Enhanced dielectric properties of poly(vinylidene fluoride)–surface functionalized BiFeO₃ composites using sodium dodecyl sulfate as a modulating agent for device applications

Abstract

In this work, we prepared a series of poly(vinylidene fluoride) (PVDF)-Surface functionalized BiFeO 3 (h-BFO)-Sodium dodecyl sulfate (SDS) composite films by solvent casting method to investigate the effect of SDS in the composites. The X-ray diffraction confirmed that the structure of h-BFO significantly changed in the PVDF-(h-BFO)-SDS composite in comparison with the rhombohedral structure of pure BiFeO 3 . The microscopic study illustrated that the composite with a higher percentage of SDS content facilitated the dispersion as well as proper distribution of ceramic particles in the polymer matrix. The presence of different functionalities of respective polymer and the modified fillers was confirmed by FTIR Spectrophotometer. The dielectric and electrical study done by Impedance Analyzer revealed that the SDS treated surface functionalized composites showed relatively higher dielectric properties than that of two phase composites and pure polymer. Finally, the ferroelectric properties of the composite films done by P-E loop tracer revealed that the SDS-treated composites showed an enhanced remanent polarization.

Dielectric Behavior and Electro-Magnetic Coupling at Room Temperature in BiFeO3/PVDF and CoFe2O4/PVDF Composites

“…Note that for reported data in Figures 4 and 5, the largest electric field obtained was only 6 kV/cm, actually. These values are similar to that used in the recent article by Mishra et al 32 To reach larger fields it is necessary to use kilovolt sources or to reduce the thickness up to orders of 100 nm. However, it must be noted that, in the present system, it is not straightforward to obtain P−E curves where coercitivity and saturation can be observed.…”

“…This is in agreement with the possibility of large size effects in these composites, with a possible change of regime form negative magnetostriction for monocrystals to positive magnetostriction for aggregates. In fact, important effects on the P – E plots of functionalized BiFeO 3 /PVDF have been recently reported by Mishra et al which may be associated with size and charge distributions of the dispersed filler.…”