Deposition model and microstructure of low temperature pyrocarbon produced by chemical vapor deposition

Low temperature pyrocarbon (PyC) was prepared by chemical vapor deposition. The microstructure of the deposited PyC was investigated by scanning and transmission electron microscopy with selected area electron diffraction. Results show that the PyC is composed of spherical carbon particles less than 2 mu m in diameter. The center of the particles is carbon black, whereas the outer layer is medium-textured PyC. The deposition of the PyC includes four steps; formation of carbon black, growth of the outer layer on the carbon black, deposition of PyC on the surface of carbon particles and aggregation of carbon particles.