Structure and microtexture of graphitized carbon film derived from aromatic polyimide film upilex Original Research Article

The structure and microtexture of the 3000 °C treated carbon film prepared from a polyimide film Upilex with a thickness of 50 μm (Upilex-3000) were studied by SEM observation and X-ray diffraction measurements. The thickness of Upilex-3000 was 30 μm. Observation of the fracture surface of Upilex-3000 by SEM indicates three kinds of microtextures: (1) skins of 230–300 nm in thickness with well-aligned layer microtexture at both the top and bottom surfaces; (2) regions with rough layer microtexture of about 1 μ in thickness each of which neighbors one of the skins; and (3) interior regions with granular microtexture. Analysis of the X-ray diffraction patterns measured in reflection and transmission modes reveals that the structure of each of the skins is a graphite structure, each of the regions with rough layer microtexture has a turbostratic structure, and the interior region with granular microtexture a turbostratic structure with interlayer spacing d002 larger than that of the regions with rough layer microtexture.