Scaling of electrical relaxation behaviour of polymer mediated spinel Zn Fe2O4

Abstract

Abstract In this work, the synthesis of ZnFe2O4 (ZF) through mediation of different polymers e.g., Polyvinyl alcohol (PVA), Polyvinylpyrrolidone (PVP) and Polyethylene glycol (PEG) were studied. The structural, micro-structural, thermal and dielectric properties were investigated. Structural characterization, XRD through Rietveld refinement confirms its face centred cubic structure. The thermal analysis of ZF through TGA /DSC signified the stability of ZF. FTIR gave the confirmation regarding the functional group associated with ZF. The Dielectric measurements were carried out by varying the frequency from 20Hz to 2MHz, the dielectric constant decreases with increase in frequency & Tanδ shows highly decrement values. The scaling of relaxation behaviour have been rigorously analysed through Impedance, Modulus and Conductivity Spectroscopy in the temperature and frequency range of 30˚C-200˚C, 20Hz - 2MHz respectively. Scaling of parameters shows the temperature independent relaxation behaviour. Modulus spectra verified the KWW function to be prevailing in ZF as function of temperature/frequency. The AC conductivity behaviour is attributed to small polaron hopping & also satisfied with Jonscher’s universal power law. Same Activation energy of around 0.5eV is found from Arrhenius fitting of Impedance, modulus & conductivity variation as a function of temeperature. The non-coincidences of the Nyquist plot of the ZF induced through different polymers confirm the non-Debye relaxation and the distribution of relaxation times being dependent over the various temperature range of study.