Pinning property of Cu/MgB2 system

Sintered Cu/MgB2 system was prepared from the mixture of Mg, B and CuO in the 10% H2/Ar atmosphere at 900 °C for 30 min. Critical current densities Jc's were estimated from magnetization data with an extended critical state model. Maximum Jc was confirmed for Cu/MgB2 including 3 at.% Cu, in which Jc at 20 K and 1 T was 1.48 times larger than that of pure MgB2. Impurity of MgCu2 nano-particles should be effective pinning centers, and flux jump at 5 K in low field region was suppressed above 7 at.% Cu content in this system.