Controlling magnetism with multiferroics

Multiferroics, materials combining multiple order parameters, offer an exciting way of coupling phenomena such as electronic and magnetic order. Using epitaxial growth and heteroepitaxy, researchers have grown high-quality thin films and heterostructures of the multiferroic BiFeO₃. The ferroelectric and antiferromagnetic domain structure and coupling between these two order parameters in BiFeO₃ is now being studied. We describe the evolution of our understanding of the connection between structure, properties, and new functionalities (including electrical control of magnetism) using BiFeO₃ as a model system.