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Relevant bibliographies by topics / Correlated electron gas

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Academic literature on the topic 'Correlated electron gas'

Author: Grafiati

Published: 4 June 2021

Last updated: 4 February 2022

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Journal articles on the topic "Correlated electron gas"

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Saarela, M., T. Taipaleenm ki, and F. V. Kusmartsev. "Charged clusters in strongly correlated electron gas." Journal of Physics A: Mathematical and General 36, no. 35 (August 20, 2003): 9223–36. http://dx.doi.org/10.1088/0305-4470/36/35/309.

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Thakur, J. S., and D. Neilson. "Superconductivity in a correlated disordered two-dimensional electron gas." Physical Review B 58, no. 20 (November 15, 1998): 13717–20. http://dx.doi.org/10.1103/physrevb.58.13717.

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Zverev, M. V., V. A. Khodel, and S. S. Pankratov. "Microscopic theory of a strongly correlated two-dimensional electron gas." JETP Letters 96, no. 3 (October 2012): 192–202. http://dx.doi.org/10.1134/s0021364012150131.

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MACDONALD, A. H. "CORRELATIONS WEAK AND STRONG: DIVERS GUISES OF THE TWO-DIMENSIONAL ELECTRON GAS." International Journal of Modern Physics B 13, no. 05n06 (March 10, 1999): 447–59. http://dx.doi.org/10.1142/s0217979299000345.

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The three-dimensional electron-gas model has been a major focus for many-body theory applied to the electronic properties of metals and semiconductors. Because the model neglects band effects, whereas electronic systems are generally more strongly correlated in narrow band systems, it is most widely used to describe the qualitative physics of weakly correlated metals with unambiguous Fermi liquid properties. The model is more interesting in two space dimensions because it provides a quantitative description of electrons in quantum wells and because these can form strongly correlated many-particle states. We illustrate the range of possible many-particle behaviors by discussing the way correlations are manifested in 2D tunneling spectroscopy experiments.

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Heinzel, T., R. Jäggi, E. Ribeiro, M. v. Waldkirch, K. Ensslin, S. E. Ulloa, G. Medeiros-Ribeiro, and P. M. Petroff. "Transport signatures of correlated disorder in a two-dimensional electron gas." Europhysics Letters (EPL) 61, no. 5 (March 2003): 674–80. http://dx.doi.org/10.1209/epl/i2003-00129-8.

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Barbaro, M. B., A. De Pace, T. W. Donnelly, and A. Molinari. "Parity-violating electron scattering from the pion-correlated relativistic Fermi gas." Nuclear Physics A 569, no. 4 (March 1994): 701–31. http://dx.doi.org/10.1016/0375-9474(94)90381-6.

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Lederer, Pascal, and J. P. Rodriguez. "de Haas–van Alphen effect in a strongly correlated electron gas." Physical Review B 46, no. 2 (July 1, 1992): 1220–23. http://dx.doi.org/10.1103/physrevb.46.1220.

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Ioffe, L. B., D. Lidsky, and B. L. Altshuler. "Effective lowering of dimensionality in the strongly correlated two dimensional electron gas." Physical Review Letters 73, no. 3 (July 18, 1994): 472–75. http://dx.doi.org/10.1103/physrevlett.73.472.

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Continentino, M. A. "Scaling Theory of the Metal-Insulator Transition in the Highly Correlated Electron Gas." Europhysics Letters (EPL) 9, no. 1 (May 1, 1989): 77–82. http://dx.doi.org/10.1209/0295-5075/9/1/014.

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Buks, E., M. Heiblum, and Hadas Shtrikman. "Correlated charged donors and strong mobility enhancement in a two-dimensional electron gas." Physical Review B 49, no. 20 (May 15, 1994): 14790–93. http://dx.doi.org/10.1103/physrevb.49.14790.

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Dissertations / Theses on the topic "Correlated electron gas"

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Uldry, Anne-Christine. "Two-particle excitations in random media." Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270724.

