Influence of magnesium powder and heat treatment on the superconducting properties of MgB2/Fe wires

The quality of precursor powders is an important factor influencing the superconducting properties and performance of in situ powder-in-tube (PIT) processed MgB2 wire. In this study, the influence of magnesium precursor powders and annealing temperatures on the transition temperatures (T-c) and critical current densities (J(c)) of in situ MgB2/Fe wires was investigated. J(c) enhancement was observed in MgB2/Fe wires when using a smaller particle size of the magnesium precursor powders. The results also show the wire samples annealed at a low temperature of 600 degrees C through a solid-solid state reaction have better J(c) values. In summary, the critical current density increases with decreasing annealing temperatures.