Study on Bi(Pb,Sb)SrCaCuO superconductors prepared by the oxalate co-precipitation technique

• Published in: Superconductor science & technology 1990-07, Vol.3 (7), p.373-376
• Main Authors: Xu, Qinlun, Cheng, Tingzhu, Li, Xiao-Guang, Yang, Li, Fan, Chengao, Wang, Haiqian, Mao, Zhiqiang, Peng, Dingkun, Chen, Zhaojia, Zhang, Yuheng
• Format: Article
• Language: English
• ISSN: 0953-2048; 1361-6668
• DOI: 10.1088/0953-2048/3/7/008

A nearly pure 110K phase of the ceramic superconductor Bi sub 1.92 Pb sub 0.38,0.3 Sb sub x Sr sub 2 Ca sub 2 Cu sub 3.2 O sub 10-- delta was obtained by the technique of co-decomposition of co-precipitated oxalate. Those samples with Sb = 0.1, Pb = 0.38 had a zero-resistance temperature of 102K. For those samples with Sb = 0.3, Pb = 0.3, T sub co was equal to 90K. Their magnetic susceptibilities all dropped sharply at 110K and did not change at 80K. X-ray diffraction revealed that there was no 80 or 20K phase but a 110K phase and a new phase. This phase itself is not superconducting above 77K, and it belongs to the monoclinic system. The average composition of the new phase is given as Bi sub 32 Pb sub 3 Sb sub 7 Sr sub 29 Ca sub 23 Cu sub 7 O sub x . Diffraction patterns, Graphs, Photomicrographs. 8 ref.--AA