electrical contact with the bottom film ...

Milaninia, Kaveh M.

382

Systems and methods for generation of hydrogen peroxide vapor  

DOE Patents (OSTI)

A system according to one embodiment includes a moisture trap for drying air; at least one of a first container and a second container; and a mechanism for at least one of: bubbling dried air from the moisture trap through a hydrogen peroxide solution in the first container for producing a hydrogen peroxide vapor, and passing dried air from the moisture trap into a headspace above a hydrogen peroxide solution in the second container for producing a hydrogen peroxide vapor. A method according one embodiment includes at least one of bubbling dried air through a hydrogen peroxide solution in a container for producing a first hydrogen peroxide vapor, and passing dried air from the moisture trap into a headspace above the hydrogen peroxide solution in a container for producing a second hydrogen peroxide vapor. Additional systems and methods are also presented.

Love, Adam H; Eckels, Joel Del; Vu, Alexander K; Alcaraz, Armando; Reynolds, John G

2014-12-02T23:59:59.000Z

383

Optical Precursors in Rubidium Vapor and Their Relation to Superradiance  

E-Print Network (OSTI)

Optical precursor is the sharp optical pulse front that does not show delay in absorptive media. In this thesis, optical precursor behavior in rubidium (Rb) vapor was investigated in the picoseconds regime. An amplified femtosecond laser was shaped...

Yang, Wenlong

2012-10-19T23:59:59.000Z

384

Photocoupling of Methane in Water Vapor to Saturated Hydrocarbons  

Science Journals Connector (OSTI)

Methane can be converted into alkanes (from C2 to C6) continuously by ultraviolet (185 nm) irradiation in the presence of water vapor. The products from this reaction are alkanes, which is different from the comp...

JunePyo Oh; Taketoshi Matsumoto; Junji Nakamura

2008-08-01T23:59:59.000Z

385

Mercury Vapor At Kawaihae Area (Thomas, 1986) | Open Energy Information  

Open Energy Info (EERE)

Mercury Vapor At Kawaihae Area (Thomas, 1986) Mercury Vapor At Kawaihae Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Mercury Vapor At Kawaihae Area (Thomas, 1986) Exploration Activity Details Location Kawaihae Area Exploration Technique Mercury Vapor Activity Date Usefulness not useful DOE-funding Unknown Notes The soil geochemistry yielded quite complex patterns of mercury concentrations and radonemanation rates within the survey area (Cox and Cuff, 1981c). Mercury concentrations (Fig. 38) showed a general minimum along the Kawaihae-Waimea roads and a broad trend of increasing mercury concentrations toward both the north and south. There is no correlation apparent between the mercury patterns and either the resistivity sounding data or the surface geology in the area. The radon emanometry data (Fig.

386

Mercury Vapor At Lualualei Valley Area (Thomas, 1986) | Open Energy  

Open Energy Info (EERE)

Mercury Vapor At Lualualei Valley Area (Thomas, 1986) Mercury Vapor At Lualualei Valley Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Mercury Vapor At Lualualei Valley Area (Thomas, 1986) Exploration Activity Details Location Lualualei Valley Area Exploration Technique Mercury Vapor Activity Date Usefulness useful DOE-funding Unknown Notes Soil mercury and radon emanation surveys were performed over much of the accessible surface of Lualualei Valley (Cox and Thomas, 1979). The results of these surveys (Figs 7 and 8) delineated several areas in which soil mercury concentrations or radon emanation rates were substantially above normal background values. Some of these areas were apparently coincident with the mapped fracture systems associated with the caldera boundaries.

387

Quantitative IR Spectrum and Vibrational Assignments for Glycolaldehyde Vapor: Glycolaldehyde Measurements in Biomass Burning Plumes  

SciTech Connect

Glycolaldehyde (GA, 2-hydroxyethanal, C2H4O2) is a semi-volatile molecule of atmospheric importance, recently proposed as a precursor in the formation of aqueous-phase secondary organic aerosol (SOA). There are few methods to measure glycolaldehyde vapor, but infrared spectroscopy has been used successfully. Using vetted protocols we have completed the first assignment of all fundamental vibrational modes and derived quantitative IR absorption band strengths using both neat and pressure-broadened GA vapor. Even though GA is problematic due to its propensity to both dimerize and condense, our intensities agree well with the few previously published values. Using the reference ?10 band Q-branch at 860.51 cm-1, we have also determined GA mixing ratios in biomass burning plumes generated by field and laboratory burns of fuels from the southeastern and southwestern United States, including the first field measurements of glycolaldehyde in smoke. The GA emission factors were anti-correlated with modified combustion efficiency confirming release of GA from smoldering combustion. The GA emission factors (g of GA emitted per kg dry biomass burned on a dry mass basis) had a low dependence on fuel type consistent with the production mechanism being pyrolysis of cellulose. GA was emitted at 0.23 ± 0.13% of CO from field fires and we calculate that it accounts for ~18% of the aqueous-phase SOA precursors that we were able to measure.

Johnson, Timothy J.; Sams, Robert L.; Profeta, Luisa T.; Akagi, Sheryl; Burling, Ian R.; Yokelson, Robert J.; Williams, Stephen D.

2013-04-15T23:59:59.000Z

388

Advanced Chemical Heat Pumps Using Liquid-Vapor Reactions  

E-Print Network (OSTI)

ically feasible systems have significant potential advantage over conventional tech nology. An electric drive reactive heat pump can use smaller heat exchangers and compressor than a vapor-compression machine, and have more flexible operating... are discussed, and performance is bounded. A discussion on liquid-vapor equilibria is included as introduction to the systems I- considered. The electric drive heat pump and TA are promising systems; the TA has potential for higher COP than absorption...

Kirol, L.

389

D/sup -/ production by charge transfer in metal vapors  

SciTech Connect

Fast D/sup -/ ions can be produced from D/sup +/ by multiple charge-transfer collisions in a metal-vapor target. Experimental cross sections and thick-target D/sup -/ yields are presented and discussed. The high D/sup -/ yield experimentally observed from charge transfer in cesium vapor is consistent with recent low-energy cross-section calculations and measurements.

Schlachter, A.S.

1980-10-01T23:59:59.000Z

390

Injection locked oscillator system for pulsed metal vapor lasers  

DOE Patents (OSTI)

An injection locked oscillator system for pulsed metal vapor lasers is disclosed. The invention includes the combination of a seeding oscillator with an injection locked oscillator (ILO) for improving the quality, particularly the intensity, of an output laser beam pulse. The present invention includes means for matching the first seeder laser pulses from the seeding oscillator to second laser pulses of a metal vapor laser to improve the quality, and particularly the intensity, of the output laser beam pulse.

Warner, Bruce E. (Livermore, CA); Ault, Earl R. (Dublin, CA)

1988-01-01T23:59:59.000Z

391

Wafer Bonding and Epitaxial Transfer of GaSb-based Epitaxy to GaAs for Monolithic Interconnection of Thermophotovoltaic Devices  

SciTech Connect

GaInAsSb/AlGaAsSb/InAsSb/GaSb epitaxial layers were bonded to semi-insulating GaAs handle wafers with SiO{sub x}/Ti/Au as the adhesion layer for monolithic interconnection of thermophotovoltaic (TPV) devices. Epitaxial transfer was completed by removal of the GaSb substrate, GaSb buffer, and InAsSb etch-stop layer by selective chemical etching. The SiO{sub x}/TiAu provides not only electrical isolation, but also high reflectivity and is used as an internal back-surface reflector. Characterization of wafer-bonded epitaxy by high-resolution x-ray diffraction and time-decay photoluminescence indicates minimal residual stress and enhancement in optical quality. 0.54-eV GaInAsSb cells were fabricated and monolithically interconnected in series. A 10-junction device exhibited linear voltage building with an open-circuit voltage of 1.8 V.

C.A. Wang; D.A. Shiau; P.G. Murphy; P.W. O'brien; R.K. Huang; M.K. Connors; A.C. Anderson; D. Donetsky; S. Anikeev; G. Belenky; D.M. Depoy; G. Nichols

2003-06-16T23:59:59.000Z

392

Tank 241-S-102 headspace gas and vapor characterization results for samples collected in March 1995  

SciTech Connect

Significant changes have been made to all of the original vapor characterization reports. This report documents specific headspace gas and vapor characterization results for all vapor sampling events to date. In addition, changes have been made to the original vapor reports to qualify the data based on quality assurance issues associated with the performing laboratories

Huckaby, J.L. [Pacific Northwest Lab., Richland, WA (United States); Bratzel, D.R. [Westinghouse Hanford Co., Richland, WA (United States)

1995-09-26T23:59:59.000Z

393

investigating the source, transport, and isotope fractionation of water vapor in the atmospheric boundary layer  

E-Print Network (OSTI)

investigating the source, transport, and isotope fractionation of water vapor in the atmospheric cospectral similarity for temperature and water vapor isotope fluxes. mixing ratio generator Routine field use in water vapor isotope research. The unit generates a stable water vapor mixing ratio by measuring

Minnesota, University of

394

Calculating the vapor pressure of water from the second law of thermodynamics  

Science Journals Connector (OSTI)

Calculating the vapor pressure of water from the second law of thermodynamics ... Thermodynamics ...

M. H. Everdell

1969-01-01T23:59:59.000Z

395

Tank Vapor Characterization Project: Annual status report for FY 1996  

SciTech Connect

In Fiscal Year 1996, staff at the Vapor Analytical Laboratory at Pacific Northwest National Laboratory performed work in support of characterizing the vapor composition of the headspaces of radioactive waste tanks at the Hanford Site. Work performed included support for technical issues and sampling methodologies, upgrades for analytical equipment, analytical method development, preparation of unexposed samples, analyses of tank headspaces samples, preparation of data reports, and operation of the tank vapor database. Progress made in FY 1996 included completion and issuance of 50 analytical data reports. A sampling system comparison study was initiated and completed during the fiscal year. The comparison study involved the vapor sampling system (VSS), a truck-based system, and the in situ vapor sampling system (ISVS), a cart-based system. Samples collected during the study were characterized for inorganic, permanent gases, total non-methane organic compounds and organic speciation by SUMMA{trademark} and TST methods. The study showed comparable sampling results between the systems resulting in the program switching from the VSS to the less expensive ISVS methodology in late May 1996. A temporal study was initiated in January 1996 in order to understand the influences seasonal temperatures changes have on the vapors in the headspace of Hanford waste tanks. A holding time study was initiated in the fourth quarter of FY 1996. Samples were collected from tank S-102 and rushed to the laboratory for time zero analysis. Additional samples will be analyzed at 1, 2, 4, 8, 16, and 32 weeks.

Silvers, K.L.; Fruchter, J.S.; Huckaby, J.L.; Almeida, T.L.; Evans, J.C. Jr.; Pool, K.H.; Simonen, C.A.; Thornton, B.M.

1997-01-01T23:59:59.000Z

396

Half integer quantum Hall effect in high mobility single layer epitaxial graphene  

E-Print Network (OSTI)

Half integer quantum Hall effect in high mobility single layer epitaxial graphene Xiaosong Wu,1 of is demonstrated here on a single graphene layer grown on the C-face of 4H silicon carbide. The mobility is 20 000. This is comparable to the best exfoliated graphene flakes on SiO2 and an order of magnitude larger than Si

397

Epitaxy of Nanocrystalline Silicon Carbide on Si(111) at Room Temperature  

E-Print Network (OSTI)

Epitaxy of Nanocrystalline Silicon Carbide on Si(111) at Room Temperature Roberto Verucchi carbide (SiC) has unique chemical, physical, and mechanical properties. A factor strongly limiting Si or plastics that cannot withstand high temperatures. Silicon carbide (SiC) has unique properties that make

Alfè, Dario

398

Transition from Epitaxial to Nonepitaxial Ordered Monolayers in Pyrolyzed 8CB Studied by STM  

E-Print Network (OSTI)

-ordered, epitaxial monolayers on graphite. We have found that adding two oxidation products (to mimic the effects of air oxidation or pyrolysis) changes the surface ordering of 8CB, causing it to form cell dimensions of one of the oxidation products, both pure oxidation products were found to form

Patrick, David L.

399

Improved One-dimensional Analysis of CMOS Photodiode Including Epitaxial-Substrate Junction  

E-Print Network (OSTI)

1 Improved One-dimensional Analysis of CMOS Photodiode Including Epitaxial-Substrate Junction J. S-dimensional analysis of CMOS photodiode has been derived in which the effect of the substrate, which forms a high-empirical expression exhibits a good agreement with the measured spectral response of n+ pepi photodiodes fabricated

Hornsey, Richard

400

Surface Science 415 (1998) 363375 Epitaxial growth of Cu onto Si(111) surfaces at low temperature  

E-Print Network (OSTI)

to 10 and 3 monolayers (ML), respectively. This change is attributed to the silicide formation on the Si(111)-(7�7) surface at 160 K is proposed. The changes in periodicity are due to the silicide rights reserved. Keywords: Copper; Epitaxy; Electron­solid diffraction; Metallic films; Metal

Hasegawa, Shuji

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


401

Fabrication of magnetic tunnel junctions with epitaxial and textured ferromagnetic layers  

DOE Patents (OSTI)

This invention relates to magnetic tunnel junctions and methods for making the magnetic tunnel junctions. The magnetic tunnel junctions include a tunnel barrier oxide layer sandwiched between two ferromagnetic layers both of which are epitaxial or textured with respect to the underlying substrate upon which the magnetic tunnel junctions are grown. The magnetic tunnel junctions provide improved magnetic properties, sharper interfaces and few defects.

