组成和制备条件对Bi-Pb-Sr-Ca-Cu-O材料超导电性的影响

THE EFFECT OF THE COMPOSITION AND PREPARING CONDITION ON THE SUPERCONDUCTIVITY OF Bi-Pb-Sr-Ca-Cu-O

制备了一系列 Bi—Pb—Sr—Ca—Cu—O 超导材料。在一定范围内,不同组分的 Bi—Pb—Sr—Ca—Cu—O 样品都能得到接近单110K 相的材料,但样品性能差别极大.性能的好坏极大地依赖着组成条件。烧结温度过高或过低都不利于提高样品的临界电流密度,850℃的烧结温度是较合适的,长时间烧结有利于110K 相的形成。样品烧结完成后,应缓慢降温退火,以保证材料充分吸氧。

A series of superconductors which approach to single 110K phase have been prepared. There are close relations between the properties and the compositions. The samples which approach to single 110K phase can be prepared by substituting Pb for Bi or Sr. However, the properties of the samples that Pb substitutes Bi are very better than that Pb substitutes Sr. The critical transit current density decreases when the sintering temperature is too high or low. The temperature 850℃ is fitter. Long sintering time is in favour of the formation of 110K phase. After sintering, sample should be cooled slowly so that they can absorb oxygen sufficiently.