Epitaxial BiFeO3 multiferroic thin film heterostructures

Journal Article

Wang, J, J.B Neaton, H Zheng, V Nagarajan, S.B Ogale, B Liu, D Viehland, V Vaithyanathan, D.G Schlom, U.V Waghmare, N.A Spaldin, K.M Rabe, M Wuttig, Ramamoorthy Ramesh

10.1126/science.1080615

Enhancement of polarization and related properties in heteroepitaxially constrained thin films of the ferroelectromagnet, BiFeO3, is reported. Structure analysis indicates that the crystal structure of film is monoclinic in contrast to bulk, which is rhombohedral. The films display a room-temperature spontaneous polarization (50 to 60 microcoulombs per square centimeter) almost an order of magnitude higher than that of the bulk (6.1 microcoulombs per square centimeter). The observed enhancement is corroborated by first-principles calculations and found to originate from a high sensitivity of the polarization to small changes in lattice parameters. The films also exhibit enhanced thickness-dependent magnetism compared with the bulk. These enhanced and combined functional responses in thin film form present an opportunity to create and implement thin film devices that actively couple the magnetic and ferroelectric order parameters.

Science

299

2003

00368075

cited By 4623

Ramesh Lab