Electronic Structure of Weakly Correlated Antiferromagnetic Metal SrCrO3: First-principles calculations

TL;DR

This study uses first-principles calculations to reveal that SrCrO3 is a rare weakly correlated antiferromagnetic metal with a favored C-type spin order, where magnetic instability dominates over orbital or lattice effects.

Contribution

The paper demonstrates that SrCrO3 is a weakly correlated AF metal with a specific C-type spin order, and analyzes the stabilization mechanism emphasizing magnetic instability.

Findings

SrCrO3 is a weakly correlated antiferromagnetic metal.

C-type spin ordering with orbital polarization is favored.

Magnetic instability drives the ground state, not orbital or lattice effects.

Abstract

By systematic first-principles calculations, we study the electronic structure and magnetic property of SrCrO$_3$. Our results suggest that SrCrO$_3$ is a weakly correlated antiferromagnetic (AF) metal, a very rare situation in transition-metal oxides. Among various possible AF states, the C-type spin ordering with small amount of orbital polarization (dxy orbital is more occupied than the d_{yz/zx} orbital) is favored. The detailed mechanism to stabilize the C-type AF state is analyzed based on the competition between the itinerant Stoner instability and superexchange, and our results suggest that the magnetic instability rather than the orbital or lattice instabilities plays an important role in this system. The experimentally observed compressive tetragonal distortion can be naturally explained from the C-type AF state. By applying the LDA+$U$ method to study this system, we show that wrong ground state will be obtained if $U$ is large.