The Kovacs effect in model glasses
摘要
We discuss the `memory effect' discovered in the 60's by Kovacs in temperature shift experiments on glassy polymers, where the volume (or energy) displays a non monotonous time behaviour. This effect is generic and is observed on a variety of different glassy systems (including granular materials). The aim of this paper is to discuss whether some microscopic information can be extracted from a quantitative analysis of the `Kovacs hump'. We study analytically two families of theoretical models: domain growth and traps, for which detailed predictions of the shape of the hump can be obtained. Qualitatively, the Kovacs effect reflects the heterogeneity of the system: its description requires to deal not only with averages but with a full probability distribution (of domain sizes or of relaxation times). We end by some suggestions for a quantitative analysis of experimental results.
关键词
引用
@article{arxiv.cond-mat/0306089,
title = {The Kovacs effect in model glasses},
author = {E. M. Bertin and J. -P. Bouchaud and J. -M. Drouffe and C. Godreche},
journal= {arXiv preprint arXiv:cond-mat/0306089},
year = {2009}
}
备注
17 pages, 6 figures; revised version