Conductivity and magnetoresistance in polypyrrole-PF6 at various doping levels

The temperature dependence of de conductivity (from 1.5 to 300 K), and magn etoresistance (up to 7T) have been studied on polypyrrole samples doped wit h PF6-(PPy - PF6) at various doping levels. In this work, the metal-insulat or transition (MIT) is tuned by varying the carrier density, and not by the extent of disorder. The conductivity data is analysed using different mode ls. The positive magnetoresistance observed for all the samples shows that electron-electron interaction is dominant.