STM D

STM D is a controlled ambient scanning tunneling microscope that operates at room temperature. The electronics, software, and microscope itself are all home-built and have undergone various modifications throughout the years. This microscope is mainly used to investigate self-assembling systems with an interest in patterning.

One area of research in the Weiss group focuses on exploiting the inherent chemical and physical properties of molecules using the “bottom-up” approach to enable patterning at the nanometer scale. A system that is of considerable interest is self-assembled monolayers (SAMs) of alkanethiolate molecules on Au(111) because they are well-ordered, robust, and have a low defect density. These attributes are primarily due to the inherent stability in the film which is a result of the S-Au covalent bond and the van der Waals forces that exist between adjacent alkyl chains in the monolayer. The properties of a SAM can be manipulated by incorporating functional groups that modify the interactions (i.e., hydrogen or covalent bonds) within the film. In this way, SAMs can be tailored for many different purposes and are being exploited in the area of nanotechnology, where it is necessary to have molecularly precise and variable devices.


Top-down view of STMD. The tip is in the center and the three piezotubes provide the Besocke walker motion.	STM image of a SAM showing defect sites (dark areas) and domain boundaries.	Perspective image of a binary component phase-separated SAM consisting of decanethiol and an amide-alkanethiol. Click here for more information.

"Phase separation within a binary self-assembled monolayer on Au{111} driven by an amide-containing alkanethiol", R. K. Smith, S. M. Reed, P. A. Lewis, J. D. Monnell, R. S. Clegg, K. F. Kelly, L. A. Bumm, J. E. Hutchison, and P. S. Weiss, J. Phys. Chem. B, 105, 1119 (2001).

"The role of buried hydrogen bonds in self-assembled mixed composition thiols on Au{111}", P. A. Lewis, R. K. Smith, K. F. Kelly, L. A. Bumm, S. M. Reed, R. S. Clegg, J. D. Gunderson, J. E. Hutchison, and P. S. Weiss, J. Phys. Chem. B., 105, 10630 (2001).

"Control and placement of molecules via self-assembly", P. A. Lewis, Z. J. Donhauser, B. A. Mantooth, R. K. Smith, L. A. Bumm, K. F. Kelly, and P. S. Weiss, Nanotechnology 12, 231 (2001).

STM D: Ambient Scanning Tunneling Microscope