Published online by Cambridge University Press: 15 February 2011
We have used low-energy electron microscopy to investigate the real-time motion of (7×7) out-of-phase domain boundaries in the (7×7) reconstruction on vicinal Si(111), just below the phase transition temperature. As a function of time, the domain boundaries wander and coalesce in one-dimension, parallel to the step edges. We have established that the motion is consistent with the statistical problem of a random walk in the presence of absorbing barriers and have measured the diffusion coefficient for domain boundary wandering. The average distance between domain boundaries becomes large as they coarsen, consequently energetic interactions are not significant in determining their arrangement on this surface.