Bi계 고온 초전도체의 2차 소결 후 특성

Characteristics of the High-Tc Superconductor in the Bi System Prepared by the 2nd, Sintering Process

Effects of the second sintering process on the superconducting characteristics of the (Bi, Pb)SrCaCuO system have been studied. It was found that the optimal calcining temperature of mixed powder may be proper to 820$^{\circ}C$ and the optimal sintering temperture was determined on 845$^{\circ}C$. The 2212 phases transitioned the 2223 phasses during the sintring process and zero resistance was attained at 108 K for the samples sintered for 264 hr. The 2223 phases changed into the 2212 phases and nonsuperconducting phases by the second grinding process. And the 2223 phases did not recover easily by the second sintering process.