ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Computer simulations and computational diagnostics are used to study a Monte Carlo Brownian walker moving through a glass of immobile force centers. Clear evidence for distinct trapping, hopping, and hindered-diffusive regimes is seen in the mean-square displacement and the probability distribution P(r,t) for a step r during delay t. In the hopping regime distinct time scales for intratrap and intertrap motion are apparent; probe localization and time scale separation depend inversely on temperature T. In the hindered-diffusion regime, the effective diffusion coefficient D¯ follows an Arrhenius temperature dependence. In this regime, 〈r2(t)〉 is very nearly linear in t, even for walkers that have only diffused a small fraction of the matrix particle nearest-neighbor distance. We infer that analytic calculations using relatively low-order time expansions should give reasonable values for D¯ of probe particles in our glass. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.471896
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