Dresden 2009 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 35: Poster Session II
MM 35.35: Poster
Wednesday, March 25, 2009, 16:30–18:30, P4
Oxygen diffusion in an reaction rate of cobalt nanoparticles stabilized with different ligands — •Britta Vogel, Axel Dreyer, Nadine Mill, Anna Regtmeier, Inga Ennen, Daniel Ebke, Simone Herth, and Andreas Hütten — Department of Physics, University of Bielefeld, D-33615 Bielefeld, Germany
Cobalt nanoparticles with a diameter of 12nm have initially been prepared with TOPO. Subsequently a ligand exchange was carried out to employ different ligands to the nanoparticles while keeping direct comparability. The decrease of the magnetic moment of the nanoparticles corresponds directly to their oxydation. According to a model of Crank for irreversible reaction in a spherical particle the uptake of oxygen in the particles was analyzed. From the fit of the obtained data to the model, information about the diffusion of oxygen in cobalt and cobalt oxide as well as the oxidationrate is deduced. Additionally the temperature dependence is discussed.