Production of nanoscale FeSi and FeCr powders for magnetofluide application using laser evaporation

K. Moras - R. Schaarschuch - W. Riehemann

Institut für Werkstoffkunde und Werkstofftechnik (IWW), Technische Universität Clausthal, D-38678 Clausthal-Zellerfeld, Germany

Abstract
Laser evaporation can be used to produce nanoscale metallic FeSi and FeCr powders with high saturation magnetisation and mean diameters of the order of 10~nm. The phase composition of the nanoscale powders depends on the composition of laser evaporated material and on the used aggregation gas during evaporation. In case of FeSi, the existence of the metallic phase in a nanoscale powder requires of small oxygen concentrations during laser evaporation. The produced nanoscale powders of FeSi and FeCr are found to be very stable in normal air although subsequential oxidation over several month can be detected. Figs 5, Refs 4.