title: Radiation-modified structure of Ge25Sb15S60 and Ge35Sb5S60 glasses.
abstract: Atomic structures of Ge(25)Sb(15)S(60) and Ge(35)Sb(5)S(60) glasses are investigated in the gamma-irradiated and annealed after gamma-irradiation states by means of high-energy synchrotron x-ray diffraction technique. The first sharp diffraction peak (FSDP) is detected at around 1.1 A(-1) in the structure factors of both alloys studied. The FSDP position is found to be stable for radiation/annealing treatment of the samples, while the FSDP intensity shows some changes between gamma-irradiated and annealed states. The peaks in the pair distribution functions observed between 2 and 4 A are related to the Ge-S, Ge-Sb, and Sb-Sb first neighbor correlations and Ge-Ge second neighbor correlations in the edge-shared GeS(42) tetrahedra, and S-S and/or Ge-Ge second neighbor correlations in the corner-shared GeS(42) tetrahedra. Three mechanisms of the radiation-/annealing-induced changes are discussed in the framework of coordination topological defect formation and bond-free solid angle concepts.
authors.affiliation: Institute of Materials, Scientific Research Company "Carat," 202 Stryjska Str., Lviv 79031, Ukraine. kavetskyy@yahoo.com
authors.forename: T
authors.initials: T
authors.lastname: Kavetskyy
authors.forename: O
authors.initials: O
authors.lastname: Shpotyuk
authors.forename: I
authors.initials: I
authors.lastname: Kaban
authors.forename: W
authors.initials: W
authors.lastname: Hoyer