Peculiarities of the Structure Analyses and Impurity Composition of HPHT- Diamonds at Laser-Induced Surface Transformation

The structure and impurity composition of the surface of multi-sector HPHT- diamond plates doped with nitrogen or boron were analyzed by laser-induced breakdown spectroscopy. Changes in the plasma spectra in the process of laser-induced transformation of the test sample surface under the action of a series of laser pulses at one selected point were recorded. It was found that after such a laser action on the sample, a different degree of surface graphitization occurs, which depends on the degree of doping of diamond with nitrogen or boron and on the crystallographic orientation of the growth sectors. In this case, an increase in the sensitivity of the LIBS method is also observed. As a result of such a difference in the process of graphitization, it becomes possible to identify the boundaries of the sectoral structure of samples and atomic structures with different strengths of interatomic chemical bonds of carbon and hydrogen. A fast algorithm for spectra processing with their normalization after each laser pulse turned out to be effective in studying samples in real-time mode. Based on the results of the measurements, experimental dependences of impurity distributions in different sectors of multisector HPHT- diamond plates doped with nitrogen or boron were obtained. Moreover, the shape of dependences for various impurities obtained in the process of pulse-to-pulse laser-induced transformation of the HPHT- diamond surface can serve as a criterion for the degree of disorder in its structure