Modeling of temperature fields in the growth volume of the high-pressure cell of the six-punch high pressure apparatus in growing of diamond crystals by T-gradient method

Abstract

Based on the finite element method a computer model is developed to determine the heat state of the six-punch high-pressure apparatus with a high-pressure cell for growing structurally perfect diamond single crystals. The temperature fields in the high-pressure cell were calculated during the growing diamond single crystals depending on the internal and outside diameters of graphite current shunt, which allows us to change the temperature at the characteristic points of high pressure cell by 20–110°C, horizontal and vertical temperature drops in a growth volume by 3–18°C and the temperature gradient in it by 0.17–2.0 deg/mm. Based by the calculations of temperature fields, the experiments were conducted and the diamond single crystals up to 5 mm in size were obtained. The crystals quality depends on the place in the growth volume and corresponds to the calculated data.