Temperature and frequency dependence of the dielectric and piezoelectric response of P(VDF–TrFE)/CoFe2O4 magnetoelectric composites

Abstract

CoFe 2 O 4 nanoparticles embedded in polyvinylidene fluoride-trifluoroethylene (P(VDF-TrFE)) matrix show suit able properties for practical applications as piezoelectric and magnetoelectric transducers. The knowledge about the dielectric and electromechanical responses of the multiferroic films in a broad frequency and temperature range is essential for applicability. The purpose of this work is to investigate the dielectric, ferroelectric and piezoelectric properties of multiferroic composites based on P(VDF-TrFE) as a host matrix and Co 2 FeO 4 as a magnetic filler. Free-standing films with a different concentration of the filler were investigated. The polarization switching was demonstrated for all the compositions. The polarization displacement hysteresis was achieved at different temperatures. The piezoelectric coefficient d 33 is not affected by different concentration of ferrite. On the other hand, the composition with the largest weight % of Co 2 FeO 4 shows higher coercive fields which is not favourable for applications. This indicates that the optimal content of the filler must be determined and taken into account when optimizing both ferroelectric and magnetoelectric properties.

Functional properties of PVDF-based NZF-BT flexible films

“…2. Two overlapped peaks can be distinguished in the real part of the complex dielectric permittivity data of all compositions above 200 K. At lower temperatures, the dielectric dispersion tends to decrease to a value less than 10 and dielectric losses go to zero for all the composite films measured, in agreement to previous investigations of PVDF-based composites [22,[28][29][30].…”

Thin-Film Polymer Nanocomposites for Multiferroic Applications

“…Recently, nanocomposites wherein P­(VDF-TrFE) is mixed with magnetic or nonferroelectric particles have been suggested for multiferroics applications. − P­(VDF-TrFE) is a fully saturated hydrocarbon compound, with no remanent magnetization. Numerous reports have been published on P­(VDF-TrFE):magnetic nanoparticle multiferroic composites. ,,,, For the magnetic properties, the reported nanocomposites show, as they should, a linear increase in saturation magnetization with the increasing amount of the nanoparticle loading.…”