Abstract
Carbon and graphite films were prepared from the laboratory-made Kapton-type polyimide film, and the electric conductivities parallel, σ//, and perpendicular, σ⊥, to the surface were measured at room temperature. Anisotropy of electric conductivity was observed even for the 700°C treated film and the ratio, σ///σ⊥, increased with raising heat treatment temperature (HTT). The carbon films formed at HTT=1200-1600°C showed nearly the same conductivity, and σ///σ⊥ in this range was 450-550. The conductivities and sailla σ///σ⊥ ratio increased with further raising HTT up to 2800°C. The structural changes of the films were also investigated by using XRD and TEM.
