GROWTH AND PERFECTION OF CRYSTALS FROM AQUEOUS-SOLUTION - CASE-STUDIES ON BARIUM NITRATE AND K-ALUM

Growth, dissolution and perfection of crystals from aqueous solution h ave been investigated using barium nitrate, Ba(NO3)(2), and K-alum, KA l(SO4)(2) . 12H(2)O, crystals as representative cases. Both ex-situ an d in-situ investigations were performed to analyze the following probl ems; (1) solutal transport phenomena around a growing or dissolving cr ystal and the effect upon the growth kinetics and perfection of the cr ystal, (2) relation between bulk and surface supersaturations, (3) eff ect of solution flow and buoyancy driven convection upon the diffusion boundary layer and surface supersaturation distribution over a face, (4) growth kinetics of a face and of spiral growth layers from individ ual growth hillocks on the face in relation to the bulk and surface su persaturations, (5) generation and behavior of lattice defects in rela tion to growth process and fluctuation in concentration, (6) differenc es in growth mechanisms and lattice defects in different growth sector s, (7) entrapment of mother liquid as inclusions, (8) origin of habit modification depending on bulk supersaturation, and (9) differences an d similarities between growth and dissolution.