Influence of n-type nickel ferrite in enhancing the AC conductivity of optimized polyaniline-nickel ferrite nanocomposite

• Published in: Applied physics. A, Materials science & processing Vol. 123; no. 4; pp. 1 - 10
• Main Authors: Megha, R., Ravikiran, Y. T., Vijaya Kumari, S. C., Thomas, S.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.04.2017; Springer Nature B.V
• Subjects: Applied physics; Characterization and Evaluation of Materials; Charge transport; Condensed Matter Physics; Distribution functions; Electron diffraction; Fourier transforms; Heterojunctions; Image transmission; Infrared spectroscopy; Machines; Manufacturing; Materials science; Nanocomposites; Nanotechnology; Nickel ferrites; Normal distribution; Optical and Electronic Materials; Particulate composites; Physics; Physics and Astronomy; Pi-electrons; Polyanilines; Processes; Scanning electron microscopy; Sol-gel processes; Surfaces and Interfaces; Thin Films; X-ray diffraction; PANI; Ferrite; Nickel Ferrite; Ferrite Particle; PANI Chain
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-017-0866-9

In the present work, n-type nickel ferrite (NF) particles prepared by sol gel autocombustion method were used to synthesize optimized polyaniline-nickel ferrite (PANI-NF) nanocomposite by in situ polymerization method. Then, NF, PANI and the composite were structurally characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Improved π -electron delocalization in PANI-NF composite as compared to that in PANI was confirmed from FTIR analysis. Interfacial interaction between PANI and NF was confirmed from XRD studies. Highly agglomerated, more densely packed particles of the composite facilitating easier charge transport were confirmed from SEM image. Transmission electron microscopy (TEM) image was analysed to calculate accurate average particle size of the composite by fitting the data to log-normal distribution function. Crystalline nature of the composite was confirmed from selected area electron diffraction (SAED) analysis. Remarkable increase in AC conductivity of the PANI-NF composite as compared to that of PANI due mainly to the formation of interfacial heterojunction barrier between p-type PANI and n-type NF was confirmed experimentally and well supported theoretically by calculating binding energy, hopping distance and density of states at Fermi level as per correlated barrier hopping (CBH) model.