Electronic and magnetic properties of the Jahn-Teller active fluoride $\mathrm{NaCrF_{3}}$ from first-principles calculations

TL;DR

This study uses first-principles calculations to analyze the electronic, magnetic, and orbital properties of the Jahn-Teller active fluoride NaCrF3, revealing its high-spin state, orbital ordering, and magnetic interactions consistent with experimental observations.

Contribution

It provides a comprehensive first-principles analysis of NaCrF3's electronic structure, magnetic ordering, and orbital configuration, elucidating the effects of Jahn-Teller distortions in fluoride perovskites.

Findings

Cr2+ ions adopt high-spin configuration with orbital ordering.

In-plane interactions are ferromagnetic, interplanar are antiferromagnetic.

Ground state is A-type antiferromagnetic, matching experiments.

Abstract

In perovskite-type compounds, the interplay of cooperative Jahn-Teller effect, electronic correlations and orbital degree of freedom leads to intriguing properties. $\mathrm{NaCrF_{3}}$ is a newly synthesized Jahn-Teller active fluoroperovskite where the $\mathrm{CrF_{6}^{4-}}$ octahedrons are considerably distorted. Based on the first-principles calculation, we analyze its electronic structure and magnetic properties. Our numerical results show that the $\mathrm{Cr^{2+}}$ ions adopt the high-spin $t_{2g\uparrow}^{3}e_{g\uparrow}^{1}$ configuration with $G$-type orbital ordering. We also estimate the magnetic exchange couplings and find that the in-plane and interplanar nearest-neighbor interactions are ferromagnetic and antiferromagnetic, respectively. The ground state of this material is $A$-type antiferromagnetic, in agreement with the experiments. Reasonable Curie-Weiss and $\mathrm{N\acute{e}el}$ temperatures compared to the experiments are given by mean-field approximation theory. Our results give a complete explanation of its electronic structure, magnetic and orbital order, and help to further comprehend the behaviors of Jahn-Teller active perovskite-type fluoride.