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Todorovic, Jelena. "Correlated transmission electron microscopy and micro-photoluminescence studies of GaAs-based heterostructured semiconductor nanowires." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for fysikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19731.

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The focus of this work was to study the nanowire (NW) optical and structural properties on a single NW level. The GaAs-based heterostructured semiconductor NWs, grown by Au-assisted molecular beam epitaxy (MBE), were studied throughout this work. Due to diversity of the NWs within each growth batch, it is essential to study the same single NWs both by di erent micro-photoluminescence (PL) and transmission electron microscopy (TEM) techniques. An efficient method for such a correlated study was developed (paper I), and applied in all following studies. The key feature is that the single NWs of desired morphology are preselected by low voltage scanning TEM (STEM) for the micro-PL study. Subsequently, TEM characterization is performed, and in such a way a detailed set of information is obtained for each single NW. Wurtzite (WZ) GaAs/AlGaAs core-shell NWs were studied to determine the fundamental optical properties of WZ GaAs, a crystal phase found only in NW form for GaAs (paper III). To this cause, low temperature powerdependent, temperature-dependent, polariztion-resolved and time-resolved micro-PL were employed in correlation with conventional TEM characterization. The room temperature (294 K) WZ GaAs bandgap was determined to be 1:444 eV±1 meV which is ~ 20 meV higher than the well known bulk zinc blende (ZB) GaAs value. On the other hand, the low temperature free exciton emission energy was found to be approximately the same as in ZB GaAs, 1:516 eV at 15 K. The conduction band symmetry of WZ GaAs is proposed to be Ƭ8. In addition, the results demonstrate that the Au-assisted MBE grown NWs can have high PL brightness. WZ GaAs/ZB GaAsSb axially heterostructured NWs were studied in order to understand the cause of variations of the ZB GaAsSb insert optical properties among the NWs (paper I, II, IV). The Sb concentration variation among and within ZB GaAsSb inserts was studied by energy dispersive X-ray spectroscopy (EDX), quantitative high angle annular dark eld (HAADF) STEM and correlated PL-TEM (paper IV). A clear trend of increasing Sb concentration with increasing insert length was observed. It was found that the Sb concentration increases gradually from the lower insert interface along the NW axis, reaches a maximum value and decreases towards the upper insert interface. The Sb concentration variation within the GaAsSb inserts induces both type I and type II optical transitions within the insert. To verify the EDX and quantitative HAADF STEM results independently, the Sb concentration was calculated from the ground state energies of the GaAsSb PL emission using an empirical model for low temperature bandgap of unstrained bulk GaAsSb. The calculated Sb concentration values were in agreement with quantitative HAADF STEM results, and systematically higher than the values obtained by the EDX quantification.

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BHANDARI, CHURNA B. "FIRST-PRINCIPLES STUDY OF ELECTRONIC AND VIBRATIONAL PROPERTIES OF BULK AND MONOLAYER V2O5." Case Western Reserve University School of Graduate Studies / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=case1459296089.

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Qiu, Lei. "Exploring 2D Metal-Insulator Transition in p-GaAs Quantum Well with High rs." Case Western Reserve University School of Graduate Studies / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=case1386337954.

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Orignac, Edmond. "Magnétisme Quantique, Bosons en interaction et basse dimensionnalité." Habilitation à diriger des recherches, Ecole normale supérieure de lyon - ENS LYON, 2013. http://tel.archives-ouvertes.fr/tel-00964641.

