GOALI: Structure of Amorphous Materials by Fluctuation Microscopy and Atomic-Level Modeling

Rensselaer Polytechnic Institute, Troy NY

Investigators

Abstract

0074273 Keblinski This is a new GOALI award funded jointly by the Division of Materials Research and the MPS Office of Multidisciplinary Activities. Keblinski does materials modeling and is collaborating with Treacy, a microscopist at NEC, to study paracrystallites (regions with medium range order) in amorphous Si and Ge using modeling and fluctuation microscopy. Both graduate and undergraduate students will be involved in this project. A recent observation of medium range order in fluctuation spectroscopy has shown the need of a structural model for an amorphous solid in place of the continuous random network which shows no medium range order. This grant will facilitate a collaborative exploration: experimentally of the conditions which induce, sustain and remove medium range order and theoretically, atomic scale models with characteristics which are particularly conducive to the existence of medium range order. This work will lead to a better understanding of the structural details of glasses as well as the thermodynamics and kinetics of their formation. %%% This is a new GOALI award funded jointly by the Division of Materials Research and the MPS Office of Multidisciplinary Activities. Keblinski at RPI and Treacy at NEC will conduct research in collaboration. Both graduate and undergraduate students will be involved. The theoretical, atomic scale modeling and simulation will be carried out at RPI with frequent exchange of results and ideas with the experimental work conducted at NEC. The newly discovered application of fluctuation microscopy has raised several questions, perhaps the most prominent is the question of medium range order. The best-known model for the structure of glass, the continuous random network model shows no medium range order. One needs an atomic level model to explore the characteristics necessary for such order to exist. Other questions might be, what are the thermodynamic consequences, what are the consequences for the kinetic processes in these glasses. ***