CuTl-Based High Temperature Superconductors

A possibility of co-existence anti-ferromagnetism and superconductivity in oxide high temperature superconductors (HTSC) is studied. Also these studies established that the Ferro-magnetism and superconductivity can co-exist in HTSC. The magnitude of superconductivity increases with enhanced carrier's density in Cu0.5Tl0.5Ba2Can-1- zMzCun-yZnyO2n+4-d (M=Mg,Be; n=3,4; y=0,1,2,3) systems. FTIR absorption measurements of Zn and Cd- doped Cu0.5Tl0.5Ba2Ca2Cu3-yMyO10-d (M=Zn, Cd; y=0, 0.5, 1.0, 1.5, 2.0) samples have shown that electron phonon mechanism different from the BCS is essential in HTSC. By carrying out excess conductivity analyses, the coherence length, inter-plane coupling strength, exponent and dimensionality of fluctuations have been studied. The coherence length along the c-axis and interlayer coupling strength J are found to increase with increases Mg and Be doping at the Ca sites. The values of these parameters are improved after post-annealing of the samples in oxygen atmosphere which showed the intrinsic role of the optimized carrier's concentration in conducting CuO2 planes in the mechanism of HTSC.