Atom-Tracking STM Data of Si Ad-dimer Diffusion on the Si(001) Surface*

B. S. Swartzentruber
Sandia National Laboratories
Albuquerque, NM 87185

This page contains some Atom-Tracking STM data that are displayed as AVI movies. The atom tracker works by locking onto selected "bumps" (or "holes") using lateral feedback. The feedback maintains the position of the STM tip at the local maximum by continually climbing uphill. Once locked, atom-track data are acquired by reading the X, Y, and Z positions of the feedback electronics as a function of time. The motion of the surface feature is reflected in the coordinates of the atom tracker. In the data below, the atom track coordinates are displayed as a cursor (black circle with a white cross) superposed on a conventional (static) STM image taken immediately before atom tracking.
[65C Atom Tracks]Image 1: Atom-track data of a selected Si dimer diffusing on the Si(001) surface acquired at 65 C. This movie is displayed time-lapsed... movie time 110 s, data acquisition time 500 s. (AVI format 178kb)

[128C Atom Tracks]Image 2: Atom-track data acquired at 128 C of a Si dimer trapped between two substrate defects. The dimer hops on average 10 times per second. This movie is displayed in slow-motion... movie time 150 s, data acquisition time 22 s. (AVI format 642kb)

Attribution: The reference for this document is: B. S. Swartzentruber, Atom-Tracking STM Data of Si Ad-dimer Diffusion on the Si(001) Surface, SAND95-2340, Sandia National Laboratories, Albuquerque, NM, October 1995.
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