Enhanced Magnetoelectric Coupling in BaTiO<sub>3</sub>-BiFeO<sub>3</sub> Multilayers—An Interface Effect
Stefan Hohenberger,
Johanna K. Jochum,
Margriet J. Van Bael,
Kristiaan Temst,
Christian Patzig,
Thomas Höche,
Marius Grundmann,
Michael Lorenz
Affiliations
Stefan Hohenberger
Felix-Bloch-Institut für Festkörperphysik, Universität Leipzig, Linnéstraße 5, D-04103 Leipzig, Germany
Johanna K. Jochum
Quantum Solid State Physics, Celestijnenlaan 200D, B-3001 Leuven, Belgium
Margriet J. Van Bael
Quantum Solid State Physics, Celestijnenlaan 200D, B-3001 Leuven, Belgium
Kristiaan Temst
Quantum Solid State Physics, Celestijnenlaan 200D, B-3001 Leuven, Belgium
Christian Patzig
Center for Applied Microstructure Diagnostics, Fraunhofer-Institut für Mikrostruktur von Werkstoffen und Systemen, Walter-Hülse-Straße 1, D-06120 Halle, Germany
Thomas Höche
Center for Applied Microstructure Diagnostics, Fraunhofer-Institut für Mikrostruktur von Werkstoffen und Systemen, Walter-Hülse-Straße 1, D-06120 Halle, Germany
Marius Grundmann
Felix-Bloch-Institut für Festkörperphysik, Universität Leipzig, Linnéstraße 5, D-04103 Leipzig, Germany
Michael Lorenz
Felix-Bloch-Institut für Festkörperphysik, Universität Leipzig, Linnéstraße 5, D-04103 Leipzig, Germany
Combining various (multi-)ferroic materials into heterostructures is a promising route to enhance their inherent properties, such as the magnetoelectric coupling in BiFeO3 thin films. We have previously reported on the up-to-tenfold increase of the magnetoelectric voltage coefficient α ME in BaTiO3-BiFeO3 multilayers relative to BiFeO3 single layers. Unraveling the origin and mechanism of this enhanced effect is a prerequisite to designing new materials for the application of magnetoelectric devices. By careful variations in the multilayer design we now present an evaluation of the influences of the BaTiO3-BiFeO3 thickness ratio, oxygen pressure during deposition, and double layer thickness. Our findings suggest an interface driven effect at the core of the magnetoelectric coupling effect in our multilayers superimposed on the inherent magnetoelectric coupling of BiFeO3 thin films, which leads to a giant α ME coefficient of 480 Vc m − 1 Oe − 1 for a 16 × (BaTiO3-BiFeO3) superlattice with a 4.8 nm double layer periodicity.
