报告一：Atomic Manipulation and Force Spectroscopy on Cu(110)-O Surface  with Low Temperature FM-AFM 

报告人： Professor Yasuhiro Sugawara, Department of Applied Physics, Graduate School of Engineering, Osaka University, Japan 

时  间：2017年2月22日（星期三），上午10:00 

地  点：南楼4层会议室 

邀请人：许瑞 程志海 （Tel：82545589） 

摘要： 

    Manipulation of single atoms and molecules is an innovative experimental technique of nanoscience. Recently, an atomic force microscopy (AFM) has been used to manipulate single atoms and molecules. Atom manipulation with an AFM is particularly promising, because it allows the direct measurement of the required forces. 

     In the present study, we investigated the forces in AFM lateral manipulation for a top single Cu atom (super Cu atom) on the Cu(110)-O surface. The AFM tip apex was coated with Cu or O atoms in situ by slightly making a tip-sample mechanical contact on the Cu(110)-O surface prior to the imaging. In the case of O-adsorbed AFM tip [1], the super Cu atom on the surface was pulled at a lateral tip position on the adjacent binding site. In contrast, in the case of Cu-adsorbed AFM tip [1], the super Cu atom was pushed over the top of the super Cu atom. Thus, we found that the forces (attractive or repulsive forces) to move an atom laterally on the surface strongly depend on the atom species of the AFM tip apex and the surface. Furthermore, in order to clarify the manipulation process, we investigated the full tip-sample potential landscape necessary to manipulate atoms. The tip-sample potentials were determined by the frequency shift versus distance curves by mathematical analysis. We found that the tip-sample potentials which move the super Cu atom laterally on the surface strongly depended on the atom species of the AFM tip apex and the surface. These results strongly suggest that the chemical nature of tip-sample interaction plays an important role in lateral atom manipulation. Furthermore, we discuss the pathways for moving the super Cu atom. 

报告人简介： 

• 1988: (Ph.D) Department of Electrical and Communication Engineering, Graduate School of Engineering, Tohoku University, Japan
• 1988: Assistant professor in Department of Electric and Communication Engineering, Graduate School of Engineering, Tohoku University, Japan
• 1989: Assistant Professor in Department of Electronic Engineering, Graduate School of Engineering, Iwate University, Japan
• 1991: Assistant Professor in Department of Physics, Graduate School of Science, Hiroshima University, Japan
• 1996: Associate Professor in Department of Electronic Engineering, Graduate School of Engineering, Osaka University, Japan.
• 2002: Professor in Department of Applied Physics, Graduate School of Engineering, Osaka University, Japan.

报告二：The investigation of local dipole moment on TiO₂(110) surface by electrostatic force microscopy 

报告人： Associate Professor Yanjun Li, Osaka University, Graduate School of engineering, Japan 

时  间：2017年2月22日（星期三），上午11:00 

地  点：南楼4层会议室 

邀请人：许瑞 程志海 （Tel：82545589）   

摘要： 

   Au/TiO₂(110) surfaces display extremely high catalytic reactivity [1]. There are many representative models that explain the emerging catalytic activity of Au nanoclusters. It is widely accepted that the perimeter interface of Au/TiO₂ is the reaction site for CO oxidation. However, the injection/extraction mechanism of electrons and the reaction process are not clarified by a comprehensive experimental description. In this study, we proposed a new method to simultaneously measuring topography, local contact potential difference (LCPD) and dipole moment distribution on TiO₂(110) surface. 

     In the experiment, the DC bias added with ac bias voltage is applied between the tip and sample. Three lock-in amplifiers are used to detect frequency shift of ,  and . The contact potential difference is numerically calculated from the divided result of  and  signals [2, 3, 4] and dipole moment is obtained from frequency shift of . Figure 1 shows the simultaneously measurement result of topography, LCPD and dipole moment images on TiO₂(110) surface. The details will be reported in the meeting. 

报告人简介： 

• 1996-1998    University of Tsukuba, Graduate school of Science and Engineering, Master
• 1998-2001    University of Tsukuba, Graduate School of engineering, Ph.D
• 2001.4          University of Tsukuba, Engineering, Post-doc
• 2001-2004    Institute for Molecular Science, Okazaki Research Fellow
• 2004-2005    Osaka University, Graduate School of engineering, Special duty Researcher,    Department of Applied Physics
• 2005-2010    Osaka University,   Graduate School of engineering, Visiting Associate Professor, Department of Applied Physics
• 2010.3           Osaka University    Graduate School of engineering,  Associate Professor