MAGNETOCONDUCTIVITY IN DOPED POLY(P-PHENYLENEVINYLENE)

Magnetoconductivity in highly doped (with H2SO4 and FeCl3) poly(p-phen ylenevinylene) (PPV) has been studied. Oriented samples with different stretching ratios were measured. A room-temperature conductivity of 1 0(3)-10(4) S cm(-1) is achieved in highly oriented PPV, depending on t he dopant. PPV-H2SO4 is metallic and has a strong positive magnetocond uctance while PPV-FeCl3 is insulating and its magnetoconductance predo minantly negative and large. In PPV-H2SO4 the magnetoconductance is an alysed with the localization-interaction model for disordered metals. The positive magnetoconductance of highly oriented PPV-H2SO4 is due to weak localization. Its size, temperature dependence and anisotropy is discussed. With a lower stretching ratio we find negative magnetocond uctance.