First Investigation of Pressure Effects on Transition from Superconductive to Metallic Phase in FeSe_0.5Te_0.5

Abstract

High-pressure resistivity experiments were performed on FeSe 0.5 Te 0.5 . The onset temperature of T c ( T c onset ) increases rapidly from 13.5 to 26.2 K upon applying pressure up to 2 GPa. Above 2 GPa, T c decreases linearly and the metallic phase was observed at P =14 GPa. The same relationship between normalized T c and pressure in both FeSe 0.5 Te 0.5 and FeSe suggests a universal pressure dependence in this system. This report presents the first observation of a phase transition from the superconducting to the metallic phase on the P – T c phase diagram.