The low- and high-temperature phases of V4O7 have been studied by ab initio calculations. At high temperature, all V atoms are electronically equivalent and the material is metallic. Charge and orbital ordering, associated with the distortions in the V pseudorutile chains, occur below the metal-insulator transition. Orbital ordering in the low-temperature phase, which is different in V3+ and V4+ chains, allows us to explain the distortion pattern in the insulating phase of V 4O7. The in-chain magnetic couplings in the low-temperature phase turn out to be antiferromagnetic but are very different in the various V4+ and V3+ bonds. The V4+ dimers formed below the transition temperature form spin singlets, but V3+ ions, despite dimerization, apparently participate in magnetic ordering.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Sep 26 2011|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics