Superconductivity and Thermal Property of MgB2/Al Composite Materials

The superconductive MgB2/Al composite material with low and high volume fractions of particles were fabricated by our special pre-packed technique. The composite material showed homogeneous distribution of MgB2 particles in the Al-matrix with neither any aggregation of particles nor defects such as cracks or cavities. The critical temperature of superconducting transition (Tc) was obtained via electrical resistivity and magnetization to be about 37~39 K. Specific heat measurements further supported these Tc findings. The Meissner effect was also verified in the liquid He, in which a piece of the composite floated above a permanent magnet. The thermal conductivity of the MgB2/Al composite material was about 25 W/K•m at 30 K, which value is much higher than those for the NbTi or Nb3Sn superconductive wires normally used in practice that are 0.5 and 0.2 W/K•m at 10 K, respectively.