Chang, Y. Austin (Middleton, WI); Yang, Jianhua Joshua (Madison, WI)

2008-11-11T23:59:59.000Z

402

Comparative study of microstructural characteristics of electrospark and Nd:YAG laser epitaxially growing coatings  

Science Journals Connector (OSTI)

As low-heat input welding processes, electrospark deposition and pulsed Nd:YAG laser cladding can be commonly used to prepare epitaxially growing coatings. However, these two processes have quite different characteristics in the energy input, the amount of materials involved, and the temperature gradient, and hence might result in dissimilar microstructural characteristics. In this paper, a comparative study has been made between microstructural characteristics in epitaxial growth coatings prepared by electrospark deposition and pulsed Nd:YAG laser cladding. Some interesting results have been achieved. Firstly, epitaxial growth coatings can be commonly achieved by these two techniques. Secondly, microstructural morphologies of these two epitaxial growth coatings are obviously different, cellular columnar structure prevails in the electrospark coating while columnar dendritic structure occupies most of the laser coating thickness, more importantly, electrospark coating remains fully columnar in the whole layer whereas laser coating tends to change from columnar to equiaxed at the top of the layer. Thirdly, electrospark coating possesses finer and more homogeneous microstructure than laser coating.

Yu-jiang Xie; Mao-cai Wang; Da-wei Huang

2007-01-01T23:59:59.000Z

403

GaAs photovoltaics and optoelectronics using releasable multilayer epitaxial assemblies  

E-Print Network (OSTI)

LETTERS GaAs photovoltaics and optoelectronics using releasable multilayer epitaxial assemblies-frequency electronics3,4 and most forms of optoelectronics5,6 . However, growing large, high quality wafers implementation. More tractable, yet still difficult, problems appear in advanced electronics and optoelectronics

Rogers, John A.

404

Self-assembly of triangular quantum dots on (111)A substrates by droplet epitaxy  

SciTech Connect

We report the self-assembly of triangular GaAs quantum dots (QDs) on (111)A substrates using droplet epitaxy. Shape transition from hexagonal to triangular QDs is observed with increasing crystallizing temperature. The mechanism of the morphological change is discussed in terms of different growth rates of step edges on a (111)A substrate.

Jo, M.; Mano, T.; Abbarchi, M.; Kuroda, T. [Advanced Photonics Materials Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Sakoda, K. [Advanced Photonics Materials Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan and Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan)

2014-05-15T23:59:59.000Z

405

Characterization of Epitaxial Film Silicon Solar Cells Grown on Seeded Display Glass: Preprint  

SciTech Connect

We report characterizations of epitaxial film crystal silicon (c-Si) solar cells with open-circuit voltages (Voc) above 560 mV. The 2-um absorber cells are grown by low-temperature (<750 degrees C) hot-wire CVD (HWCVD) on Corning EAGLE XG display glass coated with a layer-transferred (LT) Si seed. The high Voc is a result of low-defect epitaxial Si (epi-Si) growth and effective hydrogen passivation of defects. The quality of HWCVD epitaxial growth on seeded glass substrates depends on the crystallographic quality of the seed and the morphology of the epitaxial growth surface. Heterojunction devices consist of glass/c-Si LT seed/ epi n+ Si:P/epi n- Si:P/intrinsic a-Si:H/p+ a-Si:H/ITO. Similar devices grown on electronically 'dead' n+ wafers have given Voc {approx}630 mV and {approx}8% efficiency with no light trapping features. Here we study the effects of the seed surface polish on epi-Si quality, how hydrogenation influences the device character, and the dominant junction transport physics.

Young, D. L.; Grover, S.; Teplin, C.; Stradins, P.; LaSalvia, V.; Chuang, T. K.; Couillard, J. G.; Branz, H. M.

2012-06-01T23:59:59.000Z

406

X-ray radiation effects in multilayer epitaxial graphene Jeremy Hicks1  

E-Print Network (OSTI)

1 X-ray radiation effects in multilayer epitaxial graphene Jeremy Hicks1 , Rajan Arora2 , Eleazar and after exposure to a total ionizing dose (TID) of 12 Mrad(SiO2) using a 10 keV X-ray source. While we are mostly unaffected by radiation exposure. Combined with X-ray photoelectron spectroscopy (XPS) data

407

Magnetic properties of epitaxial Co-doped anatase TiO2 thin films with excellent structural quality  

SciTech Connect

The heteroepitaxy of Co-doped anatase TiO2 on LaAlO3(001) has been refined with the goal of determining the relationship between structural quality and magnetic ordering. By significantly reducing the deposition rate and substrate temperature, well-ordered Co:TiO2 films with unprecedented crystalline quality were obtained by oxygen-plasma-assisted molecular beam epitaxy, as characterized by x-ray diffraction. These films exhibit uniform Co doping, with no evidence of Co segregation or secondary phases throughout the film depth or on the surface. Despite the improvement in crystalline quality and Co distribution, the films exhibit negligible ferromagnetism, with saturation moments of only ~0.1 ?B/Co. This loss of ferromagnetism is in stark contrast to faster-grown Co:TiO2 films, where a higher growth rate and substrate temperature typically result in lower crystalline quality, a highly non-uniform Co distribution, and average saturation moments of ~1.2 ?B/Co. The presence of ferromagnetism in faster-grown Co:TiO2 does not appear to arise from intrinsic point defects present in the bulk material, such as charge-compensating oxygen vacancies, but is instead attributed to the presence of extended structural defects.

Kaspar, Tiffany C.; Droubay, Timothy C.; McCready, David E.; Nachimuthu, Ponnusamy; Heald, Steve M.; Wang, Chong M.; Lea, Alan S.; Shutthanandan, V.; Chambers, Scott A.; Toney, Michael F.

2006-07-26T23:59:59.000Z

408

Epitaxial growth of perfluoropentacene films with predefined molecular orientation: A route for single-crystal optical studies  

Science Journals Connector (OSTI)

Using atomic-force microscopy and x-ray diffraction we show that perfluoropentacene (C22F14, PFP) forms long-range ordered, epitaxial films on KCl(100) and NaF(100) cleavage planes. On both substrates the films adopt the same crystalline bulk phase, but surprisingly exhibit quite different molecular orientations, being upright oriented on NaF and recumbent oriented on KCl. Accompanied thermal desorption spectroscopy measurements indicate the absence of a stabilized seed layer, like on metals, hence suggesting that in both cases the PFP films are stabilized by an electrostatic point-in-line relationship between the outermost fluorine atoms and the alkali cations of the alkali halide surfaces. Furthermore, the transparency of both substrates was utilized to perform detailed transmission UV/Vis spectroscopy and polarized optical microscopy measurements along well-defined crystallographic directions. From these data the orientation of transition dipole moments of the various optical excitations were experimentally determined and a directional anisotropic exciton coupling was observed, which is attributed to the asymmetric molecular packing motif within the (100) plane of the PFP crystal lattice.

Tobias Breuer and Gregor Witte

2011-04-18T23:59:59.000Z

409

Numerical Simulation of Hydrodynamics of a Heavy Liquid Drop Covered by Vapor Film in a Water Pool  

SciTech Connect

A numerical study on the hydrodynamics of a droplet covered by vapor film in water pool is carried out. Two level set functions are used as to implicitly capture the interfaces among three immiscible fluids (melt-drop, vapor and coolant). This approach leaves only one set of conservation equations for the three phases. A high-order Navier-Stokes solver, called Cubic-Interpolated Pseudo-Particle (CIP) algorithm, is employed in combination with level set approach, which allows large density ratios (up to 1000), surface tension and jump in viscosity. By this calculation, the hydrodynamic behavior of a melt droplet falling into a volatile coolant is simulated, which is of great significance to reveal the mechanism of steam explosion during a hypothetical severe reactor accident. (authors)

Ma, W.M.; Yang, Z.L.; Giri, A.; Sehgal, B.R. [Royal Institute of Technology (KTH), Drottning Kristinas vaeg 33 A, 100 44, Stockholm (Sweden)

2002-07-01T23:59:59.000Z

410

Vapor etching of nuclear tracks in dielectric materials  

DOE Patents (OSTI)

A process involving vapor etching of nuclear tracks in dielectric materials for creating high aspect ratio (i.e., length much greater than diameter), isolated cylindrical holes in dielectric materials that have been exposed to high-energy atomic particles. The process includes cleaning the surface of the tracked material and exposing the cleaned surface to a vapor of a suitable etchant. Independent control of the temperatures of the vapor and the tracked materials provide the means to vary separately the etch rates for the latent track region and the non-tracked material. As a rule, the tracked regions etch at a greater rate than the non-tracked regions. In addition, the vapor-etched holes can be enlarged and smoothed by subsequent dipping in a liquid etchant. The 20-1000 nm diameter holes resulting from the vapor etching process can be useful as molds for electroplating nanometer-sized filaments, etching gate cavities for deposition of nano-cones, developing high-aspect ratio holes in trackable resists, and as filters for a variety of molecular-sized particles in virtually any liquid or gas by selecting the dielectric material that is compatible with the liquid or gas of interest.

Musket, Ronald G. (Danville, CA); Porter, John D. (Berkeley, CA); Yoshiyama, James M. (Fremont, CA); Contolini, Robert J. (Lake Oswego, OR)

2000-01-01T23:59:59.000Z

411

Spectral research on an AlGaAs epitaxial material for a terahertz quantum-cascade laser  

Science Journals Connector (OSTI)

The spectral properties of a series of AlGaAs epitaxial films were studied by using a Fourier transform infrared spectrometer with an 80-degree grazing incidence reflection unit. The AlAs-like transversal optical...

Zhi-Yong Tan; Jun-Cheng Cao

2012-04-01T23:59:59.000Z

412

Electron Beam Source Molecular Beam Epitaxy of AlxGal?xAs Graded Band Gap Device Structures  

Science Journals Connector (OSTI)

A new method has been developed for the growth of graded band-gap AlxGal?xAs alloys by molecular beam epitaxy which is based upon electron. beam evaporation of the Group III elements ... . The large dynamic respo...

R. J. Malik; A. F. J. Levi; B. F. Levine…

1989-01-01T23:59:59.000Z

413

Photodiode characteristics and band alignment parameters of epitaxial Al0.5Ga0.5P  

E-Print Network (OSTI)

Photodiode characteristics and band alignment parameters of epitaxial Al0.5Ga0.5P An Chen1,a-bandgap semiconductor AlxGa1-xP is a promising material candidate for low-noise photodiodes in blue/UV spectrum. Photodiodes were fabricated on Al0.5Ga0.5P epitaxial layer grown lattice matched on GaP substrate by molecular

Woodall, Jerry M.

414

phase coherence  

Science Journals Connector (OSTI)

The state in which two signals, such as electronic or optical signals, maintain (a) a fixed phase relationship with each other or (b) a fixed phase relationship with a third signal that can serve as a referenc...

2001-01-01T23:59:59.000Z

415

Validation of TES Temperature and Water Vapor Retrievals with ARM  

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

Validation of TES Temperature and Water Vapor Retrievals with ARM Validation of TES Temperature and Water Vapor Retrievals with ARM Observations Cady-Pereira, Karen Atmospheric and Environmental Research, Inc. Shephard, Mark Atmospheric and Environmental Research, Inc. Clough, Shepard Atmospheric and Environmental Research Mlawer, Eli Atmospheric & Environmental Research, Inc. Turner, David University of Wisconsin-Madison Category: Atmospheric State and Surface The primary objective of the TES (Tropospheric Emission Spectrometer) instrument on the Aura spacecraft is the retrieval of trace gases, especially water vapor and ozone. The TES retrievals extremely useful for global monitoring of the atmospheric state, but they must be validated. The ARM sites are well instrumented and provide continuous measurements, which

416

VAPORIZATION OF TUNGSTEN-METAL IN STEAM AT HIGH TEMPERATURES.  

