MgCo₂O₄ a spinel ceramic was studied by complex impedance spectroscopy. The measurements were performed in the temperature and frequency ranges 83 to 323 K and 40 Hz to 1 MHz, respectively. The decreasing trend in Nyquist plots semicircles was observed as a function of temperature indicating the distribution of different relaxaion processes. Two equivalent circuit models (R_gC_g)(R_gbQ_gb) below 173 K and above this temperature (R_g)(R_gbQg_b) were applied to fit the impedance data. The values obtained for R_gb and R_g from these model fitting displayed semiconducting like behavior in the material. The variable range hopping model was employed to explain electrical conduction mechanism of grains and grain-boundaries. The complex modulus analysis asserted the contribution of both bulk and grain boundaries in electrical conductivity at low temperatures. The frequency dependent ac-conductivity followed the universal Jonscher's power law. The frequency exponent n showed a decreasing trend with increasing temperature. The ac-conductivity data was further elaborated by Correlated Barrier Hopping Model (CBH).

用复阻抗谱研究了MgCo ₂ O ₄尖晶石陶瓷。测量分别在温度和频率范围83至323 K和40 Hz至1 MHz内进行。奈奎斯特曲线半圆的下降趋势是温度的函数，表明了不同弛豫过程的分布。低于173 K且高于该温度（R _g）（R _gb Qg _b）的两个等效电路模型（R _g C _g）（R _gb Q _gb）用于拟合阻抗数据。R _gb和R _g的值这些模型拟合显示出材料中的半导体行为。利用变程跳跃模型来解释晶粒和晶界的导电机理。复模量分析表明，在低温下，晶界和晶界都对导电性有贡献。随频率变化的导电率遵循通用的Jonscher幂定律。频率指数n随温度升高呈下降趋势。交流电数据由相关的势垒跳跃模型（CBH）进一步阐述。