Growth and characterization of graphite single crystals

Graphite single crystals were grown by precipitation from carbon-saturated molten iron and nickel. They were grown with low nucleation and growth rates under conditions of low supersaturation, using slow-cooling and steady-state thermal gradient methods. Crystals that were produced included thin platelets up to 3 cm across and a fraction of a millimeter thick, tabular crystals measuring several millimeters across, and a form not previously reported: columnar crystals up to 2 mm long. Details of crystal characterization, including crystal morphology, cleavage, twinning, etching, dislocation geometry and lattice distortions were examined and are reported. The crystals most nearly approaching ideality were the columnar crystals. Those with the greatest amount of mosaic substructure were the thin platelet crystals. The characterization details are correlated with growth conditions. It is concluded from this work that with sufficient attention to details and abundant patience, growth of high quality graphite crystals with substantial size has been demonstrated to be feasible.