Superconductors physical properties

In the ceramics field many of the new advanced ceramic oxides have a specially prepared mixture of cations which determines the crystal structure, through the relative sizes of the cations and oxygen ions, and the physical properties through the choice of cations and tlreh oxidation states. These include, for example, solid electrolytes and electrodes for sensors and fuel cells, fenites and garnets for magnetic systems, zirconates and titanates for piezoelectric materials, as well as ceramic superconductors and a number of other substances... 

M. S. Dresselhaus, G. Dresselhaus, and R. Saito. In Physical Properties of High Temperature Superconductors IV, edited by D. M. Ginsberg, World Scientific Publishing Co., Singapore, 1994. Vol. IV, Chapter 7. 

Many metal sulfides have important physical properties.They range from insulators, through semiconductors to metallic conductors of electricity, and some are even superconductors. 

The situation is very similar in the Chevrel phases. These are ternary molybdenum chalcogenides A,.[Mo6Xg] (A = metal, X = S, Se) that have attracted much attention because of their physical properties, especially as superconductors. The parent compound is PbMo6Sg it contains Mo6Sg clusters that are linked with each other in such a way that the free coordination sites of one cluster are occupied by sulfur atoms of adjacent clusters (Fig. 13.9). The electric properties of Chevrel phases depend on the number of valence electrons. With 24 electrons per cluster (one electron pair for each edge of the... 

Cuprammonium rayon, 11 263—265 Cuprate oxides, 23 838-839 Cuprate superconductors, 23 837 Cupric bromide, physical properties of,... 

Saito G, Yamochi H, Nakamura T, Komatsu T, Inoue T, Ito H, Ishiguro T, Kusunoki M, Sakaguchi K, Mori T (1993) Structural and physical properties of two new ambient pressure K-type BEDT-TTF superconductors and their related salts. Synth Met 55-57 2883-2890... 

Komatsu T, Matsukawa N, Nakamura T, Yamochi H, Saito G (1992) Isotope effect on physical properties of BEDT-TTF based organic superconductors. Phosphorus Sulfur Silicon Relat Elem 67 295-300... 

Saito G, Urayama H, Yamochi H, Oshima K (1988) Chemical and physical properties of a new ambient pressure organic superconductor with higher than 10 K. Synth Met 27 A331-A340... 

Single crystals are of critical importance to the study of complex solids such as the new high temperature superconductors. Single crystals are free of grain boundary effects and allow measurements of physical properties as a function of crystal orientation. 

Because these materials are the first examples of highly oxidized nonstoichiometric ceramic oxide superconductors, the determination and optimization of the physical properties has been a major technical and scientific challenge. The observed properties, and the impact of chemistry on them are reviewed here. 

Structure of YBa2Cu307. reproduced from G. F. Holland and A. M. Stacy, Physical Properties of the Quaternary Oxide Superconductor YBa2Cu3Ox, Acc. Chem. Res. 1988, 21, 8. One-dimensional Cu-O chains (shown in color) run along the crystallographic t>-axis, and two-dimensional Cu-O sheets lie in the a-b plane. Loss of colored oxygen atoms from the chains at elevated temperature results in YBa2Cu306. 

In this way, we can predict the physical properties of the multi-gaps superconductivity, if we have the superconductors with many zone structure as shown in Fig. 3. 

T. Egami and S. J. L. Billinge, in Physical Properties of High Temperature Superconductors V, ed. D. Ginsberg (Singapore, World Scientific, 1996) p. 265. 

Soon after the discovery of the quaternary borocarbide superconductors in 1994 a remarkable progress in the investigation of their physical properties could be asserted (Muller and Narozhnyi, 2001b). One reason for this rapid progress is the favorable synthesis properties of this class of materials, which resulted in high-quality polycrystalline samples over a wide range of compositions, as well as thin... 

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