Preparation and magnetic behavior of carbon-encapsulated iron nanoparticles by detonation method

Carbon-encapsulated iron (Fe@C) nanoparticles with core/shell structure have been successfully synthesized by detonation method, using a homemade composite explosive precursor. The detonation reaction was ignited by a non-electric detonator in nitrogen gas in an explosion vessel. The as-prepared detonation products were characterized by X-ray Diffraction, Transmission electron Microscopy, Raman spectroscopy and X-ray fluorescence. The magnetic behavior of the Fe@C materials was measured by vibrating sample magnetometer. The results showed that the detonation products were made up of the body centered cubic iron core and the graphitic carbon shell, of which the core diameter was in the range of 15-50 nm. Raman spectroscopy indicated that both graphitic and amorphous carbon occured in the outside shell structures. The hysteresis loops showed the as-made Fe@C nanoparticles were of superparamagnetic at 300 K temperature. A detonation reaction mechanism was proposed to explain the growth process of Fe@C nanoparticles based on these results.