Magnetic Investigation of CoFe $_{2}$ O $_{4}$ Nanoparticles Supported in Biocompatible Polymeric Micr

Magnetic investigation of spinel ferrite nanoparticles dispersed in biocompatible polymeric microspheres is reported in this study. X-ray diffraction data analysis confirms the presence of nanosized CoFe₂O₄ particles (mean size of ~8 nm). This finding is corroborated by transmission electron microscopy micrographs. Magnetization isotherms suggest a spin disorder likely occurring at the nanoparticle´s surface. The saturation magnetization value is used to estimate particle concentration of 1.6times10¹⁸ cm^-3 dispersed in the polymeric template. A T^1/2 dependence of the coercive field is determined in the low-temperature region (T < 30 K). The model of non-interacting mono-domains is used to estimate an effective magnetic anisotropy of K_eff = 0.6times10⁵ J/m³. The K_eff value we found is lower than the value reported for spherically-shaped CoFe₂O₄ nanoparticles, though consistent with the low coercive field observed in the investigated sample.