Effect of annealing temperature on the magnetic properties of CoFe_2O_4 nanoparticles

摘要

Nanocrystalline CoFe_2O_4 samples were prepared using the flash technique and annealed at different temperatures. X-ray diffraction results indicate a single-phase spinel structure. The saturation and remanent magnetization of the samples have been determined as a function of the crystallite size. An exponential decay of the coercive field with crystallite size is observed. After annealing, one of the samples at 950°C, 40 nm particles were obtained with a saturation magnetization of 64.36 emu/g, a coercivity of 396 Oe and the highest density among all the samples.