SOFT-X-RAY-ABSORPTION STUDIES OF THE ELECTRONIC-STRUCTURE CHANGES THROUGH THE VO2 PHASE-TRANSITION

We present the O 1s and V 2p absorption edges of VO2 at room temperature and at T = 120-degrees-C, i.e., below and above the metal-insulator transition temperature T(c) almost-equal-to 67-degrees-C. The O 1s spectra show a clear splitting of 1 eV in the unoccupied d-parallel-to band below T(c). Because the V 2p absorption edges are dominated by the V 2p-3d interaction in the final state, these spectra show minor changes that cannot be easily correlated with the changes in the unoccupied density of states.