Thermally-induced meandering of domain walls between (2 x 1) and c(4 x 2) regions on (001) surfaces was analyzed, using a scanning tunnelling microscope, in order to deduce the anisotropy of the surface stress tensor. At small length-scales, the domain walls exhibited random walker behavior whereas, at greater length scales (about 10nm), due to a domain-wall repulsion which originated from the anisotropy in the surface-stress tensor, a deviation from this 1-dimensional random-walk behavior was observed. A value of 0.13eV/(1 x 1) cell was found for the stress anisotropy.

Determination of surface stress anisotropy from domain wall fluctuations H.J.W.Zandvliet, B.Poelsema: Physical Review B, 1999, 59[11], 7289-92