Pd site doping effect on superconductivity in Nb₂Pd_0.76S₅

¹ Department of Physics and State Key Laboratory of Silicon Materials, Zhejiang University Hangzhou 310027, China
² Zhejiang California International NanoSystems Institute, Zhejiang University - Hangzhou 310058, China
³ Collaborative Innovation Centre of Advanced Microstructures - Nanjing 210093, China

Received: 20 December 2015
Accepted: 16 February 2016

Abstract

Pd site doping effect on superconductivity was investigated in the quasi–one-dimensional superconductor Nb₂(Pd_1−xR_x)_0.76S₅ (R=Ir, Ag) by measuring resistivity, magnetic susceptibility and Hall effect. It was found that the superconducting transition temperature is firstly slightly enhanced by partial substitution of Pd with Ir and then it is suppressed gradually as the Ir content increases further. Meanwhile Ag substitution quickly suppresses the system to a non-superconducting ground state. Hall effect measurements indicate the variations of the charge carrier density caused by Ir or Ag doping. The established phase diagram implies that the charge carrier density (or the band filling) could be one of the crucial controlling factors to determine T_c in this system.