Giant magnetoelectric effects in pseudo 1-3 heterostructure films with FeGa nanocluster-assembled micron-scale discs embedded into Bi5Ti3FeO15 matrices.

Nanocluster-assembled FeGa micron-scale discs prepared by low-energy cluster beam deposition were embedded into Bi5Ti3FeO15 matrices to form pseudo 1-3 heterostructure films. The microstructures and multiferroic properties were investigated. Good ferroelectric, piezoelectric, and ferromagnetic properties and giant magnetoelectric effects are achieved for the heterostructure films, which is ascribed to the depression of the clamped effect from the hard substrate for such pseudo 1-3 structures and the multi-interface coupling between the large magnetostrictive coefficient of FeGa micron-scale discs and the high piezoelectric coefficient of the circle surrounding the Bi5Ti3FeO15 matrices. Such a strong interface strain coupling between the micron discs and the inhomogeneously multiferroic matrices induces obvious magnetoelectric coupling behaviors. Besides, the interaction between the ferroelectric domains and the spin orders in the multiferroic matrices also contributes to the magnetoelectric output. The present work provides a potential way to fabricate clamped-free magnetoelectric films for microdevice applications.