Magnetic behavior of multi-walled carbon nanotube/polypyrrole nanocomposite

Polypyrrole (PPy) and polypyrrole-carboxylic functionalized multiwall carbon nanotube composites (PPy/f-MWNT) were synthesized by in-situ chemical oxidative polymerization of pyrrole monomer on multiwall nanotubes. The effect of the magnetic field intensity from 0 to 10KG on the conductivity of the nanocomposites was studied. The Hall coefficient and Hall mobility of PPy and PPy/ f-MWNT nanocomposite samples with different concentrations of MWNT were measured using the Van der Pauw technique in the same magnetic field range. The mobility decreased slightly with the increasing magnetic field, while the conductivity is dominated by a gradual increase in carrier density. The conductivity values demonstrate the utility of these complex composites as photovoltaic materials. With increasing CNT content, the measured magnetoresistance of the samples became more negative, which supports the fact that the average localization length of the nanocomposite materials is increased, and the charge transport is dominated by the MWNTs.