Impurity centers in synthetic and natural diamonds with a system of electron-vibronic Lines at 418 nm in luminescence spectra

Analysis of the spectra of IR absorption, ESR, and luminescence of natural and synthetic diamonds with a system of electron-vibronic lines at 418 nm in the luminescence spectrum showed the participation of nickel ions in the formation of these centers. It was assumed that the system of lines at 418 nm is the manifestation of the nickel-containing NIRIM5 center. The nature of the NIRIM5 center was discussed.