Unusual frequency dependence of ESR linewidth in polyaniline

Microscopic spin and charge dynamics in polyaniline (PANI) are studied by frequency dependence of ESR linewidth that enables us to study anisotropy of the electronic state. In the previous report, we have reported that the electronic state in PANI-HCl powder is highly one dimensional. Here, we investigate the case of PANI film protonated with camphorsulfonic acid (CSA). The main results are (1) unusual frequency dependence, (2) extremely weak interchain coupling; the anisiotropy ratio D¦D⊥ is larger than 108 around 300K, and (3) semiconducting diffusion rate along the chain, distinctive from other highly conducting polymers such as polyacetylene and polypyrrole.