The electrical properties of quenched and unquenched superconducting Bi2Sr2CaCu2Ox

Abstract
The authors have studied the electrical properties of rapidly quenched and unquenched bulk samples of granular Bi2Sr2CaCu2Ox in the presence of a magnetic field. Both materials display simple power-law voltage-current behaviour. The application of a small magnetic field produces effects equivalent to raising the temperature. The implications of these measurements for possible models for granular superconductors are discussed. They note that in some samples the properties of the higher Tc rapidly quenched form decay to those of the lower Tc unquenched form over a period of days.