Statistical analysis of dynamics of elementary processes on the surface of the growing crystal (by the AFM data)

Abstract

Evolution of the NaCl crystal surface in the process of its growth from the solution under various conditions was studied using in situ investigations by the atomic force method (AFM) and statistical approach. The mean values of tangential rate and distances between the steps statistically calculated for each time interval determine the normal rate of growth of the scanning area associated with thermodynamic conditions of growth. We worked out a criterion for characterization of the state of the stationary growth. The point when the growing surface reaches the stationary growth is characterized not only by constancy of the normal rate of growth, but also by stability of its dispersion in time. The dispersion of the normal rate of growth is calculated from the sum of the dispersion of tangential rate and the distance between the steps. In this case, the regulations observed through AFM scanning area are fair for all the faces of the growing crystal. In the case when the rate of normal growth shows little variation, and its dispersion has strong fluctuation, it is necessary to make additional time averaging. If all statistical growth parameters calculated from local AFM images vary arbitrarily during the experiment, it is not possible to make conclusions about the growth conditions of the whole crystal face. © 2004 Published by Elsevier B.V.