Confocal photoluminescence (PL) and local absorption spectroscopy were used to study the types and spatial distribution of point defects in coated diamonds, the input of which is about 30% in the Snap Lake deposit, Canada. Nitrogen concentration is on the level of several hundreds of ppm in the core, with a nitrogen-poor layer in its outer part, whereas in the coat it is usually several times higher as a result of fast growth. Nitrogen defects in the core are strongly aggregated with N3. B and B'-forms dominating, whereas A-defects are typical of the coat. The rounded shape of the coated diamonds is a result of the combined effect of partial dissolution of the octahedral core and the "abnormal" growth of the coat, which produces a fibrous structure, Analysis of PL and PL excitation spectra showed that structureless yellow-green PL of the coat is likely to be due to nickel-nitrogen complexes with their fine structure broadened in the strain fields. The presence of irradiation/annealing products such as vacancies V-0 and nitrogen-vacancy complexes NV-, N2V2 shows that the diamonds studied have undergone post-growth ionizing irradiation with further low-temperature annealing in natural conditions.
|Translated title of the contribution||Features of coated diamonds from the Snap Lake/King Lake kimberlite dyke, Slave craton, Canada, as revealed by optical topography|
|Pages (from-to)||83 - 97|
|Number of pages||15|
|Publication status||Published - 2004|
Bibliographical notePublisher: Elsevier Science BV
Other identifier: Iss. 1-4