Synthesis of superconducting Mg/MgB2 composites

Composites consisting of Mg and MgB2 phases were fabricated by liquid-metal infiltration following two routes. First, a preform of MgB2 powders was pressure infiltrated at 800 degreesC with liquid Mg, which was subsequently solidified. Second, a preform of B powders was pressure infiltrated with liquid Mg at 700 degreesC, resulting in partial, in situ formation of the MgB2 phase. Subsequent annealing at 950 degreesC increased the content of MgB2 through reaction between B and Mg. All composites exhibited a pore-free structure with no significant additional phases and were superconducting near 39 K. (C) 2001 American Institute of Physics.