CRITICAL-BEHAVIOR OF THE CONDUCTIVITY OF A 2-COMPONENT PERCOLATION SYSTEM IN THE CROSSOVER REGION

This letter examines the problem of calculating the effective conductivity of a two-component system in which the components differ markedly in conductivity, and in which the volume fraction of component x, with the higher conductivity, is close to the percolation threshold x(c). A critical exponent, which describes the x dependence of the diffusion coefficient and the conductivity of the system in the limit x --> x(c), is found.