Charles University, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, Prague, Czech Republic.
J Phys Condens Matter. 2011 Jun 1;23(21):215002. doi: 10.1088/0953-8984/23/21/215002. Epub 2011 May 9.
Submonolayer coverage of Sn on a Pt(110) surface was studied by photoemission and low-energy electron diffraction. Deposition of less than 0.6 ML at 300 K gives rise to a c(2 × 2) surface reconstruction with weak diffraction spots at the very beginning of growth, and no other LEED patterns were found at this temperature. A new (4 × 1) Sn/Pt(110) surface structure was observed after flashing to 570 K a coverage of 0.64 ML. The total Sn coverage decreased to 0.58 ML after flashing as some of the atoms diffused into deeper layers. Different Sn phases were identified on the (4 × 1) Sn/Pt(110) surface: two types of surface Sn atoms in different adsorption sites, a subsurface Sn-Pt intermetallic layer and Sn-Pt surface islands. To investigate chemical reactivity, 0.25 ML Sn/Pt(110) and 0.58 ML (4 × 1) Sn/Pt(110) surfaces were exposed to 1000 L of O(2) at 300 K. Analyses of the photoemission data provide evidence for the formation of tin oxide. The interaction with oxygen of the two surfaces is similar, independent of surface structure and the composition of the subsurface layers. The Sn concentration in the interface intermetallic layer is the main factor which influences the oxygen adsorption.
在 Pt(110) 表面上，通过光电子能谱和低能电子衍射研究了 Sn 的亚单层覆盖。在 300 K 下沉积少于 0.6 ML 会导致 c(2 × 2) 表面重构，在生长的最初阶段会出现微弱的衍射点，而在该温度下未发现其他 LEED 图案。在覆盖度为 0.64 ML 时，将温度升高至 570 K 后，观察到新的(4 × 1) Sn/Pt(110)表面结构。在闪光后，总 Sn 覆盖度降低至 0.58 ML，因为一些原子扩散到更深的层中。在(4 × 1) Sn/Pt(110)表面上鉴定出不同的 Sn 相：两种不同吸附位的表面 Sn 原子、亚表面 Sn-Pt 金属间层和 Sn-Pt 表面岛。为了研究化学活性，在 300 K 下将 0.25 ML Sn/Pt(110)和 0.58 ML(4 × 1) Sn/Pt(110)表面暴露于 1000 L O(2)中。光电子能谱数据分析提供了形成氧化锡的证据。两个表面与氧气的相互作用相似，与表面结构和亚表面层的组成无关。界面金属间层中的 Sn 浓度是影响氧吸附的主要因素。