SciTech Connect

The vaporization of tungsten from the APT spallation target dominates the radiological source term for unmitigated target overheating accidents. Chemical reactions of tungsten with steam which persist to tungsten temperatures as low as 800 C result in the formation of a hydrated tungsten-oxide which has a high vapor pressure and is readily convected in a flowing atmosphere. This low-temperature vaporization reaction essentially removes the oxide film that forms on the tungsten-metal surface as soon as it forms, leaving behind a fresh metallic surface for continued oxidation and vaporization. Experiments were conducted to measure the oxidative vaporization rates of tungsten in steam as part of the effort to quantify the MT radiological source term for severe target accidents. Tests were conducted with tungsten rods (1/8 inch diameter, six inches long) heated to temperatures from approximately 700 C to 1350 C in flowing steam which was superheated to 140 C. A total of 19 experiments was conducted. Fifteen tests were conducted by RF induction heating of single tungsten rods held vertical in a quartz glass retort. Four tests were conducted in a vertically-mounted tube furnace for the low temperature range of the test series. The aerosol which was generated and transported downstream from the tungsten rods was collected by passing the discharged steam through a condenser. This procedure insured total collection of the steam along with the aerosol from the vaporization of the rods. The results of these experiments revealed a threshold temperature for tungsten vaporization in steam. For the two tests at the lowest temperatures which were tested, approximately 700 C, the tungsten rods were observed to oxidize without vaporization. The remainder of the tests was conducted over the temperature range of 800 C to 1350 C. In these tests, the rods were found to have lost weight due to vaporization of the tungsten and the missing weight was collected in the downstream condensate system. The aerosol formed a fine white smoke of tungsten-oxide which was visible to the eye as it condensed in the laminar boundary layer of steam which flowed along the surface of the rod. The aerosol continued to flow as a smoke tube downstream of the rod, flowing coaxially along the centerline axis of the quartz glass tube and depositing by impaction along the outside of a bend and at sudden area contractions in the piping. The vaporization rate data from the 17 experiments which exceeded the vaporization threshold temperature are shown in Figure 5 in the form of vaporization rates (g/cm{sup 2} s) vs. inverse temperature (K{sup {minus}1}). Two correlations to the present data are presented and compared to a published correlation by Kilpatrick and Lott. The differences are discussed.

GREENE,G.A.; FINFROCK,C.C.

2000-10-01T23:59:59.000Z

417

Phase equilibrium data for development of correlations for coal fluids  

SciTech Connect

The overall objective of the authors' work is to develop accurate predictive methods for representations of vapor-liquid equilibria in systems encountered in coal-conversion processes. The objectives pursued in the present project include: (1) Measurements of binary vapor-liquid phase behavior data for selected solute gases (e.g., C{sub 2}H{sub 6}, CH{sub 4}) in a series of paraffinic, naphthenic, and aromatic hydrocarbon solvents to permit evaluations of interaction parameters in models for phase behavior. Solubilities of the gases in the liquid phase have been determined. (2) Evaluation of existing equations of state and other models for representations of phase behavior in systems of the type studied experimentally; development of new correlation frameworks as needed. (3) Generalization of the interaction parameters for the solutes studied to a wide spectrum of heavy solvents; presentation of final results in formats useful in the design/optimization of coal liquefaction processes.

Robinson, R.L. Jr.; Gasem, K.A.M.; Darwish, N.A.; Raff, A.M.

1991-02-01T23:59:59.000Z

418

PHASE BEHAVIOR OF LIGHT GASES IN HYDROCARBON AND AQUEOUS SOLVENTS  

SciTech Connect

Under previous support from the Department of Energy, an experimental facility has been established and operated to measure valuable vapor-liquid equilibrium data for systems of interest in the production and processing of coal fluids. To facilitate the development and testing of models for prediction of the phase behavior for such systems, we have acquired substantial amounts of data on the equilibrium phase compositions for binary mixtures of heavy hydrocarbon solvents with a variety of supercritical solutes, including hydrogen, methane, ethane, carbon monoxide, and carbon dioxide. The present project focuses on measuring the phase behavior of light gases and water in Fischer-Tropsch (F-T) type solvents at conditions encountered in indirect liquefaction processes and evaluating and developing theoretically-based correlating frameworks to predict the phase behavior of such systems. Specific goals of the proposed work include (a) developing a state-of-the-art experimental facility to permit highly accurate measurements of equilibrium phase compositions (solubilities) of challenging F-T systems, (b) measuring these properties for systematically-selected binary, ternary and molten F-T wax mixtures to provide critically needed input data for correlation development, (c) developing and testing models suitable for describing the phase behavior of such mixtures, and (d) presenting the modeling results in generalized, practical formats suitable for use in process engineering calculations. During the present period, the Park-Gasem-Robinson (PGR) equation of state (EOS) has been modified to improve its volumetric and equilibrium predictions. Specifically, the attractive term of the PGR equation was modified to enhance the flexibility of the model, and a new expression was developed for the temperature dependence of the attractive term in this segment-segment interaction model. The predictive capability of the modified PGR EOS for vapor pressure, and saturated liquid and vapor densities was evaluated for selected normal paraffins, normal alkenes, cyclo-paraffins, light aromatics, argon, carbon dioxide and water. The generalized EOS constants and substance-specific characteristic parameters in the modified PGR EOS were obtained from the pure component vapor pressures, and saturated liquid and vapor molar volumes. The calculated phase properties were compared to those of the Peng-Robinson (PR), the simplified-perturbed-hard-chain theory (SPHCT) and the original PGR equations. Generally, the performance of the proposed EOS was better than the PR, SPHCT and original PGR equations in predicting the pure fluid properties (%AAD of 1.3, 2.8 and 3.7 for vapor pressure, saturated liquid and vapor densities, respectively).

KHALED A.M. GASEM; ROBERT L. ROBINSON, JR.

1998-08-31T23:59:59.000Z

419

The development of a passive dosimeter for airborne aniline vapors  

E-Print Network (OSTI)

passive sampl1ng dosimeter was designed to measure concen- trat1ons of aniline vapor in air. Diffus1on tubes of 1. 5, 3. 0 and 4. 5 cm lengths were tested under controlled conditions of relative humid1ty, air temperature and vapor concentrations. A... of Measured vs Calculated Concentrations APPENDIX D-Student-t Test on Slopes of Measured vs Calculated Data . APPENDIX E-Statistical Analysis of Four Hour Time- Weighted Average Study on 3. 0 cm Dosimeter VITA ~pa e 42 45 48 59 62 63 65 70 73...

Campbell, James Evan

1977-01-01T23:59:59.000Z

420

Solid–Liquid–Vapor Equilibrium Models for Cryogenic Biogas Upgrading  

Science Journals Connector (OSTI)

In cryogenic upgrading processes involving dry ice formation, accurate predictions of solid–liquid, solid–vapor, and solid–liquid–vapor equilibria are fundamental for a correct design of the heat exchanger surface in order to achieve the desired biomethane purity. ... Moreover, the liquefied biogas production process, particularly interesting for cryogenic upgrading processes due to the low temperature of the obtained biomethane, requires an accurate knowledge of carbon dioxide solubility in liquid methane to avoid solid deposition. ... For some applications demanding a high energy content gas, namely vehicle fuels and injection in the natural gas grid, the biogas has to be upgraded into biomethane. ...

Mauro Riva; Marco Campestrini; Joseph Toubassy; Denis Clodic; Paolo Stringari

2014-10-13T23:59:59.000Z

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


421

Epitaxial InGaAsP/InP photodiode for registration of InP scintillation S. Luryi a,n  

E-Print Network (OSTI)

Epitaxial InGaAsP/InP photodiode for registration of InP scintillation S. Luryi a,n , A. Kastalsky scintillator InP epitaxy InGaAsP photodiodes a b s t r a c t Operation of semiconductor scintillators requires implemented an efficient and fast quaternary InGaAsP pin photodiode, epitaxially grown on the surface of an In

Stanacevic, Milutin

422

Real-time reflectance-difference spectroscopy of GaAs molecular beam epitaxy homoepitaxial growth  

SciTech Connect

We report on real time-resolved Reflectance-difference (RD) spectroscopy of GaAs(001) grown by molecular beam epitaxy, with a time-resolution of 500 ms per spectrum within the 2.3–4.0 eV photon energy range. Through the analysis of transient RD spectra we demonstrated that RD line shapes are comprised of two components with different physical origins and determined their evolution during growth. Such components were ascribed to the subsurface strain induced by surface reconstruction and to surface stoichiometry. Results reported in this paper render RD spectroscopy as a powerful tool for the study of fundamental processes during the epitaxial growth of zincblende semiconductors.

Lastras-Martínez, A., E-mail: alm@cactus.iico.uaslp.mx, E-mail: alastras@gmail.com; Ortega-Gallegos, J.; Guevara-Macías, L. E.; Nuñez-Olvera, O.; Balderas-Navarro, R. E.; Lastras-Martínez, L. F. [Instituto de Investigación en Comunicación Optica, Universidad Autónoma de San Luis Potosí, Alvaro Obregón 64, San Luis Potosí, SLP 78000 (Mexico); Lastras-Montaño, L. A. [IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Lastras-Montaño, M. A. [Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, California 93106 (United States)

2014-03-01T23:59:59.000Z

423

Effect of buffer layer growth temperature on epitaxial GaN films deposited by magnetron sputtering  

SciTech Connect

Epitaxial GaN films were deposited by reactive sputtering of a GaAs target in 100 % nitrogen at 700 deg. C on ZnO buffer layers grown at different substrate temperatures over sapphire substrates. High resolution X-ray diffraction measurements and the corresponding analysis show that the growth temperature of buffer layers significantly affects the micro-structural parameters of GaN epilayer, such as lateral coherence length, tilt and twist, while the vertical coherence length remains unaffected. The optimum substrate temperature for buffer layer growth has been found to be 300 deg. C. High epitaxial quality GaN film grown on such a buffer layer exhibited micro strain of 1.8x10{sup -4} along with screw and edge type dislocation densities of 7.87x10{sup 9} and 1.16x10{sup 11}, respectively.

Mohanta, P.; Singh, D.; Kumar, R.; Ganguli, T.; Srinivasa, R. S.; Major, S. S. [Center For Research in Nano-Technology and Science (India); Semiconductor Laser Section, RRCAT, Indore-452013 (India); Department of Metallurgical Engineering and Materials Science (India); Department of Physics, Indian Institute of Technology Bombay, Mumbai - 400076 (India)

2012-06-05T23:59:59.000Z

424

Lattice constant and substitutional composition of GeSn alloys grown by molecular beam epitaxy  

SciTech Connect

Single crystal epitaxial Ge{sub 1?x}Sn{sub x} alloys with atomic fractions of tin up to x = 0.145 were grown by solid source molecular beam epitaxy on Ge (001) substrates. The Ge{sub 1?x}Sn{sub x} alloys formed high quality, coherent, strained layers at growth temperatures below 250 °C, as shown by high resolution X-ray diffraction. The amount of Sn that was on lattice sites, as determined by Rutherford backscattering spectrometry channeling, was found to be above 90% substitutional in all alloys. The degree of strain and the dependence of the effective unstrained bulk lattice constant of Ge{sub 1?x}Sn{sub x} alloys versus the composition of Sn have been determined.

Bhargava, Nupur; Coppinger, Matthew; Prakash Gupta, Jay; Kolodzey, James [Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716 (United States)] [Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716 (United States); Wielunski, Leszek [Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854 (United States)] [Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854 (United States)

2013-07-22T23:59:59.000Z

425

Molecular Beam Epitaxial Growth of GaAs on (631) Oriented Substrates  

SciTech Connect

In this work, we report the study of the homoepitaxial growth of GaAs on (631) oriented substrates by molecular beam epitaxy (MBE). We observed the spontaneous formation of a high density of large scale features on the surface. The hilly like features are elongated towards the [-5, 9, 3] direction. We show the dependence of these structures with the growth conditions and we present the possibility of to create quantum wires structures on this surface.

Cruz Hernandez, Esteban; Rojas Ramirez, Juan-Salvador; Contreras Hernandez, Rocio; Lopez Lopez, Maximo [Physics Department, Centro de Investigacion y de Estudios Avanzados del IPN, Apartado Postal 14-740, Mexico D.F., 07000 (Mexico); Pulzara Mora, Alvaro [Universidad Nacional de Colombia - Sede Manizales, A. A. 127 (Colombia); Mendez Garcia, Victor H. [Instituto de Investigacion en Comunicacion Optica, Universidad Autonoma de San Luis Potosi, Av. Karakorum 1470, Lomas 4a Seccion, C.P. 78210, San Luis Potosi (Mexico)

2007-02-09T23:59:59.000Z

426

Low-temperature grown graphene films by using molecular beam epitaxy  

SciTech Connect

Complete graphene film is prepared by depositing carbon atoms directly on Cu foils in a molecular beam epitaxy chamber at 300 Degree-Sign C. The Raman spectrum of the film has indicated that high-quality few-layer graphene is obtained. With back-gated transistor architecture, the characteristic current modulation of graphene transistors is observed. Following the similar growth procedure, graphitization is observed at room temperature, which is consistent with the molecular dynamics simulations of graphene growth.

Lin, Meng-Yu [Institute of Electronics, National Taiwan University, Taipei, Taiwan (China); Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei, Taiwan (China); Guo, Wei-Ching; Wang, Pro-Yao [Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung, Taiwan (China); Wu, Meng-Hsun [College of Photonics, National Chiao-Tung University, Tainan, Taiwan (China); Liu, Te-Huan; Chang, Chien-Cheng [Institute of Applied Mechanics, National Taiwan University, Taipei, Taiwan (China); Pao, Chun-Wei; Lin, Shih-Yen [Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei, Taiwan (China); Lee, Si-Chen [Institute of Electronics, National Taiwan University, Taipei, Taiwan (China)

2012-11-26T23:59:59.000Z

427

(In,Mn)As quantum dots: Molecular-beam epitaxy and optical properties  

SciTech Connect

Self-assembled (In,Mn)As quantum dots are synthesized by molecular-beam epitaxy on GaAs (001) substrates. The experimental results obtained by transmission electron microscopy show that doping of the central part of the quantum dots with Mn does not bring about the formation of structural defects. The optical properties of the samples, including those in external magnetic fields, are studied.

