THE PROPERTY IMPROVEMENT OF BULK HIGH-TEMPERATURE SUPERCONDUCTORS BY PLASMA TREATMENT

An influence of atomic oxygen exposure on the superconductivity of YBa 2Cu3O7-x, Bi2Sr2Ca2Cu3O10+y and Bi2Sr2Ca1Cu2O8+z ceramics has been exa mined by the critical current density J(c), critical temperature T-c a nd X-ray diffraction measurements. It is shown that exposure of high-T -c superconductors to a low power density oxygen plasma at 473 K and 6 73 K leads to an increase of both T-c and J(c). The improvement of sup erconductivity can be explained by the passivation of dangling bonds a nd defects on grain boundaries of these materials.