Reduced anti-ferromagnetism promoted by Zn 3d10 substitution at CuO2 planar sites of Cu0.5Tl0.5Ba2Ca3Cu4O12−δ superconductors

The role of charge carriers in ZnO2/CuO2 planes of Cu0.5Tl0.5Ba2Ca3Cu4−yZnyO12−δ material in bringing about superconductivity has been explained. Due to suppression of anti-ferromagnetic order with Zn 3d10 (S=0) substitution at Cu 3d9(S=12) sites in the inner CuO2 planes of Cu0.5Tl0.5Ba2Ca3Cu4O12−δ superconductor, the distribution of charge carriers becomes homogeneous and optimum, which is evident from the enhanced superconductivity parameters. The decreased c-axis length with the increase of Zn doping improves interlayer coupling and hence the three dimensional (3D) conductivity in the unit cell is enhanced. Also the softening of phonon modes with the increased Zn doping indicates that the electron-phonon interaction has an essential role in the mechanism of high-Tc superconductivity in these compounds.