Elastic Models for the Non-Arrhenius Relaxation Time of Glass-Forming Liquids
نویسنده
چکیده
We first review the phenomenology of viscous liquids and the standard models used for explaining the nonArrhenius average relaxation time. Then the focus is turned to the so-called elastic models, arguing that these models are all equivalent in the Einstein approximation (where the short-time elastic properties are all determined by just one effective, temperature-dependent force constant). We finally discuss the connection between the elastic models and two well-established research fields of condensed-matter physics: point defects in crystals and solid-state diffusion.
منابع مشابه
Source of non-Arrhenius average relaxation time in glass-forming liquids
A major mystery of glass-forming liquids is the non-Arrhenius temperature-dependence of the average relaxation time. This paper brie ̄y reviews the classical phenomenological models for non-Arrhenius behavior ± the free volume model and the entropy model ± and critiques against these models. We then discuss a recently proposed model according to which the activation energy of the average relaxat...
متن کاملMultiple length and time scales of dynamic heterogeneities in model glass-forming liquids: a systematic analysis of multi-point and multi-time correlations.
We report an extensive and systematic investigation of the multi-point and multi-time correlation functions to reveal the spatio-temporal structures of dynamic heterogeneities in glass-forming liquids. Molecular dynamics simulations are carried out for the supercooled states of various prototype models of glass-forming liquids such as binary Kob-Andersen, Wahnström, soft-sphere, and network-for...
متن کاملA topographic view of supercooled liquids and glass formation.
Various static and dynamic phenomena displayed by glass-forming liquids, particularly those near the so-called "fragile" limit, emerge as manifestations of the multidimensional complex topography of the collective potential energy function. These include non-Arrhenius viscosity and relaxation times, bifurcation between the alpha- and beta-relaxation processes, and a breakdown of the Stokes-Eins...
متن کاملRelationship between particle elasticity, glass fragility, and structural relaxation in dense microgel suspensions.
"Fragile" glassy materials, which include most polymeric materials and organic liquids, exhibit a steep and super-Arrhenius dependence of relaxation time with temperature upon the glass transition and have been extensively studied. Yet, a full understanding of strong glass formers that exhibit an Arrhenius dependence on temperature is still lacking. In this work, we have investigated the glassy...
متن کاملLinking rigidity transitions with enthalpic changes at the glass transition and fragility: insight from a simple oscillator model.
A low temperature Monte Carlo dynamics of a Keating-like oscillator model is used to study the relationship between the nature of network glasses from the viewpoint of rigidity, the thermal reversibility during the glass transition and the strong-fragile behaviour of glass-forming liquids. The model shows that a Phillips optimal glass formation with minimal enthalpic changes is obtained under a...
متن کامل