We describe the magnetic domain structures and magnetoelectric coupling in self-assembled BiFeO3–CoFe2O4 (BFO–CFO) nanocomposite thin films grown on (110)-LaAlO3 substrates, consisting of CFO slab-shaped crystals (nanofins) embedded in a BFO matrix. The nanofins exhibit magnetic single-domain states with in-plane magnetization along their length due to shape and magnetoelastic anisotropies. The piezoresponse of the BFO matrix is affected by applying an in-plane hard axis magnetic field, indicating magnetoelectric coupling within the multiferroic composite. Conversely, an applied electric field leads to the magnetic reversal of a fraction of the nanofins as the strain transferred from the BFO alters the magnetic anisotropy, enabling switching driven by magnetostatic interactions.
In recent years, there is a surge of research interest in exotic ferroelectric topological states, motivated by their rich emerging physical properties and potential applications in nanoelectronic devices. Here, we demonstrate the observation of a sort of complex center-type topological domain structures, which exhibit a quadrant center-type (with polarization pointing to the center) topological texture for an in-plane polarization component and a cylinder domain pattern along the vertical direction, in rhombohedral structured Pb(Zr0.7Ti0.3)O3 (R-PZT) nanoislands. Such a center domain state exhibits a rather high stability, which can well maintain its topological texture after heating to above curie temperature and subsequently cooling down to room temperature. Moreover, it allows erasure by a scanning electric field, yet it can also be recovered by a similar heating and cooling process. The observation of these unique topological textures in R-PZT nanoislands might provide a good playground for further exploring their topological phase transition properties, emerging novel functionalities, and application potential.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.