A new approach to investigation of nickel defect transformation in the HPHT synthetic diamonds using local optical spectroscopy

The analysis of spatial photoluminescence distribution along a plate from synthetic diamond as grown at 1500 °C allowed us to study a sequence of formation of nitrogen–nickel optically active centers and to build maps in some cases. Several groups of vibronic systems with specific spatial distribution along the sample were separated: nitrogen‐vacancy pairs in the thin near‐ surface layer, low‐temperature centers with blue emission, nickel–nitrogen complexes with a single nickel ion and those with several nickel ions.