Towards ferroelectrically-controlled magnetism: Magnetoelectric effect in Fe/BaTiO3 multilayers

TL;DR

This paper investigates a new physical mechanism for magnetoelectric effects in ferroelectric/ferromagnetic multilayers, showing how interface bonding changes can reversibly alter magnetization with electric polarization, enabling electric control of magnetic properties.

Contribution

It introduces a novel interface bonding mechanism for magnetoelectric effects in ferroelectric/ferromagnetic multilayers based on first-principles calculations.

Findings

Significant change in magnetic moments at interfaces due to polarization reversal

Magnetoelectric effect magnitude comparable to elastically-coupled composites

Potential for electric field control of magnetic properties in thin films

Abstract

An unexplored physical mechanism which produces a magnetoelectric effect in ferroelectric/ferromagnetic multilayers is studied based on first-principles calculations. Its origin is a change in bonding at the ferroelectric/ferromagnet interface that alters the interface magnetization when the electric polarization reverses. Using Fe/BaTiO3 multilayers as a representative model we show a sizable difference in magnetic moments of Fe and Ti atoms at the two interfaces dissimilar by the orientation of the local electric dipole moment. The predicted magnetoelectric effect is comparable in magnitude with that observed in elastically-coupled composites and opens a new direction to control magnetic properties of thin-film layered structures by electric fields.