Structure and magnetic moments of mass-filtered deposited nanoparticles

Mass-filtered 3 d transition metal nanoparticles have been produced by means of an ultrahigh vacuum compatible arc cluster ion source. High resolution transmission electron microscopy images of individual Fe, Co, and FeCo alloy particles with diameters of about 12 nm reveal the crystalline structure of the nanoparticles. X-ray absorption spectroscopy confirms the purity of the particles after in situ deposition. Analysis of the x-ray magnetic circular dichroism reveals bulklike total magnetic moments in all cases and strongly enhanced orbital moments for the iron nanoparticles. Furthermore, the data hint at a chemically ordered alloy in the case of FeCo particles.