Superconducting properties of zinc substitution in Tl-2223 phase

The effect of partial replacement of copper by zinc in Tl2Ba2Ca2Cu3O10-delta superconductor phase is studied. Superconducting samples of the nominal composition Tl2Ba2Ca2Cu3-xZnxO10-delta 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 T-c critical current density J(c) and irreversibility field B-ir are calculated from electrical resistivity and AC-magnetic susceptibility measurements. (C) 2007 Elsevier B.V. All rights reserved.