Trigonal and orthorhombic Au or Pt defects in material that was also doped with Li and P were shown to be aggregates that involved substitutional Au or Pt, plus interstitial Li. The small Li hyperfine interactions, which were not resolved by electron paramagnetic resonance, could be measured by means of electron nuclear double resonance techniques. In this way, it was established that the trigonal defects consisted of AuSi-Li3 or PtSi-Li3 aggregates. The orthorhombic defects were AuSi-Li or PtSi-Li pair defects. In the case of the trigonal defects, the Li hyperfine interaction matrices were asymmetrical. The smallness of the Li hyperfine interaction suggested that ionic bonding existed between the interstitial Li ions and the substitutional AuSi or PtSi atoms.

P.Alteheld, S.Greulich-Weber, J.M.Spaeth, H.Weihrich, H.Overhof, M.Höhne: Physical Review B, 1995, 52[7], 4998-5006