Doping effects of some metallic elements for SiC/MgB2 bulk system

Abstract

Bulk samples of nominal (MgB2)0.9(SiC)0.1−xMx were prepared from the mixture of Mg, B, SiC and MnOm in the 10%H2/Ar atmosphere at 900°C for 30min, where M’s were Cu, Nb, Ag, and Pt. Critical current densities Jc’s were estimated from the magnetization data using an extended critical state model. Improvement of Jc was confirmed at 20K and 1T for the samples of x=0.03(Cu)-, 0.01(Ag)- and 0.02(Pt)-samples. Impurity of Cu–Mg–Si, Ag–Mg and Mg2PtSi were the effective pinning centers together with Mg2Si in this system.