Tin impurity centers in glassy germanium chalcogenides

Tin atoms produced by radioactive decay of ^119mm Sn and ¹¹⁹Sn impurity atoms in the structure of Ge _x S_{1 − x} and Ge _x Se_{1 − x} glasses are stabilized in the form of Sn²⁺ and Sn⁴⁺ ions and correspond to ionized states of the amphoteric two-electron center with negative correlation energy (Sn²⁺ is an ionized acceptor, and Sn⁴⁺ is an ionized donor), whereas the neutral state of the Sn³⁺ center appears to be unstable. ¹¹⁹Sn atoms produced by radioactive decay of ^119m Te impurity atoms in the structure of Ge _x S_{1 − x} and Ge _x Se_{1 − x} glasses are stabilized at both chalcogen sites (they are electrically inactive) and germanium sites.