The Annealing Kinetics of Defects in CVD Diamond Irradiated by Xe Ions

The radiation-induced optical absorption at 1.5–5.5 eV (up to the beginning of funda-
mental absorption) has been analyzed in CVD diamond disks exposed to 231-MeV $^{132}$Xe ions with
four fluences from 10$^{12}$ to 3.8 × 10$^{13}$ cm$^{-2}$. The 5 mm diameter samples (thickness 0.4 mm) were pre-
pared by Diamond Materials, Freiburg (Germany); the average grain size at growth site was around
80 μm; and the range of xenon ions was R = 11.5 μm. The intensity of several bands grows with
ion fluence, thus confirming the radiation-induced origin of the defects responsible for these bands.
The recovery of radiation damage has been investigated via isochronal (stepwise) thermal annealing
procedure up to 650 ◦C, while all spectra were measured at room temperature. Based on these spectra,
the annealing kinetics of several defects, in particular carbon vacancies (GR1 centers with a broad
band ~2 eV) and complementary C-interstitial-related defects (~4 eV), as well as impurity-related
complex defects (narrow bands around 2.5 eV) have been constructed. The experimental kinetics
have also been analyzed in terms of the diffusion-controlled bimolecular reactions. ... mehrThe migration
energies of tentatively interstitial atoms (mobile components in recombination process) are obtained,
and their dependence on the irradiation fluences is discussed.