题目:  Imaging Mechanisms of Oxidized Copper Tips in Scanning Probe Microscopy 

报告人：Dr. Harry Mӧnig, Center for Nanotechnology(CeNTech), Universitӓt Münster (Germany)  

时间：2016年3月3日（星期四），上午10:00 

地点：南楼2层会议室 

邀请人：程志海 研究员（Tel：82545589）

摘要： 

   Controlling the chemical termination of the tip apex in scanning probe microscopy not only drastically increases the reproducibility and comparability of the results but also allows to quantitatively assess the various interaction channels in a highly defined way. In this talk I will report progress particularly on metal oxide surfaces where various oxygen-induced reconstructions of copper surfaces are used as model systems. A combination of 3D noncontact atomic force microscopy (3D NC-AFM), scanning tunneling microscopy (STM) and density functional theory is employed to obtain a comprehensive understanding of the imaging mechanisms and contrast signatures of various probe tips. In particular an oxygen-terminated copper tip (CuO tip) for constant-height NC-AFM imaging of molecular species with submolecular resolution is introduced. In contrast to the widely used carbonmonoxide- (CO-) or Xe functionalized tips, the CuO tip shows only negligible lateral deflections and significantly reduced image distortions. This allows a detailed discussion of fundamental imaging mechanisms in high-resolution NC-AFM experiments conducted in the repulsive force regime. With its structural rigidity, its chemically passivated state, and high electron density at the apex, the main characteristics of the CuO tip are identified making it an interesting complementary probe for the characterization of organic nanostructures on surfaces. 

报告人简介： 

 2011  Group Leader: Nanoscale Interface Analytics Center for Nanotechnology (CeNTec) at the Westfälische Wilhelms Universität Münster (Germany) 

  2009-2011 Postdoctoral Associate: School of Engineering & Applied Science Group of Prof. Udo Schwarz, Yale University (USA) 

  2009   PhD – Free University Berlin (Germany), Group of Prof. Martha Lux-Steiner Nanoanalytics for Solar Cell Materials 

  2005    Diploma in Physics – University of Kassel (Germany), Prof René Matzdorf Scanning Tunneling Spectroscopy on Low-Dimensional Electronic Systems