Plasma treatment of high-temperature superconducting materials

The influence of plasma treatment on high-T-c bulk superconductors Bi2Sr2CaCu2O8+y and YBa2Cu3O7-x has been investigated. The results show that for quenched superconducting Bi2Sr2CaCu2O8+y samples the critical current density J(c) enhances by 3-6 times and the transition temperature T-c increases by 12-14 K after plasma treatment. It is observed that after oxygen plasma treatment at 200 degrees C the oxygen-deficient tetragonal nonsuperconducting YBa2Cu3O7-x phase can transform to orthorhombic superconducting one.