材料期刊网

With iron pentacarbonyl (Fe(CO)(5)) and ammonia (NH3) as precursors, the growth of ultrafine particles of gamma'-Fe4N (size 10-30 nm) and gamma-Fe (size 30-100 nm) occurred in the high-temperature reaction zone induced by a cw CO2 laser. The prepared particles were characterized by transmission electron microscopy, Mossbauer spectroscopy and X-ray diffraction. It was found that a lower synthesis temperature was favorable to the formation of fee gamma'-Fe4N, and a higher temperature favored the formation of gamma-Fe. In addition, the synthesis temperature has a strong effect on the structures and morphologies of gamma-Fe and gamma'-Fe4N particles. The growth mechanisms of gamma'-Fe4N and gamma-Fe particles are discussed.