THE EFFECT OF OXYGEN ON THE ESR LINEWIDTH IN POLYPYRROLE DOPED BY PF6-

ESR linewidth (Delta H-pp) of as-grown polypyrrole, PPy-PF6-, was meas ured as a function of temperature under both helium and oxygen atmosph eres to study an effect of oxygen on the ESR linewidth. Houze and Nech tschein reported that an interaction between the charge carriers on a polymer backborn and paramagnetic spins of the oxygen molecules could cause an additional ESR broadening that is proportional or inversely p roportional to the carrier diffusion rate D-parallel to in the case of strong or weak interaction, respectively. The present experimental da ta demonstrate that only the ESR linewidth under oxygen atmosphere are not enough, but other information is indispensable to discriminate th e above two cases. On the present PPy-PF6- case, supplemental data on d.c. conductivity, the ESR linewidth under helium atmosphere, VSC resi stance, etc. make it possible to conclude mechanism of oxygen effect. (C) 1997 Elsevier Science Ltd.