Superconducting cuprates

Kochelaev BI, Teitel baum GB (2005) Nanoscale Properties of Superconducting Cuprates Probed by the Electron Paramagnetic Resonance 114 205-266 Kochi JK, see RosokhaSV (2007) 126 137-160 Kohler J, see Deng (2005) 114 103-141 van Koningsbruggen, see Giitlich P (2004) 107 27-76... 

The electron density in transition metal complexes is of unusual interest. The chemistry of transition metal compounds is of relevance for catalysis, for solid-state properties, and for a large number of key biological processes. The importance of transition-metal-based materials needs no further mention after the discovery of the high-Tc superconducting cuprates, the properties of which depend critically on the electronic structure in the CuOz planes. 

Nanoscale Properties of Superconducting Cuprates Probed by the Electron Paramagnetic Resonance... 

The electron microscopy studies of the superconductive cuprates show that the different families differ from each other by the nature of their defect chemistry, in spite of their great structural similarities. For example, the La2Cu04-type oxides and the bismuth cuprates rarely exhibit extended defects, contrary to YBa2Cu307 and to the thallium cuprates. The latter compounds are characterized by quite different phenomena. 

Although the superconducting cuprates have high critical temperatures, their other superconducting properties such as critical currents and flux expulsion remain quite poor even after the large amount of research that has been made in this field (1). 

As a matter of fact, the major difficulty in applying the solution techniques to the superconducting cuprates is the choice of precursors, since the low charges of Cu, Y, Ba and their relatively large ionic radii make it difficult to find versatile soluble precursors. 

High temperature superconducting cuprates (HTSC) as catalysts... 

Figure 7.16 Structures of T, T and T types of tetragonal structures of cuprates of the type LujCuO (Ln = rare earth). The T structure with CuOj square-pyramids is obtained by combining a half of the T unit cell with a half of the T cell. The three types of Cu-O polyhedra in the three structures typify those found in the superconducting cuprates.

Figure 7.25 Variation of with hole concentration in superconducting cuprate families (from Rao Ganguli, 1995). 1, 2, 6 and 7, Bi cuprates 5, 123 cuprates 3, Laj- Sr CuO, 4, T1 cuprates. The variation of normalized with is shown in the inset (From Zhang Sato, 1993).

PHENOMENOLOGICAL DESCRIPTION OF D-WAVE CONDENSATES IN IIIGII-Tc SUPERCONDUCTING CUPRATES... 

Figure 1. Copper/oxygen layer of Superconducting cuprates. Black and white circles represent copper and oxygen atoms respectively. A pair of E-basis Wannier functions, which are a linear combination of Cu and O atomic orbitals, transforming as (x, y) are localised on every lattice point at the centre of the unit cell.

Flat band electron energy dispersion in superconducting cuprates... 

Figure 4. Theoretical gap ratios Eg(Q)/(kTc) as a function of doping for superconducting cuprates.

Heat capacity measurements on superconducting cuprates have been widely undertaken and recently Loram etal [25] reported condensation energies for a cuprate superconductor as a function of doping. In our theory the heat capacity per localised orbital (Cv IN0 is given by... 

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