Influence of different mixing ratios of Mg and B powder on structural and superconducting properties in MgB 2

Abstract

We fabricated MgB 2 bulks by an in situ Mg diffusive reaction method from compacted B and compacted mixtures of Mg and B respectively. All samples were sintered at 1100 °C for 2 h. MgO impurity phase, density, and critical current density ( J c) were found to be dependent of the starting amount of mixing Mg powder. We also found that the MgO formation in MgB 2 matrix was not mainly attributed to the starting amount of additional Mg powder for Mg diffusive reaction. This indicates that MgO presented in the starting Mg powder is hardly diffused into compacted B.