Positron annihilation experiments revealed an open-volume defect in the deep state atomic configurations of In and Ga bistable donors. The size of the open volume was equal to at least 50% of a monovacancy. The results were similar to those obtained for DX centers in the covalent AlxGa1−xAs system. It was concluded that the bond-breaking mechanism (substitutional to interstitial atomic motion) which was responsible for the metastability of point defects in covalent semiconductors was universal and extended to some highly ionic compounds.

Evidence on a Bond-Breaking Relaxation in the Bistable Centers In and Ga in CdF2. J.Nissilä, K.Saarinen, P.Hautojärvi, A.Suchocki, J.M.Langer: Physica B, 1999, 273-274, 915-8