Effect of humid atmosphere on resistivity and crystallinity behavior of BPSCCO superconductor made by solid state method

Abstract

High Tc superconductors (HTS) with the CuO2-based formula (Bi2-Sr2-Cam−1-Cum-Oy) are strongly hygroscopic material because their various phases in the CuO2-based material (Bi2-Sr2-Cam-1-Cum-Oy) are highly susceptible to attact moisture or water. In order to protect the HTS Bi,Pb-Sr-Ca-Cu-O (BPSCCO) from deterioration during fabrication process, controlled humid environment is prerequisite in formation of a stable and homogenous of 2223 phase of HTS BPSCCO. Samples have been synthesized using the solid state method with the sintering temperature of 865°C for 90 hours in air. The formation of Bi-2223 phase has been detected by XRD analysis on the samples before and after been exposed to water vapour at 40°C for 3 days. However, excessive phase of lead oxide is detected in the one before exposure to water vapour. According to temperature dependence of resistivity measurement results, samples beforeexposure to water vapour have superconductivity behavior belowcritical temperature (Tc final =100K) and conductive-like behavior above Tc onset =110K, whilst the one after exposure to water vapour for 3 days have superconductivity behaviour below critical temperature (Tc final =110K) and conductive behaviour above Tc onset =120K. The Pb-doped sample (BPSCCO) does not degrade under humidity since the Bi-2223 phase is very resilient against humidity, whereas the un-doped sample containing Bi-2212 phase decomposes when exposed to water.