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Sarah Kurtz - One of the best experts on this subject based on the ideXlab platform.
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Nitrogen-Activated Transitions, Level Repulsion, and Band Gap Reduction in GaAs{sub 1{minus}x}N{sub x } with x {lt} 0.03
Physical Review Letters, 1999Co-Authors: John D. Perkins, J. M. Olson, A Mascarenhas, Daniel J. Friedman, John F. Geisz, Yong Zhang, Sarah KurtzAbstract:We report electroreflectance spectra for a series of GaAs{sub 1{minus}x} N{sub x} samples with x{lt}0.03 . For all samples, the fundamental band gap transition (E{sub 0}) and the transition from the spin-orbit split-off valence band (E{sub 0}+{Delta}{sub 0}) are observed. For samples with x{ge}0.008 , an additional transition (E{sub +}) is observed. With Increasing Nitrogen Content, the increase in E{sub +} is linear in, and nearly equal to, the band gap reduction indicative of a Nitrogen-induced level repulsion. The directly observed E{sub +} transition may arise from either a Nitrogen-related resonant level or a disorder-activated indirect transition. {copyright} {ital 1999} {ital The American Physical Society}
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Nitrogen activated transitions level repulsion and band gap reduction in gaas sub 1 minus x n sub x with x lt 0 03
Physical Review Letters, 1999Co-Authors: John D. Perkins, J. M. Olson, A Mascarenhas, Daniel J. Friedman, John F. Geisz, Yong Zhang, Sarah KurtzAbstract:We report electroreflectance spectra for a series of GaAs{sub 1{minus}x} N{sub x} samples with x{lt}0.03 . For all samples, the fundamental band gap transition (E{sub 0}) and the transition from the spin-orbit split-off valence band (E{sub 0}+{Delta}{sub 0}) are observed. For samples with x{ge}0.008 , an additional transition (E{sub +}) is observed. With Increasing Nitrogen Content, the increase in E{sub +} is linear in, and nearly equal to, the band gap reduction indicative of a Nitrogen-induced level repulsion. The directly observed E{sub +} transition may arise from either a Nitrogen-related resonant level or a disorder-activated indirect transition. {copyright} {ital 1999} {ital The American Physical Society}
R. K. Dayal - One of the best experts on this subject based on the ideXlab platform.
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Effect of Nitrogen Content on the Tensile and Stress Corrosion Cracking Behavior of AISI Type 316LN Stainless Steels
Transactions of the Indian Institute of Metals, 2014Co-Authors: A. Poonguzhali, T. Anita, H. Shaikh, N. Sivaibharasi, R. K. DayalAbstract:This paper deals with the effect of Nitrogen on the tensile and stress corrosion cracking (SCC) behavior of type 316LN stainless steel. Yield stress (YS) and ultimate tensile stress (UTS) increased while the ductility [% total elongation (% TE)] decreased with Increasing Nitrogen Content. Evaluation by conventional assessment parameters, such as ratios of UTS, % TE and SCC susceptibility index, derived by SCC testing using the slow strain rate testing (SSRT) technique indicated an improvement in SCC resistance on Increasing the Nitrogen Content. However, crack growth rates, calculated from ratios of fracture stress from the SSRT tests in liquid paraffin and boiling 45 % magnesium chloride in SSRT tests, and the constant load tests at loads corresponding to 20 % YS in boiling 45 % magnesium chloride conclusively established that the SCC resistance of type 316LN stainless steel decreased with Increasing Nitrogen Content.
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Laser Raman microscopic studies of passive films formed on type 316LN stainless steels during pitting in chloride solution
Corrosion Science, 2010Co-Authors: S. Ramya, T. Anita, H. Shaikh, R. K. DayalAbstract:The surface films formed on type 316LN stainless steels (SS) with different Nitrogen Contents, during potentiodynamic polarization in acidified 1 M NaCl solution, were characterized by Laser Raman Spectroscopy (LRS). LRS confirmed the presence of oxides and oxychlorides of iron and chromium, hydrated chlorides and nitrates in the film. Raman mapping showed Increasing nitrate Content in the film with Increasing Nitrogen Content. The film on the uncorroded material showed the presence of chromium and molybdenum oxides. The improvement in pitting corrosion resistance of type 316LN SS with Increasing Nitrogen Content was attributed to increased amount of nitrates in the passive film.
