Phase transition in LiVO2 studied by near-edge x-ray-absorption spectroscopy

We present temperature-dependent V-2p and O-1s x-ray-absorption spectra 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 anomalously low magnetic susceptibility below the transition temperature, we propose a model in which a three-orbital sublattice is formed in the V (111) planes, which results in a total singlet state.