NEW FEATURES REGARDING THE HIGH PRESSURE AND HIGH TEMPERATURE DIAMOND SYNTHESIS GROWTH IN THE Ni-Mn-C SYSTEM WITH IRON ADDITIONS

摘要

It is well recognized that a catalyst agent is essential to synthesize diamond at high pressure and high temperature. The catalyst agent also acts as a carbon solvent and affects the properties of the final product. This is a consequence of its direct influence on the growth of diamonds crystals. The control of the growth, which is required to achieve a high quality level, is still a question open to discussion. In this work, an industrial diamond powder was synthesized from graphite using Ni-Mn as catalyst alloy added with up to 5% of iron. The synthesis was carried out at 4.5GPa and 1300℃ for 10 minutes in high pressure device with central concavity. The analysis of the cubic-shaped diamond surface topography suggests that the formation of defects on the {111} faces is most likely a consequence of a complex growth process that influences the crystal productivity and morphology.