Impedance and modulus spectroscopy of ZrO2-TiO2-V2O5 nanocomposite

High-k ZrO2-V2O5-TiO2 nanocomposite prepared by coprecipitation-calcination method was investigated by impedance and modulus spectroscopy over a frequency range of 50 Hz-5 MHz, for different temperatures. Distinct peaks at characteristic frequencies were obtained. The shifting of the peaks towards high frequency with increase in temperature indicated a temperature dependent relaxation in the nanocomposite. Complex impedance formalism showed that the maximum value of the impedance decreases as temperature increases suggesting that the sample had negative temperature coefficient of resistance. The electric analysis confirms the findings of the impedance analysis. The fmax values for Z″ and M″ are different confirming non-Debye type of relaxation. The values of activation energies based on impedance and modulus relaxation were calculated and were equal to 1.02 eV and 0.51 eV respectively.