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Les systèmes de spin antiferromagnétiques en une dimension présentent des caractéristiques remarquables. Le théorème de Mermin-Wagner montre que même dans l'état fondamental de leur Hamiltonien, ces systèmes ne possèdent pas d'ordre à longue distance dans leurs fonctions de corrélation spin-spin s'ils possèdent une symétrie continue. Néanmoins, un quasi-ordre à longue distance peut exister, avec des fonctions de corrélation spin-spin décroissant en loi de puissance avec la distance, comme par exemple dans la chaîne de spin-1/2. Ce cas est décrit par la théorie des liquides de Luttinger. Même dans le cas d'un ordre à courte distance où les fonctions de corrélations spin-spin décroissent exponentiellement, un ordre topologique peut être présent. Il peut être mis en évidence par un paramètre d'ordre dépendant des opérateurs de spin de façon non-locale ou par la présence d'excitations de bord, comme par exemple dans le cas de la chaînes de spin-1. D'autre part, il existe une équivalence formelle entre les opérateurs de spin-1/2 et les bosons de coeur dur, qui permet de traduire les propriétés des systèmes magnétiques dans le langage des bosons en interaction. Après une rapide revue des méthodes théoriques utilisées pour la description des systèmes de basse dimensionnalité, je décrirais mes travaux sur les systèmes échelles de spin antiferromagnétiques et les applications aux systèmes de bosons en interaction.

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Raymond, Stéphane. "Excitations de basse énergie dans les fermions lourds par diffusion inélastique des neutrons." Université Joseph Fourier (Grenoble), 1998. http://www.theses.fr/1998GRE10103.

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La technique de diffusion inelastique des neutrons a ete utilisee pour caracteriser le spectre des excitations magnetiques de basse energie dans les composes a electrons fortement correles cenisn, ce#1#-#xla#xru#2si#2 et ceru#2ge#2. Cenisn est un compose kondo semimetallique dont le spectre des excitations magnetiques est compose de deux modes d'energie 2 et 4 mev et respectivement piques au centre et bord de zone de brillouin. L'application d'un champ magnetique met en evidence la nature differente de ces modes : le premier se deplace vers les plus hautes energies et la reponse du second s'elargit. Les modeles de gap d'hybridation particularises pour ce compose permettent de relier le mode a 4 mev aux proprietes macroscopiques observees. La dynamique des moments magnetiques pres d'une instabilite magnetique a ete etudiee dans le compose ce#1##xla#xru#2si#2 avec x = 0. 075. De facon surprenante, un ordre magnetique non conventionnel a ete mis en evidence (m = 0. 02 #b et t#n = 1. 8 k). La dynamique de spin par rapport au compose pur a ete reliee, grace a la theorie des fluctuations de spin de moriya, aux mesures macroscopiques. L'application d'un champ magnetique sur le compose ceru#2si#2 met en evidence le changement de la reponse dynamique du systeme de part et d'autre de la transition pseudometamagnetique. La reponse quasielastique et a courte portee a bas champ est remplacee par un ordre statique a longue distance en champ fort (h = 12 t). Dans ce contexte, la phase antiferromagnetique du compose ferromagnetique ceru#2ge#2 a ete caracterisee. Il existe alors une analogie entre ce compose sous sa temperature de curie et ceru#2si#2 au dessus du champ metamagnetique.

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"Pair correlated atoms in ultracold fermi gas." 2007. http://library.cuhk.edu.hk/record=b5893369.

