title: A study of reversible gamma-induced structural transformations in vitreous Ge23.5Sb11.8S64.7 by high-resolution X-ray photoelectron spectroscopy.
abstract: The structural origin of reversible gamma-induced effects in vitreous Ge(23.5)Sb(11.8)S(64.7) has been investigated by high-resolution X-ray photoelectron spectroscopy (XPS). The changes in valence band spectrum from gamma-irradiation suggest a decrease of sulfur lone pair electron concentration accompanied by changes in bonding states of S and Ge. The appearance of additional doublets in the core-level XPS spectra of Ge, Sb, and S atoms for gamma-irradiated sample is described by the formation of over- and under-coordinated charged defect pairs (Ge(3)(-)-S(3)(+)) as a result of radiation treatment. The results verify the switching of Ge-S covalent bonds into S-S bonds as the main microstructural mechanism for gamma-induced optical effects in this glass.
authors.affiliation: Department of Materials Science and Engineering, Lehigh University, Bethlehem, Pennsylvania 18015-3195, USA.
authors.forename: Andriy
authors.initials: A
authors.lastname: Kovalskiy
authors.forename: Himanshu
authors.initials: H
authors.lastname: Jain
authors.forename: Alfred C
authors.initials: AC
authors.lastname: Miller
authors.forename: Roman Ya
authors.initials: RY
authors.lastname: Golovchak
authors.forename: Oleh I
authors.initials: OI
authors.lastname: Shpotyuk