Superconductivity at 2.5 K in the new transition-metal chalcogenide Ta₂PdSe₅

Abstract

We report the synthesis and superconducting properties of a new transition-metal chalcogenide, Ta 2 PdSe 5 . Measurements of resistivity, magnetization, and specific heat reveal that Ta 2 PdSe 5 is a bulk superconductor with T c ≃ 2.5 K . The zero-field electronic specific heat in the superconducting state can be fitted with a two-gap BCS model. The upper critical field H c2 shows a linear temperature dependence, and the value of H c2 (0) is much higher than the estimated Pauli limiting field H c 2 P and orbital limiting field H c 2 o r b . All these results of specific heat and upper critical field suggest that Ta 2 PdSe 5 is a multi-band superconductor.