Oxidation properties of Al-nanostructures on Si surfaces* P. Morgen a,d , N. Skivesen b , J. M. Jensen a,e , U. Robenhagen a , J. Andersen a , J. Kjelstrup-Hansen a,e , Z.S. Li c , and K. Pedersen b a Fysisk Institut, SDU, Campusvej 55, DK-5230 Odense M, Denmark. b Institute of Physics, Aalborg University, Denmark. c ISA, Institute of Physics and Astronomy, Aarhus University Denmark. e Present address: MIC, Lyngby, Denmark. PACS Refs: 79.60.Jv, 79.60.-I, 73.20.-r d Corresponding author, e-mail: per@fysik.sdu.dk * Supported by the Danish Research Council