Bouravleuv, A. D., E-mail: bour@mail.ioffe.ru; Nevedomskii, V. N. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)] [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Ubyivovk, E. V. [St. Petersburg State University (Russian Federation)] [St. Petersburg State University (Russian Federation); Sapega, V. F. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)] [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Khrebtov, A. I. [St. Petersburg Academic University, Nanotechnology Research and Education Centre (Russian Federation)] [St. Petersburg Academic University, Nanotechnology Research and Education Centre (Russian Federation); Samsonenko, Yu. B.; Cirlin, G. E.; Ustinov, V. M. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)] [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

2013-08-15T23:59:59.000Z

428

Growth, structure and electrical properties of epitaxial thulium silicide thin films on silicon  

SciTech Connect

Thulium silicide thin films were grown on (100) and (111) Si by evaporation of Tm metal and Si layers and annealing in a vacuum. Electron microscopy and x-ray diffraction results showed that the TmSi{sub 2{minus}x} layers are of high crystalline quality grown epitaxially on Si. Electrical resistivity measurements showed that TmSi{sub 2{minus}x} layers are metallic exhibiting magnetic ordering below 3 K. {copyright} {ital 1997 American Institute of Physics.}

Travlos, A.; Salamouras, N.; Boukos, N. [Institute of Materials Science, National Centre for Scientific Research Demokritos, Athens, (Greece) 15310] [Institute of Materials Science, National Centre for Scientific Research Demokritos, Athens, (Greece) 15310

1997-02-01T23:59:59.000Z

429

Growth of InGaAsP by molecular beam epitaxy  

SciTech Connect

Molecular beam epitaxy has been used to grow good quality films of InGaAsP on InP substrates. The films have been characterized using infrared absorption, electroreflectance, x-ray diffraction, reflection electron diffraction, and Hall measurements. Lattice matching was achieved and room-temperature mobilities up to 4600 cm/sup 2/ V/sup -1/ s/sup -1/ were measured.

Holah, G.D.; Eisele, F.L.; Meeks, E.L.; Cox, N.W.

1982-12-01T23:59:59.000Z

430

Antimony-assisted carbonization of Si(111) with solid source molecular beam epitaxy  

SciTech Connect

The carbonization of an antimony-terminated Si (111) surface in a solid source molecular beam epitaxy system is presented. Reflection high-energy electron diffraction, atomic force microscopy, x-ray photoelectron spectroscopy, and cross-sectional transmission electron microscopy are used to characterize samples grown with and without antimony termination. It is shown that the antimony-terminated surface promotes the formation of thin, smooth and continuous SiC films at a relatively low temperature of 800 °C.

Hackley, Justin; Richardson, Christopher J. K. [Laboratory for Physical Sciences, University of Maryland, College Park, Maryland 20740 (United States)] [Laboratory for Physical Sciences, University of Maryland, College Park, Maryland 20740 (United States); Sarney, Wendy L. [U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783 (United States)] [U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783 (United States)

2013-11-15T23:59:59.000Z

431

Thermodynamic study of c-axis-oriented epitaxial Pb(Zr,Ti)O3 thin films  

Science Journals Connector (OSTI)

Thermodynamic characteristics of single crystalline Pb(Zr0.52Ti0.48)O3 (PZT) were investigated using c-axis oriented PZT films. The PZT films were epitaxially grown on Pt/MgO substrate and dielectric and ferroelectric properties were measured as a function of one-dimensional stress. The stress dependence of dielectric and ferroelectric properties was examined on the basis of the Landau-Devonshire’s phenomenological theory and the free energy coefficients of single crystalline PZT films were obtained. The dielectric stiffness coefficients and electrostrictive coefficient of epitaxial PZT films were obtained to be ?1=-1.30×108 (m/F), ?11=3.07×108 (m5/C2F), ?111=-3.11×107 (m9/C2F), and Q12=-5.70×10-2 (m4/C2), which are different from the values derived from the analysis of polycrystalline PZT. The temperature dependence of dielectric constant of the PZT films showed clear Curie-Weiss law and the dielectric stiffness coefficient ?1 derived from this measurement was almost same value from the analysis of stress dependence of the dielectricity of the epitaxial PZT films.

Isaku Kanno; Yu Yokoyama; Hidetoshi Kotera; Kiyotaka Wasa

2004-02-12T23:59:59.000Z

432

The correlation of epitaxial graphene properties and morphology of SiC (0001)  

SciTech Connect

The electronic properties of epitaxial graphene (EG) on SiC (0001) depend sensitively on the surface morphology of SiC substrate. Here, 2–3 layers of graphene were grown on on-axis 6H-SiC with different step densities realized through controlling growth temperature and ambient pressure. We show that epitaxial graphene on SiC (0001) with low step density and straight step edge possesses fewer point defects laying mostly on step edges and higher carrier mobility. A relationship between step density and EG mobility is established. The linear scan of Raman spectra combined with the atomic force microscopy morphology images revealed that the Raman fingerprint peaks are nearly the same on terraces, but shift significantly while cross step edges, suggesting the graphene is not homogeneous in strain and carrier concentration over terraces and step edges of substrates. Thus, control morphology of epitaxial graphene on SiC (0001) is a simple and effective method to pursue optimal route for high quality graphene and will be helpful to prepare wafer sized graphene for device applications.

Guo, Y.; Guo, L. W., E-mail: lwguo@iphy.ac.cn, E-mail: xlchen@iphy.ac.cn; Huang, J.; Jia, Y. P.; Lin, J. J.; Lu, W.; Li, Z. L. [Research and Development Center for Functional Crystals, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Yang, R. [Nanoscale Physics and Devices Laboratory, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Chen, X. L., E-mail: lwguo@iphy.ac.cn, E-mail: xlchen@iphy.ac.cn [Research and Development Center for Functional Crystals, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Collaborative Innovation Center of Quantum Matter, Beijing 100190 (China)

2014-01-28T23:59:59.000Z

433

Sharp Fe/MgO/Ge(001) epitaxial heterostructures for tunneling junctions  

SciTech Connect

We report on the growth of epitaxial Fe/MgO/Ge(001) heterostructures by molecular beam epitaxy. The lowest oxidation and highest sharpness of the MgO/Ge interface, corresponding to a transition layer on the order of one Ge unit cell, is obtained for room temperature growth of the MgO layer followed by annealing in a vacuum at 500 C. In these conditions, the MgO layer grows epitaxially on Ge(001) with the [110] direction parallel to the [100] direction of Ge, at variance with the cube-on-cube growth on Si(001) and GaAs(001). However, in some cases, the cube-on-cube growth mode of MgO on Ge competes with the mode involving a 45{sup o} rotation, as revealed by transmission electron microscopy and photoelectron diffraction data on MgO films grown at 300 C without postannealing, and on p-doped Ge substrates. For the Fe overlayer, in all the cases reported, room temperature growth followed by annealing up to 200 C gives rise to a sharp interface and the well-known 45{sup o} rotation of the Fe lattice with respect to the MgO lattice.

Petti, D. [Politecnico di Milano; Cantoni, M. [Politecnico di Milano; Rinaldi, C. [Politecnico di Milano; Brivio, S. [Politecnico di Milano; Bertacco, R. [Politecnico di Milano; Gazquez Alabart, Jaume [ORNL; Varela del Arco, Maria [ORNL

2011-01-01T23:59:59.000Z

434

?-function-shaped Sb-doping profiles in Si(001) obtained using a low-energy accelerated-ion source during molecular-beam epitaxy  

Science Journals Connector (OSTI)

Two-dimensional (2D) buried ?-function-shaped Sb-doping profiles have been obtained in Si using a low-energy accelerated Sb-ion source during molecular-beam epitaxy. A combination of secondary-ion mass spectrometry (SIMS), capacitance-voltage (C-V) measurements, and cross-sectional transmission electron microscopy (XTEM) was used to investigate dopant distributions and to determine profile widths. The 2D-sheet Sb-doping concentration NSb, obtained by integrating SIMS ?-doping profiles in samples grown with substrate temperature Ts=620 °C and Sb-ion acceleration potentials VSb=200 and 300 V, was found to vary linearly with the product of the Sb-ion flux and the exposure time (i.e., the ion dose) over the NSb range from 5×1012 to 2×1014 cm-2. The full width at half maximum (FWHM) concentration of ?-doping profiles in Si(001) films was less than the depth resolution of both SIMS and C-V measurements (?10 and 3 nm, respectively). High-resolution XTEM lattice images show that the FWHM was ?2 nm. This is consistent with dopant incorporation simulations, based upon a multisite transition-state dopant incorporation model, which show that accelerated-beam dopant species are trapped in near-surface substitutional sites with atomic mobilities between those of surface and bulk atoms. Dopant surface segregation during growth is strongly suppressed, and the dopant distribution is determined primarily by the straggle in ion trapping distributions. The present results are compared with profile broadening observed in ?-doped layers obtained by solid-phase epitaxy of amorphous Si containing a buried Sb layer.

W.-X. Ni; G. V. Hansson; J.-E. Sundgren; L. Hultman; L. R. Wallenberg; J.-Y. Yao; L. C. Markert; J. E. Greene

1992-09-15T23:59:59.000Z

435

Disilane: A new silicon doping source in metalorganic chemical vapor deposition of GaAs  

Science Journals Connector (OSTI)

Disilane (Si2H6) is presented as a new silicon doping source in the metalorganic chemical vapor deposition of GaAs together with comparison results obtained using the conventional silane (SiH4) doping source. The dopingcharacteristics of disilane were studied over a wide range of growth conditions: temperature gas phase stoichiometry and disilane concentration in the growth ambient. Silicon incorporation by means of disilane pyrolysis showed no temperature dependence in sharp contrast to the strong temperature activated dependence found when employing silane. The decomposition reaction of disilane proved to be very efficient reducing the amount of dopant gas required by about two orders of magnitude at the lower growth temperatures. Electrical measurements on disilane?doped GaAs yield the same high mobilities as obtained in silane?doped GaAs films indicative of low compensation.

T. F. Kuech; B. S. Meyerson; E. Veuhoff

1984-01-01T23:59:59.000Z

436

A QSPR Study of the Solubility of Gases and Vapors in Water  

Science Journals Connector (OSTI)

QSPR correlation equations were developed for the prediction of the solubilities of organic gases and vapors in water. ... The Ostwald solubility coefficient (L) is defined as the ratio of the equilibrium concentrations of a gaseous compound in the liquid and in the gas phase (eq 1), where a superscript w (Lw) usually denotes water as a solvent. ... Table 2) are as follows:? the energy gap between HOMO and LUMO (EHOMO ? ELUMO), the numbers of nitrogen atoms and of oxygen atoms in the molecule, and the most negative partial charge weighted topological electronic index43a (PCWTE) defined by eq 7, where qi and qj are the Zefirov partial charges43b of the bonded atoms, rij is the respective bond lengths, and Qmin is the most negative partial charge. ...

Alan R. Katritzky; Lan Mu; Mati Karelson

1996-11-21T23:59:59.000Z

437

Unsaturated drip tests on sludge based SRL glass : the effects of prior vapor hydration.  

SciTech Connect

The behavior of a sludge-based Savannah River Laboratory (SRL) waste glasses exposed to as much as 7 years of unsaturated test conditions is reported. This test series included both as-cast glass and glass that had been pre-altered by exposure to 200 C water vapor. Actinides (except neptunium) are retained in alteration products and released primarily as solution-borne colloids and particulate when fresh glass is reacted. Pre-altered glass, however, rapidly releases most elements (including actinides) in a nearly congruent manner when first exposed to dripping water. Normalized boron release from the aged glass is more rapid than that of any other element by an order of magnitude. The response of pre-altered glass, as determined by cumulative boron release, follows a power-law behavior with time, corresponding roughly to t{sup 1/4}. This is consistent with a diffusion transport through clay alteration phases on the glass surface.

Fortner, J. A.

1998-12-18T23:59:59.000Z

438

Energy band alignment of atomic layer deposited HfO{sub 2} on epitaxial (110)Ge grown by molecular beam epitaxy  

SciTech Connect

The band alignment properties of atomic layer HfO{sub 2} film deposited on epitaxial (110)Ge, grown by molecular beam epitaxy, was investigated using x-ray photoelectron spectroscopy. The cross-sectional transmission electron microscopy exhibited a sharp interface between the (110)Ge epilayer and the HfO{sub 2} film. The measured valence band offset value of HfO{sub 2} relative to (110)Ge was 2.28 {+-} 0.05 eV. The extracted conduction band offset value was 2.66 {+-} 0.1 eV using the bandgaps of HfO{sub 2} of 5.61 eV and Ge bandgap of 0.67 eV. These band offset parameters and the interface chemical properties of HfO{sub 2}/(110)Ge system are of tremendous importance for the design of future high hole mobility and low-power Ge-based metal-oxide transistor devices.

