Monodisperse Fe nanoparticles, with a size ranging from 4 to 10 nm, have been prepared by the thermal decomposition of Fe carbonyl. The influence of oxidation on the magnetization of Fe nanoparticles has been investigated with changing the concentration of oxygen (O2) gas in the glove box, the oxygen atom (O) in ether and water (H2 O) in the reaction solution. When the concentration of oxygen in the glove box was more than 5000 ppm, a large decrease of the saturation magnetization (Ms) was observed. There was a small decrease of Ms when the O/Fe ratio was more than 10. However, in the present experimental condition, the H2O/Fe ratio from 10-2 to 10-5 had little influence on the decrease of Ms. Ms of Fe nanoparticles was decreased with a smaller particle size. However, Ms of the Fe nanoparticles with the size from 7 to 10 nm showed the size-independent behavior. Such results strongly suggested that the decrease of Ms cannot be explained by these two factors of oxidization and size effect.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering