DENSITY-FLUCTUATIONS OF ASSEMBLIES OF IRREVERSIBLY DEPOSITED PARTICLES ON SOLID-SURFACES

For general irreversible deposition processes, a relation between the variance sigma(2) of the number of deposited particles on subsystems o ut of a large surface and the available surface function Phi is obtain ed. This relation is based on a mean field assumption and follows the resolution of a master equation system. It is valid at low to intermed iate values of the surface coverage theta as shown by comparison with exact results and with numerical simulations for special deposition mo dels. In the low coverage limit, if the available surface function is written as a series expansion of the coverage theta, whose first nontr ivial term varies as theta(k), the reduced variance has a similar expa nsion, However, the prefactor of theta(k) derived in this article is i n general different in both series expansions. This result has also be en obtained by a rigorous argument based on the evolution of the k-par ticle distribution function with the coverage. (C) 1997 American Insti tute of Physics.