Combining ferromagnetic and ferroelectric materials has produced exciting new opportunities to design and produce structures with new functionalities.1,2,3 In particular, ferromagnetic/ferroelectric multilayers provide a means of making nanodevices where the magnetization is electrically controlled through magnetoelastic or magnetoelectric coupling.4,5,6 In these multilayer structures knowledge about the magnetization and polarization at the interfaces is key to understanding how these coupling mechanisms work. We use the spin polarization of secondary electrons and the intensity of backscattered electrons generated in a scanning electron microscope to simultaneously image the ferromagnetic domain structure of a ferromagnetic thin film and the ferroelectric domain structure of the underlying ferroelectric substrate. Simultaneous imaging allows straight-forward, quantitative measurements of the correlations in these complex multiferroic systems. We have successfully applied this technique to various ferromagnetic films deposited on multiferroic BiFeO3 (BFO) films and ferroelectric BaTiO3 (BTO) substrates, two systems with very different ferromagnet/ferroelectric coupling mechanisms, demonstrating how this technique provides a new local probe of magneto electric/strictive effects in multiferroic heterostructures.
Citation: Applied Physics Letters Materials
Pub Type: Journals
multiferroic, domain imaging, BiFeO3, SEMPA, electron microscopy