Growth of Cu0.5Tl0.5Ba2Ca3Cu4-yZnyO12-δ superconductor with optimum carriers

We have tried to vary the carriers concentration in Cu0.5Tl0.5Ba2Ca3Cu4-yZnyO12-δ (y = 0, 1, 1.5, 2, 2.5) superconductor with the help of post-annealing experiments carried out in nitrogen, oxygen and air and to investigate its effects on the superconductivity parameters. The zero resistivity critical temperature [Tc(R = 0)], the magnitude of diamagnetism and critical current [Ic(H = 0)] are found to increase in Zn free samples after post-annealing in oxygen and air, while these superconducting properties have been suppressed after post-annealing in nitrogen at 550 deg. C for 6 h. The post-annealing of Zn-doped samples in air has marginally increased the superconducting properties, while these properties have been suppressed after post-annealing in nitrogen and oxygen. These studies have led us to the definite conclusion that the Zn-doped material has grown with optimum carriers concentration.