Hudait, M. K.; Zhu, Y. [Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)] [Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Maurya, D.; Priya, S. [Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061 (United States)] [Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061 (United States)

2013-03-04T23:59:59.000Z

439

UNCORRECTEDPROOF 2 Vaporization, fusion and sublimation enthalpies of the  

E-Print Network (OSTI)

UNCORRECTEDPROOF 2 Vaporization, fusion and sublimation enthalpies of the 3 dicarboxylic acids from of Chemistry and Biochemistry, University of Missouri-St. Louis, 8001 Natural Bridge, St. Louis, MO 63121, USA observed previously in the sublimation enthalpies of these compounds. The results are dis- 16 cussed

Chickos, James S.

440

Vapor-side corrosion in thermal desalination plants  

SciTech Connect

This article reports the results of vapor-size corrosion monitoring studies carried out in multistage flash (MSF) desal unit No. 100 of Al-Khafji power and Desalination Plant in Saudi Arabia. Corrosion behavior of 70/30 Cu-Ni alloy, carbon steel (CS), and type 316L stainless steel (SS) was studied in vents and in the vapor size of distillers for 2,000, 4,000, and 9,000 h. Analyses of the experimental data indicated that in addition to O{sub 2}, S-containing compounds evolved during flashing of seawater reacted more with Cu-Ni alloy than with CS and type 316L SS. Explanations for comparatively higher corrosion of alloys exposed to the vapors of the first three (1 to 3) and middle (11 to 13) stages of the MSF plant are given with experimental results. Type 316L SS was found to be the alloy most resistant to vapor-side corrosion in all stages of distillers.

Asrar, N.; Malik, A.U.; Ahmed, S. [Saline Water Conversion Corp. (Saudi Arabia); Al-Khalidi, M.; Al-Moaili, K. [Al-Khafji Desalination Plant (Saudi Arabia)

1999-04-01T23:59:59.000Z

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


441

Fatigue Resistance of Asphalt Mixtures Affected by Water Vapor Movement  

E-Print Network (OSTI)

This dissertation has two key objectives: the first objective is to develop a method of predicting and quantifying the amount of water that can enter into a pavement system by vapor transport; the second objective is to identify to which extent...

Tong, Yunwei

2013-11-08T23:59:59.000Z

442

The chemical vapor deposition of zirconium carbide onto ceramic substrates  

SciTech Connect

Zirconium carbide is an attractive ceramic material due to its unique properties such as high melting point, good thermal conductivity, and chemical resistance. The controlled preparation of zirconium carbide films of superstoichiometric, stoichiometric, and substoichiometric compositions has been achieved utilizing zirconium tetrachloride and methane precursor gases in an atmospheric pressure high temperature chemical vapor deposition system.

Glass, John A, Jr.; Palmisiano, Nick, Jr.; Welsh, R. Edward

1999-07-01T23:59:59.000Z

443

A transient model for a cesium vapor thermionic converter. [Cs  

SciTech Connect

This paper presents an analytical model for simulating the transient and steady-state operation of cesium vapor thermionic converters. A parametric analysis is performed to assess the transient response of the converter to changes in fission power and width of interelectrode gap. The model optimizes the converter performance for maximum electric power to the load.(AIP)

El-Genk, M.S.; Murray, C.S.; Chaudhuri, S. (Institute for Space Nuclear Power Studies, Department of Chemical and Nuclear Engineering, The University of New Mexico, Albuquerque, New Mexico (USA))

1991-01-10T23:59:59.000Z

444

Experimental Study of Water Vapor Adsorption on Geothermal  

E-Print Network (OSTI)

Geothermal Program under Department of Energy Grant No. DE-FG07-90IDI2934,and by the Department of PetroleumSGP-TR-148 Experimental Study of Water Vapor Adsorption on Geothermal Reservoir Rocks Shubo Shang Engineering, Stanford University Stanford Geothermal Program Interdisciplinary Research in Engineering

Stanford University

445

CVD CNT CNT (Vapor-grown carbon fiber, VGCF)  

E-Print Network (OSTI)

CNT CNT CVD CNT CNT (Vapor-grown carbon fiber, VGCF) 10001300 CNT CVD Smalley CO 24 CCVD 1 #12; 27 mm 3% 200 sccm 800 10 10 Torr 300 sccm Ethanol tank Hot bath boat Ar/H2 Ar or Ethanol tank Hot bath Ethanol tank Hot bath Pressure gauge Maindraintube Subdraintube

Maruyama, Shigeo

446

Method for removing metal vapor from gas streams  

DOE Patents (OSTI)

A process for cleaning an inert gas contaminated with a metallic vapor, such as cadmium, involves withdrawing gas containing the metallic contaminant from a gas atmosphere of high purity argon; passing the gas containing the metallic contaminant to a mass transfer unit having a plurality of hot gas channels separated by a plurality of coolant gas channels; cooling the contaminated gas as it flows upward through the mass transfer unit to cause contaminated gas vapor to condense on the gas channel walls; regenerating the gas channels of the mass transfer unit; and, returning the cleaned gas to the gas atmosphere of high purity argon. The condensing of the contaminant-containing vapor occurs while suppressing contaminant particulate formation, and is promoted by providing a sufficient amount of surface area in the mass transfer unit to cause the vapor to condense and relieve supersaturation buildup such that contaminant particulates are not formed. Condensation of the contaminant is prevented on supply and return lines in which the contaminant containing gas is withdrawn and returned from and to the electrorefiner and mass transfer unit by heating and insulating the supply and return lines.

Ahluwalia, R. K. (6440 Hillcrest Dr., Burr Ridge, IL 60521); Im, K. H. (925 Lehigh Cir., Naperville, IL 60565)

1996-01-01T23:59:59.000Z

447

Sorption and Diffusion of Organic Vapors in Two Fluoroelastomers  

E-Print Network (OSTI)

Sorption and Diffusion of Organic Vapors in Two Fluoroelastomers PING WANG,* NATHANIEL S. SCHNEIDER of II in polar liquids: over 100% (wt/wt) in two ketones and a phosphate ester. Sorption isotherms deter determined from sorption kinetics, corrected for nonisothermal effects, and converted to solvent self

Wang, Ping

448

High-resolution terahertz atmospheric water vapor continuum measurements  

E-Print Network (OSTI)

High-resolution terahertz atmospheric water vapor continuum measurements David M. Slocum,* Thomas M such as pollution monitoring and the detection of energetic chemicals using remote sensing over long path lengths through the atmosphere. Although there has been much attention to atmospheric effects over narrow

Massachusetts at Lowell, University of

449

Method and apparatus to measure vapor pressure in a flow system  

DOE Patents (OSTI)

The present invention is directed to a method for determining, by a condensation method, the vapor pressure of a material with a known vapor pressure versus temperature characteristic, in a flow system particularly in a mercury isotope enrichment process.

Grossman, Mark W. (Belmont, MA); Biblarz, Oscar (Swampscott, MA)

1991-01-01T23:59:59.000Z

450

Tropical Water Vapor and Cloud Feedbacks in Climate Models: A Further Assessment Using Coupled Simulations  

Science Journals Connector (OSTI)

By comparing the response of clouds and water vapor to ENSO forcing in nature with that in Atmospheric Model Intercomparison Project (AMIP) simulations by some leading climate models, an earlier evaluation of tropical cloud and water vapor ...

De-Zheng Sun; Yongqiang Yu; Tao Zhang

2009-03-01T23:59:59.000Z

451

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

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

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

452

Economic and Technical Tradeoffs Between Open and Closed Cycle Vapor Compression Evaporators  

E-Print Network (OSTI)

and solute. Evaporation tends to be a very energy intensive process. Approximately 1000 BTUs of energy are required to vaporize one pound of water. Many techniques have been developed to reuse energy Within an evaporation system so as to vaporize... Recompression A schematic of an open cycle vapor recompression evaporator is shown in Figure 2. This method uses the vapor in an open cycle for both heating and cooling. Rather than being condensed after the last effect, steam is compressed to a slightly...

Timm, M. L.

453

Pressure dependence of phonons and excitons in InSe films prepared by metal-organic chemical vapor deposition  

Science Journals Connector (OSTI)

The pressure dependence of the Raman spectra of phase-pure InSe thin films prepared by the low-pressure metal-organic chemical vapor deposition technique has been studied using a diamond-anvil high-pressure cell. Enhancement in the intensities of the Raman modes has been observed as a result of pressure-induced “tuning” of the energy of the M1-type hyperbolic exciton in InSe at ?2.54 eV through discrete incident laser photon energies. The pressure coefficients of the phonon modes and of the hyperbolic exciton in InSe have been determined.

In-Hwan Choi and Peter Y. Yu

2003-10-27T23:59:59.000Z

454

Determination of vaporization efficiencies and overall mass transfer coefficients from a packed absorber at steady state operation  

E-Print Network (OSTI)

typical tower used in gas absorption is shown in Figure l. A gas mixture, referred to as the rich gas is introduced at the bottom of the tower and is contacted counter-currently with the lean oil introduced at the top of the tower. The gas leaving... the towe" is called the lean gas and the liquid leaving the tower is called rich oil. The heavier components in the rich gas are absorbed in part by the lean oil. The driving force for the mass transfer of a component from the vapor phase to the liquid...

McDaniel, Ronald

2012-06-07T23:59:59.000Z

455

Metamorphosis: Phases of UF{sub 6}  

SciTech Connect

A 15-minute videotape is presented. The subject matter is 150 grams of UF{sub 6} sealed in a glass tube. Close-up views show the UF{sub 6} as phase changes are effected by the addition or removal of heat from the closed system. The solid-to-liquid transition is shown as heat is added, both slowly and rapidly. The solid phases which result from freezing and from desublimation are contrasted. In the solid state, uranium hexafluoride is a nearly-white, dense crystalline solid. The appearance of this solid depends on whether it is formed by freezing from the liquid or by desublimation from the vapor phase. If frozen from the liquid, the solid particles take the form of irregularly shaped coarse grains, while the solid product of desublimation tends to be a rather formless mass without individually distinguishable particles. The changes in state are presented in terms of the UF{sub 6} phase diagram.

Dyer, R.H. [Department of Energy, Oak Ridge, TN (United States)

1991-12-31T23:59:59.000Z

456

Quantitative Analysis of Ternary Vapor Mixtures Using a Microcantilever-Based Electronic Nose  

SciTech Connect

The authors report the identification and quantification of the components of a ternary vapor mixture using a microcantilever-based electronic nose. An artificial neural network was used for pattern recognition. Dimethyl methyl phosphonate vapor in ppb concentrations and water and ethanol vapors in ppm concentrations were quantitatively identified either individually or in binary and ternary mixtures at varying concentrations.

Pinnaduwage, Lal A [ORNL; Zhao, Weichang [ORNL; Gehl, Anthony C [ORNL; Allman, Steve L [ORNL

2007-01-01T23:59:59.000Z

457

Sample Vapor Introduction Techniques for Use with Cryofocusing GC Inlet Systems  

Science Journals Connector (OSTI)

......the vapor generator was operated at atmospheric pressure for...condensed water. Other studies...Because the water vapor was...tail of the water peak. Thus...obtained from an atmospheric pressure source...the vapor generator over a 1......

Christine L. Rankin; Richard D. Sacks

1994-01-01T23:59:59.000Z

458

Epitaxial La0.5Sr0.5CoO3 thin films: Structure, magnetism, and transport  

SciTech Connect

La1 xSrxCoO3 has received considerable attention in bulk form. This is due to interest in the fundamental magnetic properties spin-state transitions and magnetic phase separation as well as potential applications in ferroelectric memory and solid-oxide fuel cells. The structure and properties in thin film form are not well understood, and the influence of dimensional confinement on effects such as magnetic phase separation is unknown. Here, we report a comprehensive investigation of structure, magnetism, and transport in strained epitaxial La0.5Sr0.5CoO3 001 films deposited on SrTiO3 001 substrates by reactive dc magnetron sputtering. The crystalline quality, phase purity, strain state, oxygen stoichiometry, morphology, and magnetic and electronic properties of the epilayers are all probed and are found to be particularly sensitive to the total sputtering gas pressure and the ratio of reactive to inert gas PO2 /PAr. The various structure-property relationships are discussed in detail, particularly with respect to the degree of oxygenation and oxygen-induced resputtering. The films are strained and tetragonally distorted due to the 1.9% lattice mismatch with SrTiO3. Significant strain relaxation occurs at thicknesses around 200 , resulting in a crossover from two-dimensional-like to three-dimensional growth. Polarized neutron reflectometry was combined with x-ray reflectometry to obtain chemical and magnetic depth profiles, which are compared with cross-sectional scanning transmission electron microscopy. The results indicate a thin 10 layer at the film/substrate interface with significantly different structural properties to the bulk of the film, as well as a strongly graded magnetic and chemical profile at the film surface due to the significant roughness. The Curie temperature was found to decrease very slowly as the thickness is reduced down to 50 , at which point a rapid decrease occurs, almost coincident with a sharp decrease in saturation magnetization. At this point, the temperature dependence of the resistivity shows a crossover from metallic to insulating, accompanied by dramatic changes in the magnetoresistance. The magnetoresistance has a negative contribution peaking around the Curie point similar to that seen in bulk, a second negative contribution occurring at low temperature only for the thinnest samples, as well as a large anisotropic magnetoresistance, which vanishes at the Curie point. Remarkably, the low temperature contribution in the thinnest x=0.5 films bears a striking resemblance to that seen in the insulating phase x0.17 in bulk, suggesting the formation of a nonmetallic phase at low thickness that is similar to the low doping bulk phase, i.e., magnetic phase separation near the interface with SrTiO3.

