Gaseous Detonation Synthesis of Carbon-Encapsulated Iron Nanoparticles

Carbon-encapsulated iron nanoparticles were formed using a gaseous detonation method in a mixture of hydrogen and oxygen in which the powder and gaseous forms of ferrocene were used as the raw materials.X-ray diffraction and transmission electron microscopy analysis shows that using either of the two different states of ferrocene yields carbon-encapsulated iron nanoparticles.The encapsulated particles were composed of iron or iron-carbon compounds as the core, and the outer shell was mainly composed of graphitic carbon.The sizes of most spherical nanoparticles varied between 5 and 30 nm.When using gaseous ferrocene in the detonation, the particle size distribution was narrower, the thickness of the shell layer was more uniform, and the particles had a higher sphericity.Using the iron-carbon alloy phase diagram, an analysis of the mechanism for gaseous detonation synthesis of carbon-encapsulated iron nanoparticles was carried out.The magnetic hysteresis loops of carbon-encapsulated iron nanoparticles were analyzed, which exhibit the dual natures of hard magnetic and paramagnetic.