Solidity of viscous liquids. V. Long-wavelength dominance of the dynamics

Abstract

This paper is the fifth in a series exploring the physical consequences of the solidity of glass-forming liquids. Paper IV proposed a model where the density field is described by a time-dependent Ginzburg-Landau equation of the nonconserved type with rates in $k$ space of the form ${\Gamma }_0+D{k}^2$. The model assumes that $D\gg {\Gamma }_0{a}^2$ where $a$ is the average intermolecular distance; this inequality expresses a long-wavelength dominance of the dynamics which implies that the Hamiltonian (free energy) to a good approximation may be taken to be ultralocal. In the present paper we argue that this is the simplest model consistent with the following three experimental facts: 1) Viscous liquids approaching the glass transition do not develop long-range order; 2) The glass has lower compressibility than the liquid; 3) The alpha process involves several decades of relaxation times shorter than the mean relaxation time. The paper proceeds to list six further experimental facts characterizing equilibrium viscous liquid dynamics and shows that these are readily understood in terms of the model; some are direct consequences, others are quite natural when viewed in light of the model.

References in corpus (6)

• Fragility and compressibility at the glass transition
• Single-order-parameter description of glass-forming liquids: A one-frequency test
• Solidity of viscous liquids. IV. Density fluctuations
• Ten themes of viscous liquid dynamics
• Solidity of viscous liquids. III. Alpha relaxation
• Violations of conservation laws in viscous liquid dynamics

Cited by in corpus (5)

• Investigation of the shear-mechanical and dielectric relaxation processes in two mono-alcohols close to the glass transition
• Distance-as-time in physical aging
• Convergence of Kähler-Ricci flow on Fano manifolds, II
• Displacement correlations in a two-dimensional colloidal liquid and their relationship with shear strain correlations
• Rheological model for the alpha relaxation of glass-forming liquids and its comparison to data for DC704 and DC705