Size Control of α‐Al2O3 Platelets Synthesized in Molten Na2SO4 Flux

Abstract

α‐Al2O3 platelet powders were synthesized in molten Na2SO4 flux. The size of α‐Al2O3 platelets was significantly reduced when partially decomposed rather than pure Al2(SO4)3 was used as the source of Al2O3; a further reduction in the platelet size was realized through additional seeding with nanosized α‐Al2O3 seeds. The addition of microsized α‐Al2O3 platelet seeds significantly influenced the platelet morphology of the final powder, as well. The platelet size of the final powder was in direct proportion to the size of the platelet seeds, and was in reverse proportion to the cube root of the platelet seed content.