Spinodal Decomposition and High-TC Superconductivity

1987 ◽  
Vol 99 ◽  
Author(s):  
Robert S. Markiewicz
Keyword(s):  
High Temperature ◽  
Spinodal Decomposition ◽  
Density Of States ◽  
Significant Contribution ◽  
Correlation Energy ◽  
High Temperature Superconductivity ◽  
Electron Exchange ◽  
Band Theory ◽  
High Tc ◽  
Lifshitz Point

ABSTRACTThe singularity in the density of states near a Lifshitz point makes a significant contribution to electron exchange and correlation energy, which does not show up in conventional band theory calculations. This paper discusses several consequences of this fact for high temperature superconductivity.

Granular Aspects of High Tc Superconductivity

1990 ◽  
Vol 195 ◽  
Author(s):  
Guy Deutscher
Keyword(s):  
High Temperature ◽  
High Temperature Superconductivity ◽  
Original Publication ◽  
High Tc ◽  
High Tc Superconductivity ◽  
Bulk Ceramic ◽  
Ceramic Samples ◽  
Granular Superconductors

ABSTRACTAs Bednorz and Muller noted in their original publication reporting on the discovery of high temperature superconductivity, their oxides present many of the features of granular superconductors. This behavior was first primarily ascribed to poor connectivity of the grains in the bulk ceramic samples. but later studies have pointed out to more fundamental reasons for these similarities. We will discuss them after first reviewing the well established properties of low Tc granular superconductors.

Electron-Doped High Tc Superconductors

MRS Bulletin ◽  
1990 ◽  
Vol 15 (6) ◽  
pp. 60-67 ◽  
Author(s):  
M. Brian Maple
Keyword(s):  
High Temperature ◽  
High Temperature Superconductivity ◽  
High Temperature Superconductors ◽  
Building Blocks ◽  
The United States ◽  
Charge Carriers ◽  
Critical Temperatures ◽  
High Tc ◽  
Prevailing View ◽  
Identical Crystal

Since the discovery of high temperature superconductivity in layered copper-oxide compounds in the latter part of 1986, an enormous amount of research has been carried out on these remarkable materials. Prior to 1989, the prevailing view was that the charge carriers responsible for superconductivity in these materials were holes that move through conducting CuO2 planes. The CuO2 planes are the basic building blocks of the crystal structures of all the presently known oxides with superconducting critical temperatures Tc greater than ~30 K. Recently, new superconducting materials have been discovered in Japan and the United States in which the charge carriers involved in the superconductivity appear to be electrons, rather than holes, that reside within the conducting CuO2 planes. These findings could have important implications regarding viable theories of high temperature superconductivity as well as strategies for finding new high temperature superconductors.The new electron-doped materials have the chemical formula Ln2-xMxCuO4-y and exhibit superconductivity with superconducting critical temperatures Tc as high as ~25 K for x ≍ 0.15 and y ≍ 0.02. Superconductivity has been discovered for M = Ce and Ln = Pr, Nd, Sm, and Eu, and for M = Th and Ln = Pr, Nd, and Sm. A related compound with the identical crystal structure, Nd2CuO4-x-y Fx, has also been found to display superconductivity withTc ≍ 25 K. Recently, it has been observed that superconductivity with Tc ≍ 25 K can even be induced in nonsuperconducting Nd2-xCexCuO4-y compounds by substituting Ga or In for Cu. Thus, it appears that the CuO2 planes can be doped with electrons, rendering the Ln2CuO4-y parent compounds metallic and superconducting, by substituting electron donor elements at sites within, as well as outside, the CuO2 planes; i.e., by substituting (1) Ce4+ or Th4+ ions for Ln3+ ions; (2) F1- ions for O2- ions; and (3) Ga3+ or In3+ ions for Cu2+ ions.

scholarly journals Review on origin of the unusual high-Tc superconductivity in Ca1−xRExFe2As2 (RE = La, Ce, Pr, Nd)

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
W. Zhou ◽  
Z. X. Shi
Keyword(s):  
High Temperature ◽  
Transition Temperature ◽  
Crystal Structures ◽  
High Temperature Superconductivity ◽  
Iron Pnictides ◽  
Iron Based Superconductors ◽  
High Tc ◽  
High Tc Superconductivity ◽  
Iron Based

AbstractSince the discovery of high temperature superconductivity in iron pnictides in 2008, many iron-based superconductors (IBSs) with various crystal structures have been exploited.Among them, superconductivity with the onset transition temperature T

