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Article Dans Une Revue Comptes Rendus. Physique Année : 2012

Atomic structure of bulk metallic glasses and their supercooled liquid states probed by high-energy synchrotron light.

Résumé

Like non-metallic glasses, many bulk metallic glasses manifest a glass-transition temperature T-g during heating prior to crystallisation. While the exact nature of the atomic structure of a metallic glass depends on its thermo-mechanical history (quench-rate, plastic deformation, ... ), a unique and reproducible average atomic structure is attained if the glass transition temperature can be approached in a reversible manner. However, a metallic glass is always metastable and crystallises within a time t near or above its T-g in such a way that any reciprocal or real-space information on the fully glassy state at T >= T-g must be completed within acquisition times tau(a) << t and this condition is in general difficult to attain with conventional X-ray diffraction devices. Here we report on experiments using high-energy, high-flux synchrotron light in the transmission for probing of the atomic structure of bulk metallic glasses. Examples are given of the determination of the isochoric glass transition T-g and the quenched-in free-volume. Finally, we report on the evolution of the atomic structure in the supercooled liquid region (T > T-g) and its role in the enhancement of glass formability. (C) 2011 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Domaines

Matériaux

Dates et versions

hal-00728098 , version 1 (04-09-2012)

Identifiants

Citer

K. Georgarakis, A.R. Yavari, D.V. Louzguine, G. Vaughan, W. J. Botta. Atomic structure of bulk metallic glasses and their supercooled liquid states probed by high-energy synchrotron light.. Comptes Rendus. Physique, 2012, 13 (3), pp.218-226. ⟨10.1016/j.crhy.2011.12.010⟩. ⟨hal-00728098⟩
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