{"title":"An STM study on the diffusion of O atoms on a CO-covered Ru(0001) surface—The role of domain boundaries","authors":"Ann-Kathrin Kügler , Hannah Illner , Joost Wintterlin","doi":"10.1016/j.susc.2024.122597","DOIUrl":null,"url":null,"abstract":"<div><p>We investigate tracer diffusion at the domain boundaries in an adsorption layer, an effect that corresponds to grain boundary diffusion in 3D polycrystalline solids. Experiments were performed on adsorbed O atoms on a Ru(0001) surface in a layer of CO molecules. The CO molecules form a <span><math><mrow><mrow><mo>(</mo><mrow><msqrt><mn>3</mn></msqrt><mspace></mspace><mi>x</mi><mspace></mspace><msqrt><mn>3</mn></msqrt></mrow><mo>)</mo></mrow><mi>R</mi><msup><mn>30</mn><mo>∘</mo></msup></mrow></math></span> structure which displays translational domains. High-speed scanning tunneling microscopy (STM) was used to image the motion of the O atoms. The data show that single O atoms preferentially move along the domain walls which in the STM movies appear as disordered, fluctuating stripes between the ordered domains. The diffusion coefficient of the O atoms is one order of magnitude higher than the diffusion coefficient in the ordered domains. By comparison with previous experiments on completely disordered CO layers, it is concluded that the diffusion is similarly promoted by the enhanced fluctuations in the disordered domain walls.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"751 ","pages":"Article 122597"},"PeriodicalIF":2.1000,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0039602824001481/pdfft?md5=56584dd5332ca4fc5c5a34180b11b3f8&pid=1-s2.0-S0039602824001481-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Surface Science","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0039602824001481","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
We investigate tracer diffusion at the domain boundaries in an adsorption layer, an effect that corresponds to grain boundary diffusion in 3D polycrystalline solids. Experiments were performed on adsorbed O atoms on a Ru(0001) surface in a layer of CO molecules. The CO molecules form a structure which displays translational domains. High-speed scanning tunneling microscopy (STM) was used to image the motion of the O atoms. The data show that single O atoms preferentially move along the domain walls which in the STM movies appear as disordered, fluctuating stripes between the ordered domains. The diffusion coefficient of the O atoms is one order of magnitude higher than the diffusion coefficient in the ordered domains. By comparison with previous experiments on completely disordered CO layers, it is concluded that the diffusion is similarly promoted by the enhanced fluctuations in the disordered domain walls.
我们研究了吸附层中畴边界的示踪剂扩散,这种效应相当于三维多晶固体中的晶界扩散。实验是在 Ru(0001) 表面的 CO 分子层中吸附 O 原子。CO 分子形成了 (3x3)R30∘ 结构,显示出平移域。利用高速扫描隧道显微镜 (STM) 对 O 原子的运动进行了成像。数据显示,单个 O 原子优先沿着畴壁运动,在 STM 电影中,畴壁表现为有序畴之间的无序波动条纹。O 原子的扩散系数比有序畴内的扩散系数高一个数量级。通过与之前在完全无序的 CO 层上进行的实验进行比较,可以得出结论:无序畴壁的波动增强同样促进了扩散。
期刊介绍:
Surface Science is devoted to elucidating the fundamental aspects of chemistry and physics occurring at a wide range of surfaces and interfaces and to disseminating this knowledge fast. The journal welcomes a broad spectrum of topics, including but not limited to:
• model systems (e.g. in Ultra High Vacuum) under well-controlled reactive conditions
• nanoscale science and engineering, including manipulation of matter at the atomic/molecular scale and assembly phenomena
• reactivity of surfaces as related to various applied areas including heterogeneous catalysis, chemistry at electrified interfaces, and semiconductors functionalization
• phenomena at interfaces relevant to energy storage and conversion, and fuels production and utilization
• surface reactivity for environmental protection and pollution remediation
• interactions at surfaces of soft matter, including polymers and biomaterials.
Both experimental and theoretical work, including modeling, is within the scope of the journal. Work published in Surface Science reaches a wide readership, from chemistry and physics to biology and materials science and engineering, providing an excellent forum for cross-fertilization of ideas and broad dissemination of scientific discoveries.