2018/05/12 by Anshul D. S. Parmar, Parmar, Anshul D. S., S. Sengupta +4
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Glass properties and applications #Material Dynamics and Properties #Soft Condensed Matter (cond-mat.soft) #Theoretical and Computational Physics #cond-mat.soft
paper · pdf · doi:10.48550/arxiv.1805.04671
openalex publication_date 2018/05/12 · arxiv created 2018/05/22 · arxiv updated 2018/05/24 · openalex created_date 2022/10/06 · openalex updated_date 2026/07/28
The slow down of dynamics in glass forming liquids as the glass transition is approached has been characterised through the Adam-Gibbs relation, which relates relaxation time scales to the configurational entropy. The Adam-Gibbs relation cannot apply simultaneously to all relaxation times scales unless they are coupled, and exhibit closely related temperature dependences. The breakdown of the Stokes-Einstein relation presents an interesting situation to the contrary, and in analysing it, it has recently been shown that the Adam-Gibbs relation applies to diffusion coefficients rather than to viscosity or structural relaxation times related to the decay of density fluctuations. However, for multi-component liquids -- the typical cases considered in computer simulations, metallic glass formers, etc. -- such a statement raises the question of which diffusion coefficient is described by the Adam-Gibbs relation. All diffusion coefficients can be consistently described by the Adam-Gibbs relation if they bear a power law relationship with each other. Remarkably, we find that for a wide range of glass formers, and for a wide range of temperatures spanning the normal and the slow relaxation regimes, such a relationship holds. We briefly discuss possible rationalisations of the observed behaviour.