Large magnetoelectric coupling in ferromagnetic/ferroelectric superlattices with asymetric interfaces

• An approach is proposed to realize cumulative ME coupling in FM/FE superlattice.
• A monolayer of different metal breaks inversion symmetry between the two interfaces.
• We use FeM/PbTiO3 (M=Ni, Pt and Ag) as the model system to investigate the ME effects.
• Combination of different ME coupling mechanisms produces large cumulative ME effect.

In this Letter, we investigate an attractive approach providing large and cumulative magnetoelectric coupling in ferromagnetic/ferroelectric superlattice by inserting a monolayer of different metal (ferromagnetic or normal metal) at one interface. Using first-principles calculations on FeM/PbTiO3 (M=Ni, Pt and Ag) as a model system, the recorded high magnetoelectric coefficients are obtained in one unit cell with the insertion of Ni and Pt monolayer. A carefully analysis reveals that the large magnetoelectric effects are determined by combinations of several different mechanisms including interface bonding, spin-dependent screening, and distinct type of magnetic interactions.