Pressure Induced Metallization of BaMn2As2

TL;DR

This study investigates how applying pressure induces a transition from insulating to metallic behavior in BaMn2As2, revealing an insulator-metal transition and potential superconductivity at high pressures.

Contribution

It provides the first detailed pressure-dependent electrical and structural analysis of BaMn2As2, demonstrating pressure-induced metallization and possible superconductivity.

Findings

Insulator to metal transition occurs around 4.5 GPa.

Complete metallization observed at 5.8 GPa.

Possible emergence of superconductivity at 5.8 GPa.

Abstract

The temperature and pressure dependent electrical resistivity rho(T,P) studies have been performed on BaMn2As2 single crystal in the 4.2 to 300 K range upto of 8.2 GPa to investigate the evolution of its ground state properties. The rho(T) shows a negative co-efficient of resistivity under pressure upto 3.2 GPa. The occurrence of an insulator to metal transition (MIT) in an external P ~4.5 GPa is indicated by a change in the temperature co-efficient in the rho(T) data at ~36 K . However complete metallization in entire temperature range is seen at a P~5.8 GPa. High pressure XRD studies carried out at room temperature also shows an anomaly in the pressure versus volume curve around P ~ 5 GPa, without a change in crystal structure, indicative of an electronic transition. Further, a clear precipitous drop in rho(T) at ~17 K is seen for P ~5.8 GPa which suggests the possibility of the system going over to a superconducting ground state.