John F. Geisz - One of the best experts on this subject based on the ideXlab platform.
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effective mass and conduction band dispersion of gaasn gaas quantum wells
Physica E-low-dimensional Systems & Nanostructures, 2002Co-Authors: Czes??aw Skierbiszewski, Tadek Suski, S P łepkowski, Wolfgang Jantsch, Piotr Perlin, John F. GeiszAbstract:Abstract Recently published results for the effective mass in GaAsN/GaAs quantum wells reach values as large as 0.5 m 0 for 1% N in the quantum well and then a decrease with Increasing Nitrogen Content. The effective mass was obtained by fitting experimentally measured optical transitions energies with calculated ones using a parabolic band model. In this work we arrive at different conclusions. First, we prove experimentally that the parabolic band approximation is insufficient for the case of InGaAsN and GaAsN alloys. Then we show that by taking into account the strong nonparabolicity of the conduction band, we obtain an effective mass in GaAsN/GaAs quantum wells Increasing from 0.095 m 0 to 0.115 m 0 for a Nitrogen Content varying from 1% to 3%.
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conduction band resonant Nitrogen induced levels in gaas sub 1 x n sub x with x
Physical Review B, 2001Co-Authors: J D Perkins, A Mascarenhas, John F. Geisz, D J FriedmanAbstract:We report electroreflectance spectra between 1 and 4 eV for GaAs{sub 1-x}N{sub x} samples with x<3%. In addition to four intrinsic GaAs transitions, three Nitrogen-induced optical transitions, E{sub +}, E{sub +}+{Delta}{sub 0}, and E{sup *}, were observed. The weak and heretofore unknown E{sup *} transition was observed in four samples with 0.1 to 2.4 % Nitrogen and occurs 0.1 to 0.3 eV below the {approx}3 eV intrinsic E{sub 1} transition. Opposite to E{sub +},E{sup *} decreases in energy with Increasing Nitrogen Content. Furthermore, in the dilute limit, both E{sub +} and E{sup *} appear to converge to the known conduction-band-resonant Nitrogen-impurity level N{sub x}.
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Nitrogen-Activated Transitions, Level Repulsion, and Band Gap Reduction in GaAs{sub 1{minus}x}N{sub x } with x {lt} 0.03
Physical Review Letters, 1999Co-Authors: John D. Perkins, J. M. Olson, A Mascarenhas, Daniel J. Friedman, John F. Geisz, Yong Zhang, Sarah KurtzAbstract:We report electroreflectance spectra for a series of GaAs{sub 1{minus}x} N{sub x} samples with x{lt}0.03 . For all samples, the fundamental band gap transition (E{sub 0}) and the transition from the spin-orbit split-off valence band (E{sub 0}+{Delta}{sub 0}) are observed. For samples with x{ge}0.008 , an additional transition (E{sub +}) is observed. With Increasing Nitrogen Content, the increase in E{sub +} is linear in, and nearly equal to, the band gap reduction indicative of a Nitrogen-induced level repulsion. The directly observed E{sub +} transition may arise from either a Nitrogen-related resonant level or a disorder-activated indirect transition. {copyright} {ital 1999} {ital The American Physical Society}
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Nitrogen activated transitions level repulsion and band gap reduction in gaas sub 1 minus x n sub x with x lt 0 03
Physical Review Letters, 1999Co-Authors: John D. Perkins, J. M. Olson, A Mascarenhas, Daniel J. Friedman, John F. Geisz, Yong Zhang, Sarah KurtzAbstract:We report electroreflectance spectra for a series of GaAs{sub 1{minus}x} N{sub x} samples with x{lt}0.03 . For all samples, the fundamental band gap transition (E{sub 0}) and the transition from the spin-orbit split-off valence band (E{sub 0}+{Delta}{sub 0}) are observed. For samples with x{ge}0.008 , an additional transition (E{sub +}) is observed. With Increasing Nitrogen Content, the increase in E{sub +} is linear in, and nearly equal to, the band gap reduction indicative of a Nitrogen-induced level repulsion. The directly observed E{sub +} transition may arise from either a Nitrogen-related resonant level or a disorder-activated indirect transition. {copyright} {ital 1999} {ital The American Physical Society}
Günther H. Frischat - One of the best experts on this subject based on the ideXlab platform.
