Effect of composition changes on the structural relaxation of a binary mixture -: art. no. 021502

被引:113
作者
Götze, W [1 ]
Voigtmann, T [1 ]
机构
[1] Tech Univ Munich, Dept Phys, D-85747 Garching, Germany
来源
PHYSICAL REVIEW E | 2003年 / 67卷 / 02期
关键词
D O I
10.1103/PhysRevE.67.021502
中图分类号
O35 [流体力学]; O53 [等离子体物理学];
学科分类号
070204 ; 080103 ; 080704 ;
摘要
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.
引用
收藏
页数:14
相关论文
共 49 条
[1]  
Arnold V.I, 2003, Catastrophe Theory
[2]   INTERACTION BETWEEN PARTICLES SUSPENDED IN SOLUTIONS OF MACROMOLECULES [J].
ASAKURA, S ;
OOSAWA, F .
JOURNAL OF POLYMER SCIENCE, 1958, 33 (126) :183-192
[3]   MODE-COUPLING THEORY FOR THE GLASS-TRANSITION IN A SIMPLE BINARY MIXTURE [J].
BARRAT, JL ;
LATZ, A .
JOURNAL OF PHYSICS-CONDENSED MATTER, 1990, 2 (18) :4289-4295
[5]   Nonergodicity transitions in colloidal suspensions with attractive interactions [J].
Bergenholtz, J ;
Fuchs, M .
PHYSICAL REVIEW E, 1999, 59 (05) :5706-5715
[6]   DELOCALIZATION OF SMALL PARTICLES IN A GLASSY MATRIX [J].
BOSSE, J ;
THAKUR, JS .
PHYSICAL REVIEW LETTERS, 1987, 59 (09) :998-1001
[7]   Low-density ionic glass [J].
Bosse, J ;
Wilke, SD .
PHYSICAL REVIEW LETTERS, 1998, 80 (06) :1260-1263
[8]  
Bosse J, 1997, PROG THEOR PHYS SUPP, P13, DOI 10.1143/PTPS.126.13
[9]   SELF-DIFFUSION IN SUPERCOOLED BINARY LIQUIDS [J].
BOSSE, J ;
KANEKO, Y .
PHYSICAL REVIEW LETTERS, 1995, 74 (20) :4023-4026
[10]   High-permittivity ionic glass predicted from mode-coupling calculations [J].
Chen, HC ;
Wilke, SD ;
Bosse, J .
PHYSICAL REVIEW B, 1999, 60 (17) :12045-12050