|Title:||Diffusion Coefficient of Particles in Lattices with Random-Barriers and Wide Distribution of Transition Rates|
|???metadata.dc.contributor.*???:||Prof. K. W. Kehr|
|Publisher:||Addis Ababa University|
|Abstract:||We have investigated the mean-square displacements of particles that perform random walks in two and three-dimensional lattices with random barriers with uniform distributions of activation energies. The lattice we considered is a mathematical lattice. For the same model Avramov, Milchev, and Argyrakis [phys.rev.E 47 2303 (1993)] discussed the crossover between anomalous and normal diffusion, but they did not Analyze the behavior of the mean-square dispalcements at long times where normal diffusion occurs. We point out that the asymptotic diffusion coefficients are well described by the effective-medium theory in the range of parameters investigated; they are in disagreement with the predictions of critical-path arguments in dimension d=3.|
|Description:||A Thesis Presented to the School of Graduate Studies and the Faculty of Science Addis Ababa University in Partial Fulfillment of the Requirements for the Degree Master of Science in Physics|
|Appears in Collections:||Thesis - Physics|
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