Nanoparticle production by plasma

The paper describes a system designed for magnetic as well as nonmagnetic n anoparticle production for ferrofluids and magneto-rheological fluids. Part icles of Fe3O4 with a mean diameter of 11.65 nm were obtained by melting th e steel and sputtering the molten metal in the argon plasma jet. The therma l decomposition of Fe(Co), in plasma led to the obtaining of magnetic parti cles with a mean diameter of 12.2 nm. Through thermal decomposition in plas ma of Fe 2-etilhexamaleath, amorphous and crystalline graphite particles we re obtained with a mean diameter of 6.4 nm, useful for producing conductive magnetic liquids. The vaporization of the steel in argon plasma and in hel ium plasma respectively, led to obtaining of particles of alpha-Fe and Fe3O 4 with diameters in the range 3-90 nm. (C) 1999 Elsevier Science S.A. All r ights reserved.