Study on the properties of Bi-2212 under different high pressure heat treatments

At 4． 2K，the high － temperature superconducting material Bi － 2212 has an outstanding current － carrying capacity in magnetic field． It is currently the most promising high temperature superconducting material under high field ( ＞ 20T) ． High － pressure heat treatment process is one of the important factors determining the performance of Bi － 2212 superconducting wire． The wire diameters，critical current and n value of Bi － 2212 superconducting wire under 3MPa and 5MPa pressure were studied． Confirmed the effect of different pressure on the constant temperature zone of the heat treatment furnace． The results show that the properties of Bi － 2212 wire are similar after heat treatment at pressures of 3MPa and 5MPa． The pressure of 3MPa is easier to realize and the requirements on equipment are lower.