Electrical conductivity of vapor-grown carbon fibers

Carbon fibers grown by pyrolysis of natural gas were heat-treated at temperatures ranging from 1400 to 3000°C, and characterized by X-ray diffraction. Their electrical resistivity is reported for temperatures between 10 and 370 K, and explained for heat treatment above 2200°C using a simple graphitic band model. Filaments heat-treated at lower temperatures and as-grown fibers show a resistivity with a small temperature dependence.