Monte-Carlo analysis of tracer diffusion mechanisms in YBa2Cu3O6+c

A method for estimating, via the Monte-Carlo simulation, the most often rea lized diffusion mechanisms in 2D ordered structures is presented. Taking as an example the diffusion of oxygen ions in 123 - YBCO high temperature sup erconductor we propose several diffusion mechanisms and show to what extent they depend on the temperature and concentration of the diffusing particle s. Our results are compared with the ones proposed earlier on the basis of energy arguments. We find also additional trajectories, different from thos e earlier reported in that system.