Torija, Maria [University of Minnesota; Sharma, M [University of Minnesota; Fitzsimmons, M. R. [Los Alamos National Laboratory (LANL); Varela, M [Oak Ridge National Laboratory (ORNL); Leighton, chris [University of Minnesota

2008-01-01T23:59:59.000Z

459

A TWO-DIMENSIONAL, FINITE-DIFFERENCE MODEL OF THE PHASE DISTRIBUTION AND VAPOR  

E-Print Network (OSTI)

Size Determination .................................................................. 31 Mass Balance Calculation ......................................................................... 33 Data Requirements

460

Bundles of carbon nanotubes generated by vapor-phase growth Maohui Ge and Klaus Sattler  

E-Print Network (OSTI)

Z.t They were initially found at the end of an electrode in the arc discharge method and were later produced, thinning and opening of the tubes by oxidation was observed.4v5In the arc discharge method the generation of the tubes might be initiated by the substrate and proceed due to the electric field between the two elec

Sattler, Klaus

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


461

A Gas Lift Bioreactor for Removal of Contaminants from the Vapor Phase  

Science Journals Connector (OSTI)

...conditions, and the reactor was again allowed...of samplings and analysis took place. The...while maintaining reliability of the degradative...was fed into the reactor inlet at different...phenol found in the reactor contents unless...be detected by GC analysis under the conditions...

B. D. Ensley; P. R. Kurisko

1994-01-01T23:59:59.000Z

462

High Rates of Oxygen Reduction over a Vapor Phase–Polymerized PEDOT Electrode  

Science Journals Connector (OSTI)

...electrode. Recently, the development of chemical polymerization...application of the PEDOT electrocatalyst concept would require...from the anode to the cathode is a major issue in...2 reduction on the cathode side (9). In...31). Thus, the development of the gas-ICP-electrolyte...

Bjorn Winther-Jensen; Orawan Winther-Jensen; Maria Forsyth; Douglas R. MacFarlane

2008-08-01T23:59:59.000Z

463

Controlled Vapor Phase Growth of Single Crystalline, Two-Dimensional GaSe  

E-Print Network (OSTI)

, and have the potential to enable next-generation electronic and optoelectronic devices. However, controlled-generation electronic and optoelectronic devices such as photodetectors and field-effect transistors. T wo-generation electronic and optoelectronic devices. Although most research has focused on 2D transition metal

Geohegan, David B.

464

Defect ordering in epitaxial a-GaN(QQ01) H. Z. Xiao, N.-E. Lee, R. C. Powell,") Z. Ma, L. J. Chou,b) L. H. Allen, J. E. Greene,  

E-Print Network (OSTI)

epitaxial wurtzite-structure o-GaN films, grown by gas-source molecular-beam epitaxy, plasma-assisted, including gas-source molecular-beam epitaxy (GSMBE),' reactive-ion MBE (RIMBE), plasma- assisted MBE (PAMBE- purity (99.9995%) NH3 flux, regulated with a mass-flow con- `kurrent address: Solar Cells Inc., 1702 N

Allen, Leslie H.

465

Raman and electron microscopic studies of Si{sub 1-x}Ge{sub x} alloy nanowires grown by chemical vapor deposition  

SciTech Connect

Si{sub 1-x}Ge{sub x} alloy nanowires (SiGeNWs) were grown by Au-catalyzed chemical vapor deposition and studied by Raman spectroscopy, transmission electron microscopy (TEM), and energy-dispersive x-ray spectroscopy (EDS) in TEM (TEM-EDS). The relationship between the growth parameters and the structure of the SiGeNWs was clarified by systematically changing the growth conditions over a wide range. Raman and TEM-EDS results demonstrated that the SiGeNWs consist of a lower Ge composition core and a higher Ge composition shell epitaxially grown on the surface of the core. The effects of oxidation on the structure of the SiGeNWs were studied. It was found that oxidation leads to segregation of the Ge atoms at the interface between the SiGeNWs and SiO{sub 2}, which in turn results in a large inhomogeneity in Ge composition. Oxidation at a very low rate in a diluted oxygen gas atmosphere is required to avoid the formation of Ge particles and minimize the inhomogeneity.

Kawashima, Takahiro; Imamura, Goh; Fujii, Minoru; Hayashi, Shinji; Saitoh, Tohru; Komori, Kazunori [Advanced Devices Development Center, Matsushita Electric Industrial Co., Ltd., 3-1-1 Yagumo-Nakamachi, Moriguchi, Osaka 570-8501 (Japan); Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501 (Japan); Image Devices Development Center, Matsushita Electric Industrial Co., Ltd., 3-1-1 Yagumo-Nakamachi, Moriguchi, Osaka 570-8501 (Japan)

2007-12-15T23:59:59.000Z

466

Molecular-beam epitaxy growth of strontium thiogallate T. Yang, B. K. Wagner, M. Chaichimansour, W. Park, Z. L. Wang,a)  

E-Print Network (OSTI)

Molecular-beam epitaxy growth of strontium thiogallate T. Yang, B. K. Wagner, M. Chaichimansour, W-beam epitaxy growth and characterization of cerium doped strontium thiogallate SrGa2S4:Ce thin film phosphors growth of cerium doped strontium thiogallate on quartz substrates was first reported in 1994.3 Here we

Wang, Zhong L.

467

Nanostructure formation during ion assisted growth of GaN by molecular beam epitaxy Bentao Cui and P.I. Cohen  

E-Print Network (OSTI)

Nanostructure formation during ion assisted growth of GaN by molecular beam epitaxy Bentao Cui and P.I. Cohen Department of Electrical and Computer Engineering and Department of Chemical Engineering Prairie, MN 55344 (Dated: March 4, 2005) Ion beam assisted molecular beam epitaxy was used to grow Ga

Cohen, Philip I.

468

Mercury Vapor At Mokapu Penninsula Area (Thomas, 1986) | Open Energy  

Open Energy Info (EERE)

Mokapu Penninsula Area (Thomas, 1986) Mokapu Penninsula Area (Thomas, 1986) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Mercury Vapor At Mokapu Penninsula Area (Thomas, 1986) Exploration Activity Details Location Mokapu Penninsula Area Exploration Technique Mercury Vapor Activity Date Usefulness not useful DOE-funding Unknown Notes The high degree of cultural activity (e.g. residential areas, streets, jet runways, etc.) on Mokapu both limited the extent of the soil geochemical surveys performed and rendered their interpretation much more difficult. Soil mercury concentrations and radon emanometry data on the peninsula showed a few localized high values (Figs 13, 14), but no consistent correlation between the anomalous zones and geologic features could be

469

Detonation wave driven by condensation of supersaturated carbon vapor  

Science Journals Connector (OSTI)

An experimental observation of a detonation wave driven by the energy of condensation of supersaturated carbon vapor is reported. The carbon vapor was formed by the thermal decay of unstable carbon suboxide C3O2 behind shock waves in mixtures containing 10–30% C3O2 in Ar. In the mixture 10% C3O2+Ar the insufficient heat release resulted in a regime of overdriven detonation. In the mixture 20% C3O2+Ar measured values of the pressure and wave velocity coincident with calculated Chapman-Jouguet parameters were attained. In the richest mixture 30% C3O2+Ar an excess heat release caused the slowing down of the condensation rate and the regime of underdriven detonation was observed.

A. Emelianov; A. Eremin; V. Fortov; H. Jander; A. Makeich; H. Gg. Wagner

2009-03-10T23:59:59.000Z

470

Fabrication of solid oxide fuel cell by electrochemical vapor deposition  

DOE Patents (OSTI)

In a high temperature solid oxide fuel cell (SOFC), the deposition of an impervious high density thin layer of electrically conductive interconnector material, such as magnesium doped lanthanum chromite, and of an electrolyte material, such as yttria stabilized zirconia, onto a porous support/air electrode substrate surface is carried out at high temperatures (approximately 1100.degree.-1300.degree. C.) by a process of electrochemical vapor deposition. In this process, the mixed chlorides of the specific metals involved react in the gaseous state with water vapor resulting in the deposit of an impervious thin oxide layer on the support tube/air electrode substrate of between 20-50 microns in thickness. An internal heater, such as a heat pipe, is placed within the support tube/air electrode substrate and induces a uniform temperature profile therein so as to afford precise and uniform oxide deposition kinetics in an arrangement which is particularly adapted for large scale, commercial fabrication of SOFCs.

Brian, Riley (Willimantic, CT); Szreders, Bernard E. (Oakdale, CT)

1989-01-01T23:59:59.000Z

471

Fabrication of solid oxide fuel cell by electrochemical vapor deposition  

DOE Patents (OSTI)

In a high temperature solid oxide fuel cell (SOFC), the deposition of an impervious high density thin layer of electrically conductive interconnector material, such as magnesium doped lanthanum chromite, and of an electrolyte material, such as yttria stabilized zirconia, onto a porous support/air electrode substrate surface is carried out at high temperatures (/approximately/1100/degree/ /minus/ 1300/degree/C) by a process of electrochemical vapor deposition. In this process, the mixed chlorides of the specific metals involved react in the gaseous state with water vapor resulting in the deposit of an impervious thin oxide layer on the support tube/air electrode substrate of between 20--50 microns in thickness. An internal heater, such as a heat pipe, is placed within the support tube/air electrode substrate and induces a uniform temperature profile therein so as to afford precise and uniform oxide deposition kinetics in an arrangement which is particularly adapted for large scale, commercial fabrication of SOFCs.

Riley, B.; Szreders, B.E.

1988-04-26T23:59:59.000Z

472

Specific Mass Estimates for A Vapor Core Reactor With MHD  

SciTech Connect

This study investigated the development of a system concept for space power generation and nuclear electric propulsion based on a vapor core reactor (VCR) with magnetohydrodynamic (MHD) power conversion system, coupled to a magnetoplasma-dynamic (MPD) thruster. The VCR is a liquid-vapor core reactor concept operating with metallic uranium or uranium tetrafluoride (UF{sub 4}) vapor as the fissioning fuel and alkali metals or their fluorides as working fluid in a closed Rankine cycle with MHD energy conversion. Gaseous and liquid-vapor core reactors can potentially provide the highest reactor and cycle temperature among all existing or proposed fission reactor designs. This unique feature makes this reactor concept a very natural and attractive candidate for very high power (10 to 1000 MWe) and low specific mass (0.4 to 5 kg/kWe) nuclear electric propulsion (NEP) applications since the MHD output could be coupled with minimal power conditioning to MPD thrusters or other types of thruster for producing thrust at very high specific impulse (I{sub sp} 1500 to 10,000 s). The exceptional specific mass performance of an optimized VCRMHD- NEP system could lead to a dramatic reduction in the cost and duration of manned or robotic interplanetary as well as interstellar missions. The VCR-MHD-NEP system could enable very efficient Mars cargo transfers or short (<8 month) Mars round trips with less initial mass in low Earth orbit (IMLEO). The system could also enable highly efficient lunar cargo transfer and rapid missions to other destinations throughout the solar system. (authors)

Knight, Travis; Smith, Blair; Anghaie, Samim [Innovative Nuclear Space Power and Propulsion Institute (INSPI), PO Box 116502, University of Florida, Gainesville, FL 32611-6502 (United States)

2002-07-01T23:59:59.000Z

473

Heat Recovery in Distillation by Mechanical Vapor Recompression  

E-Print Network (OSTI)

be classified generally into two types,.aerodynamic and positive displacement (Figure 5). Among the various types of compressors, centrifugal, reciprocating, lobe and screw have been used for vapor recompression. I AXIAL AERODYNAMIC I I CENTRIFUGAL I... speeds of centri fugal compressors make them highly susceptible to erosion from entrained liquid droplets. This ero sion can reduce the efficiency and cause dynamic instability from rotor imbalance and mechanical failure. Next, it is important...

Becker, F. E.; Zakak, A. I.

474

High average power magnetic modulator for metal vapor lasers  

DOE Patents (OSTI)

A three-stage magnetic modulator utilizing magnetic pulse compression designed to provide a 60 kV pulse to a copper vapor laser at a 4.5 kHz repetition rate is disclosed. This modulator operates at 34 kW input power. The circuit includes a step up auto transformer and utilizes a rod and plate stack construction technique to achieve a high packing factor.

Ball, Don G. (Livermore, CA); Birx, Daniel L. (Oakley, CA); Cook, Edward G. (Livermore, CA); Miller, John L. (Livermore, CA)

1994-01-01T23:59:59.000Z

475

Methanol vaporization and injection system for internal combustion engine  

SciTech Connect

An engine equipped with an alcohol vaporization injection system operates as a four stroke cycle diesel engine that transfers the heat of exiting exhaust gases and cylinder head walls to the fuel. The engine runs on alcohol. The alcohol becomes vaporized and its pressure is high enough so that when a valve is opened between the high pressure fuel line and the combustion chamber (when it is at the peak of its compression ratio) enough alcohol will enter the combustion chamber to allow proper combustion. The overall advantages to this type of alcohol vaporization injection system is that it adds relatively few new mechanisms to the spark ignition four cycle internal combustion engine to enable it to operate as a diesel engine with a high thermal efficiency. This alcohol injection system exploits the engine's need for greater volumes of alcohol caused by the alcohol's relatively low heat of combustion (When compared to gasoline) by using this greater volume of fuel to return greater quantities of heat back to the engine to a much greater degree than other fuels can.

