Hybrid nickel ferrite nanotubes doped polyaniline nanocomposite and its dielectric properties.

Nanotubes of nickel ferrite were prepared by citrate method and were used in nanocomposite synthesis via in situ polymerization technique. The structural and surface morphology characterization was carried out by FTIR, XRD, and SEM techniques. FTIR spectra show the characteristic peaks of benzenoid ring, quinoid ring, and nickel ferrite stretching of tetrahedral and octahedral sites. XRD pattern shows that NiFe2O4 nanotubes has a cubic spinal structure and remains undistorted even after dispersion in polyaniline matrix. The SEM image of 15% wt nanocomposite shows that the polyaniline coated nickel ferrite nanotubes form a length about 100 nm. Furthermore, the DC conductivity shows three steps conductivity feature and among all prepared nanocomposites, 15% wt one shows high conductivity of 1.89 S/cm. This is due to high absorption of activation energy 0.213 × 10−2 J/mol and elongation of nanocomposites chain length which is confirmed from the negative thermal coefficient graph. The VSM study shows the saturation magnetization decrease after formation of polyaniline nanocomposite. The dielectric properties were analyzed by impedance analyzer and it was found that 15% wt nanocomposite shows the lowest dielectric constant and dielectric loss as a result of high ac conductivity of about 1.32 S/cm which is due to sharp drop in bulk resistance and low relaxation time of 0.1375 µsec as evidenced from cole–cole plot. [ABSTRACT FROM AUTHOR]