In-situ Synthesis and Characterization of Polyaniline/Nickel Ferrite Hybrid Nanocomposites: Tailoring Dielectric and Magnetic Properties

This study elucidates the synthesis of polyaniline/nickel ferrite (PANI/NF) hybrid nanocomposites (NCs) via in-situ chemical oxidative polymerization, incorporating nickel ferrite (NF) at different weight fractions (5%, 10%, and 20%) into the PANI matrix. Extensive characterizations of the structural, optical, morphological, dielectric, and magnetic properties of the PANI/NF composites were conducted. X-ray diffraction (XRD) analysis verified the homogeneous dispersion of NF nanoparticles within the PANI matrix. Fourier-transform infrared (FTIR) spectroscopy identified potential interactions between the PANI macromolecules and NF nanoparticles. Ultraviolet-visible (UV-Vis) optical absorption spectroscopy revealed a decrease in both direct and indirect optical band gaps of the PANI/NF composites with increasing NF content. Scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX), along with Field Emission Scanning Electron Microscopy (FESEM), confirmed the effective incorporation of NF into the PANI matrix. Dielectric measurements were performed to assess the real (K') and imaginary (K'') components of dielectric permittivity, dielectric loss tangent (tan delta), and AC conductivity (sigma ac) as functions of frequency and composition. Nyquist plots of the samples exhibited a depressed semi-circle, indicating a non-Debye capacitive nature. The AC conductivity of PANI and its composites increases with frequency, following Jonscher's universal power law. The improved conductivity of PANI with the addition of NF correlates with a decrease in the band gap. Magnetic characterization, through magnetization curves, compared pure PANI with PANI/NF composites, demonstrating the potential for tuning the magnetic properties of PANI by controlled NF integration during polymerization. The results suggest significant interfacial interactions between the polymer matrix and NF nanoparticles within the NCs, leading to modified dielectric and magnetic properties. The ability to precisely engineer the properties of the NCs through varying proportions of PANI and NF nanoparticles highlights the innovative potential of these materials in advanced technological applications. This study markedly advances the field of conducting polymer-ferrite composites, providing a foundation for novel applications in diverse technological domains.