Superconducting and Martensitic Transitions of V3Si and Nb3Sn under High Pressure

Electrical resistivity and specific heat measurements have been performed under high pressure to reveal the interplay between the martensitic transition and the superconductivity of V 3 Si and Nb 3 Sn. For V 3 Si, superconducting transition temperature T c increases with increasing pressure up to 4 GPa, where the martensitic transition temperature T M merges with T c . T c is insensitive to the pressure between 4 and 9 GPa, and is suppressed on further compression accompanied with a decrease of the electrical resisitivity at T c and an increase of the superconducting transition width. The similar tendency is also observed in Nb 3 Sn. The martensitic transition seems to play an important role in superconductivity.