American Vacuum Society - 51st International Symposium, Anaheim, CA, 11/14 - 11/19/04 (poster)

Highly Stable Variable Temperature STM for Atomically and Time Resolved Imaging: The Dynamics of Self-Assembly at Surfaces

Bogdan Diaconescu and Karsten Pohl

Self-ordering growth of nanoarrays on strained interfaces is an attractive option for preparing highly ordered nano-templates of specific feature size densities. High-tech methods used for reducing of the feature sizes may thus be supplanted by this simple and elegant patterning technique. Reconstructed surfaces, e.g. Au(111) or Pt(111), and monolayer thick strained films, e.g. Ag or Cu on Ru(0001), exhibit well-ordered networks of misfit dislocations. These networks can serve as templates for the growth of mesoscopic-scale structures of large-scale order and size uniformity. The combination of interfacial stress and corrosion creates self-ordering arrays of unprecedented regularity. The great potential of this natural templating approach is that the feature sizes and densities are predicted to depend on the interfacial stress in these strained layers. We have the unique capability of being able to measure the resulting driving forces of self-assembly directly through time-resolved scanning tunneling microscopy. This enables us to determine the stability and elastic constants of 2D nano-templates.1 For this purpose we designed and build a highly stable VT-STM. It allows us to study the dynamics of self-assembly at strained metallic interfaces at the atomic scale in the temperature range 80-400K. An overview of the instrumental setup and its performance will be given by variable temperature studies of self-organisation of nanostructures on Au(111) and Ag, and Cu films on Ru(0001) at different thicknesess.
Supported by NSF-CAREER-DMR-0134933 and ACS-PRF-37999-G5.

1 K. Pohl et al., Nature 397, 238 (1999)