EPR identification of the 〈100〉-split[B−N]+interstitialcy in diamond

Abstract

Based on the ${}^{11}\mathrm{B}$ and ${}^{14}\mathrm{N}$ hyperfine interactions determined by using the electron paramagnetic resonance technique, the NIRIM-4 center in electron-irradiated boron-doped synthetic diamond crystal has been identified as a 〈100〉-split $[\mathrm{B}\ensuremath{-}\mathrm{N}{]}^{+}$ interstitialcy. The ${\mathrm{C}}_{2v}$ symmetry of the spectrum requires that the nitrogen atom and boron atom lie on the same [100] axis. The contributions to the wave function of the unpaired electron from the atomic orbitals of nitrogen and boron are almost purely $p$-like, with the directions of $p$ orbitals along [011] and [01\ifmmode\bar\else\textasciimacron\fi{}1], respectively.