CHARACTERIZATION OF SIMULATED MICROSTRUCTURES IN POLYDISPERSE PARTICLE DEPOSITION

The deposition of polydisperse particles under the influence of gravit y is examined using computer simulation. A parameter, sigma, that repr esents the standard deviation of particle size is used for studying th e effect of the variation in polydispersity on the resulting microstru ctures. Structural correlations are examined through contact networks, radial and angular distribution functions, and diffraction patterns. The results show that the onset of ordering appears near sigma = 0.05 as sigma is decreased. The long-range ordering of the structures is no t influenced by the introduction of a small amount of polydispersity, which may increase the uniformity of local density distribution in the angular direction. Polydisperse systems with small deviations in size display stronger positional order in some directions and this in turn contributes to the uniformity of overall packing structures.