Particle-Size Distribution of CoFe2O4 Formed by the Coprecipitation Method

The particle size distribution of CoFe2O4 formed by the coprecipitation method was investigated by x-ray diffraction and electron microscopy. In the x-ray diffraction method, 〈110〉 column length distributions were calculated by Warren's procedure. A particle size distribution was obtained from the 〈110〉 column length distribution by assuming that each particle was a spherical crystallite. The particle size distribution of CoFeO4 formed at 100°C covered a range of 0–350 Å and showed a maximum at 180–200 Å on volume base. From changes of the 〈110〉 column-length distribution by heat treatments, it was suggested that crystal growth of smaller particles was noticeably advanced at a temperature of 300°–400°C. The above results were supported by electron microscopy.