Optimizing piezoelectric and magnetoelectric responses on CoFe₂O₄/P(VDF-TrFE) nanocomposites

Abstract

Magnetoelectric nanocomposite films composed of magnetostrictive CoFe 2 O 4 nanoparticles with sizes between 35 and 55 nm embedded in P(VDF-TrFE) have been successfully prepared by a solvent casting method. The ferroelectric, piezoelectric, magnetic and magnetoelectric properties of the nanocomposite and their variation with the wt% of the ferrite filler, thickness of the composite and direction of the applied magnetic field have been investigated. Ferroelectric and piezoelectric properties are improved when small amount of ferrite nanoparticles were added to the polymeric matrix. Magnetic properties vary linearity with ferrite content. The highest magnetoelectric response of 41.3 mV/cmOe was found in the composite with 72wt% when a 2.5 kOe DC field was transversely applied to the sample surface. This value is among the highest reported in two phase particulate polymer nanocomposites. Thickness of the composite has no influence in the magnetoelectric response, allowing tailoring sensor thickness for specific applications. The good value of the magnetoelectric coefficient and the flexibility of the films make these composites suitable for applications in magnetoelectric smart devices.

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

“…Resulting from these interesting properties, the high ME coupling of ferrite-PVDF composites has been already reported and often discussed [2,[14][15][16].…”

“…Concerning the magnetostrictive phase of polymer-based ME composites, CoFe 2 O 4 has been preferably used due to its large magnetostrictive coefficients, high Curie temperature and chemical stability 14,15]. Resulting from these interesting properties, the high ME coupling of ferrite-PVDF composites has been already reported and often discussed [2,[14][15][16].…”

Osteoblast, fibroblast and in vivo biological response to poly(vinylidene fluoride) based composite materials

“…The preparation of the most recent PVDF-based composites aims to improve the polymer piezoelectric properties and/or to add new and interesting properties for distinct applications. In particular, the addition of magnetic nanoparticles allows to obtain magnetoelectric and multiferroic composites for sensors and cell stimulation [9]; the addition of Ag particles allows larger dielectric response and antimicrobial properties [10]; the zeolites addition allows increasing dielectric properties, functional properties, and controlled drug release [11]; the ceramic fillers to improve electroactivity [12] and the addition of carbon nanotubes increases dielectric and mechanical properties [13]. On the other hand, once fillers have been introduced into the polymer matrix, biomaterial-cell interaction is modified and novel bioactivity or even suppression of biocompatibility can occur [14,15].…”

Magnetoelectric polymer nanocomposite for flexible electronics

“…A high ME response of 156 mV/cmOe was measured under 3.1 kOe DC bias field. This value is considered among the highest reported for two phase particulate polymer nanocomposites, 1,3 and it is attributed to the large interfacial area between the NWs and the polymer. The ME response curve also shows that the ME coupling is driven by a strain mediated effect and is mainly due to strain transfer caused by the non-linear magnetostriction effect of the Fe NWs.…”

“…% of CoFe 2 O 4 at 2.5 kOe DC bias magnetic field. 3,4 In this kind of multiferroic nanocomposites, the effective coupling properties are strongly dependent on the characteristics of the interface between the polymer and the ferromagnetic fillers. Surface interfacial area to volume ratio is a key factor and therefore high aspect ratio ferromagnetic nanostructures are preferred over spherical nanoparticles.…”