Structural Analysis of Orthorhombic Distortions in Perovskite Thin Films under Epitaxial Strain and Their Consequences on the Electronic Properties.*

The rare-earth vanadate perovskites exhibit a phase diagram featuring a strong coupling between structural, electronic and magnetic properties linked to 3d-orbital interactions. Epitaxial strain acts on octahedral rotations and crystal field symmetry to alter this lattice-orbit coupling. In this study, LaVO₃ thin films were investigated by X-ray diffraction and scanning transmission electron microscopy, which reveals two different orientations of octahedral tilting for compressive and tensile strain state as well as the occurrence (for tensile strain) and absence (for compressive strain) of a structural phase transitions at low temperatures. Ab−initio calculations correctly predict the strain effect on the tilt pattern orientation. Muon spin spectroscopy reveals that the magnetic transition is differently affected by the epitaxial strain.