title: Observation of the role of subcritical nuclei in crystallization of a glassy solid.
abstract: Phase transformation generally begins with nucleation, in which a small aggregate of atoms organizes into a different structural symmetry. The thermodynamic driving forces and kinetic rates have been predicted by classical nucleation theory, but observation of nanometer-scale nuclei has not been possible, except on exposed surfaces. We used a statistical technique called fluctuation transmission electron microscopy to detect nuclei embedded in a glassy solid, and we used a laser pump-probe technique to determine the role of these nuclei in crystallization. This study provides a convincing proof of the time- and temperature-dependent development of nuclei, information that will play a critical role in the development of advanced materials for phase-change memories.
authors: Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign (UIUC), Urbana, IL 61801, USA.
authors: Bong-Sub
authors: BS
authors: Lee
authors: Geoffrey W
authors: GW
authors: Burr
authors: Robert M
authors: RM
authors: Shelby
authors: Simone
authors: S
authors: Raoux
authors: Charles T
authors: CT
authors: Rettner
authors: Stephanie N
authors: SN
authors: Bogle
authors: Kristof
authors: K
authors: Darmawikarta
authors: Stephen G
authors: SG
authors: Bishop
authors: John R
authors: JR
authors: Abelson