Room Temperature Preparation of Nanocrystalline MnCuZn Ferrite Powder by Auto-Combustion of Nitrate-Citrate Gels

摘要

MnCuZn ferrite powders with particle size about 30nm were directly synthesized by Sol-Gel auto-combustion method at the room temperature. The formation process of the nanocrystallites, including the auto-combustion and thermal decomposition of the precursor, was investigated by DTA-TG and IR. The structure and magnetic properties of the nanocrystalline powders were characterized by XRD and VSM techniques. It is revealed that the precursor nitrate-citrate xero gel exhibits auto-combustion behavior while it is ignited in air at room temperature, and the remainder after the combustion is nanosized MnCuZn ferrite powder with spinel structure. The coercive force H_c is high as compared to reported bulk values. The effect of heat treatment on the magnetic properties of nanoparticles was also studied.