Spin and orbital occupation and phase transitions in V2O3
PhysRevB_61_11506.pdf 66.6 KB
Tjeng, L. H.
Allen, J. W.
Chen, C. T.
Honig, J. M.
de Groot, F. M. F.
Sawatzky, G. A.
Polarization dependent x-ray-absorption measurements were performed on pure and Cr-doped V2O3 single crystals in the antiferromagnetic insulating, paramagnetic insulating, and metallic phases. The orbital occupation of the V 3d2 ion is found to depend appreciably on the phase, but always with the S = 1 character, requiring an explanation which is beyond the elegant simplicity of the pure one-band Hubbard model or of models in which the a1g orbital is projected out by means of a simple dimerization. The results reveal the critical role of the spin and orbital dependence of the on-site 3d-3d Coulomb energy, and a mechanism is proposed to explain the closing or opening of the band gaps which are of much higher energy scale than the transition temperatures.
Physical Review B - Condensed Matter and Materials Physics
|date of issued||
American Physical Society
Copyright (c) 2000 American Physical Society.
Graduate School of Advanced Sciences of Matter