Nano-crystalline copper ferrites from secondary iron oxide (mill scale)

Nano-crystalline copper ferrite compacts have been synthesized using mill scale fines via conventional oxide ceramic process. The effects of firing temperatures and time on both physical and magnetic properties of the compacts were studied. Archimedes method as well as the universal testing machine was used for determining the physical properties of the compacts. Meanwhile, the types of phase formed and the magnetic properties of the produced samples were investigated using X-ray diffraction, scanning electron microscope and vibrating sample magnetometer. The results indicated that with a firing temperature of 1100 °C, the compact possesses higher compressive (832 kg/cm2) strength and higher bulk density (3.93 g/cm3), whereas higher saturation magnetization (45.2 emu/g) and lower coercivity (6.13 Oe) were achieved for compacts fired at 1200 °C. The effect of firing time at optimum firing temperature on physical and magnetic properties of the produced compacts seems to be insignificant. The crystal structure of the copper ferrite was transformed from its tetragonal into a cubic structure accompanying the dissociation of a part of the copper ferrite into delafossite at high firing temperature.