IRON-OXIDE-BASED NANOPARTICLES PRODUCED BY PULSED INFRARED-LASER PYROLYSIS OF FE(CO)(5)

The synthesis of nanosized (1-100 nm) particles is an active research field in chemical processing technologies. The process may be of parti cular relevance in the case of the widely used iron-based materials. I n this paper, we report on the preparation and characterization of ult rafine powders produced by pulsed infrared laser pyrolysis of iron pen tacarbonyl, Fe(CO)(5), in sensitized mixtures. The synthesis is perfor med in a flow reactor, at rather high pressure (400 mbar) and high las er fluence (similar to 5 J cm(-2)). The average diameter of the partic les is 30 nm. Different characterization methods of the fine powder ag ed in atmosphere indicate the presence of a substantial oxidic portion , identified as the beta-Fe2O3 . H2O form. Some experimental observati ons suggest the possibility of iron-oxides formation during synthesis in the flow reactor. The relevant mechanisms for this reaction route a re discussed. (C) 1998 Elsevier Science S.A. All rights reserved.