The invention discloses laminated ferroelectric / magnetic multiferroic and magnetoelectric
composite film and preparation method thereof. The film comprises a substrate, a ferroelectric
oxide layer and a
magnetic oxide layer, and also a buffer layer positioned between the substrate layer and the ferroelectric
oxide layer or the
magnetic oxide layer. The layer can be LaNiO3, YBa2Cu3O7-x or SrRuO3, among which LaNiO3 is preferred. The preparation method comprises the following steps: firstly, buffer layer
sol is prepared; secondly, the buffer layer
sol is uniformly coated on the substrate to obtain the buffer layer; thirdly,
sol of the ferroelectric
oxide layer and the
magnetic oxide layer is respectively prepared; fourthly, the sol obtained in step 3 is coated on the buffer layer, and then the end product is obtained. After the
composite film is introduced into the buffer layer, the stress restraint of the substrate to the
composite film is effectively reduced, the magnetoelectric
coupling performance of the composite film with laminated structure is obviously enhanced, the cost is reduced, the preparation technique is simple, the requirement on the equipment is low, and the compatibility with the prior technique is good.