Temperature Effects on Properties of Bi(2223) High Temperature Superconducting Tapes

The critical current density Jc and n-value have been studied from 40 K to critical temperature for four types of Bi-system 2223 tapes with different sheaths.The experimental results demonstrate that the change of Jc can be divided into three parts and n-value has some decrease with a decrease in temperature.In engineering application,a proper working temperature can be selected to satisfy the practical requirement.Furthermore,the temperature effects on critical stress for Ag-sheath tape was also studied.The results demonstrate that the critical stress does not change monotonously with a decrease in temperature.It increases first,then decreases with the further decrease in temperature.