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Kinetics of Relaxation at the Liquid-Glass Transition

Published online by Cambridge University Press:  26 February 2011

Laurent J. Lewis
Laurent J. Lewis*
Affiliation:
Département de physique et Groupe de recherche sur les couches minces, Université de Montréal, C.P. 6128, Succursale A, Montréal, Québec, Canada H3C 3J7
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Abstract

We use molecular-dynamics simulations to investigate relaxation processes near the liquid-glass transition for a realistic model of the metal-metalloid system Ni80P20. We find that relaxation proceeds in two stages, excluding phonons: fast (or conformational) relaxation, related to local rearrangements of atoms, and slow relaxation, connected with atomic transport, i.e. diffusion. These processes are usually referred to as β and α, respectively. Our simulations show that diffusion exists even in the glass state, where it proceeds mostly by jumps, in contrast to the liquid phase where it is continuous. This relaxation mechanism is well described by a stretched exponential (Kohlrausch) law, in accord with recent modecoupling theories for supercooled liquids. The fast relaxation regime, on the other hand, does not appear to be well described by the theory.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 205: Symposium F – Kinetics of Phase Transformations , 1990 , 393
Copyright
Copyright © Materials Research Society 1992

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