Near-Tg crystallization in super-cooled liquids and glasses

Abstract

We shall research and develop new active glasses and glass-ceramics presenting application-relevant functionalities, such as high mechanical strength and electrical conductivity, biological, optical or catalytic activity, and/or combinations of these properties. A fundamental understanding of these properties will be sought on the basis of the structural organization of these materials on different length scales. We will apply state-of-the art NMR, EPR, EXAFS and vibrational spectroscopy to characterize the local and medium-range order, as well as the full resolution range of optical and electron microscopies, XRD and microanalyses for elucidating nano- and microstructures. This comprehensive experimental approach will be complemented by molecular dynamics simulations. Using this experimental modeling strategy, we will further seek a fundamental understanding of glass sintering and crystallization in terms of the mechanisms, thermodynamics and kinetics of viscous now, as well as crystal nucleation and growth, enabling us to exercise control of these processes by developing appropriate forming process and thermal treatment protocols. In a concerted effort, the participating laboratories will jointly investigate a number of important benchmark systems, which are deemed particularly promising for applications either as structural reinforcement materials (dental and bio glass-ceramics), optical materials (laser glasses), materials for electrochemical energy storage devices (electrolytes, high-temperature seals), and catalytically active systems. Prof. Gupta will participate in our CEPID project FAPESP #2013/07793-6. He will work on the fundamental understanding of glass crystallization in terms of the mechanisms, thermodynamics and kinetics of crystal nucleation and growth, and relaxation in deep undercooled glasses (at ~Tg). (AU)