METALLIC TEMPERATURE-DEPENDENCE IN THE CONDUCTING POLYMER, POLYANILINE - SPIN DYNAMICS STUDY 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 HCI. The main results are (a) D(parallel-to) above 150 K follows metallic temperature dependence of T(-d) with d=2-3, (b) an abrupt change in D(parallel-to) is found around 150 K, and (c) the anisotropy ratio D(parallel-to)/D(perpendicular-to) is larger than nearly 10(5) around 150 K. These results lead us PANI being the highly one dimensional electronic system.