Berlin 2012 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 14: Poster: Glasses I (jointly with DY)

CPP 14.8: Poster

Dienstag, 27. März 2012, 18:15–20:15, Poster A

Shear moduli of two dimensional binary glasses — •Rabea Seyboldt¹, David Hajnal², Fabian Weysser¹, and Matthias Fuchs¹ — ¹FB Physik, Universität Konstanz, 78457 Konstanz, Germany — ²Institut für Physik, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany

We studied the shear moduli of two-component glasses in two dimensions within mode coupling theory. Varying the concentration, strong mixing effects can be observed along the glass transition lines for two interaction potentials. Hard disks with size ratios between 0.3 and 0.9, and point particles interacting with (magnetic) dipoles of strength ratio between 0.1 and 0.6 are considered. Equilibrium structure factors (partially obtained from Monte Carlo simulations) and glass form factors show that a softening of the elastic shear constant of glass upon adding another component arises from a dilution effect of the majority component. For very disparate mixtures, an anomalous elastic strengthening results from what we interpret as clustering of the smaller particles in the voids between the larger ones. This among other things might indicate a close-by glass-glass transition. Simulation data on hard disk mixtures show that the theory underestimates the moduli by around 50%, but otherwise captures the qualitative trends (within the rather large simulational error bars).