Antisite defects in Ge–Te and Ge–As–Te semiconductor glasses

The formation of antisite defects in Ge$_{20}$Te$_{80}$ and Ge$_{15}$As$_{4}$Te$_{81}$ vitreous alloys in the form of tin atoms in tellurium sites and tellurium atoms in germanium sites is shown by emission Mössbauer spectroscopy with the $^{119mm}$Sn($^{119m}$Sn), $^{119m}$Te($^{119m}$Sn), $^{125}$Sn($^{125}$Te), and $^{125m}$Te($^{125}$Te) isotopes. It is shown that the isovalent substitution of germanium atoms by tin atoms does not vary the symmetry of the local surrounding of germanium sites, while tin and tellurium atoms reconstruct their local surrounding in sites unnatural for them.