An effective method to improve the growth rate of large single crystal diamonds under HPHT processes: optimized design of the catalyst geometric construction

In this work, we presented the influence of catalyst geometric construction on temperature distribution, flow structure, the transport processes of the carbon atoms, and the resulting diamond growth in the process of HPHT diamond synthesis. Several catalyst geometry models were tested, and the experimental results of growth rates were compared with numerical simulations. We revealed that increasing the protrusion diameter of the convex-shaped catalysts could significantly improve the growth rate of diamonds. The diamond growth rate was improved from 1.6 mg h⁻¹ to 4 mg h⁻¹ when the protrusion diameter was enlarged by 2 mm. These results will be discussed through the characteristic distributions of the temperature and convection fields in the process of diamond growth.

In this work, we presented the influence of catalyst geometric construction on temperature distribution, flow structure, the transport processes of the carbon atoms, and the resulting diamond growth in the process of HPHT diamond synthesis.

Synthesis of large diamond single crystals under high pressure and high temperature through effective utilization of the synthesis cavity

To make maximal use of the synthesis cavity and improve the production efficiency, we designed the double seed bed method to synthesize large diamond crystals under high pressure and high temperature (HPHT) conditions, and the results were both theoretically calculated and verified by experiments.

Preparation of “natural” diamonds by HPHT annealing of synthetic diamonds

In this paper, IIa, Ib, N-doped and N–H co-doped diamonds were studied, and the interaction mechanisms between hydrogen and nitrogen in the diamonds were investigated in detail.