Self-Organization of Ultrathin Vanadium Oxide Layers on a Rh(111) Surface during a Catalytic Reaction. Part II: A LEEM and Spectromicroscopy Study

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• 作者：Florian Lovis ; Martin Hesse ; Andrea Locatelli ; Tevfik. O. Mentes抬 ; Miguel A虂. Nin虄o ; Gerhard Lilienkamp ; Benjamin Borkenhagen ; Ronald Imbihl
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：October 6, 2011
• 年：2011
• 卷：115
• 期：39
• 页码：19149-19157
• 全文大小：989K
• 年卷期：v.115,no.39(October 6, 2011)
• ISSN：1932-7455

文摘

Upon exposure of ultrathin vanadium oxide layers on Rh(111) (胃_V 0.2 MLE) to the H₂ + O₂ reaction, we observe the reversible formation of stationary macroscopic stripe patterns caused by lateral redistribution of the vanadium oxide. These patterns are investigated in the 10^鈥? mbar range at around 750 K, employing LEEM (low energy electron microscopy), microprobe-LEED and microprobe-XPS. The stripe patterns evolve via several stages and structures: essentially, vanadium oxide nanoislands with a (鈭? 脳 鈭?)R19.1掳 structure are reduced from V⁺⁵ to V³⁺ and condense into a macroscopic (2 脳 2) oxide phase upon increasing p(H₂). The orientation of the stripe patterns is determined by step bunches, which introduce a diffusional anisotropy. The stationary patterns are discussed within the concept of reactive phase separation.