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

We report the synthesis and superconducting properties of a new transition-metal chalcogenide, Ta2PdSe5. Measurements of resistivity, magnetization, and specific heat reveal that Ta2PdSe5 is a bulk superconductor with T-c similar or equal to 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-c2(P) and orbital limiting field H-c2(orb) All these results of specific heat and upper critical field suggest that Ta2PdSe5 is a multi-band superconductor.