THE ATOMIC-STRUCTURE OF CO DIMERS IN SILICON

We present Mossbauer spectra for Co-related point defects in silicon w ith emphasis on Co dimers. With the help of ab initio total energy cal culations we show that dimers constructed from two interstitial Co-i p oint defects would not be stable. Dimers involving substitutional Co-S i point defects are also not stable unless in aggregates with donors. We show that an aggregate involving one Si-i self-interstitial is the most likely candidate for the Co dimer observed experimentally.