The production rate of the neutral <001>-split self-interstitial (measured via the electron paramagnetic resonance concentration of the R2 defect) was studied in type-IIa diamond. The samples were irradiated with 2MeV electrons at 110 to 350K, using a beam flux of 7.5 x 1013/cm2. Upon annealing at 700K, the neutral <001>-split self-interstitial (R2) defect was mobile and annealed out with an associated energy of 1.6eV, plus some loss of neutral vacancies. A significantly reduced production rate of R2 at 110 to 350K was attributed to radiation-enhanced annealing.

The Production and Annealing Stages of the Self-Interstitial Defect in Diamond. D.J.Twitchen, D.C.Hunt, C.Wade, M.E.Newton, J.M.Baker, T.R.Anthony, W.F.Banholzer: Physica B, 1999, 273-274, 644-6