AC conductivity and dielectric properties of MnO₂ nanostructures prepared at different temperatures

Abstract An aqueous KMnO4 solution and ethylene glycol were used through the simple in situ redox interaction that was carried out under ambient conditions to create manganese dioxide (MnO2) nanostructures. The as-prepared MnO 2 nanostructures are amorphous. After heating at different calcination temperatures, the amorphous MnO 2 nanostructures converted into crystalline MnO 2 nanostructures. Scanning electron microscopy and powder x-ray diffraction were used to characterize the synthesized MnO2 nanostructures. Also, their AC impedance spectroscopic properties were investigated. PXRD analysis measurement reveals that the crystallinity of the sample increased upon heating MnO2 nanostructures from 200 to 500 °C. In addition, notable changes in morphologies have been observed. The AC electrical conductivity and dielectric properties are measured for all MnO 2 nanostructures in the 10 Hz to 100 MHz frequency range at environs conditions. The behavior indicates the increase in conductivity of α -MnO 2 sample prepared at high temperature with increased frequency dependence.