Pd site doping effect on superconductivity in Nb2Pd0.76S5

TL;DR

This study explores how doping Pd sites with Ir or Ag affects superconductivity in Nb2Pd0.76S5, revealing that charge carrier density influences the superconducting transition temperature and phase stability.

Contribution

It provides the first detailed analysis of how Ir and Ag doping modulate superconductivity and charge carrier density in Nb2Pd0.76S5, establishing a phase diagram for this system.

Findings

Ir doping slightly enhances Tc initially, then suppresses it with more doping.

Ag doping rapidly suppresses superconductivity, leading to a nonsuperconducting state.

Charge carrier density variations correlate with changes in superconducting properties.

Abstract

Pd site doping effect on superconductivity was investigated in quasi-one-dimensional superconductor Nb2(Pd1-xRx)0.76S5 (R=Ir, Ag) by measuring resistivity, magnetic susceptibility and Hall effect. It was found that superconducting transition temperature (Tc) is firstly slightly enhanced by partial substitution of Pd with Ir and then it is suppressed gradually as Ir content increases further. Meanwhile Ag substitution quickly suppresses the system to a nonsuperconducting ground state. Hall effect measurements indicate the variations of 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 Tc in this system.