Closed curved graphite-like structures formation on micron-size diamond

The annealing of diamond particles (d≈1000 nm) at 1800–2000 K leads to the formation of nanometric closed curved graphitic structures (CCGS) with tubular or conical forms as well as to defective extended graphitic structures. The intermediate structures that occur during the diamond transformation to curved graphitic structures have been observed. At the interface between diamond and evolving graphite the formation of two curved graphite sheets from three diamond planes (111) were detected. The CCGS formation is probably a self-assembling process. CCGSs are proposed to enhance electron emission from diamond surfaces.