Superconductivity and crystal structure of a new class of ternary transition metal phosphides TT/t'P (TZr, Nb, Ta and T/t'Ru, Rh)

Abstract A new series of superconducting ternary transition metal phosphides TT/t'P (TZr, Nb, Ta and T/t'Ru, Rh) was synthesized. A single-crystal structural determination for ZrRuP yielded an orthorhombic structure (space group, Pnam ) with a final R value of 0.036. The superconducting transition temperature is strongly dependent on the electronic structure with TaRhP possessing the highest T c of 4.7 K. The compound ZrRuP crystallizes in two modifications: the hexagonal phase has a T c of 13.0 K and the orthorhombic structure has a T c of 3.5 K. The relationship between the crystal chemistry and superconducting properties for these two modifications is discussed.