Effect of iodine incorporation on the electrical properties of amorphous conducting carbon films

In this work, the influence of iodine incorporation on the electrical properties of amorphous conducting carbon films, prepared by the vapor phase pyrolysis of maleic anhydride, is reported and discussed. X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies reveal structural changes in the system. The anomalous behavior in-the electrical properties of the intercalated system at low temperatures is investigated. The system shows a positive temperature coefficient of resistance (TCR) at low temperatures, which suggests reasons for the induced ordering of the system at low temperatures with the iodine incorporation. Also, a systematic increase in the conductivity of the sample is observed. The crossover temperature depends on the disorder in the system. The results indicate the possibility of metal-insulator (M-I) transition as a function of preparation temperature, iodine concentration and magnetic field. (C) 2003 Elsevier Science Ltd. All rights reserved.