Synthesis of Monodisperse Iron Nanoparticles with a High Saturation Magnetization Using an Fe(CO)x-Oleylamine Reacted Precursor

Monodisperse Fe nanoparticles with a high saturation magnetization were synthesized by thermal decomposition of a newly developed Fe(CO)(x)-oleylamine reacted precursor. The coordinate bond of the Fe(CO)(x)-oleylamine reacted precursor is different from conventional Fe(CO)(5), and the CO ligands are partially replaced by oleylamine. The coordinate bond of the Fe(CO)(x)-oleylamine reacted precursor had a large influence on the size of the Fe nanoparticles, and as a result, the nanoparticle diameter could be controlled in the range from 2.3 to 10 nm by changing the reaction temperature and time for the precursor. The saturation magnetizations for 10 and 2.3 nm diameter NPs were 192 and 160 emu/g(Fe) at 5 K. The high M-S of the Fe NPs was attributed to lesser amounts of impurities, such as C and O.