Microstructural characterization and electrical conductivity of CuxMn3−xO4 (0.9≤x≤1.3) spinels produced by optimized glycine-nitrate combustion and mechanical milling processes

The optimized GNP-mechanical milling process was then applied on CuxMn3−xO4 (0.9≤x≤1.3) spinels to probe the effect of copper content on electrical conductivity. In this case, all stoichiometries were sintered at 1250 °C for 2 h. The results showed that the conductivity increases from 52 to 140 S cm−1 by increasing the copper content in the range of 0.9≤x≤1.3 at 750 °C. This arises from a gradual increase in Mn3+-Mn4+ octahedrally located ion pairs.