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

The critical current density J_c 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 J_c 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.