Bayley, R.I.

1980-05-06T23:59:59.000Z

476

Program plan for the resolution of tank vapor issues  

SciTech Connect

Since 1987, workers at the Hanford Site waste tank farms in Richland, Washington, have reported strong odors emanating from the large, underground high-level radioactive waste storage tanks. Some of these workers have complained of symptoms (e.g., headaches, nausea) related to the odors. In 1992, the U.S. Department of Energy, which manages the Hanford Site, and Westinghouse Hanford Company determined that the vapor emissions coming from the tanks had not been adequately characterized and represented a potential health risk to workers in the immediate vicinity of the tanks. At that time, workers in certain areas of the tank farms were required to use full-face, supplied-breathing-air masks to reduce their exposure to the fugitive emissions. While use of supplied breathing air reduced the health risks associated with the fugitive emissions, it introduced other health and safety risks (e.g., reduced field of vision, air-line tripping hazards, and heat stress). In 1992, an aggressive program was established to assure proper worker protection while reducing the use of supplied breathing air. This program focuses on characterization of vapors inside the tanks and industrial hygiene monitoring in the tank farms. If chemical filtration systems for mitigation of fugitive emissions are deemed necessary, the program will also oversee their design and installation. This document presents the plans for and approach to resolving the Hanford Site high-level waste tank vapor concerns. It is sponsored by the Department of Energy Office of Environmental Restoration and Waste Management.

Osborne, J.W.; Huckaby, J.L.

1994-05-01T23:59:59.000Z

477

Hydrogen absorption in epitaxial W/Nb(001) and polycrystalline Fe/Nb(110) multilayers studied in-situ by X-ray/neutron scattering techniques and X-ray absorption spectroscopy  

SciTech Connect

Hydrogen can be absorbed in large quantities by 100 {angstrom} thin Nb layers embedded in epitaxial W/Nb and polycrystalline Fe/Nb multilayers. The solubility and the hydrogen-induced structural changes of the host lattice are explored in-situ by small-angle neutron/X-ray reflectometry and high-angle diffraction. These measurements reveal for both systems that the relative out-of-plane expansion of the Nb layers is considerably larger than the relative increase of the Nb interplanar spacing indicating two distinctly different mechanisms of hydrogen absorption. In Fe/Nb multilayers, hydrogen expands the Nb interplanar spacing in a continuous way as function of the external pressure. In contrast, the Nb lattice expansion is discontinuous in epitaxial W/Nb multilayers: A jump in the Nb(002) Bragg reflection position occurs at a critical hydrogen pressure of 1 mbar. In-situ EXAFS spectroscopy also exhibits an irreversible expansion of the Nb lattice in the film plane for p{sub H{sub 2}}> 1 mbar. This can be regarded as a structural phase transition from an exclusively out-of-plane to a three-dimensionally expanded state at low and high hydrogen pressures, respectively.

Klose, F.; Rehm, C.; Fieber-Erdmann, M.; Holub-Krappe, E.; Bleif, H. J.; Sowers, H.; Goyette, R.; Troger, L.; Maletta, H.

1999-11-02T23:59:59.000Z

478

Examining the Adsorption (Vapor?Liquid Equilibria) of Short-Chain Hydrocarbons in Low-Density Polyethylene with the SAFT-VR Approach  

Science Journals Connector (OSTI)

Examining the Adsorption (Vapor?Liquid Equilibria) of Short-Chain Hydrocarbons in Low-Density Polyethylene with the SAFT-VR Approach ... The versatility of the SAFT-VR approach in the prediction of fluid-phase equilibria of complex fluids is illustrated for systems of short and long hydrocarbons. ... 1999, 1, 2057), the phase behavior of pure long-chain n-alkane molecules was examined using the SAFT-VR approach; the intermolecular potential parameters were found to tend to a limiting value as the chain length of the n-alkane increases. ...

Clare McCabe; Amparo Galindo; M. Nieves García-Lisbona; George Jackson

2001-07-28T23:59:59.000Z

479

Fundamental optical properties of InN grown by epitaxial lateral overgrowth method  

SciTech Connect

Optical properties of InN grown by the epitaxial lateral overgrowth (ELO) method have been studied using photoluminescence (PL) and excitation-correlation (EC) measurements. The PL spectrum is analyzed by free-electron recombination band (FERB) model, which shows that the ELO sample has a very low background carrier concentration (n=5.5*10{sup 16}[cm{sup ?3]}). EC measurements show that the dependences of the band gap renormalization and Auger effect on the carrier concentrations are similar in spite of the different physical origins.

Kametani, Tatsuma; Kamimura, Jumpei; Inose, Yuta; Kunugita, Hideyuki; Kikuchi, Akihiko; Kishino, Katsumi; Ema, Kazuhiro [Department of Engineering and Applied Science, Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo 102-8554 (Japan)

2013-12-04T23:59:59.000Z

480

A portable molecular beam epitaxy system for in situ x-ray investigations at synchrotron beamlines  

SciTech Connect

A portable synchrotron molecular beam epitaxy (MBE) system is designed and applied for in situ investigations. The growth chamber is equipped with all the standard MBE components such as effusion cells with shutters, main shutter, cooling shroud, manipulator, reflection high energy electron diffraction setup, and pressure gauges. The characteristic feature of the system is the beryllium windows which are used for in situ x-ray measurements. An UHV sample transfer case allows in vacuo transfer of samples prepared elsewhere. We describe the system design and demonstrate its performance by investigating the annealing process of buried InGaAs self-organized quantum dots.

Slobodskyy, T. [Institute for Synchrotron Radiation, Karlsruhe Institute of Technology - 76344 Eggenstein-Leopoldshafen (Germany); Institut fuer Angewandte Physik und Zentrum fuer Mikrostrukturforschung, Jungiusstrasse 11, D-20355 Hamburg (Germany); Schroth, P.; Grigoriev, D.; Minkevich, A. A.; Baumbach, T. [Institute for Synchrotron Radiation, Karlsruhe Institute of Technology - 76344 Eggenstein-Leopoldshafen (Germany); Hu, D. Z.; Schaadt, D. M. [Institute for Applied Physics/DFG-Center for Functional Nanostructures, Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Institute for Energy Research and Physical Technologies, Technical University Clausthal, Am Stollen 19B, 38640 Goslar (Germany)

2012-10-15T23:59:59.000Z

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


481

Tank 241-TX-118 headspace gas and vapor characterization results for samples collected in September 1994 and December 1994  

SciTech Connect

Significant changes have been made to all of the original vapor characterization reports. This report documents specific headspace gas and vapor characterization results for all vapor sampling events to date. In addition, changes have been made to the original vapor reports to qualify the data based on quality assurance issues associated with the performing laboratories

Huckaby, J.L. [Pacific Northwest Lab., Richland, WA (United States); Bratzel, D.R. [Westinghouse Hanford Co., Richland, WA (United States)

1995-09-27T23:59:59.000Z

482

Growth and structure of epitaxial Pb{sub 1-x}Mn{sub x}Se(Ga) films  

SciTech Connect

The growth and structure of Pb{sub 1-x}Mn{sub x}Se (Ga) (N{sub Ga} = 0.8 at %) films with thicknesses of 0.3-0.5 {mu}m, grown on single-crystal PbSe{sub 1-x}S{sub x} (100) substrates by molecular-beam epitaxy, have been studied. It is established that films grow in a face-centered cubic lattice with the (100) orientation, reproducing the substrate orientation. The optimal conditions for obtaining photosensitive epitaxial films with perfect crystal structure are determined (W{sub 1/2} = 70-80'').

Nuriyev, I. R., E-mail: mhagiyev@yahoo.com; Gadzhiyev, M. B.; Sadigov, R. M. [National Academy of Sciences of Azerbaijan, Institute of Physics (Azerbaijan)

2009-03-15T23:59:59.000Z

483

Vibrational spectra of nanowires measured using laser doppler vibrometry and STM studies of epitaxial graphene : an LDRD fellowship report.  

SciTech Connect

A few of the many applications for nanowires are high-aspect ratio conductive atomic force microscope (AFM) cantilever tips, force and mass sensors, and high-frequency resonators. Reliable estimates for the elastic modulus of nanowires and the quality factor of their oscillations are of interest to help enable these applications. Furthermore, a real-time, non-destructive technique to measure the vibrational spectra of nanowires will help enable sensor applications based on nanowires and the use of nanowires as AFM cantilevers (rather than as tips for AFM cantilevers). Laser Doppler vibrometry is used to measure the vibration spectra of individual cantilevered nanowires, specifically multiwalled carbon nanotubes (MWNTs) and silver gallium nanoneedles. Since the entire vibration spectrum is measured with high frequency resolution (100 Hz for a 10 MHz frequency scan), the resonant frequencies and quality factors of the nanowires are accurately determined. Using Euler-Bernoulli beam theory, the elastic modulus and spring constant can be calculated from the resonance frequencies of the oscillation spectrum and the dimensions of the nanowires, which are obtained from parallel SEM studies. Because the diameters of the nanowires studied are smaller than the wavelength of the vibrometer's laser, Mie scattering is used to estimate the lower diameter limit for nanowires whose vibration can be measured in this way. The techniques developed in this thesis can be used to measure the vibrational spectra of any suspended nanowire with high frequency resolution Two different nanowires were measured - MWNTs and Ag{sub 2}Ga nanoneedles. Measurements of the thermal vibration spectra of MWNTs under ambient conditions showed that the elastic modulus, E, of plasma-enhanced chemical vapor deposition (PECVD) MWNTs is 37 {+-} 26 GPa, well within the range of E previously reported for CVD-grown MWNTs. Since the Ag{sub 2}Ga nanoneedles have a greater optical scattering efficiency than MWNTs, their vibration spectra was more extensively studied. The thermal vibration spectra of Ag{sub 2}Ga nanoneedles was measured under both ambient and low-vacuum conditions. The operational deflection shapes of the vibrating Ag{sub 2}Ga nanoneedles was also measured, allowing confirmation of the eigenmodes of vibration. The modulus of the crystalline nanoneedles was 84.3 {+-} 1.0 GPa. Gas damping is the dominate mechanism of energy loss for nanowires oscillating under ambient conditions. The measured quality factors, Q, of oscillation are in line with theoretical predictions of air damping in the free molecular gas damping regime. In the free molecular regime, Q{sub gas} is linearly proportional to the density and diameter of the nanowire and inversely proportional to the air pressure. Since the density of the Ag{sub 2}Ga nanoneedles is three times that of the MWNTs, the Ag{sub 2}Ga nanoneedles have greater Q at atmospheric pressures. Our initial measurements of Q for Ag{sub 2}Ga nanoneedles in low-vacuum (10 Torr) suggest that the intrinsic Q of these nanoneedles may be on the order of 1000. The epitaxial carbon that grows after heating (000{bar 1}) silicon carbide (SiC) to high temperatures (1450-1600) in vacuum was also studied. At these high temperatures, the surface Si atoms sublime and the remaining C atoms reconstruct to form graphene. X-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM) were used to characterize the quality of the few-layer graphene (FLG) surface. The XPS studies were useful in confirming the graphitic composition and measuring the thickness of the FLG samples. STM studies revealed a wide variety of nanometer-scale features that include sharp carbon-rich ridges, moire superlattices, one-dimensional line defects, and grain boundaries. By imaging these features with atomic scale resolution, considerable insight into the growth mechanisms of FLG on the carbon-face of SiC is obtained.

Biedermann, Laura Butler

2009-09-01T23:59:59.000Z

484

Vapor–liquid equilibrium for binary system of tetrahydrothiophene + 2,2,4-trimethylpentane and tetrahydrothiophene + 2,4,4-trimethyl-1-pentene at 358.15 and 368.15 K  

Science Journals Connector (OSTI)

Isothermal vapor–liquid equilibrium (VLE) for tetrahydrothiophene + 2,2,4-trimethylpentane and tetrahydrothiophene + 2,4,4-trimethyl-1-pentene at 358.15 and 368.15 K were measured with a circulation still. All systems studied exhibit positive deviation from Raoult's law. No azeotropic behavior was found in all systems at the measured temperatures. The experimental results were correlated with the Wilson model and compared to COSMO-SAC predictive model. Analyses of liquid and vapor phase composition were determined with gas chromatography. All VLE measurements passed the three thermodynamic consistency tests used. The activity coefficients at infinite dilution are also presented.

