Journal of Electron Microscopy 49(1): 163-172 (2000)
© 2000 Oxford University Press
Plan-view imaging of oxygen-induced reconstruction on Ag(110) surface. I. The possibility of imaging surface oxygen
1Electron Microscopy Laboratory, School of Materials Science and Engineering, Tsinghua University Beijing 100084
2Laboratory of Atomic Imaging of Solids, Institute of Metal Research, Chinese Academy of Sciences Shenyang 110015, People's Republic of China
*To whom correspondence should be addressed: Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China.E-mail: jzhu{at}mail.tsinghua.edu.cn
Surface reconstruction on Ag(110) induced by oxygen adsorption was studied by the plan-view imaging technique of high-resolution electron microscopy (HREM). Systematic multislice simulations were carried out to find the optimal experimental conditions for imaging the surface oxygen. It was found theoretically that there exist a series of characteristic values of objective lens defoci and sample thicknesses under which the surface and the bulk can be imaged clearly and simultaneously. These optimal imaging conditions were used to interpret the experimental micrographs. While the basic features of the surface reconstruction of O/Ag(110) in the HREM images are consistent with those revealed by scanning tunnelling microscopy (STM), there are some new features that have not been reported with STM. These phenomena give some evidence to the existence of subsurface oxygen.
Keywords plan-view imaging of surfaces, silver, surface reconstruction, high-resolution electron microscopy, computer simulation
Received 28 September 1998, accepted 6 December 1999