Nonequilibrium free energy and kinetic
roughening of steps on the Kossel(001) surface
Cuppen HM,
Meekes H, van Enckevort WJP, Vlieg E, Knops HJF
PHYSICAL
REVIEW B 69 (24): Art. No. 245404 JUN 2004
Abstract:
This paper studies the nonequilibrium energetics of growth steps. It
discusses the energy and free energy of a [100] step on a Kossel(001)
crystal surface as a function of the driving force in the case that
two-dimensional nucleation is not active. Theoretical expressions for
these energies are derived and are found to agree with data obtained
from Monte Carlo simulations of step flow. The nonequilibrium
expressions allow us to propose that the vanishing of the step free
energy beyond a critical value of the driving force defines the onset
of the kinetic roughening regime. This is found to agree with the
earlier phenomenological criteria for this transition.