Magnetoelectric Effect in Ferromagnetic Ferroelectrics

The essence of magnetoelectric effect is the possibility of appearance of magnetization M induced by electric field E and electric polarization P induced by magnetic field H. For linear magnetoelectric effect (in weak fields) 

The first observation of ME effect by D.N. Astrov [16] constituted a breakthrough in its investigations. Nevertheless, it became immediately clear that expected technical applications were hampered by small effect magnitude, restricted number of the materials where ME effect can be manifested as well as poor understanding of the physical mechanisms responsible for the effect. Later it was shown [17] that ME effect magnitude in monophased materials is restricted by the inequality 

It follows from Eq. (1.19) that ME effect can be large mainly in ferroelectric and/or in ferromagnetic materials and especially in secondary ferroics, namely in ferromagnetoelectrics with coexistence of spontaneous magnetization and electric polarization. 

Last years, the revival of interest and corresponding increase of the number of the works devoted to ME effect in solids was related to the discovery of the large 

The materials with ME effect consist of about 50 % composites and 25 % single phase systems, which are the secondary ferroics. The other 25 % include solid solutions, laminar structures consisting of several layers with thickness about one millimeter as well as nanostructures in the form of thin films, nanorods etc. 

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