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Relationship between Entropic Bottleneck in Free Energy Landscape, Nonexponential Relaxation and Fragility of Glass-Forming Liquids

Dwaipayan Chakrabarti·Biman Bagchi
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Abstract

A mesoscopic model is proposed to explain the anomalous dynamics in a supercooled liquid as its glass transition temperature is approached from above. The model is based on the assumption of $β$ organized $α$ process, with the requirement of coherent excitation of a minimum critical number $N_{c}$ of $β$ processes in the surroundings of a total $N_β$. Numerical evaluation of the model shows that the growth in this critical number in the background of a modest $N_β$ can lead to a severe entropic bottleneck and slow down the dynamics to an extent observed near real glass transition. The fragility of the glass-forming liquid is shown to be correlated with the growth of the ratio $γ(= N_{c}/N_β)$.

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Dwaipayan Chakrabarti, Biman Bagchi. 2003-03-09. Relationship between Entropic Bottleneck in Free Energy Landscape, Nonexponential Relaxation and Fragility of Glass-Forming Liquids. https://arxiv.org/abs/cond-mat/0303153

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