Interplay among Spin, Orbital and Lattice Degrees of Freedom in $t_{2g}$ Electron Systems with Edge-Sharing Network of Octahedra

TL;DR

This paper theoretically investigates the complex interactions among spin, orbital, and lattice degrees of freedom in $t_{2g}$ electron systems with edge-sharing octahedral networks, revealing the significance of anisotropic orbital interactions and magnetic field effects.

Contribution

It provides a detailed analysis of the interplay among spin, orbital, and lattice degrees of freedom in $t_{2g}$ systems with edge-sharing structures, highlighting the role of anisotropy and weak Jahn-Teller coupling.

Findings

Orbital anisotropy is crucial in edge-sharing geometries.

Interplay between spin and lattice affects magnetization in chromium spinels.

Weak Jahn-Teller coupling still leads to significant spin-orbital-lattice interactions.

Abstract

Transition metal oxides whose lattice structure has edge-sharing network of octahedra constitute a diverse group of intriguing materials besides compounds with corner-sharing octahedra such as perovskites. We present a theoretical investigation of the interplay among spin, orbital and lattice degrees of freedom in these materials. We focus on $t_{2g}$ electron systems where a keen competition among those degrees of freedom is expected to emerge under a relatively weak Jahn-Teller coupling. We study the interplay between spin and orbital degrees of freedom in vanadium spinels and titanium pyroxenes. We clarify the important role of the strong anisotropy in the orbital interactions due to the edge-sharing geometry. We also discuss the interplay between spin and lattice in chromium spinels focusing on the magnetization process under the external magnetic field.