【摘要】 采用固相反应法合成了名义组分为Bi_1.75Pb_0.3Sr₂Ca_2.3Cu_5.6O_y的样品,对各种条件下烧制的样品进行了相结构分析,并测量了交流磁化率和电阻—温度关系。总结实验规律,以“高温”烧结后,“低温”分段处理的工艺路线,制备了零电阻温度为111K的单相多晶超导体。利用日本岛津DT—40热分析系统对该单相材料进行了热分析,结果表明,在800～900℃的高温下,样品周围的氧浓度越大,其超导相的结构越稳定,因而样品的熔点就越高。根据这一结论,我们进一步讨论了掺Pb有利于样品内高T_c相形成和稳定的原因。更多还原

【Abstract】 A single phase high T,, of the ceramic supercondutor Bi-Pb-Sr-Ca-Ca-O was obtained by the solid state reaction method in air. The samples were annealed at different temperature, then quenched in liquid-nitrogen, We have found that the low Tc phase and other phases formed at the temperature lower than 840℃ and the high Tc phase is only formed at the temperature higher than 840℃. Based on these, We have prepared the high T,. single phase superconductor with zero-resistivity temperature T=111K from Bi1.75Pb0.2Sr2.0Ca2.3Cu3.8Oy by sintering at "high temperature" and stage, treating at "low temperature" .Also we have found the important faction of oxygen to the thermostability of this material.更多还原