Magnetoelectric coupling at the epitaxial Ni/PbTiO3 heterointerface from first principles

The magnetoelectric coupling at the epitaxial ferromagnetic/ferroelectric heterointerface depends strongly on the detailed bonding mechanism and the type of magnetic interaction among the interfacial atoms. First-principles density-functional calculations of the electronic structure and magnetoelectric coupling at the epitaxial Ni/PbTiO3 heterointerface are performed. Our results demonstrate that the interfacial magnetoelectric coupling in this system originates from the interface bonding and the peculiar pdσ-type magnetic interaction between interfacial Ni and O atoms, which results in a large change of magnetic moments on Ni atoms near the interface. Furthermore, it is this peculiar interfacial magnetic interaction that leads to an extraordinary oscillating behavior of magnetic moments across the entire Ni slab, which may have important practical implication in multiferroic devices.