Absence of Definite Scaling Laws in Raman Scattering from Fractals

Abstract

The frequency dependence of the Raman coupling coefficient $C(\ddot{I}‰)$ is calculated numerically for square and cubic percolation clusters. No general scaling law in terms of the macroscopic parameters such as the fractal dimension $D$ or the spectral dimension $\overline{d}$ is found. $C(\ddot{I}‰)$ is sensitive to the microscopic structure of the clusters and depends on: site- or bond-percolation, presence or absence of dangling bonds, scattering mechanism and polarization, presence or absence of polarizability disorder. This situation makes the derivation of macroscopic parameters from Raman experiments unreliable.

4 pages revtex, 4 figures upon request, UTF-OS-301092