期刊
APPLIED SURFACE SCIENCE
卷 432, 期 -, 页码 115-120出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.apsusc.2016.11.145
关键词
Thermal stability; Oxide-supported metal model catalyst; Samarium; Alumina
类别
资金
- National Basic Research Program of China [2013CB834605]
- Natural Science Foundation of China [U1232102, 21403205]
- Scientific Research Grant of Hefei Science Center of CAS (SRG-HSC) [2015SRG-HSC031]
- Users with Potential of Hefei Science Center of CAS (SRG-HSC) [2015HSC-UP022]
The structural evolution of Sm nanoclusters on ultrathin film of Al2O3 epitaxially grown on Ni3Al(111) substrate at elevated temperatures was investigated in-situ using synchrotron radiation photoemission spectroscopy (SRPES), X-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM). The vapor-deposited metallic Sm onto the Al2O3 thin film at 300 K is partially oxidized, leading to the appearance of both Sm2+ and Sm3+ states at low coverages, due to the charge transfer from Sm to oxide film. The complete oxidation of the Sm, i.e., all Sm2+ converted to Sm3+, occurs when the sample is annealed to 500 K. Further annealing results in the diffusion of Sm into the Al2O3 lattice. At similar to 900 K, the formation of a SmAlO3 complex is observed. However, this complex starts to decompose and desorb from the surface at temperature higher than 1200 K. Interestingly, it is found that Sm can promote the oxidation of Ni3Al substrate and thicken the alumina film when Sm is deposited at room temperature onto the Al2O3/Ni3Al(111) substrate followed by annealing in oxygen environment at similar to 800 K. (C) 2016 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据