Results 211 to 220 of about 195,760 (256)
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Silicon-Hydrogen Bonding and Hydrogen Diffusion in Amorphous Silicon
MRS Proceedings, 1995ABSTRACTDespite its importance for technological applications, the behavior of hydrogen in amorphous silicon is not fully understood. In particular, the anomalously low activation energy (1.5 eV) for hydrogen diffusion has remained unexplained. We investigate the interaction of hydrogen with dangling bonds using first-principles pseudopotential-density-
, Van de Walle CG, , Street
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MRS Proceedings, 1992
ABSTRACTThe diffusion constant of hydrogen DH(t) in hydrogenated amorphous silicon (a-Si:H) is strongly dependent on the Si-bonded H content CH of the films. It increases by over four orders of magnitude for CH ranging from 1 to 19 at. %. In an rf sputter-deposited film of CH ∼5 at. % it increases with time at 300 ≤ T ≤ 362°C.
R. Shinar, H. Jia, X.-L. Wu, J. Shinar
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ABSTRACTThe diffusion constant of hydrogen DH(t) in hydrogenated amorphous silicon (a-Si:H) is strongly dependent on the Si-bonded H content CH of the films. It increases by over four orders of magnitude for CH ranging from 1 to 19 at. %. In an rf sputter-deposited film of CH ∼5 at. % it increases with time at 300 ≤ T ≤ 362°C.
R. Shinar, H. Jia, X.-L. Wu, J. Shinar
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Diffusion of Hydrogen in Hydrogen-Quenched Nickel
Japanese Journal of Applied Physics, 1977The recovery process of hydrogen dissolved in excess in nickel is studied by means of the hydrogen-quenching method which is a modified Schultz's method. Two recovery stages of electrical resistance are found. The lower temperature stage is a new one which presumably arises from trapping and/or clustering of hydrogen atoms in the interior of the ...
Kohji Yamakawa, Francisco Eiichi Fujita
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Nonadiabatic Effects in Hydrogen Diffusion in Metals*
Zeitschrift für Physikalische Chemie, 1992Molecular dynamic simulations for hydrogen diffusion in Pd are perfomed, using a potential based on the embedded-atom method. It is found that a single adiabatic Born-Oppenheimer potential energy surface cannot reproduce the wave-vector dependence of the quasielectric peak obtained in neutron scattering studies.
, Li, , Wahnström
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Solid State Communications, 1990
Abstract We have measured, by ERA, the hydrogen diffusion constant DH at 400°C in five undoped aSi:H/cSi thin films. The deposition temperatures of these films were successively 50, 100, 150, 200 and 250°C so that the corresponding nominal H-concentrations were ranging from 18 to 11 at .
X.-M. Tang, J. Weber, Y. Baer, F. Finger
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Abstract We have measured, by ERA, the hydrogen diffusion constant DH at 400°C in five undoped aSi:H/cSi thin films. The deposition temperatures of these films were successively 50, 100, 150, 200 and 250°C so that the corresponding nominal H-concentrations were ranging from 18 to 11 at .
X.-M. Tang, J. Weber, Y. Baer, F. Finger
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MRS Proceedings, 1990
ABSTRACTIn order to improve our understanding of the motion of hydrogen and the mechanism by which structural changes occurr, two sets of a-SiC:H samples obtained by glow-discharge at different substrate temperatures and power densities, respectively without and with hydrogen flow, were analyzed.Results from structural, optical and electrical ...
F. DEMICHELIS +3 more
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ABSTRACTIn order to improve our understanding of the motion of hydrogen and the mechanism by which structural changes occurr, two sets of a-SiC:H samples obtained by glow-discharge at different substrate temperatures and power densities, respectively without and with hydrogen flow, were analyzed.Results from structural, optical and electrical ...
F. DEMICHELIS +3 more
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?Uphill? hydrogen diffusion effects and hydrogen diffusion coefficients in palladium
International Journal of Hydrogen Energy, 1997Information concerning measurements of hydrogen diffusion coefficients over α- and β-phase ranges of hydrogen content in the palladium/hydrogen system is summarized. The utilization of palladium as a hydrogen purification membrane has constituted a background for observations of “uphill” hydrogen diffusion effects.
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Materials Testing, 2001
This research focused on the development of a diffusible hydrogen sensor for steel welds. The sensor is based on the chemochromic reaction of WO 3 with hydrogen. The sensor is inexpensive, produces results quickly and has been shown to correlate with hydrogen concentrations derived using the standard gas chromatography method.
Rodney D. Smith Ii +4 more
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This research focused on the development of a diffusible hydrogen sensor for steel welds. The sensor is based on the chemochromic reaction of WO 3 with hydrogen. The sensor is inexpensive, produces results quickly and has been shown to correlate with hydrogen concentrations derived using the standard gas chromatography method.
Rodney D. Smith Ii +4 more
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Visualization of Diffusive Hydrogen
Materials Science Forum, 2010In recent years, the use of hydrogen as a clean energy has been paid attention to in terms of the prevention of global warming. Tanks composed solely of steel and cylinders consisting of aluminum liner reinforced with C-FRP in the surrounding are used to store high-pressure hydrogen gas in hydrogen stations and in fuel cell vehicles, respectively.
Takahito Watakabe +2 more
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