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

Vapor-solid reactions were applied to monofilament and 6-filament AIMI MgB2 wires. A layer J(c) of similar to 10(5) A cm(-2) was achieved by the generation of a highly dense MgB2 layer after reaction at 625 degrees C for 8 to 16 h. It was found that the critical current, I-c, and engineering current density, Je, reached maximum values of 92.3 A and 1.15 x 10(4) A cm(-2) at 4.2 K, 10 T when the multifilament AIMI wire was heat-treated at 625 degrees C for 14 h. Transport I(c)s were also measured at 10-20 K for the wire heat-treated at 625 degrees C for 16 h. Phase formation investigations suggested that even better performance of I-c and J(e) could be attained in multifilamentary AIMI MgB2 wires after further conductor optimization.