In-plane magnetization and electronic structures in BiFeO₃/graphene superlattice

We predict the presence of gapped electronic structures in an artificial superlattice of graphene embedded in (111)-oriented BiFeO3 layers based on first-principles calculations. Due to the electron transfer and the proximity effect at the BiFeO3/graphene interface, we find that magnetic moments of Fe atoms near a graphene layer were slightly less than that of bulk Fe atoms. Regarding the ferromagnetic moment orientation of Fe atoms in perovskite BiFeO3, we reveal that the in-plane magnetization gives the ground state. The bandgap depends on the magnetization direction and the separation between the graphene layer and the perovskite BiFeO3 slab, which might be adjusted by applying external uniaxial stress in an experiment. Our results provide a route for designing hybrid 2D materials with emerging properties that are not available in single materials alone.