EXAFS Studies of （Pb,Cd） 1212 phase superconductor and （Bi,Cd）1212 phase compound

• 作者: ShiqiangWei YeTao
• 来源期刊: 同步辐射装置用户科技论文集
• 学科: 化学
• 关键词: 超导体相 (Pd Cd)1212 化合物相 (Bi Cd)1212
• 年，卷（期）: 1999,（1）
• 页码范围: 55-57
• 页数: 3页
• 分类号: O614.433

摘要

We synthesized (Pb,Cd)Sr2(Y,Ca)Cu2O7+x,phase superconductor.After substitution of Pb with Bi,the BiCd1212 phase shows no superconductivity.Although previous EXAFS study has shown the local structure environment of the Cu is similar in both compounds,EXAFS results of Bi and Pb here demonstrate that σ2 of Pb-Oin-plane is larger than that of Bi-O inplane,whereas σ^2 of Pb-Oapical is smaller than that of Bi-O,wherase σ^2 of Pb-O apical is smaller than that of Bi-Oapical.The Sr shell features are also differnet,it appeared that superconductivity needs some disorder .in carrier reservoir layer,which is due to the substitutional defect caused by different ionic radii.