Electric control of magnetism at the Fe/BaTiO3 interface

• Published in: Nature communications Vol. 5; no. 1; p. 3404
• Main Authors: Radaelli, G., Petti, D., Plekhanov, E., Fina, I., Torelli, P., Salles, B. R., Cantoni, M., Rinaldi, C., Gutiérrez, D., Panaccione, G., Varela, M., Picozzi, S., Fontcuberta, J., Bertacco, R.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 03-03-2014; Nature Publishing Group
• Subjects: 639/301/119/997; ATOMIC AND MOLECULAR PHYSICS; ferroelectricity; Humanities and Social Sciences; interfaces; magnetism; magnetoelectric coupling; multidisciplinary; Science; Science (multidisciplinary); spintronics
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms4404

Interfacial magnetoelectric coupling is a viable path to achieve electrical writing of magnetic information in spintronic devices. For the prototypical Fe/BaTiO
3
system, only tiny changes of the interfacial Fe magnetic moment upon reversal of the BaTiO
3
dielectric polarization have been predicted so far. Here, by using X-ray magnetic circular dichroism in combination with high-resolution electron microscopy and first principles calculations, we report on an undisclosed physical mechanism for interfacial magnetoelectric coupling in the Fe/BaTiO
3
system. At this interface, an ultrathin oxidized iron layer exists, whose magnetization can be electrically and reversibly switched on and off at room temperature by reversing the BaTiO
3
polarization. The suppression/recovery of interfacial ferromagnetism results from the asymmetric effect that ionic displacements in BaTiO
3
produces on the exchange coupling constants in the interfacial-oxidized Fe layer. The observed giant magnetoelectric response holds potential for optimizing interfacial magnetoelectric coupling in view of efficient, low-power spintronic devices.
Interfacial magnetoelectric coupling could lead to a new generation of memory devices. Here, Bertacco and colleagues observe a large electric-field switchable magnetoelectric coupling effect in iron/barium titanate heterostructures, which is due to a thin oxidized iron layer.