Calculation of the temperature distribution at the HPHT growing of diamond single crystals in cells with two growth layers

Abstract

Finite element method was used to calculate the distribution of temperatures in growth cells of the toroid TC-40 -type HPA. The experimental investigations of the process of growing type IIa diamond single crystals were performed in high-pressure cells with two growth layers. It is shown that in using the cell materials having appropriate properties and defined configuration of the system of the resistive heating the temperature gradients are 5.4–5.6°C/mm and the growth rate is 2.46 mg/h. The total weight of obtained structurally perfect type IIa diamond single crystals in the upper and lower growth layers is 1.18 and 1.13 carats, respectively, the nitrogen content in all grown crystals is 1–3 ppt.