Date of this Version
We have prepared and studied iron-oxide nanoparticles coated with oleic acid (OA) and Pluronic® polymer. The mean diameter of the iron-oxide nanoparticles was 9.3(±)0.8 nm. Saturation magnetization values measured at 10 K varied from 66.1(±0.7) emu/g to 98.7(±0.5) emu/g. At 300 K the loops showed negligible coercive field. The peaks in zero-field-cooled susceptibility decreased from 280 to 168 K with increasing OA concentration up to 10.6 wt %, and remained nearly constant for higher concentrations. This suggests that incomplete coverage of the OA allows small, interacting agglomerates to form.