Roksana Bavand, Département de génie physique, École Polytechnique de Montréal, Montréal, QC, Canada. 

Ru nanoparticles (NPs) were deposited onto highly oriented pyrolytic graphite and characterized by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Each of the several Ru core XPS spectra characterized (3s, 3p and 3d) was found to be composed of three symmetric components; together with two metal oxide O1s components, these give evidence of a rather complex oxide initially formed. The valence band (4d and 5s) spectra clearly demonstrate an increase of the Kubo gap, as well as a 4d→5s electron spill-over, with decreasing NP size. TEM studies, as a function of deposition rate, show that, with insufficient time for the NP condensation energy to dissipate, the initially well-separated NPs are capable of migrating and aggregating. This indicates substrate bonding that is weaker than expected.

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Cette conférence est présentée par le RQMP Versant Nord du Département de physique de l'Université de Montréal et le Département de génie physique de Polytechnique Montréal.