Iron-Based Nanopowders Containing α-Fe, Fe3C, and γ-Fe Particles Synthesised in Microwave Torch Plasma and Investigated with Mössbauer Spectroscopy

Abstract

Two Fe-based nanopowders were synthesised using microwave torch discharge at 1 bar. The main channel of the discharge was operating in Ar, which flowed through the central nozzle of an electrode, whereas the reactive mixture H2/Fe(CO)5 was added through a concentric outer nozzle. Besides rarely observed γ-Fe particles (for the first sample: dXRD = 30 nm, 35 wt %; for the second sample: dXRD = 9 nm, 33 wt %) samples also included α-Fe, Fe3C, and Fe3O4/γ-Fe2O3 particles. The presence of γ-Fe phase was proved by the interpretation of the XRD patterns and the Mössbauer spectra taken at 293 and 5 K.