Tuning of Carrier Concentration and Superconductivity in High-Entropy-Alloy-Type Metal Telluride (AgSnPbBi)(1-x)/4InxTe

TL;DR

This study explores how varying indium doping in a high-entropy-alloy-type telluride affects its carrier concentration and superconductivity, revealing that In doping induces superconductivity with a maximum Tc of 3.0 K.

Contribution

It demonstrates the effect of indium doping on carrier concentration and superconductivity in (Ag,In,Sn,Pb,Bi)Te, providing insights into tuning properties of HEA-type superconductors.

Findings

In doping induces superconductivity in (Ag,In,Sn,Pb,Bi)Te.

Maximum Tc observed is 3.0 K at x=0.3.

In increases electron carriers as indicated by Seebeck coefficient decrease.

Abstract

High-entropy-alloy-type (HEA-type) compound superconductors have been drawing much attention as a new class of exotic superconductors with local structural inhomogeneity. NaCl-type (Ag,In,Sn,Pb,Bi)Te is a typical HEA-type superconductor, but the carrier doping mechanism had been unclear. In this study, we synthesized (Ag,In,Sn,Pb,Bi)Te with various In concentration using high-pressure synthesis: the studied system is (AgSnPbBi)(1-x)/4InxTe (x = 0-0.4). Single-phase samples were obtained for x = 0-0.3. A semiconductor-like temperature dependence of resistivity was observed for x = 0, while superconductivity appeared for the In-doped samples. The highest transition temperature (Tc) was 3.0 K for x = 0.3. The Seebeck coefficient decreases with increase of x, which suggests that In3+ generates electron carriers in (AgSnPbBi)(1-x)/4InxTe. Tuning of carrier concentration and superconducting properties of (Ag,In,Sn,Pb,Bi)Te would be useful for further investigation of exotic superconductivity in the HEA-type compound.