Why glass elasticity affects the thermodynamics and fragility of supercooled liquids.

ABSTRACT: Supercooled liquids are characterized by their fragility: The slowing down of the dynamics under cooling is more sudden and the jump of specific heat at the glass transition is generally larger in fragile liquids than in strong ones. Despite the importance of this quantity in classifying liquids, explaining what aspects of the microscopic structure controls fragility remains a challenge. Surprisingly, experiments indicate that the linear elasticity of the glass--a purely local property of the free energy landscape--is a good predictor of fragility. In particular, materials presenting a large excess of soft elastic modes, the so-called boson peak, are strong. This is also the case for network liquids near the rigidity percolation, known to affect elasticity. Here we introduce a model of the

SUBMITTER: Yan L 

PROVIDER: S-EPMC3631624 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature