Pressure-induced Superconductivity in AgSbTe2

TL;DR

This study reveals that AgSbTe2, a thermoelectric material, becomes superconducting under pressure, with critical temperature increasing as pressure rises, showing pressure can tune thermoelectric materials into superconductors.

Contribution

First demonstration of pressure-induced superconductivity in AgSbTe2, expanding understanding of pressure effects on thermoelectric materials.

Findings

Superconductivity appears at 0.38 GPa with Tc of 3.2 K.

Tc increases with pressure, reaching 6.9 K at 31.9 GPa.

Superconducting state correlates with increased electronic density of states.

Abstract

AgSbTe2 is a well-known thermoelectric material with a high Seebeck coefficient and intrinsically low thermal conductivity, but its behavior under pressure remains largely unexplored. Here we report a systematic investigation of the structural, electronic, and transport properties of non-stoichiometric AgSbTe2 under high pressure. At ambient pressure, the material can be described as having a cubic crystal structure that remains stable up to 21.7 GPa beyond which it loses long-range structural order, while its crystal system fully recovers upon decompression. Remarkably, superconductivity emerges at a very low pressure of 0.38 GPa with an onset superconducting critical temperature (Tc) of 3.2 K. Tc increases with increasing pressure, reaching 6.9 K at 31.9 GPa, and peaks at 7.4 K during decompression. Magnetic-field-dependent transport measurements and electronic structure calculations reveal an evolution of the superconducting state driven by an enhanced electronic density of states at the Fermi level under compression. Our findings uncover pressure-induced superconductivity in AgSbTe2 and demonstrate that pressure can effectively tune the electronic ground state of thermoelectric materials, extending their functionality beyond thermoelectric energy conversion.