Nonlinear Phenomena in Complex Systems, 2003, Vol.6, No.2, pp.630-638

NONLINEAR PHENOMENA IN COMPLEX SYSTEMS
An Interdisciplinary Journal

2003, Vol.6, No.2, pp.630-638

Anomalous Light Scattering Close to Percolation Threshold
P.S. Grinchuk

Light scattering problem in a heterogeneous medium with high concentration of scatterers is considered. The approach is proposed, where the influence of such parameters as an average distance between particles and the wavelength of an incident radiation on the scattering process is described within the framework of a model of randomly overlapping spheres. This approach explains a maximum of the radiation scattering for some concentrations of scattering centers, that was observed in a number of experimental works, by the existence of a geometrical (percolation) phase transition in the system. Position of the scattering maximum corresponds to a percolation threshold for the aforementioned model. The critical exponents describing intensity of scattered radiation in the vicinity of threshold concentration are found. The proposed approach is applied to the description and optimization of heat-insulating properties of composite ceramic microspheres - paint coating. The percolation approach is generalized also for the case of high-porous fibrous materials. The method is proposed to determine the material density which provides the optimal heat-insulating properties.
Key words: continuum percolation, scattering of radiation, critical exponents, heterogeneous medium, heat insulation materials

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