Kinetic roughening of the Kossel (1 0 0) surface

Kinetic roughening is not a phase transition and, as such, it lacks a sharp definition. Therefore, the many criteria used to mark the onset of kinetic roughening, are expected to give different results. Criteria stemming from the classical two-dimensional nucleation theory are frequently used. Exper imentalists, on the other hand, observe a transition from flat to rounded c rystal facets at certain driving forces, or measure the growth rate as a fu nction of the driving force and find a change from exponential to linear gr owth kinetics. It is assumed that these experimental phenomena coincide wit h the onset of kinetic roughening. In this paper, the extent of the differe nces between these criteria is investigated by means of Monte Carlo simulat ions on a Kossel (1 0 0) SOS model. The four criteria studied yield differe nt values for the critical driving force, although three of them show a sim ilar, almost linear, dependence of the critical driving force on the neares t-neighbor bond strength. (C) 1999 Elsevier Science B.V. All rights reserve d.