Electron paramagnetic resonance studies were made of nitrogen-doped diamond that was 15N enriched, electron-irradiated and annealed. Electron paramagnetic resonance spectra from two new nitrogen-containing S = ½ defects were detected and labelled WAR9 and WAR10. It was shown that the properties of these defects were consistent with their being the <001>-nitrogen split interstitial and the <001>-nitrogen split interstitial–<001>-carbon split interstitial pair, respectively. An explanation was also provided for why these defects had not been discovered previously.

Electron Paramagnetic Resonance Studies of Nitrogen Interstitial Defects in Diamond. S.Felton, B.L.Cann, A.M.Edmonds, S.Liggins, R.J.Cruddace, M.E.Newton, D.Fisher, J.M.Baker: Journal of Physics - Condensed Matter, 2009, 21[36], 364212