INFORMATION ENTROPY OF COMPLEX STRUCTURES

The information entropy function provides a sensitive measure of the c omplexity of a multi-component material system, where ''complexity'' r efers to the range of length scales over which morphological features are present. This is demonstrated for an evolving, two-phase microstru cture simulated by a population of interacting particles on a two-dime nsional surface. The information entropy increases at all length scale s as the initially random configuration of particles evolves to produc e a distribution of ramified clusters. Maxima in the normalized inform ation entropy function, which is obtained by subtracting the informati on entropy of a perfectly random configuration from that of the cluste red configuration, occur at length scales for which the system most di ffers from a random configuration, while minima occur at length scales for which the system is periodic or relatively ordered. Besides analy sis of complex microstructures, information entropy is useful in detec ting features present in any collection of data.