PHASE-TRANSITION IN LIVO2 STUDIED BY NEAR-EDGE X-RAY-ABSORPTION SPECTROSCOPY

We present temperature-dependent V-2p and O-1s x-ray-absorption spectr a of LiVO2. The aim of this study is to monitor changes in electronic structure on going through the phase transition. The spectral changes turn out to be very small: the V-3d-O-2p hybridization does not change considerably, and the symmetry of the V-ion ground state (high-spin T -3(1)) is retained. To explain our results, together with the anomalou sly low magnetic susceptibility below the transition temperature, we p ropose a model in which a three-orbital sublattice is formed in the V (111) planes, which results in a total singlet state.