Erlin Sapei; Petri Uusi-Kyyny; Kari I. Keskinen; Juha-Pekka Pokki; Ville Alopaeus

2010-01-01T23:59:59.000Z

485

Headspace vapor characterization of Hanford Waste Tank 241-T-110: Results from samples collected on August 31, 1995. Tank Vapor Characterization Project  

SciTech Connect

This report describes the results of vapor samples taken from the headspace of waste storage tank 241-T-110 (Tank T-110) at the Hanford Site in Washington State. Pacific Northwest National Laboratory (PNNL) contracted with Westinghouse Hanford Company (WHC) to provide sampling devices and analyze samples for inorganic and organic analytes collected from the tank headspace and ambient air near the tank. The analytical work was performed by the PNNL Vapor Analytical Laboratory (VAL) by the Tank Vapor Characterization Project. Work performed was based on a sample and analysis plan (SAP) prepared by WHC. The SAP provided job-specific instructions for samples, analyses, and reporting. The SAP for this sample job was {open_quotes}Vapor Sampling and Analysis Plan{close_quotes}, and the sample job was designated S5056. Samples were collected by WHC on August 31, 1995, using the Vapor Sampling System (VSS), a truck-based sampling method using a heated probe inserted into the tank headspace.

McVeety, B.D.; Thomas, B.L.; Evans, J.C. [and others

1996-05-01T23:59:59.000Z

486

Final Report for ARM Project Measuring 4-D Water Vapor Fields with GPS  

SciTech Connect

Water vapor is a primary element in the Earth’s climate system. Atmospheric water vapor is central to cloud processes, radiation transfer, and the hydrological cycle. Using funding from Department of Energy (DOE) grant DE-FG03-02ER63327, the University Corporation for Atmospheric Research (UCAR) developed new observational techniques to measure atmospheric water vapor and applied these techniques to measure four dimensional water vapor fields throughout the United States Southern Great Plains region. This report summarizes the development of a new observation from ground based Global Positioning System (GPS) stations called Slant Water Vapor (SW) and it’s utilization in retrieving four dimensional water vapor fields. The SW observation represents the integrated amount of water vapor between a GPS station and a transmitting satellite. SW observations provide improved temporal and spatial sampling of the atmosphere when compared to column-integrated quantities such as preciptitable water vapor (PW). Under funding from the DOE Atmospheric Radiation Measurement (ARM) program, GPS networks in the Southern Great Plains (SGP) region were deployed to retrieve SW to improve the characterization of water vapor throughout the region. These observations were used to estimate four dimensional water vapor fields using tomographic approaches and through assimilation into the MM5 numerical weather model.

Braun, John

2006-02-06T23:59:59.000Z

487

Kinetics of disilane molecule decomposition on the growth surface of silicon in vacuum gas-phase epitaxy reactors  

Science Journals Connector (OSTI)

The range of the characteristic decomposition rates of dihydride molecule radicals adsorbed by the silicon surface in the temperature interval 450–700°C is experimentally found for a number of kinetic models. A r...

L. K. Orlov; T. N. Smyslova

2012-11-01T23:59:59.000Z

488

Journal of Crystal Growth 241 (2002) 4550 Boron doping of silicon layers grown by liquid phase epitaxy  

E-Print Network (OSTI)

advantage. One disadvantage of tin is that layers grown using a tin melt may *Corresponding author. Tel Energy Systems, Department of Engineering, Australian National University, Acton, 0200, Australia film solar cell applications as it allows the growth of a back surface field and a lightly doped bulk

489

Abbreviated epitaxial growth mode (AGM) method for reducing cost and improving quality of LEDs and lasers  

DOE Patents (OSTI)

The use of an abbreviated GaN growth mode on nano-patterned AGOG sapphire substrates, which utilizes a process of using 15 nm low temperature GaN buffer and bypassing etch-back and recovery processes during epitaxy, enables the growth of high-quality GaN template on nano-patterned AGOG sapphire. The GaN template grown on nano-patterned AGOG sapphire by employing abbreviated growth mode has two orders of magnitude lower threading dislocation density than that of conventional GaN template grown on planar sapphire. The use of abbreviated growth mode also leads to significant reduction in cost of the epitaxy. The growths and characteristics of InGaN quantum wells (QWs) light emitting diodes (LEDs) on both templates were compared. The InGaN QWs LEDs grown on the nano-patterned AGOG sapphire demonstrated at least a 24% enhancement of output power enhancement over that of LEDs grown on conventional GaN templates.

Tansu, Nelson; Chan, Helen M; Vinci, Richard P; Ee, Yik-Khoon; Biser, Jeffrey

2013-09-24T23:59:59.000Z

490

Process for selectively patterning epitaxial film growth on a semiconductor substrate  

DOE Patents (OSTI)

A process is disclosed for selectively patterning epitaxial film growth on a semiconductor substrate. The process includes forming a masking member on the surface of the substrate, the masking member having at least two layers including a first layer disposed on the substrate and the second layer covering the first layer. A window is then opened in a selected portion of the second layer by removing that portion to expose the first layer thereunder. The first layer is then subjected to an etchant introduced through the window to dissolve a sufficient amount of the first layer to expose the substrate surface directly beneath the window, the first layer being adapted to preferentially dissolve at a substantially greater rate than the second layer so as to create an overhanging ledge portion with the second layer by undercutting the edges thereof adjacent to the window. The epitaxial film is then deposited on the exposed substrate surface directly beneath the window. Finally, an etchant is introduced through the window to dissolve the remainder of the first layer so as to lift-off the second layer and materials deposited thereon to fully expose the balance of the substrate surface.

Sheldon, Peter (Golden, CO); Hayes, Russell E. (Boulder, CO)

1986-01-01T23:59:59.000Z

491

Anisotropy of the solid-state epitaxy of silicon carbide in silicon  

SciTech Connect

A new method for the solid-state synthesis of epitaxial layers is developed, in which a substrate participates in the chemical reaction and the reaction product grows not on the substrate surface, as in traditional epitaxial methods, but inside the substrate. This method offers new opportunities for elastic-energy relaxation due to a mechanism operating only in anisotropic media, specifically, the attraction of point defects formed during the chemical reaction. The attracting point centers of dilatation form relatively stable objects, dilatation dipoles, which significantly reduce the total elastic energy. It is shown that, in crystals with cubic symmetry, the most favorable arrangement of dipoles is the ?111? direction. The theory is tested by growing silicon carbide (SiC) films on Si (111) substrates by chemical reaction with carbon monoxide CO. High-quality single-crystal SiC-4H films with thicknesses of up to 100 nm are grown on Si (111). Ellipsometric analysis showed that the optical constants of the SiC-4H films are significantly anisotropic. This is caused not only by the lattice hexagonality but also by a small amount (about 2–6%) of carbon atoms remaining in the film due to dilatation dipoles. It is shown that the optical constants of the carbon impurity correspond to strongly anisotropic highly oriented pyrolytic graphite.

Kukushkin, S. A., E-mail: kukushkin_s@yahoo.com; Osipov, A. V. [Russian Academy of Sciences, Institute of Problems of Machine Science (Russian Federation)

2013-12-15T23:59:59.000Z

492

Asymmetric Electron Transport at Monolayer-Bilayer Heterojunctions of Epitaxial Graphene  

SciTech Connect

The symmetry of the graphene honeycomb lattice is a key element determining many of graphene s unique electronic properties, such as the linear energy-momentum dispersion and the suppressed backscattering 1,2. However, line defects in large-scale epitaxial graphene films, such as grain boundaries, edges, surface steps, and changes in layer thickness, often break the sublatttice symmetry and can impact transport properties of graphene profoundly 3-6. Here we report asymmetric electron transport upon polarity reversal at individual monolayer-bilayer (ML-BL) boundaries in epitaxial graphene on SiC (0001), revealed by scanning tunneling potentiometry. A greater voltage drop is observed when the current flows from BL to ML graphene than in the reverse direction, and the difference remains nearly unchanged with increasing current. This is not a typical nonlinear conductance due to electron transmission through an asymmetric potential. Rather, it indicates the opening of a dynamic energy gap at the Fermi energy due to the Coulomb interaction between the injected nonequilibrium electron density and the pseudospin polarized Friedel oscillation charge density at the boundary. This intriguing heterojunction transport behavior opens a new avenue towards novel quantum functions such as quantum switching.

Li, An-Ping [ORNL] [ORNL; Clark, Kendal W [ORNL] [ORNL; Zhang, Xiaoguang [ORNL] [ORNL; Gu, Gong [University of Tennessee, Knoxville (UTK)] [University of Tennessee, Knoxville (UTK); He, Guowei [Carnegie Mellon University (CMU)] [Carnegie Mellon University (CMU); Feenstra, Randall [Carnegie Mellon University (CMU)] [Carnegie Mellon University (CMU)

2014-01-01T23:59:59.000Z

493

Process for selectively patterning epitaxial film growth on a semiconductor substrate  

DOE Patents (OSTI)

Disclosed is a process for selectively patterning epitaxial film growth on a semiconductor substrate. The process includes forming a masking member on the surface of the substrate, the masking member having at least two layers including a first layer disposed on the substrate and the second layer covering the first layer. A window is then opened in a selected portion of the second layer by removing that portion to expose the first layer thereunder. The first layer is then subjected to an etchant introduced through the window to dissolve the first layer a sufficient amount to expose the substrate surface directly beneath the window, the first layer being adapted to preferentially dissolve at a substantially greater rate than the second layer so as to create an overhanging ledge portion with the second layer by undercutting the edges thereof adjacent the window. The epitaxial film is then deposited on the exposed substrate surface directly beneath the window. Finally, an etchant is introduced through the window to dissolve the remainder of the first layer so as to lift-off the second layer and materials deposited thereon to fully expose the balance of the substrate surface.

Sheldon, P.; Hayes, R.E.

1984-12-04T23:59:59.000Z

494

Big-Data RHEED analysis for understanding epitaxial film growth processes  

SciTech Connect

Reflection high energy electron diffraction (RHEED) has by now become a standard tool for in-situ monitoring of film growth by pulsed laser deposition and molecular beam epitaxy. Yet despite the widespread adoption and wealth of information in RHEED image, most applications are limited to observing intensity oscillations of the specular spot, and much additional information on growth is discarded. With ease of data acquisition and increased computation speeds, statistical methods to rapidly mine the dataset are now feasible. Here, we develop such an approach to the analysis of the fundamental growth processes through multivariate statistical analysis of RHEED image sequence. This approach is illustrated for growth of LaxCa1-xMnO3 films grown on etched (001) SrTiO3 substrates, but is universal. The multivariate methods including principal component analysis and k-means clustering provide insight into the relevant behaviors, the timing and nature of a disordered to ordered growth change, and highlight statistically significant patterns. Fourier analysis yields the harmonic components of the signal and allows separation of the relevant components and baselines, isolating the assymetric nature of the step density function and the transmission spots from the imperfect layer-by-layer (LBL) growth. These studies show the promise of big data approaches to obtaining more insight into film properties during and after epitaxial film growth. Furthermore, these studies open the pathway to use forward prediction methods to potentially allow significantly more control over growth process and hence final film quality.

Vasudevan, Rama K [ORNL; Tselev, Alexander [ORNL; Baddorf, Arthur P [ORNL; Kalinin, Sergei V [ORNL

2014-01-01T23:59:59.000Z

495

Lateral Self-Aligned p-Type In2O3 Nanowire Arrays Epitaxially Grown on  

E-Print Network (OSTI)

and carried by the carrier gas and then condensed on the substrates. The source and samples were heated to 800 nanowire (NW) and nanorod (NR) arrays has been achieved by a vapor transport and condensation method. It is an important material that has applications in optoelec- tronic devices and sensors for gas and biological

Wang, Zhong L.

496

Mercury Vapor At Salt Wells Area (Henkle, Et Al., 2005) | Open Energy  

Open Energy Info (EERE)

Mercury Vapor At Salt Wells Area (Henkle, Et Al., 2005) Mercury Vapor At Salt Wells Area (Henkle, Et Al., 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Mercury Vapor At Salt Wells Area (Henkle, Et Al., 2005) Exploration Activity Details Location Salt Wells Area Exploration Technique Mercury Vapor Activity Date - 2005 Usefulness useful DOE-funding Unknown Exploration Basis Adsorbed mercury soil geochemical surveys and radiometric geophysical surveys were carried out in conjunction with geologic mapping to test the application of these ground-based techniques to geothermal exploration at three prospects in Nevada by Henkle Jr. et al. in 2005. Mercury soil vapor surveys were not widely used in geothermal exploration in the western US at the time, although the association of mercury vapors with geothermal

497

MEASUREMENTS AND RETRIEVALS FROM A NEW 183-GHz WATER VAPOR RADIOMETER IN  

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

MEASUREMENTS AND RETRIEVALS FROM A NEW 183-GHz WATER VAPOR RADIOMETER IN MEASUREMENTS AND RETRIEVALS FROM A NEW 183-GHz WATER VAPOR RADIOMETER IN THE ARCTIC Cadeddu, Maria Argonne National Laboratory Category: Instruments A new G-band (183 GHz) vapor radiometer (GVR), developed and built by Prosensing Inc. (http://www.prosensing.com), was deployed in Barrow, Alaska, in April 2005. The radiometer was deployed as part of the ongoing Atmospheric Radiation Measurement (ARM) program's effort to improve water vapor retrievals in the cold, dry Arctic environment. The instrument measures brightness temperatures from four double sideband channels centered at 1, 3, 7, and 14 GHz from the 183.31-GHz water vapor line. Atmospheric emission in this spectral region is primarily due to water vapor, with some influence from liquid water. The GVR will remain in Barrow

498</