DC electrical conductivity of nanocrystalline Mn₃O₄ synthesized through a novel sol-gel route

Manganese oxides have generated considerable interest in recent years due to their electronic and magnetic properties with potential industrial applications. Among manganese oxides, Mn₃O₄ is one of the stable oxides with normal spinel structure and it has variety of important applications. In the present work nanocrystalline Hausmannite, Mn₃O₄ with phase purity and average crystallite size of 8 nm was synthesized through a novel sol-gel route at a temperature of 0-5°C. The samples were annealed at different temperatures to understand the thermal stability and the structural characterization was done using techniques such as X-ray powder diffraction (XRD), Transmission Electron Microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FTIR). The UV visible absorption spectra of the samples show that there are two types of transitions corresponding to Mn²⁺ ions and Mn³⁺ ions. The dc electrical conductivity of the samples increases in comparison with that of bulk.