METALLIC TEMPERATURE-DEPENDENCE OF MICROSCOPIC ELECTRICAL-CONDUCTIVITY IN HCL-DOPED POLYANILINE STUDIED BY ESR

Microscopic spin and charge dynamics in polyaniline (PANI) are studied by ESR. Temperature dependence of the diffusion rates along a polymer chain D-parallel to and across chains D-perpendicular to was determined for the emeraldine salt form with HCl/N approximate to 0.62 and 0.27. The main results are (a) in y=0.62, D-parallel to above 150 K follows metallic temperature dependence of T--d with d=2 similar to 3 and an abrupt change in D-parallel to is found around 150 K, and (b) in both y=0.62 and 0.27, the anisotropy ratio D-parallel to/D-perpendicular to is larger than 10(3) around 300 K. These results lead us PANI being the highly one dimensional electronic system.