Metallic temperature dependence in the conducting polymer, polyaniline: Spin dynamics study by ESR

Abstract

Microscopic spin and charge dynamics in polyaniline (PANI) are studied by ESR. Temperature dependence of the diffusion rates along a polymer chain D and across chains D⊥ was determined for the emeraldine salt form with HCl. The main results are (a) D above 150 K follows metallic temperature dependence of T-d with d=2∼3, (b) an abrupt change in D is found around 150 K, and (c) the anisotropy ratio DD⊥ is larger than nearly 105 around 150 K. These results lead us PANI being the highly one dimensional electronic system.