Critical Behavior of the Dielectric Constant of a Random Composite near the Percolation Threshold

Abstract

Measurements are reported of a singularity in the dielectric constant of a random metal-insulator composite below the percolation threshold. The composite sample consists of small silver particles randomly dispersed throughout a KCl matrix. The dielectric constant is found to obey a scaling relation with a critical exponent of $s=0.73\ifmmode\pm\else\textpm\fi{}0.07$.