Oxide oxide superconductor composites : sintering and electrical properties of Bi-2212/insulator composites.

In order to improve the electrical and/or mechanical properties of bismuth cuprate superconductors, composites have been elaborated by pressing polycr ystalline Bi2Sr2CaCu2O8+delta (2212) mixed with two insulator oxides into p ellets, which were sintered near 800 degrees C. A large domain of compositi on was investigated. The Bi2CuO4 (2001) oxide reacts with the Bi-2212, decr eases its T-c value but can increase its mechanical resistance. The Bi2Sr3C aO7 (2310) oxide seems not to react with the 2212. A zero resistance at low temperature (> 40K) is observed up to 30 vol. % of superconductor oxide (2 0 vol. % taking into account the insulating cavities) in the 2310/2212 comp osites.