Simple Preparation of Carbon-coated Iron Particles Having High Iron Content

Carbon-coated iron materials were synthesized by a pyrolysis method using FeCp 2 and Fe(CO) 5 /di-n-propyl-amine (DNPA) as starting materials. It was found that the Cp group was pyrolyzed to form carbon structure, whereas almost all of the CO group disappeared during pyrolysis and only DNPA could be an origin of the carbons. As a result, in the FeCp 2 -derived particles, the carbon yield was as high as 92.7% and iron content was 32.5%. In the Fe(CO) 5 /DNPA-derived particles, while the iron content was as high as 87%, the yield was only 16.2%. The structural and magnetic properties of these as-made materials suggest that α-Fe particles (5-20 nm), possibly forming the magnetic field, were covered with thick carbon layer having external particle size of ca. 0.5-1 μm. There were no iron species such as γ-Fe, FeC and Fe 2 O 3 formed in the pyrolysis conditions employed.