Ferroelectric and magnetic studies on unpoled Poly (vinylidine Fluoride)/Fe3O4 magnetoelectric nanocomposite structures

Multifunctional nanocomposites of poly(vinylidene fluoride) reinforced by carbon nanotubes and magnetite nanoparticles

“…Figure 5a presents hysteresis loops as recorded at room temperature for polymer nanocomposites, including CNT and Fe 3 O 4 nanoparticles. The hysteresis loops confirm the ferromagnetic behavior of nanocomposites, which is attributed to magnetic nanoparticle content [13]. This magnetic behaviour is also observed in other similar composites systems [14].…”

“…phase of PVDF appearing at 2% = 17.8, 18.5, 20 and 26.8°, are assigned to the lattice planes of (100), (020), (110) and (021) respectively [30]. Furthermore, for samples containing Fe 3 O 4 the diffraction peak at 30.6°a re assigned to Fe 3 O 4 crystalline plane of (220) [13]. In fact, with the increase in the addition of Fe 3 O 4 , the peak becomes increasingly prominent.…”

“…For pristine PVDF a main peak around 173°C and a shoulder around 166°C were observed. The existence of double melting peak is generally attributed to the presence of crystallites of different thickness, variety of crystallites perfection, re-melting of crystallites formed during heating or existence of polymorphism [13]. When the samples were cooled from the melt, a single crystallization peak was found and the crystallization temperature, T c , of pure PVDF was observed at 138°C.…”

“…In composite films of PVDF/Fe 3 O 4 which are fabricated by solvent casting method, it was found that the inclusion of nanosized Fe 3 O 4 significantly enhances the crystallinity of PVDF and the ! phase content [13]. Also, increased crystallinity enhances the ferrimagnetic properties of these composites whereas the latter improves the thermal stability and polarization effects.…”

Magnetoelectric coupling in Fe 3 O 4 /P(VDF-TrFE) nanocomposites

“…Thus, the ME coupling is described as an extrinsic product property since neither phase (piezoelectric nor magnetic/magnetostrictive) is magnetoelectric. Intrinsic linear ME effect has been observed in single-phase materials (intrinsic ME effect) such as antiferromagnetic Cr2O3 crystal or multiferroic BiFeO3 compound but the associated ME susceptibilities are low compared to those of laminate composites [22][23][24][25][26][27].Among the piezoelectric compounds some specific functional polymers such as Poly(vinylidine Fluoride) (PVDF) polymer and its copolymer Poly(vinylidene fluride/trifluoroethylene) P(VDF-TrFE) have been widely studied and used as organic matrix in magnetoelectric structures for their interesting ferroelectric properties [7,9,10,11,[20][21][22][23][24][25][26][28][29][30][31][32][33][34]. Although the higher ME coefficients have been reported for ceramic composites [35], an advantage of using P(VDF-TrFE) -Fe3O4 composites is the more simple elaboration process in a various range of shapes and the absence of brittleness.…”