Theory of magnetoelectric coupling in 2–2-type magnetostrictive/piezoelectric composite film with texture

Abstract

It is well accepted that textures in polycrystalline films have significant effects on film properties. The magnetoelectric (ME) coupling in a 2–2-type multiferroic composite film was theoretically discussed using Landau–Ginsburg–Devonshire theory, where the influences of dispersive texture and residual stress were considered. As an example, the 2–2-type CoFe2O4/BaTiO3 composite film was theoretically analysed, wherein the case of both the magnetostrictive phase and the piezoelectric phase with (0 0 1)-oriented texture was considered. Our results show that the ME coupling is enhanced with the texture degree of the piezoelectric phase and/or the magnitude of the residual tensile stress, but weakened with the magnitude of residual compressive stress. With increasing texture degree of the magnetostrictive phase, the ME coupling is enhanced when the texture degree is smaller than a critical value, but weakened when the texture degree is larger than the critical value.