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Growth mechanism of crystals from aqueous solutions
Author(s) -
Šolc Z.,
Söhnel O.
Publication year - 1973
Publication title -
kristall und technik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0023-4753
DOI - 10.1002/crat.19730080706
Subject(s) - supersaturation , drop (telecommunication) , crystal (programming language) , evaporation , dissolution , aqueous solution , surface layer , chemistry , layer (electronics) , surface (topology) , constant (computer programming) , crystallography , thermodynamics , geometry , physics , telecommunications , organic chemistry , computer science , programming language , mathematics
Microscopic processes occurring on the surface of a growing crystal or a dissolving one were observed by microcinematography. The crystals under observation were grown either in a drop of solution by evaporation or in a constant‐temperature microscope stage at a chosen supersaturation. Small (approx. 0.1 mm) and large (approx. 10 mm) crystals of NaCl, Pb(NO 3 ) 2 , NaNO 3 , CdI 2 , KDP and ADP were studied. It is concluded qualitatively that the layers, in general polygonal, originating in one or several active centres, are formed on the crystal face, never at the corners or edges. – The average velocity of layer motion was studied quantitatively in dependence on their thickness and supersaturation. The layer motion at constant supersaturation considerably fluctuated. – Surface patterns created by moving layers agree in most cases with predictions of the dislocation theory. Two categories of steps were found on the surface: ”real” macrosteps and shock waves. – The velocity of layer motion for most compounds lies within (1–10) · 10 −4 cm · s −1 .