High Density Bi-System Superconductor Prepared under High Pressure

Superconducting ceramic Bi0.8Pb0.2SrCaCu2Ox was directly obtained for the first time by means of high pressure sintering without any additional annealing. The superconductor sintered at 1 GPa and 500 ℃ for 2 h had a phase transition at 97 K (zero resistance), which was not observed before. The sintered sample reaches a density of 6.23 g/cm3 (about 95% of the theoretical density), much higher than that of the conventionally prepared samples, which usually have densities of only about 4~5 g/cm3.