Mean-field theory of kinetic smoothening of growth steps

The kinetics and structure of an isolated [110] step on a (001) surface of a Kossel crystal is considered in the framework of a self-consistent mean-field approach taking into account first- and second-nearest neighbors' interaction. A new step growth mechanism is suggested and described quantitatively, in which the incorporation of growth units from solution into kink sites by a series process via step sites can be faster than the direct incorporation. We show that under the dominance of series processes kinetic smoothening takes place that results in a drastic change of the [110] step structure from being rough in equilibrium to smooth during growth.