Rapid Synthesis of MgB 2 by Inductive Heating

The effect of a rapid internal magnesium diffusion synthesis on the electrical, magnetic, and microstructural properties of binary MgB2 bulk samples has been investigated. We have used a laboratory-made induction furnace to reduce the reaction time, typically of many hours, to few minutes. We report a comparison between two samples reacted at the same temperature with the induction furnace and with a commercial resistance oven. We have observed that the critical temperature and the width of the superconducting transition are not affected by the heat treatment. The induction heating leads to an increase of the critical current density at high fields, correlated with an enhancement of the upper critical field. This paper exposes the potentiality of the proposed fast process, which allows tuning the parameters of the heat treatment in ranges that would not be accessible with traditional ovens. The technique can be scaled for the preparation of wires and powders.