Giant direct magnetoelectric effect in strained multiferroic heterostructures

The direct magnetoelectric (ME) effect mediated by lattice strains induced in a ferroelectric film by a ferromagnetic substrate is evaluated using first-principles-based calculations. To that end, the strain sensitivity of ferroelectric polarization and the film permittivity are calculated as a function of the in-plane biaxial strain for Pb(Zr0.52Ti0.48)O3 films under various depolarizing fields. It is found that the ME voltage coefficient varies nonmonotonically with this strain and may reach giant values exceeding 100 Vcm-1 Oe-1 over a strain range that can be controlled through the electrical boundary conditions.