Effects of carbonyl nickel powders on {100}-oriented single diamond under high pressure and high temperature

In this paper, perfect {100}-oriented single diamonds with higher nitrogen concentration are successfully synthesized at a pressure of 5.5 GPa and temperature ranging from 1285 to 1294 °C by the adjustment of catalyst (Fe64Ni36) components. The content of carbonyl nickel powders has significant effect on the nitrogen concentration and the growth rate of the diamond crystals. Fourier transform infrared (FTIR) measurements reveal that the value of nitrogen concentration for the synthesized diamond is up to approximately 1020 ppm. Furthermore, basing on the diamond surface configuration, the structure of growth steps arranged layer by layer on {111} face is noticed using scanning electron microscopy (SEM), whereas the occurrence is not observed on {100} face.

► Diamonds {100}-oriented with higher nitrogen content are successfully synthesized.
► The concentration of nitrogen increases as the carbonyl nickel content increasing.
► The different defects between {111} and {100} faces are observed.