Abstract

Fe nanopowders were successfully synthesized by plasma arc discharge (PAD) process using Fe rod. The influence of chamber pressure on the microstructure was investigated by means of X-ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM), Transmission Electron Microscopy (TEM) and X-ray Photoelectron Spectroscopy (XPS). The prepared particles had nearly spherical shapes and consisted of metallic cores (a-Fe) and oxide shells (Fe_3O_4), The powder size increased with increasing chamber pressure due to the higher dissolution and ejection rate of H_2 and gas density in the molten metal.

• Keywords: Fe nanopowder;Plasma arc discharge;Core/shell structures;