Duality and effective conductivity of random two-phase flat systems
S. A. Bulgadaev
Landau Institute for Theoretical Physics RAS, 142432 Chernogolovka, Moscow Reg., Russia
PACS: 73.61.-r, 75.70.Ak
Abstract
The possible functional forms of the effective
conductivity σe of the randomly inhomogeneous two-phase systems
at arbitrary values of concentrations are discussed.
Two explicit approximate expressions for effective conductivity are found
using a duality relation, a series expansion of σe in the
inhomogeneity parameter z
and some additional conjectures about functional form
of σe. They differ from the effective medium approximation,
satisfy all necessary requirements
and reproduce the known formulas for σe in weakly inhomogeneous
case. This can signify also that σe of the
two-phase randomly inhomogeneous systems may be a nonuniversal function,
depending on some details of the structure of the random inhomogeneities.