EVIDENCE FOR GLIDE AND ROTATION DEFECTS OBSERVED IN WELL-ORDERED GRAPHITE FIBERS

New structural features observed in heat-treated vapor-grown carbon fi bers (VGCF's), produced by the thermal decomposition of hydrocarbon va por, are reported using image analysis of the lattice plane structure observed by transmission electron microscopy (TEM) and atomic force mi croscopy (AFM). The TEM lattice image of well-ordered graphite fibers (heat-treated VGCF's at 2800 degrees C) was treated by a two-dimension al fast Fourier transform, showing sharp bright spots associated with the 002 and 100 lattice planes. The heat-treated VGCF's consist of a p olygonally shaped shell, and the long and short fringe structures in t he TEM lattice image reflect the 002 and 100 lattice planes, respectiv ely. From this analysis, new facts about the lattice structure are obt ained visually and quantitatively. The 002 lattice planes remain and a re highly parallel to each other along the fiber axis, maintaining a u niform interlayer spacing of 3.36 Angstrom. The 100 lattice planes are observed to make several inclined angles with the 002 lattice planes relative to the plane normals, caused by the gliding of adjacent graph ene layers. This work visually demonstrates coexistence of the graphit ic stacking, as well as the gliding of the adjacent graphene layers, w ith a gliding angle of about 3-20 degrees. These glide planes are one of the dominant stacking defects in heat-treated VGCF's. On the other hand, turbostratic structural evidence was suggested by AFM observatio ns. The structural model of coexisting graphitic, glide, and turbostra tic structures is proposed as a transitional stage to perfect three-di mensional stacking in the graphitization process, These structural fea tures could also occur in common carbons and in carbon nanotubes.