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Pong, Yue Hin = 超低溫費米氣體中的對關聯粒子 / 龐宇軒.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2007.
Includes bibliographical references (leaves 77-81).
Text in English, abstracts in English and Chinese.
Pong, Yue Hin = Chao di wen fei mi qi ti zhong de dui guan lian li zi / Pang Yuxuan.
Chapter 1 --- Introduction --- p.1
Chapter 2 --- Review on BCS theory --- p.4
Chapter 2.1 --- BCS in uniform gas --- p.4
Chapter 2.2 --- Hartree Fock Bogoliubov equations --- p.7
Chapter 2.3 --- Regularization techniques --- p.13
Chapter 2.4 --- Homogeneous solution to HFB --- p.15
Chapter 3 --- HFB Computation --- p.17
Chapter 3.1 --- Example: 1D infinite well --- p.18
Chapter 3.2 --- Example: 1D SHO --- p.22
Chapter 3.3 --- Example: Spherical harmonic oscillator --- p.23
Chapter 3.4 --- Conclusion --- p.26
Chapter 4 --- Natural Orbits --- p.28
Chapter 4.1 --- Two-point correlation functions --- p.29
Chapter 4.2 --- Connection with the BCS --- p.32
Chapter 4.3 --- Natural orbits in a spherical harmonic potential --- p.33
Chapter 4.4 --- Remarks --- p.38
Chapter 5 --- Bosonic characters of atomic Cooper pairs across resonance --- p.43
Chapter 5.1 --- Resonance in Fermi gas --- p.44
Chapter 5.2 --- Bosonic tests --- p.50
Chapter 5.3 --- Choosing a Cooper pair wave function --- p.52
Chapter 5.3.1 --- Cooper pair I --- p.52
Chapter 5.3.2 --- Cooper pair II --- p.55
Chapter 5.4 --- Results in a uniform gas --- p.55
Chapter 5.5 --- Remark --- p.61
Chapter 6 --- Time dependent BCS: A numerical study --- p.63
Chapter 6.1 --- Time evolution in uniform BCS --- p.64
Chapter 6.2 --- Perturbation to interaction strength --- p.66
Chapter 6.2.1 --- Sudden decrease in the interaction strength --- p.66
Chapter 6.2.2 --- Sinusoidal variation of interaction strength --- p.68
Chapter 6.2.3 --- A decaying energy gap --- p.69
Chapter 6.3 --- Perturbation to particle numbers --- p.71
Chapter 6.4 --- Remarks --- p.74
Chapter 7 --- Summary and Outlook --- p.75
Chapter 7.1 --- Outlook --- p.75
Bibliography --- p.77
Chapter A --- Analytic solutions to homogeneous BCS --- p.82
Chapter B --- Local Density Approximation (LDA) --- p.84
Chapter B.1 --- One dimensional LDA --- p.85
Chapter C --- Finding the regularized Green's Function --- p.87
Chapter D --- Variational approach to finding natural orbits --- p.90
Chapter D.1 --- Variation with respect to natural orbits --- p.90
Chapter D.2 --- Variation with respect to the occupation amplitude --- p.93

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Sikkema, Arnold Eric. "Spin gaps in two models of strongly correlated electron systems." Thesis, 1997. http://hdl.handle.net/2429/6803.

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Two aspects of strongly correlated electron systems are studied in this thesis. Hubbard-type models are thought to be at the basis of high-critical-temperature superconductivity. One interaction which has not had much study is the nearest-neighbour hopping of on-site singlet pairs. We refine earlier renormalization group arguments and, using the density-matrix renormalization group method, numerically confirm their prediction that a spin gap opens at infinitesimal pair-hopping amplitude V > 0 in the one-dimensional tight-binding model. We also find a phase separation transition at a finite V > 0 as well as a spin-gap transition at a finite V < 0. The exotic magnetic behaviour of heavy-fermion materials involves an interplay between the screening of local moments from each other and the formation of a magnetic state of long range order. While the single-impurity Kondo Hamiltonian is thought to model some aspects of this behaviour, the properties of the Kondo lattice model away from half-filling are largely unknown. We determine the presence of a spin-gap region in the phase diagram of the one-dimensional Heisenberg-Kondo lattice model and make predictions about certain concealed dimerization order parameters.

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Book chapters on the topic "Correlated electron gas"

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Zverev, M., and V. Khodel. "Chapter 6. Microscopic Theory of a Strongly Correlated Two-Dimensional Electron Gas." In Strongly Correlated Electrons in Two Dimensions, 189–217. Penthouse Level, Suntec Tower 3 8 Temasek Boulevard Singapore 038988: Pan Stanford Publishing Pte. Ltd., 2016. http://dx.doi.org/10.1201/9781315364575-7.

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Johnston, R., and L. Schweitzer. "The Density of States of a Two-Dimensional Electron Gas in a Perpendicular Magnetic Field Under the Influence of a Correlated Random Potential." In Springer Series in Solid-State Sciences, 71–74. Berlin, Heidelberg: Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/978-3-642-83114-0_11.

