Tuning the magnetic properties of V2O3 / CoFeB heterostructures across the V2O3 structural transition

In this work, we investigate the effects of the V2O3structural phase transition on the magnetic properties of anamorphous magnetic thin film of CoFeB in contact with it. V2O3thin films are deposited epitaxially on sapphiresubstrates, reaching bulklike properties after few nm of growth. By means of temperature dependent Kerreffect characterizations, we prove that crossing the V2O3structural phase transition induces reproducible andreversible changes to CoFeB magnetic properties, especially to its coercive field. By decreasing the oxide layerthickness, its effects on the magnetic layer decreases, while reducing the magnetic layer thickness maximizesit, with a maximum of 330% coercive field variation found between the two V2O3structural phases. By simplytuning the temperature, this systematic study shows that the engineering of V2O3structural transition induceslarge interfacial strain and thus strong magnetic property variations to an amorphous thin film, opening widepossibilities in implementing strain-driven control of the magnetic behavior without strict requirements onepitaxial coherence at the interface.