High-transition-temperature superconducting particles in an insulating matrix

A number of new bulk granular superconductors consisting of high transition-temperature (T/sub co/) superconducting particles of V3Si, NbN or Mo5Pb1S8 embbeded in a variety of resins have been prepared. The resistive superconducting transition temperature T/sub c/ for these composite conductors is, in general, less than half of T/sub co/. In samples containing V3Si powder (approx.20μm in average particle size), T/sub c/ as high as 7.5K has been achieved. The superconducting properties, electrical and magnetic, can be understood if these materials can be considered as 3-dimensional arrays of Josephson junctions. Potential applications for these bulk granular superconductors are discussed