Structural analysis of pyrolytic carbon deposits on a planar cordierite substrate

摘要

Pyrolytic carbon deposits were produced by chemical vapor deposition on a planar substrate of cordierite using methane as a source gas.The structure of the deposits was characterized by light microscopy,scanning electron microscopy(SEM)and transmission electron microscopy(TEM)combined with electron-energy-loss spectroscopy(EELS).The surface morphology is characterized by a cell structure induced by grains elongated perpendicular to the substrate surface.Energetic shift and intensity fluctuation of plasmon peaks in EELS spectra taken from cell and interface regions between the cells correlate with an alteration of the SEM image contrast observed on freshly fractured surfaces.This correlation suggests the presence of a mixture of two materials exhibiting different crystallization degrees.The material located at the interface is more amorphous-like in comparison to the graphite-like material located within cells.