Phase formation and transport properties of vapor-solid reacted AIMI MgB2 superconductors

Abstract

Vapor-solid reactions were applied to monofilament and 6-filament AIMI MgB2 wires. A layer Jc of ∼ 105 A cm−2 was achieved by the generation of a highly dense MgB2 layer after reaction at 625 °C for 8 to 16 h. It was found that the critical current, Ic, and engineering current density, Je, reached maximum values of 92.3 A and 1.15 × 104 A cm−2 at 4.2 K, 10 T when the multifilament AIMI wire was heat-treated at 625 °C for 14 h. Transport Ics were also measured at 10–20 K for the wire heat-treated at 625 °C for 16 h. Phase formation investigations suggested that even better performance of Ic and Je could be attained in multifilamentary AIMI MgB2 wires after further conductor optimization.