Transport properties of ion-implanted and chemically doped polyaniline films

The low-temperature de conductivity and magnetoconductivity of ion-implanted (Ar+) and chemically doped (H2SO4) polyaniline films have been studied. The metal-insulator transition has been observed for ion-implanted polyaniline films on increasing the irradiation dose to 3x10(17) ions cm(-2). The maximum values of the room-temperature conductivity reached 800 S cm(-1) for ion-implanted and 8 S cm(-1) far chemically doped polyaniline films. In both cases, for samples on the insulator side of the metal-insulator transition, sigma(T)=sigma(0)exp[-[T-0/T](m)], where m similar to 0.5, whereas for the most heavily ion-implanted polyaniline films sigma(T similar to-T at T>20 K; the minimum in the sigma(T) occurs at T similar to 20 K and a negative magnetoconductance Delta sigma(H,T)similar to H-2 has been observed. It is shown that electron-electron Coulomb interactions play an important role in charge-carrier transport in ion-implanted polyaniline films near the metal-insulator transition.