Superconducting properties of zinc substitution in Tl-2223 phase

The effect of partial replacement of copper by zinc in Tl2Ba2Ca2Cu3O10−δ superconductor phase is studied. Superconducting samples of the nominal composition Tl2Ba2Ca2Cu3−xZnxO10−δ with x ranging from 0 to 0.6 are prepared under normal pressure by a one step of solid-state reaction technique. The samples are characterized by using X-ray powder diffraction, scanning electron microscope (SEM) and EDX. The X-ray data indicate that the partial replacement of Cu2+ions by Zn2+ions does not influence the tetragonal structure of the samples, and the lattice parameters a and c vary according to the difference in the ionic radii of Cu and Zn. The superconducting parameters, such as superconducting transition temperature Tc, critical current density Jc and irreversibility field Bir are calculated from electrical resistivity and AC-magnetic susceptibility measurements.