Reversible control of magnetism is reported for a Fe thin film in proximity of a $\mathrm{Ba}\mathrm{Ti}{\mathrm{O}}_3$ single crystal. Large magnetization changes emerge in response to ferroelectric switching and structural transitions of $\mathrm{Ba}\mathrm{Ti}{\mathrm{O}}_3$ controlled by applied electric fields and temperature, respectively. Interface strain coupling is the primary mechanism altering the induced magnetic anisotropy. As a result, coercivity changes up to 120% occur between the various structural states of $\mathrm{Ba}\mathrm{Ti}{\mathrm{O}}_3$. Up to 20% coercivity change is achieved via electrical control at room temperature. Our all solid state ferroelectric-ferromagnetic heterostructures open viable possibilities for technological applications.

• Received 22 August 2007

DOI:https://doi.org/10.1103/PhysRevB.76.092108