Structural analysis and dielectric behavior of low-temperature synthesized nickel cobaltite

In this study, we investigated the structural and dielectric properties of nickel cobaltite (NiCo2O4) synthesized via low temperature sol-gel auto combustion method. From the analysis of the XRD pattern of nickel cobaltite samples, we observed that the synthesized samples were pure and exhibited the Fd3m space group, which corresponds to a face-centered cubic crystalline structure. The average d-spacing calculated using Bragg's law measured 2.37 Å. Furthermore, Debye-Scherrer's formula was used to calculate the average particle size, which was found to be 26.80 nm. The dielectric properties of nickel cobaltite were successfully investigated at room temperature. We observed a higher value of dielectric constant at lower frequency (> 3 Hz). As the frequency increased, the dielectric constant rapidly decreased. The Cole-Cole plot of impedance also confirmed the presence of grain boundaries.