ELECTRIC AND MAGNETIC-PROPERTIES OF CHEMICAL-VAPOR-DEPOSITION CARBON-FILMS

Carbonaceous films with metallic luster have been prepared by pyrolytic chemical vapor deposition on the inside surface of a quartz tube at 1000-degrees-C using hydrocarbon including oxygen atoms such as phenols as raw material. The x-ray diffraction, electrical conductivity, thermoelectric power, and electron-spin-resonance (ESR) characteristics of the films heat treated to between 1000 and 2800-degrees-C have been examined. These results indicate complete graphitization of the films by the heat treatment. The three-dimensional ordering of crystallites in the films and increase in the electrical conductivity have proceeded in the range 2000-2200-degrees-C. The concomitant fall in the thermoelectric power in the same range suggests the contribution of two carriers (holes and electrons). The increasing rate of g shift has been also enhanced in this range. The unusual broadening in the ESR linewidth has occurred around the temperature where a localized center appears and seems to be caused by scattering of mobile charge carriers at the localized centers.