Structural, magnetic and dielectric properties of polyaniline/MnCoFe2O4 nanocomposites

•An auto-combustion method support to prepare less size of particles.•The particle size influences more on dielectric property.•Effect of ultrasonication on the PANI/MnCoFe2O4 was also investigated.

Ferromagnetic PANI containing MnCoFe2O4 nanocomposites were synthesized by in-situ chemical polymerization of aniline incorporated MnCoFe2O4 nanoparticles (20%, 10% w/w of fine powders) with and without ultrasonic treatment. The MnCoFe2O4 nanoparticles were synthesized by auto combustion method. The PANI/MnCoFe2O4 nanocomposites were characterized with Fourier transform infrared (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The average particle size of the resulting PANI/MnCoFe2O4 nanocomposites was confirmed from the TEM and XRD analysis. The structure and morphology of the composites were confirmed by FT-IR spectroscopy, XRD and SEM. In addition, the electrical and magnetic properties of the nanocomposites were investigated. The PANI/MnCoFe2O4 nanocomposites under applied magnetic field exhibited the hysteresis loops of ferromagnetic nature at room temperature. The variation of Dielectric constant, Dielectric loss, and AC conductivity of PANI/MnCoFe2O4 nanocomposites at room temperature as a function of frequency in the range 50 Hz–5 MHz has been studied. Effect of ultrasonication on the PANI/MnCoFe2O4 nanocomposites was also investigated.