STUDY ON Sb-DOPED Bi SYSTEM SUPERCONDUCTOR

Abstract

In the samples of Sb proper doping Bi-Sr-Ca-Cu-O system, the content of the high temperature phase (110K phase) is obviously much higher than that of the Sb-free samples'. Sb has a function of accelerating the formation of the high Tc phase. For the nominal composition of Bi2-xSbxSr2Ca2.5Cu3.7Oy x = 0.1 is most beneficial to the formation of the high Tc phase, After quenching in liquid nitrogen and annealing at low teperatures, it is found that the low Tc phase (80K phase) is firstly formed when the samples are sintered at 865℃, then the low Tc phase changes to the high Tc phase, until all materials become the high Tc phase eventually. The value of Tc increases continuously with time lasting. If annealed at lower em-perature, the high Tc phase will change to the low Tc phase. Based on this discovering, after sintering at high temperature, for a long time, fast cooling to a low temperature, annealing for some time, then naturally cooling to room temperature, we have successfully prepared the high Tc single phase superconductor with zero resistance temperature 113K.