Mössbauer Studies of the Local Surrounding of Atoms in Amorphous and Crystalline Ge₂Sb₂Te₅ Films

Abstract—Using the method of absorption Mössbauer spectroscopy on ¹¹⁹Sn, ¹²¹Sb, and ¹²⁵Te isotopes, it is demonstrated that the local structure of germanium atoms changes during the crystallization of amorphous Ge₂Sb₂Te₅ films (their tetrahedral symmetry changes to octahedral symmetry). The surrounding of antimony and tellurium atoms does not change, although for antimony atoms, it is similar to that in the Sb₂Te₃ compound. The antistructural defects of tin in the antimony and tellurium nodes of the crystalline films Ge²Sb²Te⁵ are identified by the method of emission Mössbauer spectroscopy on the ^119mSn impurity centers formed after the radioactive decay of the parent atoms ¹¹⁹Sb and ^119mTe.