Compositional changes of the first sharp diffraction peak in binary selenide glasses

Abstract

Compositional changes of the first sharp diffraction peak ͑FSDP͒ in the measured structure factor have been studied for several binary selenide glasses using pulsed-neutron and high-energy x-ray diffraction techniques. The observed variations in the FSDP ͑factor of 10 in the amplitude and Ϸ0.5 Å −1 in the peak position͒ reflect multiple aspects in the glass network on both the short-and intermediate-range scales and are also correlated with macroscopic properties. An empirical relation has been discovered relating the compositional dependence of the FSDP position to the local coordination number of the guest atom.

Radiation-modified structure of Ge25Sb15S60 and Ge35Sb5S60 glasses

“…43. Our results demonstrate that combination of the void model 34,35 and NFC-related structural units 36 is quite applicable to interpret the radiation-/annealing-induced changes in the FSDP intensity and confirm a relation of the FSDP both with short-and intermediate-range scales.…”

“…Origin of the FSDP on the structure factors of Ge 25 Sb 15 S 60 and Ge 35 Sb 5 S 60 glasses is explained in terms of the void-based model 34,35 and network-forming cation-cation structural units. 36 It is established that the combination of these approaches can interpret plausibly the radiation-/ annealing-induced changes in the FSDP intensity.…”

“…1͑b͒ and 2͑b͔͒. We suppose that increasing intensity of the FSDP with increasing Ge content could be explained ͑i͒ with the so-called "void-based model" introduced in first principles by Wright et al 34 and developed later by Elliott, 35 and ͑ii͒ within the approach of Bychkov et al 36 based on the network-forming cation ͑NFC͒ related structural units.…”

“…41 However, it should be noted that this concept alone cannot always explain the origin of the FSDP. 42,43 In such situation, the approach of Bychkov et al 36 based on the NFC structural units, which relates FSDP with multiple changes in the glass network both on the short-and medium-range scales, comes under consideration.…”

Topological Ordering and Viscosity in the Glass-Forming Ge–Se System: The Search for a Structural or Dynamical Signature of the Intermediate Phase

“…The results from the present neutron diffraction (ND) work were obtained using either the GEM or SANDALS diffractometer. In the case of the FSDP, these results are compared to those obtained from the ND and high energy X-ray diffraction (XRD) work of Bychkov et al (2005); the high energy XRD work of Shatnawi et al (2008); the ND work of Ramesh Rao et al (1998); the XRD work of Sharma et al (2005) and Wang et al (2004); and the anomalous X-ray scattering work of Hosokawa (2001) and Hosokawa et al (2003). The pairs of vertical dashed (black) or chained (red) lines, and associated horizonal arrows, mark compositions for which ∆Hnr ≃ 0 as found in the present work or in the work of Boolchand et al (2001a), respectively.…”