Impurity diffusion and microstructure in diamonds deformed at high pressures and temperatures

Results of a comprehensive study of the influence of deformation at high-pressure and high-temperature conditions on diamond microstructure and nitrogen diffusion are presented. Selection of the pressure medium allows the introduction of different types of extended defects (dislocations, mechanical twins). Despite clear differences in microstructure of diamonds deformed in variable pressure mediums, the relationship between the deformation and the rate of aggregation of the C to A nitrogen defects is still not clear. In some cases the deformation apparently increases the aggregation rate; in others no effect or even a decrease in the conversion rate was observed.