Pressure-dependent magnetization and magnetoresistivity studies on the tetragonal FeS (mackinawite): revealing its intrinsic metallic character

TL;DR

This study reveals that tetragonal FeS (mackinawite) is intrinsically metallic, with pressure enhancing its metallic behavior at lower temperatures, challenging previous notions of its nonmetallic nature.

Contribution

The paper demonstrates that FeS is inherently metallic and shows how pressure suppresses weak localization, extending metallic behavior to lower temperatures.

Findings

FeS is intrinsically metallic contrary to previous reports.

Pressure reduces weak localization, enhancing metallic behavior.

Metallic character persists down to 75 K at 3 GPa.

Abstract

The transport and magnetic properties of the tetragonal Fe$_{1+\delta}$S were investigated using magnetoresistivity and magnetization within 2$\leq T\leq $300 K, $H\leq$70 kOe and $P\leq$ 3.0 GPa. In addition, room-temperature X-ray diffraction and photoelectron spectroscopy were also applied. In contrast to previously reported nonmetallic character, Fe$_{1+\delta}$S is intrinsically metallic but due to a presence of a weak localization such metallic character is not exhibited below room temperature. An applied pressure reduces strongly this additional resistive contribution and as such enhances the temperature range of the metallic character which, for $\sim$3 GPa, is evident down to 75 K. The absence of superconductivity as well as the mechanism behind the weak localization will be discussed.