Investigation of role of antisite disorder in the pristine cage compound FeGa$_3$

TL;DR

This study explores how controlled antisite disorder in FeGa$_3$ influences its electronic and magnetic properties, revealing a transition from semiconducting to metallic behavior driven by site disorder.

Contribution

It provides new insights into how antisite disorder affects the ground state of FeGa$_3$, linking structural disorder to electronic and magnetic phase transitions.

Findings

Disorder induces a transition from semiconducting to metallic state.

Site disorder hierarchy influences magnetic properties.

Quantitative analysis of Fe and Ga site occupation deviations.

Abstract

The role of controlled disorder in the strong correlated narrow gap semiconductor candidate FeGa$_3$ has been investigated. Polycrystalline samples were synthesized by the combination of arc-melting furnace and successive annealing processes. Deviations of the occupation number of Fe and Ga sites from those expected in the pristine compound were quantified with X-ray analysis. Besides that, electrical transport and magnetization measurements reveal that hierarchy in Fe and Ga site disorder tunes the ground state of FeGa$_3$ from paramagnetic semiconducting to a magnetic metal. These findings are discussed within the framework of Anderson metal-insulator transitions and spin fluctuations.