FEM‐analysis of a multiferroic nanocomposite – comparison of experiment and numerical simulation

Abstract

AbstractThe combination of electric and magnetic materials opens new possibilities in the field of sensor technologies and data storage [1]. These magneto‐electric (ME) materials have the property to change a physical ferroic quantity into another, i.e. a magnetic field can change the electric polarization and vice versa. The combination of multiple ferroic characteristics within materials is called multiferroic. Since magneto‐electric single‐phase materials are rare in nature and typically operate only at very low temperature, they are not favorable in technical applications. However, ME composites, consisting of ferroelectric and ferromagnetic phases, produce a strain‐induced magneto‐electric product property at room temperature [2]. In these composites, two different effects can be differentiated, the direct and the converse ME effect. The first one describes a polarization which is magnetically caused. In detail, a magnetic field is applied which produces a deformation of the magneto‐active phase which is transferred to the electro‐active phase and as a consequence this phase exhibits a polarization. Therefore, one can discover a strain‐induced polarization. The second effect to observe is a magnetization caused by an electric field. In our contribution, we focus on a (1‐3) composite, where cobalt ferrite nanopillars are embedded in a barium titanate matrix, see the experiments described in [3]. In the numerical simulations we compare the changes of the strain‐induced inplane polarizations of the ferroelectric matrix with experimental measurements. Furthermore, we analyze the magneto‐electric coupling coefficient. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)