Effect of Zn on pinning properties in MgB 2 bulk system

Abstract

Bulk samples of nominal Zn x (MgB 2) 1− x were prepared from the mixture of Mg, B, and ZnO in the Ar atmosphere at 900 °C for 30 min, where x was 0–0.1. Critical current densities J c’s were estimated from the magnetization data using an extended critical state model. Improvement of J c was confirmed at 20 K and 1 T for the sample of x = 0.02–0.04. Secondary phase of Mg–Zn alloy may be the effective pinning centers in this system.