Superconductivity in efficient thermoelectric Cu$_3$Sb$_{0.98}$Al$_{0.02}$Se$_4$

TL;DR

This study demonstrates pressure-induced superconductivity in a thermoelectric material Cu$_3$Sb$_{0.98}$Al$_{0.02}$Se$_4$, revealing a dome-shaped Tc up to 3.2 K linked to structural phase transition.

Contribution

It reports the discovery of superconductivity in a thermoelectric alloy under pressure, linking structural transformation to superconducting properties.

Findings

Superconductivity appears at around 8.5 GPa

Maximum Tc of 3.2 K at 12.7 GPa

Structural transition to orthorhombic phase

Abstract

Both superconductivity and thermoelectricity offer promising prospects for daily energy efficiency applications. The advancements of thermoelectric materials have led to the huge improvement of the thermoelectric figure of merit in the past decade. By applying pressure on a highly efficient thermoelectric material Cu$_{3}$Sb$_{0.98}$Al$_{0.02}$Se$_4$, we achieve dome-shape superconductivity developing at around 8.5 GPa but having a maximum critical temperature of 3.2 K at pressure of 12.7 GPa. The novel superconductor is realized through the first-order structural transformation from its initial phase to an orthorhombic one. The superconducting phase is determined in the ultimate formation of the Cu-Al-Sb-Se alloy.