Comparative study of FeCr2S4 and FeSc2S4: Spinels with orbitally active A site

TL;DR

This study uses first-principles calculations to compare two Fe-based spinel compounds, revealing how differences in electronic hybridization lead to distinct magnetic behaviors and frustration effects.

Contribution

It uncovers the microscopic origins of the differing magnetic properties in FeCr2S4 and FeSc2S4 due to hybridization differences, advancing understanding of orbitally active spinels.

Findings

FeSc2S4 exhibits significant magnetic frustration.

Differences in hybridization affect magnetic exchange interactions.

FeCr2S4 shows less magnetic frustration.

Abstract

Using first-principles density functional calculations, we perform a comparative study of two Fe based spinel compounds, FeCr2S4 and FeSc2S4. Though both systems contain an orbitally active A site with an Fe2+ ion, their properties are rather dissimilar. Our study unravels the microscopic origin of their behavior driven by the differences in hybridization of Fe d states with Cr/Sc d states and S p states in the two cases. This leads to important differences in the nature of the magnetic exchanges as well as the nearest versus next nearest neighbor exchange parameter ratios, resulting into significant frustration effects in FeSc2S4 which are absent in FeCr2S4.