  CoFe2O4 nanoparticles were synthesized using gelatin as a polymerizing agent.
Structural, morphological and magnetic properties of samples treated at
different temperatures were investigated by X-ray diffraction, scanning
electron microscopy, Mossbauer spectroscopy and magnetization measurements. Our
results revealed that the samples annealed at 623 K and temperatures above 973
K have a cation distributions given by (Co0.19Fe0.81)[Co0.81Fe1.19]O4 and
(Co0.06Fe0.94)[Co0.94Fe1.06]O4, respectively. The particle sizes varied from 73
to 296 nm and the magnetocrystalline anisotropy, K1, has values ranging from
2.60x10^6 to 2.71x10^6 J/m3, as determined from the law of approach to
saturation applied to the MxH data at high field. At 5 K, the saturation
magnetization, coercive field and (BH)max varied from 76 to 95 Am2/kg, 479.9 to
278.5 kA/m and 9.7 to 20.9 kJ/m3, respectively. The reported values are in good
agreement with near-stoichiometric cobalt ferrite samples.
