Strain and electric field control of magnetic and electrical transport properties in a magnetoelastically coupled Fe3O4/BaTiO3 (001) heterostructure

We present a study of the control of electric field induced strain on the magnetic and electrical transport properties in a magneto-elastically coupled artificial multiferroic Fe3O4/BaTiO3 heterostructure. In this Fe3O4/BaTiO3 heterostructure, the Fe3O4 thin film is epitaxially grown in the form of bilateral domains, analogous to a-c stripe domains of the underlying BaTiO3(001) substrate. By in-situ electric field dependent magnetization measurements, we demonstrate the extrinsic control of the magnetic anisotropy and the characteristic Verwey metal-insulator transition of the epitaxial Fe3O4 thin film in a wide temperature range between 20-300 K, via strain mediated converse magnetoelectric coupling. In addition, we observe strain induced modulations in the magnetic and electrical transport properties of the Fe3O4 thin film across the thermally driven intrinsic ferroelectric and structural phase transitions of the BaTiO3 substrate. In-situ electric field dependent Raman measurements reveal that the electric field does not significantly modify the anti-phase boundary defects in the Fe3O4 thin film once it is thermodynamically stable after deposition and that the modification of the magnetic properties is mainly caused by strain induced lattice distortions and magnetic anisotropy. These results provide a framework to realize electrical control of the magnetization in a classical highly correlated transition metal oxide.