%0 Journal Article %K thin films %K Epitaxial growth %K ferroelectricity %K Magnetization %K Magnetoelectric coupling %K Atomic-level engineering %K Interfacial coupling %K Thin-film multiferroics %A Ramamoorthy Ramesh %A N.A Spaldin %B Nature Materials %D 2007 %G eng %P 21-29 %R 10.1038/nmat1805 %T Multiferroics: Progress and prospects in thin films %V 6 %X Multiferroic materials, which show simultaneous ferroelectric and magnetic ordering, exhibit unusual physical properties and in turn promise new device applications as a result of the coupling between their dual order parameters. We review recent progress in the growth, characterization and understanding of thin-film multiferroics. The availability of high-quality thin-film multiferroics makes it easier to tailor their properties through epitaxial strain, atomic-level engineering of chemistry and interfacial coupling, and is a prerequisite for their incorporation into practical devices. We discuss novel device paradigms based on magnetoelectric coupling, and outline the key scientific challenges in the field. © 2007 Nature Publishing Group.