Electrical relaxation dynamics in EVA/BaFe₁₂O₁₉ copolymer composites

Organic inorganic polymer systems were synthesized using ethylene–vinyl acetate copolymer (EVA) as polymer matrix and barium hexa-ferrite (BFO: BaFe₁₂O₁₉) as the inorganic phase by adopting solution casting procedure to ensure better dispersion. The BFO ferrite was first synthesized by the popular sol–gel combustion technique via urea root with ethylene glycol as gelation agent. Rietvelt analysis is performed for the phase quantification, structure refinement of BFO with the XRD diffraction patterns. Once the structure of the BFO is confirmed 0 wt%, 2.5 wt%, 5 wt% and 10 wt% of EVA/BFO polymer inorganic systems were synthesized for the dielectric and electrical investigation in the frequency range 100 Hz–1 MHz. A detailed analysis of the dielectric behavior of the above composites such as dielectric permittivity, dielectric loss tangent (tan δ), dielectric modulus spectra, impedance spectra and electrical conductivity is being reported in this communication. The 5 wt% of BFO in EVA/BFO polymer composite displayed interesting properties than the other wt% composites namely it has high dielectric constant and it showed the relaxation phenomenon in the temperature range of 70–85 °C. The capacitance and resistance values were derived from the simulation of the Nyquist plots with the help of an electrical circuit.