Stacked AA graphite has been synthesized using a high-density dc plasma in hydrogen-methane mixtures. Graphene layers have been grown epitaxially with 2-1 registration between the AA graphitic edges and the (111) surface of diamond. In addition, a new graphite crystal structure containing A A' graphene layers, where alternate planes are translated by half the hexagon width, is formed by 1-1 registry. The resulting interplanar distances of the AA graphite at the interface range from 2.20 Å for the 1-1 registration to 4.40 Å for the 2-1 registration and have been measured directly by high-resolution transmission electron microscopy (TEM). The appearance of the characteristic d -spacings, 3.55, 2.15, 1.80, 1.75 (not fully resolved), and 1.25 Å in the selective area diffraction patterns from the TEM, are consistent with reflections from the (001), (100), (102), (002), and (110) planes of the AA graphite. Simulation of the diffraction patterns, employing the structural factors of graphene, confirms the existence of AA graphite. © 2008 American Institute of Physics.
|Journal||Journal of Chemical Physics|
|Publication status||Published - 2008|