Some properties of diamonds synthesized in the new Mg–Ni–C system

Abstract

Diamonds obtained in the Mg–C system were found to exhibit semi-conducting properties and cubic morphology. In these cases, strict synthesis processing parameters are required (8.0–8.5 GPa and 1800–2100 °C). The present work aims to study the mechanical and electrical properties of diamonds in the new Mg–Ni–C system. The new system has the advantage of allowing the reduction of synthesis parameters. The Mg–Ni alloy was initially produced by the preparation (4.0 GPa/1300 °C) of a Mg and Ni powders mixture. Diamond synthesis was conducted (5.5–7.7 GPa and 1250–1700 °C) with compositions varying between 15 at% Mg+85 at% Ni, and 85 at% Mg+15 at% Ni. Semi-conducting diamond was obtained with granulometry ranging from 40 to 250 μm. Some crystals displayed a cubic morphology. The best results were obtained for pressures ranging from 6.5 to 7.7 GPa, and temperatures ranging from 1550 °C to 1700 °C.

Keywords:

• high pressure
• diamond synthesis
• catalytic
• properties