Influences of additive sulfur on the synthesis of industrial diamonds, using Ni70Mn25Co5 alloy powder as catalyst

Sulfur was introduced to the synthesis of industrial diamonds using Ni70Mn25Co5 alloy powder as catalyst. Optical microscope, XRD, XPS, and SEM were utilized for observation and detection. The influences of additive sulfur on the synthesis have been investigated from several aspects such as the diamond-forming conditions, the composition of synthesized sample and inclusions in diamond, and the morphology character of diamonds etc. The results indicate that the formation of MnS, which should have been in a solid state during the synthesis, has an important influence on the synthesis of industrial diamonds.