Ferromagnetic interaction in poly(<i>m</i>-aniline): Electron spin resonance and magnetic susceptibility

Abstract

Ferromagnetic interaction among the spins in poly(m-aniline) has been suggested by electron spin resonance and magnetic susceptibility measured at low temperatures. From the g-value analysis, these spins are found to be located on nitrogens although they are in some degree delocalized on phenyl rings. Doping of this polymer with iodine leads to an increase in the spin concentration up to 1020 spins⋅(g-polymer)−1. Saturation magnetization of 0.30 emu⋅G⋅g−1 and spin clusters of S=1 are observed in the iodine-doped polymer from the temperature and field dependence of the magnetization. Through-bond interaction, depending on the topology of a polymer skeleton, is considered to operate between rather distant spins through the spin polarization with antiferromagnetic array of the phenyl rings.