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Plakida, N. M., and V. S. Oudovenko. "s+d Mixing in Cuprates: Strong electron correlations and superconducting gap symmetry." In Open Problems in Strongly Correlated Electron Systems, 111–16. Dordrecht: Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-010-0771-9_12.

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"Homogeneous Electron Gas." In Correlated Electrons in Quantum Matter, 25–37. WORLD SCIENTIFIC, 2012. http://dx.doi.org/10.1142/9789814390934_0003.

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"Strongly correlated electron systems: heavy fermions; the one—dimensional electron gas." In Green's Functions for Solid State Physicists, 235–58. PUBLISHED BY IMPERIAL COLLEGE PRESS AND DISTRIBUTED BY WORLD SCIENTIFIC PUBLISHING CO., 1998. http://dx.doi.org/10.1142/9781860944031_0011.

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Zverev, M. V., and V. A. Khodel. "Chapter 6 Microscopic Theory of a Strongly Correlated Two-Dimensional Electron Gas." In Strongly Correlated Electrons in Two Dimensions, 189–217. Jenny Stanford Publishing, 2017. http://dx.doi.org/10.4324/9781315364575-6.

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TAKAHASHI, Minoru. "One-Dimensional Electron Gas with Delta-Function Interaction at Finite Temperature." In Exactly Solvable Models of Strongly Correlated Electrons, 388–406. WORLD SCIENTIFIC, 1994. http://dx.doi.org/10.1142/9789812798268_0033.

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TAKADA, Yasutami. "VARIATIONAL THEORY OF SUPERCONDUCTIVITY WITH APPLICATION TO THE ELECTRON GAS." In Proceedings of the Yamada Conference XVIII on Superconductivity in Highly Correlated Fermion Systems, 374–77. Elsevier, 1987. http://dx.doi.org/10.1016/b978-1-4832-2920-1.50102-5.

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Haldane, F. D. M. "‘Luttinger liquid theory’ of one-dimensional quantum fluids I: Properties of the Luttinger model and their extension to the general 1D interacting spinless Fermi gas." In Exactly Solvable Models of Strongly Correlated Electrons, 416–40. WORLD SCIENTIFIC, 1994. http://dx.doi.org/10.1142/9789812798268_0035.

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Andriotis, Antonis N., and Madhu Menon. "Successive Spin-Correlated Local Processes Underlying the Magnetism in Diluted Magnetic Semiconductors and Related Magnetic Materials." In Advances in Chemical and Materials Engineering, 13–27. IGI Global, 2016. http://dx.doi.org/10.4018/978-1-5225-0290-6.ch002.

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Recent works have suggested that the defect induced magnetism in Diluted Magnetic Semiconductors (DMSs), Transition Metal Oxides (TMOs) and related materials is facilitated and enhanced by codoping and the synergistic action between the codopants. In the present work we demonstrate that the proposed defect synergy is the result of the interplay among correlated spin-polarization processes which take place in a successive way in neighborhoods centered at the codopants and include their first nearest neighbors. These processes result in a reduction in the superexchange coupling which in turn causes an enhancement in the ferromagnetic coupling (FMC) among the magnetic dopants. The proposed FMC is demonstrated using ab initio calculations of the electronic properties of codoped ZnO, GaN and TiO2.

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Conference papers on the topic "Correlated electron gas"

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Terletska, Hanna, Vladimir Dobrosavljevic, Adolfo Avella, and Ferdinando Mancini. "Experimental Signatures of Intrinsic Phase Separation in Magnetically Doped Two-Dimensional Electron Gas." In LECTURES ON THE PHYSICS OF STRONGLY CORRELATED SYSTEMS XIV: Fourteenth Training Course in the Physics of Strongly Correlated Systems. AIP, 2010. http://dx.doi.org/10.1063/1.3518909.

