Role of 3d electrons in the rapid suppression of superconductivity in the dilute V doped spinel superconductor LiTi2O4

The microscopic effects of V doping in LiTi2O4 have been poorly understood. The present study employs x-ray absorption near-edge structure (XANES) and resonant inelastic soft-x-ray scattering (RIXS) spectroscopy to understand the change in the electronic structure due to dilute V doping in spinel LiTi2O4 and the possible origin for the rapid suppression of superconductivity in these compounds. Results from the XANES spectra at Ti L and K edges and Ti L-RIXS show that Ti exists in a mixed-valence state and, with V doping, the unoccupied states of Ti in the t(2g) band increase. The rapid suppression of superconductivity is associated with the change in Ti 3d electrons and Ti-O hybridization.