Preparation and Properties of Tl-Ca-Ba-Cu-O

Abstract

The superconducting properties, T c and J c , of compounds in the Tl-Ca-Ba-Cu-O system were investigated on bulk specimens sintered at temperatures between 890°C and 940°C. It was determined that 910°C was the optimum temperature for the formation of the high- T c phase. This heat treatment temperature produces the maximum values of T c (zero-resistance) and J c (77 K, 0 T), 118 K and 600 A/cm 2 , respectively. The results of X-ray diffraction and magnetic susceptibility measurements show that the volume fraction of high- T c phase is maximized at this temperature.