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Hameeuw, K. J. "Beyond RPA: dynamical exchange effects and the two-dimensional electron gas." In LECTURES ON THE PHYSICS OF HIGHLY CORRELATED ELECTRON SYSTEMS VIII: Eighth Training Course in the Physics of Correlated Electron Systems and High-Tc Superconductors. AIP, 2004. http://dx.doi.org/10.1063/1.1800736.

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Kobayashi, Keita, Masahiko Okumura, Yukihiro Ota, Susumu Yamada, and Masahiko Machida. "Ferromagnetism in Multi-Orbital Fermi Gas Loaded on a One-Dimensional Optical Lattice." In Proceedings of the International Conference on Strongly Correlated Electron Systems (SCES2013). Journal of the Physical Society of Japan, 2014. http://dx.doi.org/10.7566/jpscp.3.016006.

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Tennery, V. J., L. F. Allard, T. A. Nolan, and M. H. Rawlins. "Application of Electron Microscopy for the Analysis of the Mechanical Behavior of Advanced Ceramics." In ASME 1988 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1988. http://dx.doi.org/10.1115/88-gt-72.

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The microstructure and fracture surfaces of two commercially available silicon nitride ceramics have been characterized using techniques of scanning and analytical transmission electron microscopy. These results have been correlated to mechanical property data (obtained from static and dynamic fatigue tests using four-point flexural test methods both at room temperature and at elevated temperature). For one of the materials, the results clarified failure mechanisms. For the other, the results showed how processing variables can affect microstructure (and thus mechanical behavior), and emphasized particularly that mechanical tests of billet-derived specimens may be unreliable in predicting the mechanical behavior of production components.

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Mannan, Sarwan, and John deBarbadillo. "Long Term Thermal Stability of INCONEL Alloy 783." In ASME 1998 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/98-gt-508.

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Recently developed INCONEL® alloy 783 (nominal composition of Ni-34Co-26Fe-5.4Al-3Nb-3Cr) is precipitation strengthened by Ni3Al-type Gamma Prime and NiAl-type Beta Phases. Due to its low co-efficient of thermal expansion (CTE), high strength, and good oxidation resistance alloy 783 has been specified for use in aircraft gas turbine components such as rings, casings, shrouds, and seals and has been considered for use in a number of other critical industrial turbine components. In this study, commercially produced alloys 783, 718, and 909 were annealed and aged following recommended heat treatments. The materials were then isothermally exposed at 1100°F (593°C) for times up to 10,000 hours. At 1000 hour intervals, specimens of these alloys were removed from the furnace and subjected to room temperature tensile (RTT) and high temperature tensile (HTT) testing at 1200°F (649°C). The microstructure of as-produced and exposed materials was characterized using optical microscopy, Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). Variation in tensile properties with isothermal exposure time was correlated with the microstructure.

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Mutasim, Zaher Z., and Lulu L. Hsu. "Evaluation of Thermal-Sprayed Bronze Abradable Coatings: Effect of Temperature and Time on Coating Microstructure and Performance." In ASME 1993 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1993. http://dx.doi.org/10.1115/93-gt-371.

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Metallurgical evaluation was conducted on thermally-sprayed bronze coatings that are commonly found in gas turbine labyrinth seals. These bronze coatings serve as abradable surfaces for air/air and air/oil seals operating at low temperatures. As-coated and post-oxidation coating microstructures were examined metallographically to establish the coating’s functional life at various operating temperature ranges. Oxidation tests at several temperatures and times were carried out in order to construct a time-temperature map that could be used to predict the useful life of this bronze coating as correlated to gas turbine bronze seals returned from field service. Scanning electron microscopy in conjunction with polarized light microscopy were utilized to identify the presence of red cuprous oxide, a key factor in the determining the extent of internal oxidation.

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Schulz, U., K. Fritscher, and M. Peters. "Thermocyclic Behavior of Variously Stabilized EB-PVD Thermal Barrier Coatings." In ASME 1996 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1996. http://dx.doi.org/10.1115/96-gt-488.

