Evaluation of (BH)max and magnetic anisotropy of cobalt ferrite nanoparticles synthesized in gelatin

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]O-4 and (Co0.06Fe0.94)[Co0.94Fe1.06]O-4, respectively. The particle sizes varied from 73 to 296 nm and the magnetocrystalline anisotropy, K-1, has values ranging from 2.60 x 10(6) to 2.71 x 10(6) J/m(3), as determined from the law of approach to saturation applied to the M x H data at high field. At 5 K, the saturation magnetization, coercive field and (BH)(max) varied from 76 to 95 Am-2/kg, 479.9 to 278.5 kA/m and 9.7 to 20.9 kJ/m(3), respectively. The reported values are in good agreement with near-stoichiometric cobalt ferrite samples. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.