Structural electrical and dielectric properties of hexa ferrite based polymer composite

Abstract

newline In the present time, polymer based composites have attracted significant attention newlinein electrical industries due to their versatile application such as energy storage devices, newlineportable electronics, hybrid electrical vehicles, redder, electro-optical, sensor etc. These newlinepolymer composites are good candidate for potential applications in the manufacture of newlinethe electrical devices because of their good mechanical strength, high break down newlinestrength, ease of processing and low cost but low dielectric constant. newlineThe present thesis reports on the research dealing with the fabrication and newlinecharacterization of ferrite based polymer composites. Highly flexible inorganic organic newlinecomposite films of barium hexaferrite [BaFe12O19,BHF] and/or strontium hexaferrite newline[SrFe12O19,SHF] particles with different polymer matrix such as Ethylene vinyl newlineacetate(EVA),Styrene butadiene rubber (SBR) Ethylene-propylene-diene terpolymer newline(EPDM) and poly vinylidene fluoride(PVDF) polymer have been prepared with different newlineweight percentage by adopting cost effective solution casting method. The phase newlineformation of inorganic fillers BHF and SHF were confirmed by X-ray powder diffraction newline(XRD)analysis, the cell parameters of these phases were refined by Rietveld refinement newlinetechnique. The uniform distribution of fillers in the polymer matrix was ascertained by newlinethe scanning electron microscope (SEM). The dielectric and electrical measurement of newlinethe samples were conducted in the frequency range 1 kHz to 1 MHz. The frequency newlinedependence dielectric study was explained on the basis of polarization mechanism and newlineMaxwell-Wagner theory. A systematic investigation of the dielectric behavior i.e.; and#949; newline(dielectric permittivity), tan and#948; (dielectric loss), M and M (dielectric modulus) and and#963;ac newline(electrical conductivity) were reported. The interaction between fillers and polymer in newlinethe composite films has been studied by FTIR and UV-Visible analysis. The TGA newlinethermo gram of polymer composites indicates the thermal resistance of the material newlineincreases due to the filler content. The kinetics of thermal degradation of the composites newlinewere carried out by the popular Coats-Redfern method. The kinetic parameters of the newlinedegradation process such as order of reaction, Arrhenius constant and the activation newlineenergy (Ea) were also reported. With light weight and improved electric and dielectric