Pk. Kahol et al., ELECTRON-LOCALIZATION EFFECTS ON THE CONDUCTING AND MAGNETIC STATES IN POLYANILINE COPOLYMERS, Physical review. B, Condensed matter, 50(5), 1994, pp. 2809-2814
The methyl-ring-substituted derivative of polyaniline shows increased
electron localization compared to polyaniline, and the mechanism for t
his increased localization has been proposed as due to a decrease in t
he interchain diffusion rate caused mainly by enhanced disorder due to
random positioning of the methyl groups. We have investigated this is
sue by studying the magnetic and transport behavior of the copolymer p
oly(aniline)x(p-fluoroaniline)1-x at five values of x. We find that th
e electron-localization length in the copolymer is nearly equal to the
conjugation length, and it decreases on decreasing x. The comparison
of this behavior with that for poly(o-toluidine) and other alkyl-ring-
substituted derivatives of polyaniline shows that the primary cause of
electron localization in the polyaniline derivatives is enhanced inte
rchain disorder. Our results also seem to provide some support for a m
odel of polyaniline comprised of metallic islands consisting of single
, isolated strands of the polymer.