REAL-TIME HOT-STAGE HIGH-VOLTAGE TRANSMISSION ELECTRON-MICROSCOPY PRECIPITATION OF CDS NANOCRYSTALS IN GLASSES - EXPERIMENT AND THEORETICAL-ANALYSIS

Hot-stage high-voltage (1.5 MeV) transimission electron microscopy was used to directly observe CdS nanocrystals precipitated in a silicate glass and a theoretical framework of nanocrystal coarsening kinetics more appropriate than the popularly used Lifshitz-Slyozov-Wagner theory was developed. Nanocrystallite nucleation and coarsening were monitored in situ by video taping of bright-field images of the edges of thin (less than 2 mum) glass fragments heated in the hot stage; crystallite size distribution was obtained from the taped experimental observations. The effects of electron-beam heating and diffusion out of the nanocrystals were included in developing the theoretical analysis of coarsening kinetics which were used, in turn, to interpret the experimental size distribution curves.