Abstract: | The paper is aimed at the elucidation of the limits to which the faceted forms of KDP crystals preserve their stability and beyond which a skeletal growth from stagnant solutions takes place. In order to avoid the natural convections the experiments were performed in two-dimensional cells. On the basis of quantitative criteria, it has been shown that the kinetic regime of growth has been replaced by a diffusion one when the concentration on the crystal surface drops with respect to the bulk value with 0.1% to 0.2%. The critical size above which the KDP crystal no longer retains its polyhedral growth mode in a diffusion regime since a gross morphological defect in the form of a depression appears on its (010) face has been compared with the theoretical expressions derived by Cahn and Chernov. |