Impedance Spectroscopy in Ni<sub>0.3</sub>Zn<sub>0.7</sub>Fe<sub>2</sub>O<sub>4</sub>

Abstract

Abstract. Impedance spectroscopies were used to investigate the electrical properties of spinel Ni0.3Zn0.7Fe2O4 (NZF) ceramics. Measurement was done using NOVO Dielectric Spectrometer from frequency 0.01 Hz to 3 x 106 Hz at temperature 30°C to 200°C. Resistivity response phenomena had been observed in sample sintered at 1100°C and carriers involved are mainly due to electron hopping mechanism between n-type and p-type carriers. The high and low response of grain and grain boundary regions were determined by plotting imaginary part versus real part of resistivity. An equivalent RC circuit of the experimental result had been constructed using a model that had been proposed by Hill and Pickup (1985). The model consists of parallel combination of 2 Havriliak-Negami (1966) model, resistivity and dielectric constant where ρ = 5.79 x 106 Ωm and ε = 4.45. It is found that 0.40 ± 0.01 eV, 0.14 ± 0.01 eV and 0.13 ± 0.01 eV and 0.38 ± 0.01 eV (extrinsic region) and 0.50 ± 0.01 eV (intrinsic region) for ac and dc activation energy respectively by using Arrhenius plot.