New assembly design suitable for tower-shaped large size single-crystal diamond growth under high pressure and high temperature

Abstract

During the synthesis of tower-shaped large size single crystal diamonds, a concave growth defect always occurs on the top surface of the diamonds when using the temperature gradient growth (TGG) method under high pressure and high temperature (HPHT) conditions. To explain the formation of these defects, we have analyzed experimental results, and performed theoretical calculations. Then, we designed a new assembly that is suitable for tower-shaped diamond growth. Compared to the traditional assembly, it can effectively eliminate the growth defects and provide a more suitable convection field for tower diamond growth. Simulation and experimental results confirm the effectiveness of the proposed design. The new assembly can be widely used in the industrial and commercial production of synthetic diamonds.