Formation of Ruthenium−Tin Nanoparticles on Al2O3/Ni3Al(111) from an Organometallic Precursor

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• 作者：Alexander Uhl ; Yu Lei ; Homa Khosravian ; Conrad Becker ; Klaus Wandelt ; Richard D. Adams ; Michael Trenary ; Randall J. Meyer
• 刊名：Journal of Physical Chemistry C
• 出版年：2010
• 出版时间：October 14, 2010
• 年：2010
• 卷：114
• 期：40
• 页码：17062-17068
• 全文大小：345K
• 年卷期：v.114,no.40(October 14, 2010)
• ISSN：1932-7455

文摘

A thin Al₂O₃/Ni₃Al(111) film was prepared under ultrahigh vacuum conditions by surface oxidation of a Ni₃Al(111) single crystal. Using scanning tunneling microscopy, it was found that the film does not cover the substrate entirely, which allows two surfaces and their adsorption properties to be investigated in a single study. The sample was subsequently exposed to the vapor of an organometallic compound, Ru₃(CO)₉(μ-SnPh₂)₃. The interaction between the ligand sphere of the adsorbate and the relatively inert oxide film favors diffusion rather than static adsorption; however, some coverage is observed also on alumina. Upon heating, the images of the sample surface suggest that the bimetallic centers of the molecules lose their ligands and nucleate as particles on the surface. On the oxide film, the particles grow three-dimensionally, whereas they do not go beyond monolayer thickness on the unoxidized surface areas. Particles can be found on the oxide even after heating the sample as high as 925 K, despite a pronounced diffusion at room temperature of the precursor to the unoxidized surface patches.