Synthesis and Structure of Fe-Fe3O4 Nanoparticles with "Core-Shell" Architecture Capsulated in a Graphite-Like Carbon Matrix

Nanoparticles of iron (α-Fe) and iron oxide (Fe3O4) with a core-shell structure (α-Fe core, Fe3O4 shell) covered with additional graphite-like carbon layer have been synthesized. The samples were obtained by solid-phase pyrolysis of iron phthalocyanine (FePc) at a pyrolysis temperature of 1000°C, followed by annealing in an oxygen atmosphere at a temperature of 250°C. The composition, structure and morphology of the samples were investigated by transmission and scanning transmission electron microscopy with elemental mapping, synchrotron X-ray diffraction and Raman spectroscopy.