Orbital occupancy and hybridization in strained SrV O3 epitaxial films

Oxygen packaging in transition metal oxides determines the metal-oxygen hybridization and electronic occupation at metal orbitals. Strontium vanadate (SrVO3), having a single electron in a 3d orbital, is thought to be the simplest example of strongly correlated metallic oxides. Here, we determine the effects of epitaxial strain on the electronic properties of SrVO3 thin films, where the metal-oxide sublattice is corner connected. Using x-ray absorption and x-ray linear dichroism at the VL2,3 and O K edges, it is observed that tensile or compressive epitaxial strain change the hierarchy of orbitals within the t2g and eg manifolds. Data show a remarkable 2p-3d hybridization, as well as a strain-induced reordering of the V3d(t2g,eg) orbitals. The latter is itself accompanied by a consequent change of hybridization that modulates the hybrid π∗ and σ∗ orbitals and the carrier population at the metal ions, challenging a rigid band picture.Financial support from the Spanish Ministry of Science, Innovation and Universities, through the “Severo Ochoa” Programme for Centres of Excellence in R&D (FUNFUTURE, CEX2019-000917-S) and the MAT2017-85232-R project, from the AEI/FEDER, UE (PID2020-118479RB-I00), and from Generalitat de Catalunya (2017 SGR 1377), is acknowledged. The work of M.M. has been done as a part of the Ph.D. program in Physics at Universitat Autònoma de Barcelona and was financially supported by the Spanish Ministry of Science, Innovation and Universities (BES-2015-075223). A.V. and R.V. acknowledge support by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) for funding through TRR 288-422213477 (Project B05). J.S. acknowledges support from Project No. 2017 SGR 579 from AGAUR, Generalitat de Catalunya