Structure and Magnetic Properties of Co2.73Fe0.27O4 Synthesized by the Heat-Decomposition Method
Co2.73Fe0.27O4 nanoparticles were synthesized using the heat-decomposition method followed by annealing treatment. X-ray diffraction (XRD) analysis shows that most of the peaks are close to the data for antiferromagnetic Co3O4, while weak peaks of CoFe2O4 are also detected. It indicates that the prepared particles can be reckoned as a composite with a small size of the FM particles embed in a large thickness of the AFM matrix. The magnetic hysteresis loops of Co2.73Fe0.27O4 powders were measured at 10 K by using the zero-field cooling (ZFC) and field cooling (FC) procedures and show negative and downward shifts, and the shifts finally disappear when temperature increases to 200 K. We suggest that exchange bias effect in Co2.73Fe0.27O4 is mainly related with the exchange interactions at the interfaces between the FM CoFe2O4 nanoparticles and the frozen spins around them.
Yuan Ming Huang
Z. H. Gan et al., "Structure and Magnetic Properties of Co2.73Fe0.27O4 Synthesized by the Heat-Decomposition Method", Solid State Phenomena, Vols. 181-182, pp. 352-355, 2012