Resonant inelastic x-ray scattering study of doping and temperature dependence of low-energy excitations in La1-xSrxVO3 thin films

We present a temperature- and doping-dependent resonant inelastic x-ray scattering experiment at the V L-2,L-3 and O K edges in La1-xSrxVO3 thin films with x = 0 and x = 0.1. This material is a canonical example of a compound that exhibits a filling-control metal-insulator transition and undergoes orbital ordering and antiferromagnetic transitions at low temperature. Temperature-dependent measurements at the V L-3 edge reveal an intra-t(2g) excitation that blueshifts by 40 meV from room temperature to 30 K at a rate that differs between the para- and antiferromagnetic phases. The line shape can be partially explained by a purely local model using crystal field theory calculations. For the low Sr concentration x = 0.1, the doping is shown to affect the local electronic structure primarily on the O sites, beyond a simple Mott-Hubbard picture. Furthermore, the presence of phonon overtone features at the O K edge evidences that the low-energy part of the spectrum is dominated by phonon response.