Rapid Preparation of Superconductor, Tl₂Ba₂Ca₂Cu₃O₁₀, with T_c of 127 K

Abstract

Tl-based superconductors, Tl₂Ba₂Ca_n-1Cu₃O_2n+4, were synthesized and the effect of calcium concentration on the superconductor phase formation was studied. The method involved the synthesis of T1₂Ba₂Ca_2.5Cu₃O_y by sintering in an evacuated quartz tube at 860°C for 12 h. The sintering time was required much less than those of other synthesizing methods of superconductors. The superconductor synthesized by this method was found to have the critical temperatures, T_czero=127 K and T_cmag=130 K. It was also found that the Hg doping into the Tl₂Ba₂Ca_2.5Cu₃O_y led to the stabilization of T1-2223 structure, and the phase with the composition of Tl_1.8Hg_0.2Ba₂Ca_2.5Cu₃O_y, exhibited T_czero=127 K and T_cmag=127 K.