Observations were made of orthorhombic Au-Li and Pt-Li pairs by using electron paramagnetic resonance, electron nuclear double resonance techniques and MCDA spectroscopy. It was possible to mistake the electron paramagnetic resonance spectra as being due to orthorhombic isolated point defects. Electron nuclear double resonance examination was required in order to detect the Li partner of the pair. A comparison of the MCDA spectra with conventional infra-red absorption showed that the optical spectra which were usually associated with the isolated substitutional Au point defect were excited from a paramagnetic ground state. It was shown that the interpretation of the Si-NL50 center as being the isolated substitutional AuSi0 defect was unlikely.

S.Greulich-Weber, P.Alteheld, J.Reinke, H.Weihrich, H.Overhof, J.M.Spaeth: Semiconductor Science and Technology, 1995, 10[7], 977-82