High conductivity and positive magnetoresistance in the organic metal poly (3-methylthiophene)

Temperature dependence of conductivity and magnetoresistance have been measured in new highly conducting triflimide [(CF3SO2)2N−]-doped poly (3-methylthiophene) films. Besides the very high room temperature conductivity, several arguments lead to the conclusion that this material lies in the critical regime of the metal-insulator transition. The magnetoresistance is positive even at low magnetic fields. This behaviour is significant of a spin-alignment transport mechanism.