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Alkali-Resistant Magnesium Aluminosilicate Oxynitride Glasses
ChemInform, 2010Co-Authors: Bärbel Steffestun, Günther H. FrischatAbstract:Glasses containing up to 3.3 wt% Nitrogen were prepared in the system MgO-Al[sub 2]O[sub 3]-SiO[sub 2]-AlN-Si[sub 3]N[sub 4]. Glass transition temperature, density, and elastic properties increased with Increasing Nitrogen Content. Resistance against aqueous alkaline solutions was determined by weight loss measurements, solution and surface analysis. The good durability of both oxide and oxynitride glasses is caused by a protective surface layer. The introduction of Nitrogen decreases the alkaline attack. The data suggest that Nitrogen is incorporated as Si-N bonds.
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Alkali‐Resistant Magnesium Aluminosilicate Oxynitride Glasses
Journal of the American Ceramic Society, 1993Co-Authors: Bärbel Steffestun, Günther H. FrischatAbstract:Glasses containing up to 3.3 wt% Nitrogen were prepared in the system MgO-Al[sub 2]O[sub 3]-SiO[sub 2]-AlN-Si[sub 3]N[sub 4]. Glass transition temperature, density, and elastic properties increased with Increasing Nitrogen Content. Resistance against aqueous alkaline solutions was determined by weight loss measurements, solution and surface analysis. The good durability of both oxide and oxynitride glasses is caused by a protective surface layer. The introduction of Nitrogen decreases the alkaline attack. The data suggest that Nitrogen is incorporated as Si-N bonds.
K C Hsieh - One of the best experts on this subject based on the ideXlab platform.
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luminescence quenching and the formation of the gap1 xnx alloy in gap with Increasing Nitrogen Content
Applied Physics Letters, 1992Co-Authors: J N Baillargeon, K Y Cheng, G E Hofler, P J Pearah, K C HsiehAbstract:A study of the luminescence properties of epitaxial GaP containing atomic N grown by molecular beam epitaxy using NH3 and PH3 as the column V sources was conducted. The 77 K photoluminescence spectra of the N‐doped epitaxial GaP showed a continuous redshift, from 5691 A (2.18 eV) to 6600 A (1.88 eV), resulted when the N concentration exceeded ∼5–7×1019 cm−3. This energy shift was found to be consistent with energy gap predictions using the dielectric theory of electronegativity for the GaP1−xNx system. The data also indicate that the emission intensity was maximum for N∼1×1020 cm−3, and then monotonically decreases with Increasing N Content. This is consistent with the formation of an indirect band‐gap semiconductor.
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Luminescence quenching and the formation of the GaP1−xNx alloy in GaP with Increasing Nitrogen Content
Applied Physics Letters, 1992Co-Authors: J N Baillargeon, G E Hofler, P J Pearah, Kangguo Cheng, K C HsiehAbstract:A study of the luminescence properties of epitaxial GaP containing atomic N grown by molecular beam epitaxy using NH3 and PH3 as the column V sources was conducted. The 77 K photoluminescence spectra of the N‐doped epitaxial GaP showed a continuous redshift, from 5691 A (2.18 eV) to 6600 A (1.88 eV), resulted when the N concentration exceeded ∼5–7×1019 cm−3. This energy shift was found to be consistent with energy gap predictions using the dielectric theory of electronegativity for the GaP1−xNx system. The data also indicate that the emission intensity was maximum for N∼1×1020 cm−3, and then monotonically decreases with Increasing N Content. This is consistent with the formation of an indirect band‐gap semiconductor.
