Synthesis of nanocrystalline NiCuZn ferrite powders by sol–gel auto-combustion method

A nitrate–citrate gel was prepared from metal nitrates and citric acid by sol–gel process, in order to synthesize Ni 0.25Cu 0.25Zn 0.50Fe 2O 4 ferrite. The thermal decomposition process was investigated by DTA-TG, IR and XRD techniques. The results revealed that the nitrate–citrate gel exhibits self-propagating combustion behavior. After combustion, the gel directly transformed into single-phase, nano-sized NiCuZn ferrite particles with spinel crystal structure. The synthesized powder can be densified at a temperature lower than 900°C. The sintered body possesses fine-grained microstructure, good frequency stability and high-quality factor compared to the sample prepared by conventional ceramic route.