Critical current densities in single-crystal Bi2.2Sr2Ca0.8Cu2O8+δ

Abstract
We report transport and magnetic measurements of critical current densities in single crystals of high Tc superconductors in the Bi‐Sr‐Ca‐Cu‐O system. Transport measurements of Jc were made using a pulse method, while a vibrating sample magnetometer was used to measure MH loops of oriented crystals in fields up to 15 kOe. Values for transport Jc in zero applied field are higher than those of Ba2YCu3O7 single crystals at comparable temperatures. Also we observe a strong magnetic field dependence for Jc at temperatures above ∼20 K.