Tracer Diffusion in a System with Randomly Distributed Traps

摘要

An approximate theory for tracer diffusion on a lattice containing randomlydistributed traps and in the presence of a finite concentration of diffusion particles which preclude double occupancy of any site is developed by extending earlier theories of diffusion in a many particle system on perfect lattices using random walk concepts. Both blocking and dynamic correlation effects are considered. The theoretical results are compared with computer simulation in a two dimensional square lattice with two types of traps over the entire concentration range for particles and traps. The agreement between the simulation results and the theory gives confidence that the approximation will be valid more widely in models of diffusion in disordered lattices.