Suppression of magnetism under pressure in FeS: a LDA+DMFT study

TL;DR

This study uses LDA+DMFT calculations to reveal how pressure suppresses magnetism in FeS by increasing spin itinerancy and inducing a transition from a Fermi-liquid to an orbital-selective state, beyond simple spin state changes.

Contribution

It provides a detailed theoretical analysis of magnetic suppression in FeS under pressure, highlighting the role of electronic structure modifications and spin itinerancy.

Findings

Magnetic moment decreases with pressure

FeS transitions to a Fermi-liquid state at high pressure

Orbital-selective regime emerges as pressure decreases

Abstract

We show that evolution of magnetic properties in FeS under pressure cannot be explained only in terms of a spin state transition. While uniform compression does show substantial suppression of the local magnetic moment and increase of the weights of configurations with low spin, analysis of the local spin-spin correlation function demonstrates increase of the spin itinerancy. This is related to a strong modification of the electronic structure under pressure: in the high-pressure phase FeS is in the Fermi-liquid state, while decrease of the pressure moves the system to an orbital-selective regime.