Suppression of Nonmagnetic Insulating State by Application of Pressure in Mineral Tetrahedrite Cu$_{12}$Sb$_{4}$S$_{13}$

TL;DR

This study investigates how applying pressure suppresses the metal-insulator transition in mineral tetrahedrite Cu$_{12}$Sb$_{4}$S$_{13}$, revealing a pressure-induced transition from insulating to metallic states.

Contribution

It provides the first detailed pressure-dependent phase diagram of Cu$_{12}$Sb$_{4}$S$_{13}$ and demonstrates the suppression of its insulating state under pressure.

Findings

MIT is suppressed and disappears at ~1.0 GPa

Nonmagnetic insulating ground state confirmed by NMR

Pressure induces anomalies in resistivity

Abstract

The mineral tetrahedrite Cu$_{12}$Sb$_{4}$S$_{13}$ exhibits a first-order metal--insulator transition (MIT) at $T_{\rm MI}$ = 85 K and ambient pressure. We measured the $^{63}$Cu-NMR at ambient pressure and the resistivity and magnetic susceptibility at high pressures. $^{63}$Cu-NMR results indicate a nonmagnetic insulating ground state in this compound. The MIT is monotonically suppressed by pressure and disappears at $\sim1.0$ GPa. Two other anomalies are observed in the resistivity measurements, and the pressure -- temperature phase diagram of Cu$_{12}$Sb$_{4}$S$_{13}$ is constructed.