Abstract
Behaviors of the diamond formation reactions from graphite carbon source under the excess pressure in a molten metallic solution of carbon is characterized by the appearance of the regrown graphite, and can be optionally controlled by relative thermodynamical stabilities of the source, the regrown graphite and diamond to be formed, which are adjusted by the reaction pressure and its sequential change. Detailed understanding of the growth process in the temperature gradient method leads to an improved geometry of the growth space for an efficient growth. Problem of the growth surface is also discussed from the view points of "sound" growth without entrapping the solvent and incorporation of the solvent-composing elements as impurities dissolved in diamond.
