Another method to for achieving high degree of magnetoelectric coupling is to mix ferroelectric (e.g. BaTiO₃) and ferromagnetic (e.g. CoFe₂O₄) materials and utilize the strain between two phases to introduce magneto-electric coupling. Such a coupling requires that two phase have good contact between them i.e. to have an interface through which properties can coupled such as in the form of composites, epitaxial multilayers and laminates. For a few systems, the data is shown in the table below.

Table 8.2   Magnetoelectric coupling constant data for selected two-phase magnetoelectric systems

In two phase structures, as evident from some of references, one can create large changes in the magnetization owing to strain due to the ferroelectric phase transition of the ferroelectric material during film growth or one can also attempt to alter the magnetic structure by applying a field the piezoelectric material which thereby generates a strain in the magnetic material in the vicinity. Epitaxial growth of layers allows very good interfacial contact between two materials as shown in case of BaTiO₃ and CoFe₂O₄ which has potential to improve the coupling of parameters