Study of Structural, Electrical, and Dielectric Properties of Hexaferrite-PANI Nanocomposites

Y-type hexaferrite with nominal composition SrCa0.5Ba0.5ZnNiGa0.4 Fe11.6O22 was prepared by sol-gel technique. Conducting polymer, polyaniline was synthesized by chemical polymerization method, and Ferrite-Polyaniline composites with 20 % ferrite (C1), 30% ferrite (C2), and 40% (C3) ferrite were prepared by mechanical blending. The synthesized samples were characterized by XRD, electrical resistivity, and dielectric measurements. At room temperature, the dc resistivity of pure PANI is very low but the resistivity of nanocomposites C1, C2, and C3 increases due to random distribution of ferrite filler particles. The crystallite size was obtained using the Scherrer formula ~ 21.23nm. The permittivity of ferrite-PANI composites is high at lower frequencies due to effective grain boundary contribution and it decreases with the increase in frequency due to conducting grains following the Maxell Wagner model. The variation in the imaginary part of the dielectric constant and loss tangent with frequency also showed similar behavior. The increase in resistivity and decrease in dielectric constant as a function of composition in nanocomposites make them potential candidates for recording media and chip inductors.