Orbital occupancy and hybridization in strained SrV O 3 epitaxial films

Abstract

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.