HIGH Tc STUDIES IN SVERDLOVSK

1988 ◽  
Vol 02 (06) ◽  
pp. 1331-1379 ◽  
Author(s):  
B. N. GOSHCHITSKII ◽  
V. L. KOZHEVNIKOV ◽  
M. V. SADOVSKII
Keyword(s):  
High Temperature ◽  
High Temperature Superconductivity ◽  
High Temperature Superconductors ◽  
Structural Phase ◽  
Nmr Relaxation ◽  
Structural Phase Transitions ◽  
High Tc ◽  
Review Reports ◽  
Academy Of Sciences

This review reports the main experimental results on superconducting lattice and electron properties of high-temperature superconductors of the type La 2−x Sr x CuO 4 and YBa 2 Cu 3 O 7 obtained at three institutes of the Ural Branch of the USSR Academy of Sciences in Sverdlovsk. Special attention is paid to investigations of structural phase transitions, heat capacity, optic and magnetic properties, NMR relaxation and the role of radiation disordering under the influence of fast neutron irradiation. In conclusion, a brief review of possible theories to explain high-temperature superconductivity in metal oxides is given.

HIGH Tc SUPERCONDUCTIVITY OF Sr-La-Cu-O AND Ba-Y-Cu-O THIN FILMS

1987 ◽  
Vol 01 (04) ◽  
pp. 177-180 ◽  
Author(s):  
B.R. ZHAO ◽  
L. LI ◽  
Y. LU ◽  
H.S. WANG ◽  
Y.H. SHI ◽  
...  
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Liquid Nitrogen ◽  
High Temperature Superconductivity ◽  
Oxide System ◽  
High Tc ◽  
High Tc Superconductivity ◽  
Short Time ◽  
Perovskite Type

In a very short time after it was reported1 that perovskite-type Ba-La-Cu oxide system could have high temperature superconductivity, many new results were reported.2,3 Later, Y was substituted for La to form Ba-Y-Cu oxides and the Tc rose to the liquid nitrogen region.4 In this report we describe the results obtained with the Sr-La-Cu-O and Ba-Y-Cu-O thin films.

THE ELECTRONIC STRUCTURE AND SUPERCONDUCTIVITY OF THE HIGH Tc COPPER OXIDES

1988 ◽  
Vol 02 (02) ◽  
pp. 167-180 ◽  
Author(s):  
M. SCHLUTER
Keyword(s):  
Electronic Structure ◽  
High Temperature ◽  
High Temperature Superconductivity ◽  
Copper Oxides ◽  
High Tc ◽  
Localized Orbital

The electronic structure and possible superconductivity mechanisms of the new high Tc copper oxides are discussed. The conventional band picture is contrasted with the localized orbital Mott-Hubbard picture for the electronic groundstate. The nature of quasiparticles introduced by doping of the insulating parent compounds depends on assumptions made for the underlying groundstate. Possible pairing mechanisms of these particles that have been proposed to lead to high temperature superconductivity are analyzed.

The Progress on Study of Isotope Effects in High TC Copper Oxide Superconductors

2007 ◽  
Vol 546-549 ◽  
pp. 1957-1960
Author(s):  
Yu Chen ◽  
Xin Min Huang ◽  
Jian Wu Wang ◽  
Xiao Shan Zeng
Keyword(s):  
High Temperature ◽  
Copper Oxide ◽  
Isotope Effect ◽  
High Temperature Superconductivity ◽  
Isotope Effects ◽  
Oxide Superconductors ◽  
High Tc ◽  
Mechanism Research ◽  
Dope Region ◽  
Copper Oxide Superconductors

Through the review of the correlation on the isotope effects research and superconductivity mechanism research as well as the progress on the study of the isotope effects in the high Tc copper oxide superconductors, we have found the fundamental factors that cause the different changes of the isotope effect value in different dope region in high Tc cupper oxide superconductors. We point the high-temperature superconductivity mechanism possible origin phonons mediation electrons.

A NEW HIGH-Tc SUPERCONDUCTOR YBa2Ca2Cu3Ox

1989 ◽  
Vol 03 (16) ◽  
pp. 1233-1236
Author(s):  
A. SHIMA ◽  
T. SHOJI ◽  
M. UKAKU ◽  
Y. WATANABE ◽  
Y. TAZAWA ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
High Temperature Superconductivity ◽  
Liquid Nitrogen Temperature ◽  
X Ray Diffraction ◽  
Oxide Compound ◽  
High Tc ◽  
X Ray ◽  
High Tc Superconductor ◽  
New Superconductor

We report that the high temperature superconductivity observed in a new ceramic Y–Ba–Ca–Cu oxide compound which exhibited the onset of superconductivity clearly at above 90 K and became completely superconductive at liquid nitrogen temperature (77 K). Powder X-ray diffraction analysis showed that the crystal structure of this new superconductor had the same one as a YBa 2 Cu 3 O x.

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