Magnetoresistance of polyaniline doped by AMPSA

Free standing films (~60 μm thick) of polyaniline (PANI) doped with 2-acryloamino-2-methyl-1-propanesulfonic acid(AMPSA) are prepared by the solution casting method [1]. PANI-AMPSA shows a positive temperature coefficient of resistivity (TCR) down to 80 K, and at T<80 K it becomes negative. An anisotropic magnetoconductance (MC) has been observed in 3D isotropic samples of PANI-AMPSA. The sign of the transverse magnetoconductance (MC) is positive at 4.2 and 2.6 K. The longitudinal MC is negative at T<6 K. The longitudinal MC (negative) increases rapidly (nearly 10%) at T<2 K. This behavior of MC shows the interplay of weak localization (WL) and electron-electron (e-e) interaction and hopping contributions in 3D isotropic samples of PANI AMPSA