Converse magnetoelectric effects in Fe³O⁴/BaTiO ³ multiferroic hybrids

The quantitative understanding of converse magnetoelectric effects, i.e., the variation of the magnetization as a function of an applied electric field, in extrinsic multiferroic hybrids is a key prerequisite for the development of future spintronic devices. We present a detailed study of the strain-mediated converse magnetoelectric effect in ferrimagnetic Fe³O⁴ thin films on ferroelectric BaTiO³ substrates at room temperature. The experimental results are in excellent agreement with numerical simulation based on a two-region model. This demonstrates that the electric field induced changes of the magnetic state in the Fe³O⁴ thin film can be well described by the presence of two different ferroelastic domains in the BaTiO³ substrate, resulting in two differently strained regions in the Fe³O⁴ film with different magnetic properties. The two-region model allows to predict the converse magnetoelectric effects in multiferroic hybrid structures consisting of ferromagnetic thin films on ferroelastic substrates.