Three dimensionality of ‘‘metallic’’ states in conducting polymers: Polyaniline

Abstract

Anisotropic-conductiity (σ), thermopower, and dielectric-constant studies show that oriented polyaniline salt is representative of a class of quasi-one-dimensional disordered conductors where coupled parallel chains form ‘‘metallic’’ bundles in which electron wave functions are extended three dimensionally. This is in contrast to isolated conducting chains in conventional 1D conductors. The bundles correspond to crystalline regions of the polymer. The results are important for understanding the stabilization of metallic states and achievement of high σ in conducting polymers.