Enhancement in magnetoelectric response in CoFe2O4–BaTiO3 heterostructure

Co Fe 2 O 4 – Ba Ti O 3 heterostructure was epitaxially grown on the (001)-SrTiO3 substrate via pulsed laser deposition, in which the bottom BaTiO3 layer epitaxially grown on the substrate acts as a buffer layer and effectively reduces the coherent constraint in the magnetic layer arising from the substrate. Microstructure studies from x-ray diffraction and electron microscopies showed good coherent epitaxy thin films of the (001)-CoFe2O4 and (001)-BaTiO3 on the substrate, which exhibits simultaneously strong ferroelectric and ferromagnetic responses. An obvious direct magnetoelectric coupling effect was observed in the thin films, which shows an enhancement compared to previous NiFe2O4–BaTiO3 heterostructures.