Materials Science on the Atomic Scale: Three-Dimensional Atomic Force Microscopy and its Applications
Mehmet Z. Baykara
Date: Friday, October 28, 2011
Place: EA 409
Entire scientific disciplines such as mechanics and chemistry are governed by the interactions between atoms and molecules. On surfaces, atomic-scale force and energy fields direct the behavior of many scientifically and technologically important phenomena such as corrosion, adhesion, friction, and surface catalysis. To advance our knowledge of the fundamentals governing these subjects, it would be useful to quantify force and energy interactions between the surface of interest and a probe with atomic resolution. For example, in the case of a catalytically active surface, this would allow a study of the role and effectiveness of atomic-scale surface defects as active sites, potentially making important contributions to this key field for energy research. Moreover, a study of lateral forces on the atomic scale would provide new insights regarding the atomic origins of friction, another field of intense research and technological importance.
In this talk, we will show that the new method of three-dimensional atomic force microscopy (3D-AFM) developed by our research group at Yale University can be used towards achieving the goals described above [1,2]. 3D-AFM measurements on the surface of graphite provide important atomic-scale clues regarding the excellent frictional properties of this solid lubricant, while the combination of 3D-AFM with simultaneous scanning tunneling microscopy (STM) allows the quantification of the effect of surface defects on the chemical reactivity of individual oxygen atoms on the surface oxide layer of copper (100). A brief discussion regarding the current limitations of the 3D-AFM technique as well as future challenges will conclude the talk.
: M. Z. Baykara et al., Advanced Materials 22, 2838 (2010).
: B. J. Albers et al., Nature Nanotechnology 4, 307 (2009).