Nickel Isotope Effects in the 1.4 eV Centre in Synthetic Diamond

Abstract

Synthetic diamonds grown using a solvent-catalyst containing nickel give optical absorption and luminescence with zero-phonon structure at 1.401 and 1.404 eV. We show that the zero-phonon lines are split as a result of the different natural isotopes of nickel. The sign and magnitude of the splitting are consistent with this assignment.

Investigation of nickel lattice sites in diamond: Density functional theory and x-ray absorption near-edge structure experiments

“…The high spectral resolution spectrum reveals two peaks of similar intensities located at 1.401 and 1.404 eV. Careful optical studies of the fine structure attributed unambiguously this center to a defect containing one single nickel atom, 47 the intensities of the lines observed in the fine structure being related to the natural abundances of nickel isotopes. This optical feature has been unambiguously associated with the EPR center NIRIM-2, 47 but has a controversial origin.…”

“…Careful optical studies of the fine structure attributed unambiguously this center to a defect containing one single nickel atom, 47 the intensities of the lines observed in the fine structure being related to the natural abundances of nickel isotopes. This optical feature has been unambiguously associated with the EPR center NIRIM-2, 47 but has a controversial origin. It has been attributed to isolated interstitial nickel Ni 29 VNi + i (3d 9 ) in a NiB complex, 35 and recently to the nickel divacancy VNi [Ni]), the 1.4-eV center is weak and other optical structures such as 1.883 and 2.51 eV are dominant.…”

Is dispersed nickel in natural diamonds associated with cuboid growth sectors in diamonds that exhibit a history of mixed-habit growth?

“…In pioneering CL spectroscopic studies of natural and synthetic diamonds Dean [5] discovered a near-IR, 1.40 eV (884 nm) emission from synthetic diamond grit, which he attributed to N impurity. Further work made clear that the 1.40 eV centre, together with some other optical centres, arose from incorporation of Ni, not N [6][7][8][9].…”

Magnetic circular dichroism of the 1.404-eV interstitial nickel absorption transition in high-pressure synthetic diamond

“…Isotope splittings on the sharp zerophonon lines, with intensity ratios that matched the abundance ratios of the naturally occurring Ni isotopes, conclusively identified a single Ni atom as part of the defect. 5,6 Uniaxial stress and Zeeman PL studies by Nazaré et al 6 have led to the conclusion that ͑i͒ the defect has trigonal symmetry, ͑ii͒ both the ground doublet and excited singlet states have effective spins, Sϭ1/2, and ͑iii͒ the groundstate levels associated with the 1.401-and 1.404-eV transitions have ⌫ 4 and ⌫ 5,6 symmetry ͑of the C 3v double group͒, respectively, while the upper state common to both transitions is ⌫ 4 . In these studies, the g values of the lower state of the doublet, determined from the Zeeman results, agreed approximately with the g values of the EPR study.…”