Strong mesoscopic transverse growth suppression in high-speed unidirectional growth of KDP single crystals

Abstract

We show a strong mesoscopic transverse growth arrest that co-exists with a high-speed longitudinal growth in single-crystalline KDP crystals with large aspect ratios. To explain this unique growth morphology, which cannot be explained by any current theories, we introduce a new set of surface concentration rate equations and demonstrate a molecular-orientation-selective surface self-shielding and channeling mechanism. We introduce a local supersaturation and calculate crystal growth driving force and growth rate, demonstrating quick arrest of both quantities as results of molecule-orientation selectivity based self-shielding and channeling effects. The growth dynamics thus derived can satisfactorily explain all experimental observations in single-crystalline KDP crystal growth reported here.