Formation of graphite encapsulated iron nanoparticles during mechanical activation and annealing analyzed by Mossbauer spectroscopy

摘要

The investigation performed by means of Mossbauer spectroscopy, X-ray diffraction and transmission electron microscopy demonstrated that the interaction in the system iron-amorphous carbon proceeds via the formation of nano-sized iron particles (10-40 nm) and the carbide nano- phases distributed over amorphous carbon matrix. The annealing of these samples causes a crystallization of the amorphous carbon, decomposition of nano-sized carbide phases and formation of iron nanoparticles (50-100 nm) encapsulated by graphite.