Characterization of Carbon-Encapsulated Nickel and Iron Nanoparticles by Means of X-ray Absorption and Photoelectron Spectroscopy

Nickel and iron nanoparticles encapsulated in carbon were synthesized by contactless levitation melting of metal drops and their evaporation in a flow of an inert gas containing a hydrocarbon. The products were characterized by means of transmission electron microscopy, photoelectron spectroscopy, and X-ray absorption spectroscopy. It was established that carbon coating protects the metallic nanoparticles from the environmental degradation by providing a barrier against oxidation and ensures stability of the ferromagnetic core metal inside that provides their extremely high catalytic activity, biocompatibility, and nontoxicity.