THE INFLUENCE OF WEAK-LOCALIZATION AND COULOMB INTERACTION ON THE LOW-TEMPERATURE RESISTANCE AND MAGNETORESISTANCE OF ION-IMPLANTED METALLIC POLYANILINE FILMS

The low temperature conductivity and magnetoresistance of ion implante d (Ar+) metallic polyaniline films have been studied. For the samples with R(1.9K)/R(300K) similar to 1.2, temperature dependence of the she et resistivity at T < 15 K is described by the law Delta R(T)/R(T-0)si milar to - lgT. The temperature coefficient of resistivity for the mos t metallic samples was found to chanes sign from negative to positive at T < 20 K and back to negative at T < 1.6 K. Magnetoresistance at T > 1 K was found to be positive and Delta R(H,T)/Delta R(0,T)similar to H-2 and similar to lgH in weak and strong magnetic fields. Negative m agnetoresistance was observed at T < 1 K in weak perpendicular magneti c fields. The results obtained are explained in terms of weak localiza tion and electron-electron Coulomb interaction theories in a quasi-two -dimensional disordered system.