Magnetic structure and orbital ordering in BaCoO3 from first-principles calculations

TL;DR

This study uses first-principles calculations to explore the electronic, magnetic, and orbital properties of BaCoO3, revealing an insulating ferromagnetic state with specific orbital ordering.

Contribution

It provides a detailed first-principles analysis of BaCoO3's magnetic and orbital structure, highlighting the importance of LDA+U in capturing its insulating behavior.

Findings

LDA+U predicts an insulating ferromagnetic ground state.

GGA predicts a metallic ground state.

Orbital ordering is alternating along Co-Co chains.

Abstract

Ab initio calculations using the APW+lo method as implemented in the WIEN2k code have been used to describe the electronic structure of the quasi-one-dimensional system BaCoO3. Both, GGA and LDA+U approximations were employed to study different orbital and magnetic orderings. GGA predicts a metallic ground state whereas LDA+U calculations yield an insulating and ferromagnetic ground state (in a low-spin state) with an alternating orbital ordering along the Co-Co chains, consistent with the available experimental data.