TEM INVESTIGATION OF CVD GRAPHITE ON NICKEL

Graphite films have been deposited by chemical vapour deposition from C2H4 at 1170 K on polycrystalline Ni substrates. The graphite films we re characterized with respect to surface morphology and microstructure . The interface between the deposited graphite and the Ni grains was i nvestigated by transmission electron microscopy. A smooth interface be tween the graphite and the Ni was observed. Electron diffraction was u sed to determine orientation relationships between the graphite and th e Ni grains. Four different Ni grain orientations were found and for a ll four the graphite layers grow parallel to the Ni grain surface. A n ucleation and growth mechanism involving hydrogen abstraction reaction s and formation of polycyclic hydrocarbons has been proposed.