Physics – Condensed Matter – Statistical Mechanics
Scientific paper
1999-01-25
Physics
Condensed Matter
Statistical Mechanics
39 page (double spaced), 2 figures
Scientific paper
10.1007/s100510050902
We study self-diffusion within a simple hopping model for glassy materials. (The model is Bouchaud's model of glasses [J.-P. Bouchaud, J. Physique I 2, 1705 (1992)], as extended to describe rheological properties [P. Sollich, F. Lequeux, P. Hebraud and M.E. Cates, Phys. Rev. Lett. 78, 2020 (1997)].) We investigate the breakdown, near the glass transition, of the (generalized) Stokes-Einstein relation between self-diffusion of a tracer particle and the (frequency-dependent) viscosity of the system as a whole. This stems from the presence of a broad distribution of relaxation times of which different moments control diffusion and rheology. We also investigate the effect of flow (oscillatory shear) on self-diffusion and show that this causes a finite diffusivity in the temperature regime below the glass transition (where this was previously zero). At higher temperatures the diffusivity is enhanced by a power law frequency dependence that also characterises the rheological response. The relevance of these findings to soft glassy materials (foams, emulsions etc.) as well as to conventional glass-forming liquids is discussed.
Cates Michael E.
Evans Mike R. L.
Sollich Peter
No associations
LandOfFree
Diffusion and rheology in a model of glassy materials does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Diffusion and rheology in a model of glassy materials, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Diffusion and rheology in a model of glassy materials will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-494531