Convecto-diffusive Solidification of Electronic and Optical Materials

摘要

Direct observations were made on the shape of solid-liquid interface of silver-doped lead bromide to study solute distribution and effect of solidification parameters on the quality of crystals. With increasing translation velocity, the interface changed from convex to depressed and then formed a cavity in the center of the growth tube. We observed a new kind of toroidal instability at the solid-liquid interface. Further increase in translation velocity caused the morphological breakdown of the interface. Theoretically predicted stability boundaries for double-diffusive convection and morphological breakdown were in good agreement with the experimentally observed growth conditions.