Influence of deposition pressure on texture of pyrolytic graphite during chemical vapour deposition

To investigate the influence of deposition pressure on the texture of pyrolytic graphite, a series of experiments were carried out. The pyrolytic graphites were fabricated at 2000 degrees C with propylene as the carbon source and nitrogen as the carrier gas in a system pressure from 1.1 to 1.8 kPa. Results show that lowering the deposition pressure will increase the density and thin the growth cones. The reduce of deposition pressure will also cause an increasing in the degree of graphitisation extracted from X-ray diffraction patterns and the value of (I-G/I-D) in Raman spectra. Therefore, lower deposition pressure is more inclined to yield high texture pyrolytic graphite. Finally, the deposition mechanism was discussed.