Abstract

Diamonds have been synthesized by a combustion flame route using C₂H₂+O₂. Crystals formed under various conditions were studied in detail for better understanding of the growth mechanisms involved. New evidence has been obtained which show clearly a double spiral crystal growth mechanism operating on some (111) faces of diamond crystals of cubo-octahedral habit. SEM observations suggest that initially formation of a step in a <110> direction pinned at two sites, possibly as a result of high temperature slip, occurs on the (111) face; these two sites become in effect screw dislocation outcrops of opposite sign enabling a double spiral growth mechanism to become operative.

© 1995 Optical Society of America