William Johnson - What are Glasses?: Atomic Organization and the Price of Nonconformity
As a simple liquid like molten gold is cooled below its melting point, its atoms undergo an abrupt crystallization transition, freezing into a regular pattern so that the atoms are grouped in identical local neighborhoods. If there are nonconforming atoms in the liquid—for example, silicon atoms dissolved in the gold—they may prefer a different type of "neighborhood." Too many nonconformists, and crystallization will become impeded. The liquid still solidifies on cooling, but instead of crystallizing, it vitrifies—transforms into a glass.
Such glasses differ from crystals in profound and often surprising ways, and Johnson will describe these scientific and practical consequences based on his experience studying metallic glasses.
William L. Johnson is the Ruben F. and Donna Mettler Professor of Engineering and Applied Science at Caltech.
This is a free event; no tickets or reservations are required.
Presented by: Caltech Committee on Institute Programs