Electronic structure of V4O7: Charge ordering, metal-insulator transition, and magnetism

Article

关键词: CRYSTAL-STRUCTURE;    MOTT-HUBBARD;    LOCALIZATION;    PEROVSKITES;    VO2;   

DOI  :  10.1103/PhysRevB.84.115138

来源: SCIE

【 摘 要 】

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 V4O7. 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.

【 授权许可】

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