Superconductivity of MRuP and MNiP (M=Mo or W) prepared at high pressure

Ternary metal phosphides MRuP (M=Mo or W) with a Co2P-type structure and MNiP(M=Mo or W) with a Fe2P-type structure have been prepared at around 1600°C and 4 GPa. The electrical and magnetic properties of these compounds were studied at low temperature. The superconductivity of these compounds is observed at around 15.5 K for the molybdenum phosphides, and at 5 K for the wolfram phosphides. These are new superconductors. Both ternary molybdenum phosphides have the highest Tc among the metal phosphides.