Metal–insulator transition in iodinated amorphous conducting carbon films

In this work, the effect of iodine incorporation on the electrical conductivity, magnetic susceptibility (\chi) and magnetoresistance (MR) of amorphous conducting carbon (a-C) films has been discussed. Variation in conductivity of a-C films depends on the sample preparation conditions and iodine concentration. Evidence of metal-insulator (M-I) transition as a function of pyrolysis temperature is observed for iodinated (a-C:I) samples. The temperature dependent magnetic susceptibility of a-C:I sample shows a Curie behavior at low temperatures. The positive magnetoresistance is observed for all the samples irrespective of the conduction regimes. This is accounted by the electron-electron interaction in the a-C:I system.