The resistance and the capacitance of ${\mathrm{N}\mathrm{i}}_{0.2}{\mathrm{Z}\mathrm{n}}_{0.8}{\mathrm{F}\mathrm{e}}_2{\mathrm{O}}_4$nanocrystalline ferrite prepared by solid state method were measured as a function of frequency in the range 50 Hz–10 MHz at various temperatures (340 K–600 K). The electrical and dielectric properties of spinel ferrite were determined and studied as a function of temperature. The decrease of real impedance values with the increase in frequency is explained using the model of Maxwell–Wagner interfacial polarization. We found that the relaxation time is strongly dependent on frequency and temperature. The impedance plane plots present three semicircle arcs associated to three different relaxation phenomena. Electrical equivalent circuit was determined to explain the dielectric measurements. Activation energies determined from both dc resistance and distribution of the relaxation times are similar. Frequency and temperature dependency of the giant dielectric constant values have been discussed using the model of charge carrier hopping.

的电阻和电容 ${\mathrm{ñ}\mathrm{一世}}_{0.2}{\mathrm{ž}\mathrm{ñ}}_{0.8}{\mathrm{F}\mathrm{Ë}}_2{\mathrm{Ø}}_4$在各种温度（340 K–600 K）下，通过固态方法制备的纳米晶铁氧体均作为频率在50 Hz–10 MHz范围内的函数进行测量。确定并研究了尖晶石铁氧体的电和介电性能随温度的变化。麦克斯韦-瓦格纳界面极化模型解释了实际阻抗值随频率增加而降低的情况。我们发现，弛豫时间在很大程度上取决于频率和温度。阻抗平面图显示了与三个不同的松弛现象相关的三个半圆弧。确定等效电路以解释介电测量。由直流电阻和弛豫时间分布确定的激活能量是相似的。