The graphitization process and the synthesis of diamonds from a C-Ni-Mn system

The influence of the degree of graphitization on the synthesis of diamond obtained from a HP-HT process using an anvil type high pressure device was studied for different types of graphites. The degree of graphitization was measured by a new parameter the percentage of hexagonal perfection (PHP). Results have shown that for samples with a PHP below 50% no diamond was formed. This suggested that a minimum degree of graphitization must be present for a successful HP-HT for diamond synthesis. (C) 2004 Published by Elsevier Ltd.