Express-analysis of nitrogen content in CVD-diamonds by FTIR-spectrometry

Natural and synthetic diamonds most often contain nitrogen impurities, which can form tens of impurity and impurity-vacancy centers in the crystal structure of diamond. At the same time, crystals properties of and possibility of their use in specific application strongly depend on the diamonds impurity composition. In this work, we investigated by the method of Fourier-transform infrared spectrometry (FTIR) the impurity composition of HPHT-diamond substrates and changes in it after the deposition of diamond layers by the CVD-method. We used Ardis 300 for deposition of diamond layers from methane-hydrogen plasma with 3% methane at a temperature of 1100 °C, a pressure of 26.7 kPa and a power of 3800 W on diamond HPHT-substrates containing from 70 to 200 ppm of nitrogen. The proposed technique makes possible to study the integral content of impurities in diamond, which will make it possible to quickly evaluate the result of the diamond layers synthesis and conclude about the possibility of their application in various fields of science and technology, as well as use in jewelry industry.