Nanocrystallization in Fluorochlorozirconate Glass-Ceramics

Heat treating fluorochlorozirconate (FCZ) glasses nucleates nanocrystals in the glass matrix, resulting in a nanocomposite glass-ceramic that has optical properties suitable for use as a medical imaging plate. Understanding the way in which the nanocrystal nucleation proceeds is critical to controlling the optical behavior. The nucleation and growth of nanocrystals in FCZ glass-ceramics was investigated with in situ transmission electron microscopy heating experiments. The experiments showed the nucleation and growth of previously unreported BaF₂ nanocrystals in addition to the expected BaCl₂ nanocrystals. Chemical analysis of the BaF₂ nanocrystals shows an association with the optically active dopant previously thought only to interact with BaCl₂ nanocrystals. The association of the dopant with BaF₂ crystals suggests that it plays a role in the photoluminescent (PL) properties of FCZ glass-ceramics.