2002/12/20 by W. Götze, Th. Voigtmann, Thomas Voigtmann · 6 citations
Chemical Engineering · Chemistry · Engineering · Materials Science · Mathematics · Physics and Astronomy · #Amplitude #Binary number #Chemistry #Condensed matter physics #Glass transition #Hard spheres #Light scattering #Material Dynamics and Properties #Materials science #Mathematics #Mixing (physics) #Nuclear magnetic resonance #Optics #Phase Equilibria and Thermodynamics #Physics #Plateau (mathematics) #Quantum mechanics #Relaxation (psychology) #Scattering #Thermodynamic properties of mixtures #Thermodynamics #cond-mat.soft
paper · pdf · doi:10.1103/physreve.67.021502
arxiv created 2002/12/20 · openalex publication_date 2003/02/19 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Within the mode-coupling theory for idealized glass transitions, we study the evolution of structural relaxation in binary mixtures of hard spheres with size ratios delta of the two components varying between 0.5 and 1.0. We find two scenarios for the glassy dynamics. For small size disparity, the mixing yields a slight extension of the glass regime. For larger size disparity, a plasticization effect is obtained, leading to stabilization of the liquid due to mixing. For all delta, a decrease of the elastic moduli at the transition due to mixing is predicted. A stiffening of the glass structure is found as is reflected by the increase of the Debye-Waller factors at the transition points. The critical amplitudes for density fluctuations at small and intermediate wave vectors decrease upon mixing, and thus the universal formulas for the relaxation near the plateau values describe a slowing down of the dynamics upon mixing for the first step of the two-step relaxation scenario. The results explain the qualitative features of mixing effects reported by Williams and van Megen [Phys. Rev. E 64, 041502 (2001)] for dynamical light-scattering measurements on binary mixtures of hard-sphere-like colloids with size ratio delta=0.6.