EPR STUDY OF POLYANILINE PERCHLORATES - SPIN SPECIES-RELATED TO CHARGE-TRANSPORT

The spin susceptibilities chi of polyaniline perchlorates prepared by different methods were determined from electron paramagnetic resonance spectra. The observed chi vs. T curves can be explained by the sum of a Curie term and a thermally activated term. The C-spin species which is responsible for the Curie term is produced upon protonation of pol yaniline base, but the concentration is independent of the protonation level. In contrast, the concentration of the TA-spin species that sho ws the thermally activated susceptibility has a close correlation with macroscopic electrical conductivity. Both spin species are intrinsic of polyaniline salts, and the TA-spin species is expected to be respon sible for interchain hopping of charge carriers.