Effect of ultrasonication on particle size and magnetic properties of polyaniline NiCoFe2O4 nanocomposites

• An auto-combustion method support to prepare less size of particles.
• Nature of the samples was influenced by sonication.
• The longer time of ultrasonic treatment in increased viscosity of polymer mixture.

Polyaniline nanocomposites (PANI/NiCoFe2O4) have been synthesized by in-situ chemical polymerization of aniline in the presence of NiCoFe2O4 nanoparticles (20%, 10% w/w of fine powders) with and without ultrasonic treatment. The average particle size of NiCoFe2O4 synthesized by auto-combustion method is 32 nm. The particle size of the PANI nanocomposites synthesized vary in the range of 24–41 nm. The structure, morphology and magnetic properties of PANI and nanocomposites are characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM) and Vibrating sample magnetometer (VSM). The nanocomposites are further characterized by Fourier transform infrared spectra (FTIR), Thermogravimetric analysis (TGA) and second harmonic generation (SHG) activity. The nature of PANI/NiCoFe2O4 is visualized through the SEM and TEM images and also the presence of NiCoFe2O4 on PANI is confirmed with FTIR spectra. XRD patterns of NiCoFe2O4 have higher intense diffraction peaks than PANI/NiCoFe2O4 nanocomposites. Hysteresis measurements revealed that the saturation magnetization (Ms) increases with increase in ferrite content whereas, coercivity decreases. Ferromagnetic nature of PANI/NiCoFe2O4 nanocomposites are confirmed by VSM. FTIR investigation indicates that the main absorption peaks corresponding to the spinel structure appeared at around 600 cm−1; it is due to the NiCoFe2O4 tetrahedral and octahedral stretching vibrations.