Publication Date:
2017-07-28
Description:
Nature Materials 16, 792 (2017). doi:10.1038/nmat4935 Authors: Christopher E. Pueblo, Minhua Sun & K. F. Kelton The dynamical behaviour of liquids is frequently characterized by the fragility, which can be defined from the temperature dependence of the shear viscosity, η (ref. ). For a strong liquid, the activation energy for η changes little with cooling towards the glass transition temperature, Tg. The change is much greater in fragile liquids, with the activation energy becoming very large near Tg. While fragility is widely recognized as an important concept—believed, for example, to play an important role in glass formation—the microscopic origin of fragility is poorly understood. Here, we present new experimental evidence showing that fragility reflects the strength of the repulsive part of the interatomic potential, which can be determined from the steepness of the pair distribution function near the hard-sphere cutoff. On the basis of an analysis of scattering data from ten different metallic alloy liquids, we show that stronger liquids have steeper repulsive potentials.
Print ISSN:
1476-1122
Electronic ISSN:
1476-4660
Topics:
Chemistry and Pharmacology
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Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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Natural Sciences in General
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Physics
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