Gas release from the ZrO2-Y2O3 ceramics used in the seeded growth of diamond single crystals

Gas release from the ZrO2-Y2O3 ceramics used for the seeded growth of diamond single crystals in a temperature range from 100 to 700°C and a pressure of 10−4 Pa is investigated. It is experimentally found that the air content in the pores of ceramic elements of the container is 0.086 sccm3/g. The coefficient of the gas release and diffusivity are determined; this allows one to determine the degassing time for which the gas fraction from the sample attains a definite value from the starting amount. It is revealed that vacuum annealing at a temperature no lower than 700°C and P = 10−4 Pa provides a decrease in the content of the adsorbed gas on the parts of the reaction cell by an order of magnitude.