GROWTH OF CRYSTALS IN PRESENCE OF IMPURITIES - A HYPOTHESIS BASED ON A KINETIC APPROACH

A hypothesis is proposed concerning the growth of crystals in the pres ence of impurities soluble in the parent phase but insoluble in the cr ystal. The hypothesis is based on: (i) a kinetic model developed by Bl iznakov, where it is assumed that the impurity layers exert a passive resistance towards the growth of crystals, (ii) results obtained by Ka ischew concerning the nucleation of crystals on. foreign substrate; ac cording to which the heterogeneous nucleation is more favourable than the homogeneous one, in the presence of the same supersaturation, and (iii) a statement of Distler and co-workers that a foreign intermediat e layer contains ''single crystal'' structural information about the c rystal face where the layer has been formed.