An effective method for elimination of the defects in diamond caused by physical field asymmetry in high-pressure synthesis cavities

Abstract

In this work, we found that growth defects with terrace pits were formed during the growth of diamond synthesized for a long time using a temperature gradient growth method under high pressure and high temperature conditions. To explain the formation of defects, the temperature field and flow field under the catalyst growth conditions were analysed for the first time using finite element method simulations. The simulation results accurately explain the formation mechanism of growth defects on diamond crystals, with the calculated results showing good agreement with the experimental data. Excitingly, we propose two simple and effective methods for the elimination of the defects by merely adjusting the catalyst thickness and diameter. These methods not only improve the quality of large single crystal diamond, but also help to reduce the cutting cost of commercial diamond.