Growth promoting effect of organic impurities on growth kinetics of KAP and KDP crystals

Abstract

The experimental results of the influence of a variety of organic impurities differing in their chemical behavior on the growth rates of different faces of KAP and KDP crystals are presented. It was observed that, with increasing additive concentration in practically all experiments, an impurity leads first to an increase and then a decrease in the growth rate, passing through a maximum. These features of the influence of an additive on crystal growth kinetics depend on the chemical nature of both the impurity and the crystal face. The initial growth promoting effect of additives is discussed in terms of the chemical nature of the materials used in the experiments and changes in the thermodynamic and kinetic parameters involved in the crystal growth models. The analysis suggests that the growth promoting effect is not connected with a decrease in the edge free energy in a simple manner.