Structural and electronic phase transitions in FePS$_3$ under the application of pressure

TL;DR

This study investigates pressure-induced structural and electronic phase transitions in FePS$_3$, revealing a metal-insulator transition and two structural phase changes in this two-dimensional antiferromagnetic Mott insulator.

Contribution

The paper reports the discovery of a pressure-driven insulator-metal transition in FePS$_3$ and proposes models for its new high-pressure structures, advancing understanding of 2D magnetic materials.

Findings

Insulator-metal transition observed at high pressure

Two structural phase transitions identified via x-ray diffraction

Metallic state onset evidenced by electrical transport measurements

Abstract

Two-dimensional materials have proven to be a prolific breeding ground of new and unstudied forms of magnetism and unusual metallic states, particularly when tuned between their insulating and metallic phases. In this paper we present work on a new metal to insulator transition system FePS$_3$ . This compound is a two-dimensional van-der-Waals antiferromagnetic Mott insulator. Here we report the discovery of an insulator-metal transition in FePS$_3$, as evidenced by x-ray diffraction and electrical transport measurements, using high pressure as a tuning parameter. Two structural phase transitions are observed in the x-ray diffraction data as a function of pressure and resistivity measurements show evidence of onset of a metallic state at high pressures. We propose models for the two new structures that can successfully explain the x-ray diffraction patterns.