Piezoresponse force microscopy and magnetic force microscopy characterization of γ-Fe2O3–BiFeO3 nanocomposite/Bi3.25La0.75Ti3O12 multiferroic bilayers

The multiferroic behavior of epitaxial γ-Fe2O3–BiFeO3 (composite)/Bi3.25La0.75Ti3O12 bi-layered heterostructures grown on SrRuO3/SrTiO3 (1 1 1) substrates has been studied using piezoresponse force microscopy, magnetic force microscopy and magnetometry. The ferroelectric domain structure is ascribed to the BiFeO3 phase while the magnetism originates in the γ-Fe2O3 phase of the composite layer. Our studies demonstrate the presence and switching of magnetic and ferroelectric domains within the same area of the sample. This confirms the presence of multiferroic behavior at the nanoscale in our γ-Fe2O3–BiFeO3 nanocomposite thin films.