Superconductivity of Bi_0.7Pb_0.3SrCaCu_1.8O_y

Abstract

Superconductors(Tc=110K) have been synthesized in the process of researching fundamental conditions of preparation with starting composition of Bi_0.7Pb_0.3SrCaCu_1.8O_y. The measurements and analysis such as electrical resistivity, X-ray diffraction, DTA, SEM and micro-Raman scattering have led to the conclusion: 1)the sintering condition of 830°C, 244 hours produces superconductor of Tc=110K, 2)this system shows an abnormal behavior in electrical resistivity near 145K, 3)X-ray diffraction analysis suggests that with increasing in sintering period of time, high-Tc phase increases in its ratio to low-Tc phase, 4)DTA result indicates that the best sintering is realized at the temperature at which the possible peritectic reaction may begin.