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The demand for increasing gas inlet temperatures in modem gas turbines up to 1500°C and above is the main reason for the need for more reliable thermal barrier coatings. New ceramics should provide higher phase stability and better resistance against chemical attack by pollutants in the combustion gas. Electron-beam physical vapor deposition (EB-PVD) processed, ZrO2-based TBCs were generated on bond-coated superalloy directionally solidified (DS) samples. Common yttria-stabilized zirconias of two different compositions, as well as novel stabilizers like CeO2 and La2O3 were investigated. A columnar structure was established during high-rate deposition in all cases. Diameter, degree of ordering of the columns and phase composition depended on stabilizer oxide and content. The role of differences of vapor pressures is addressed with regard to chemical homogeneity of the coatings. The performance of the TBCs having various stabilizers was investigated in a cyclic oxidation furnace test and in a burner rig at Mach 0.3. The results were correlated to the type and content of stabilizer with special emphasis on phase analyses. Evaporation of new ceramic compositions necessitates special precautions because the vapor pressures of the components may differ too much. A new dual-source evaporation coater allows the production of these innovative TBCs with close control of chemistry. The potential of the equipment will be discussed.

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Zimmer, J., D. Nielsen, T. A. Anderson, M. Schade, N. Saha, and G. Thome. "Characterization and Elimination of Forward Snapback Defects in GaAs Light Emitting Diodes." In ISTFA 1996. ASM International, 1996. http://dx.doi.org/10.31399/asm.cp.istfa1996p0239.

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Abstract The p-n junction of a GaAs light emitting diode is fabricated using liquid phase epitaxy (LPE). The junction is grown on a Si doped (~1018/cm3) GaAs substrate. Intermittent yield loss due to forward voltage snapback was observed. Historically, out of specification forward voltage (Vf) parameters have been correlated to abnormalities in the junction formation. Scanning electron (SEM) and optical microscopy of cleaved and stained samples revealed a continuous layer of material approximately 2.5 to 3.0 urn thick at the n-epi/substrate interface. Characterization of a defective wafer via secondary ion mass spectroscopy (SIMS) revealed an elevated concentration of O throughout the region containing the defect. X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES) data taken from a wafer prior to growth of the epi layers did not reveal any unusual oxidation or contamination. Extensive review of the processing data suggested LPE furnace pressure was the obvious source of variability. Processing wafers through the LPE furnace with a slight positive H2 gas pressure has greatly reduced the occurrence of this defect.

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Singh, Rupinder, and Sehijpal Singh. "Experimental Investigations for Reducing Effect of Sensitization in Tungsten Inert Gas Welding." In ASME 2008 Pressure Vessels and Piping Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/pvp2008-61078.

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Stainless steels are considered to have very good resistance to general and localized corrosion due to their chromium content. This property of corrosion resistance constitutes the main criterion for selecting austenitic grades of steels for service in the chemical, nuclear and aerospace industries although their mechanical properties are relatively modest. However, this resistance can degrade when structural components manufactured from these steels are used in a chemically aggressive environment, especially when service involves exposure to high temperatures like in welding. This exposure gives rise to precipitation of chromium carbides producing chromium depletion at grain boundaries that brings about the inter-granular corrosion or sensitization of these materials. Austenitic stainless steel (316L) is one of the corrosion resistance material used extensively in the oil production, chemical and power generation industries for transportation and reservoir of corrosive products. In spite of its corrosion resistance property there exist severe problems of sensitization. In the present work an effort has been made to reduce the effect of sensitization in Tungsten Inert Gas welding of Austenitic stainless steel (316L). Three welding procedures (namely conventional, back step and skip welding) in Tungsten Inert Gas welding have been used to control exposure time of the weld pool to higher temperatures, in order to study the effect of sensitization on mechanical properties (such as tensile strength, yield strength, percentage elongation and hardness). The results of this study suggested that the better mechanical properties were attained by the skip welding procedure and recommended welding parameters are 90 Amp current and 10 L/min of gas flow rate for a 5 mm thick work piece. Noticeable change in amount/extent of sensitization was observed using a scanning electron microscope (SEM) analysis within the various welding specimens prepared using the various procedures. Further mechanical properties (like strength and hardness) have been correlated with the extent of sensitization, which show remarkable decreases when the amount/extent of sensitization increases.

