The annealing of diamond particles (d approximate to 1000 nm) at 1800-
2000 K leads to the formation of nanometric closed curved graphitic st
ructures (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. (C) 1998 Published by Elsevier Science B.V. All rights reser
ved.