Study of structural and D.C. electrical properties of Mn-Ni nanoferrites for electrical energy storage applications

Mn-Ni nanoferrite system (MnxNi1-xFe2O4) was synthesized by co-precipitation method followed by heat treatment at 500°C. In order to search for microwave radar frequency applications, the ferrite samples are analyzed for their structural and electrical properties as a function of substitution of Mn2+. The substitution of Mn2+ promotes the increase in crystallite size and lattice parameter. It was observed that the D.C electrical resistivity of the sintered samples decreases over a temperature range of 303 K – 423 K (30°C - 150°C) indicating semiconducting behavior of samples. The Curie temperatures (TC), which indicates transition of magnetic order from ferromagnetic to paramagnetic order. The activation energy (ΔE) for the thermally activated hopping process, which specifies the energy required for the charge carriers for hopping process, was also observed to be decreasing. These materials can be used to store electrical energy such as capacitors because of their dielectric nature.