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arXiv · 1405.4593

Strain and Spin-Orbit Coupling Induced Orbital-Ordering in Mott Insulator BaCrO3

Hyo-Sun Jin·Kyo-Hoon Ahn·Myung-Chul Jung·K. -W. Lee
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Abstract

Using ab initio calculations, we have investigated an insulating tetragonally distorted perovskite BaCrO$_3$ with a formal $3d^2$ configuration, the volume of which is apparently substantially enhanced by a strain due to SrTiO$_3$ substrate. Inclusion of both correlation and spin-orbit coupling (SOC) effects leads to a metal-insulator transition and in-plane zigzag orbital-ordering (OO) of alternating singly filled $d_{xz}+id_{yz}$ and $d_{xz}-id_{yz}$ orbitals, which results in a large orbital moment $M_L$ ~ -0.78 $\mu_B$ antialigned to the spin moment $M_S$ ~ $2|M_L|$ in Cr ions. Remarkably, this ordering also induces a considerable $M_L$ for apical oxygens. Our findings show metal-insulator and OO transitions, driven by an interplay among strain, correlation, and SOC, which is uncommon in 3d systems.

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Hyo-Sun Jin, Kyo-Hoon Ahn, Myung-Chul Jung, K. -W. Lee. 2014-05-19. Strain and Spin-Orbit Coupling Induced Orbital-Ordering in Mott Insulator BaCrO3. https://doi.org/10.1103/physrevb.90.205124

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