ИСТИНА

Materials with multiferroics properties have attracted research interest due to the promising prospects of practical applications. Use of such materials allows to increase energy efficiency and reduce the design complexity of various devices. Moreover, the description of coupling mechanisms between magnetic, electric and mechanical properties of such materials is of fundamental scientific importance. Among multiferroics with ferroelectric and ferromagnetic types of ordering, composite structures established themselves as those having larger value of magnetoelectric transformation (change of polarization under the influence of magnetic field and vice versa, change of magnetization under the influence of electric field). Recently the new type of composite multiferroics based on magnetorheological elastomers (MRE) was proposed. Three-phase multiferroic composite – ferromagnetic and ferroelectric particles embedded in elastic polymer medium – was shown to demonstrate magnetoelectric transformation. Model of the mechanism based on the elastic coupling of ferromagnetic and ferroelectric particles was proposed. It was also shown, that magnetorheological ferroelectric foam filled with the elastomer with iron particles demonstrates reverse magnetoelectric effect. In this work the reverse magnetoelectric effect in four-component composite structures based on ferroelectric foam was investigated. Ferroelectric foam with PZT particles was prepared using PDMS silicone compound. MRE with iron and barium ferrite particles were used as fillers of the foams. Samples of two types of MRE and filled foam without PZT particles were also investigated as reference samples. Magnetic properties of the samples were investigated using vibrating sample magnetometer LakeShore 7400 Series in the magnetic field range ±16 kOe. For the measurement of magnetoelectric transformation experimental setup was additionally provided with high voltage power supply. Magnetization curves were measured under the applied electric field in the range 0-5kV/mm. Measurements were carried out in parallel and perpendicular mutual orientations of magnetic and electric fields. Samples of four-component composites demonstrated the magnetoelectric transformation. Rearrangement of ferroelectric particles in the foam under electric field leads to the deformation of pore walls. This deformation induces mechanical stresses in the MRE filling the foam. Then the reverse magnetodeformational effect appears as a change in sample magnetization. Thus, composite structure on the basis of ferroelectric foam demonstrates mulltiferroic properties and can be developed for further improvement of the observed effects.