Pressure-driven electronic and structural phase transition in intrinsic magnetic topological insulator MnSb2Te4

TL;DR

This study investigates how applying pressure induces electronic and structural phase transitions in the magnetic topological insulator MnSb2Te4, revealing suppression of magnetic order and a transition to a metallic state.

Contribution

It provides the first detailed analysis of pressure-induced phase transitions in MnSb2Te4, linking magnetic, structural, and electronic changes with experimental and theoretical evidence.

Findings

Magnetic order is suppressed near 10 GPa.

Structural changes include amorphization above 16.6 GPa.

Evidence of insulator-metal transition confirmed by Raman and XRD.

Abstract

Intrinsic magnetic topological insulators provide an ideal platform to achieve various exciting physical phenomena. However, this kind of materials and related research are still very rare. In this work, we reported the electronic and structural phase transitions in intrinsic magnetic topological insulator MnSb2Te4 driven by hydrostatic pressure. Electric transport results revealed that temperature dependent resistance showed a minimum value near short-range antiferromagnetic (AFM) ordering temperature TN', the TN' values decline with pressure, and the AFM ordering was strongly suppressed near 10 GPa and was not visible above 11.5 GPa. The intensity of three Raman vibration modes in MnSb2Te4 declined quickly starting from 7.5 GPa and these modes become undetectable above 9 GPa, suggesting possible insulator-metal transition, which is further confirmed by theoretical calculation. In situ x-ray diffraction (XRD) demonstrated that an extra diffraction peak appears near 9.1 GPa and MnSb2Te4 started to enter an amorphous-like state above 16.6 GPa, suggesting the structural origin of suppressed AFM ordering and metallization. This work has demonstrated the correlation among interlayer interaction, magnetic ordering, and electric behavior, which could be benefit for the understanding of the fundamental properties of this kind of materials and devices.