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Dubey, Rahul, Raja Allavikutty, R. Velmurugan, and R. Jayaganthan. "Effect of Cryogenic Temperature Rolling on High Speed Impact Behavior of AA 6082 Thin Targets." In ASME 2019 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/imece2019-10931.

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Abstract Aluminium alloy AA 6082-T6 was rolled at cryogenic and room temperatures to final thickness of 0.5 mm after 75% thickness reduction and subjected to high speed impact. The deformed alloy was investigated for its ballistic properties due to potential applications in aerospace and automotive sectors. The cryogenic and room temperature rolled samples were subjected to normal high-speed impact using a gas gun arrangement to shoot nosed projectiles at velocities higher than the ballistic limits. Phantom ‘V611’ high-speed camera was used to measure the initial and residual velocities of the projectile. Nano-indentation was performed to relate hardness of the initial sample with the observed impact behaviour. Detailed fractographic studies were conducted using Scanning Electron Microscopy (SEM) to substantiate the possible failure mechanisms upon impact. Electron Backscatter Diffraction (EBSD) and Energy Dispersive X-ray Spectroscopy (EDS) were used to characterize the microstructure of the deformed samples. The high speed impact data is correlated with the metallographic observations in this study.

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Reports on the topic "Correlated electron gas"

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Thomas, John E. Simulating strongly correlated electrons with a strongly interacting Fermi gas. Office of Scientific and Technical Information (OSTI), May 2013. http://dx.doi.org/10.2172/1080278.

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2

Agrawal, Asha Weinstein, and Hilary Nixon. What Do Americans Think About Federal Tax Options to Support Transportation? Results from Year Twelve of a National Survey. Mineta Transportation Institute, June 2021. http://dx.doi.org/10.31979/mti.2021.2101.

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This report summarizes the results from the twelfth year of a national public opinion survey asking U.S. adults questions related to their views on federal transportation taxes. A nationally-representative sample of 2,516 respondents completed the online survey from February 5 to 23, 2021. The questions test public opinions about raising the federal gas tax rate, replacing the federal gas tax with a new mileage fee, and imposing a mileage fee just on commercial travel. In addition to asking directly about support for these tax options, the survey collected data on respondents’ views on the quality of their local transportation system, their priorities for federal transportation spending, their knowledge about gas taxes, their views on privacy and equity matters related to mileage fees, travel behavior, and standard sociodemographic variables. This large set of variables is used to identify personal characteristics and opinions correlated with support for the tax options. Key findings include that large majorities supported transportation improvements across modes and wanted to see the federal government work towards making the transportation system well maintained, safe, and equitable, as well as to reduce the system’s impact on climate change. Findings related to gas taxes include that only 2% of respondents knew that the federal gas tax rate had not been raised in more than 20 years, and 71% of respondents supported increasing the federal gas tax by 10 cents per gallon if the revenue would be dedicated to maintenance. With respect to mileage fees, roughly half of respondents supported some form of mileage fee, whether that was assessed on all travel or just on commercial travel, 62% believe that low-income drivers should pay a reduced mileage fee rate, and 52% think that electric vehicles should pay a lower rate than gas and diesel vehicles. The analysis of trends across the survey series, which has run from 2010 to 2011, shows that support for both higher gas taxes and a hypothetical new mileage fee has risen slowly but steadily, and Americans’ experience with COVID over the past year has not disrupted those trends. Finally, support for the tax and fee options varies mostly by most personal characteristics, but there are frequently large differences correlated with age, community type, and political affiliation.

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