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O. I. Shpotyuk E. R. Skordeva R. Ya. Golovchak V. D. Pamukchieva A. P. Kovalskii 《Journal of Applied Spectroscopy》1999,66(5):749-753
The radiative-optical properties of chalcogenide glass-like semiconductors of the As2S2−Ge2S3 system in the region of a topological 2D-3D-phase transition are investigated. It is shown that γ-irradiation of samples
by an absorbed dose of 4.4 · 106 Gy leads to a longwave shift of their optical-transmission edge in the spectrum. The effect observed depends on the structural
type of the glasses investigated and changes considerably near the 2D-3D-phase transition. Two components of the transmission-edge
shift are detected: a static component, which remains unchanged for a long time after irradiation of the samples, and a dynamic
one, which gradually fades in 2–3 months. It is suggested that the microstructural mechanism of these changes is attributable
to processes of coordination defect formation in the structural skeleton of the samples.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, pp. 657–660, September–October, 1999. 相似文献
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An atomistic view on Johari–Goldstein secondary β-relaxation processes responsible for structural relaxation far below the glass transition temperature (Tg ) in network glasses is developed for the archetypal chalcogenide glass, As20Se80, using positron annihilation lifetime, differential scanning calorimetry, Raman scattering and nuclear magnetic resonance techniques. Increased density fluctuations are shown to be responsible for the initial stage of physical ageing in these materials at the temperatures below Tg . They are correlated with changes in thermodynamic parameters of structural relaxation through the glass-to-supercooled liquid transition interval. General shrinkage, occurred during the next stage of physical ageing, is shown to be determined by the ability of system to release these redundant open volumes from the glass bulk through the densification process of glass network. 相似文献
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A. IngramR. Golovchak M. KostrzewaS. Wacke M. ShpotyukO. Shpotyuk 《Physica B: Condensed Matter》2012,407(4):652-655
Compositional dependence of average positron lifetime is studied systematically in typical representatives of binary As-S and As-Se glasses. This dependence is shown to be in opposite with molar volume evolution. The origin of this anomaly is discussed in terms of bond free solid angle concept applied to different types of structurally-intrinsic nanovoids in a glass. 相似文献
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A mechanism for γ-ray-induced changes in the optical properties of ternary Ge–As sulphide glasses is analysed at the microstructural level. It is shown, using IR FFT spectroscopy, that these changes are associated with chemical bond switching accompanied by coordination topological defect formation. 相似文献
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The structure of binary GexS100 − x chalcogenide glasses (10 < x < 30) is determined by high-resolution X-ray photoelectron spectroscopy (XPS). On the basis of compositional dependence of fitting parameters for Ge and S core level XPS spectra, the ratio between edge- and corner-shared tetrahedra is determined. It is shown that short-range order of these glasses includes fragments of high-temperature crystalline form of GeS2. When subjected to X-irradiation, the structure of investigated glasses appears to become more homogeneous than that of the as-prepared samples. 相似文献
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