Atomic structure of As₂S₃–Ag chalcogenide glasses

Abstract

Abstract(As 0.4 S 0.6 ) 100-x Ag x glasses (x = 0, 4, 8, 12 at.%) have been studied with high-energy x-ray diffraction, neutron diffraction and extended x-ray absorption spectroscopy at As and Ag Kedges. The experimental data were modelled simultaneously with the reverse Monte-Carlo simulation method. Analysis of the partial pair correlation functions and coordination numbers extracted from the model atomic configurations revealed that silver preferentially bonds to sulphur in the As 2 S 3 -Ag ternary glasses, which results in the formation of homoatomic As-As bonds. Upon addition of Ag, a small proportion of Ag-As bonds (N AgAs ≈ 0.3) is formed in all three ternary compositions, while the direct Ag-Ag bonds (N AgAg ≈ 0.4) appear only in the glass with highest Ag content (12 at.%). Similar to the g-As 2 S 3 binary, the mean coordination number of arsenic is close to three and that of sulphur is close to two in the As 2 S 3 -Ag ternary glasses. The first sharp diffraction peak on the total structure factors of As 2 S 3 binary and (As 0.4 S 0.6 ) 100-x Ag x ternary glasses is related to the As-As and As-S correlations.

As_4S_4 role on the photoinduced birefringence of silver-doped chalcogenide thin films

“…Silver induces the dissociation of S-S chains in behalf of the formation of AgS 3/2 pyramids. Sulfur atoms in remaining As-S-As links are eliminated, resulting in the formation of As-As bonds [34] (Figs. 9(a)-(b)).…”

A Review of High-Energy X-Ray Diffraction from Glasses and Liquids

“…Modern technological applications include mouldable intra-red optics and fibers, lenses, memory devices, and phase change materials. High energy X-ray diffraction studies have been carried out on selenides [85][86][87][88][89][90][91], for example, see Figure 4, sulfides [92][93][94][95][96][97][98], arsenides [96][97][98], tellurites [99][100][101][102][103][104], and chalcohalides [105][106][107]. Bychkov et al found a complex variation in network formation and destruction versus composition in binary chalcogenides [85].…”

“…Bychkov et al found a complex variation in network formation and destruction versus composition in binary chalcogenides [85]. Chemical ordering effects [98] and conduction pathways in fast-ion conducting chalcogenide glasses have also been an area of significant interest relating structure to changes in ion transport [87,88,94,95,[105][106][107].…”

Structural study of AsS2–Ag glasses over a wide concentration range

“…Ag binds preferentially to excess S atoms and avoids As. It is to be mentioned that in the As 2 S 3 -Ag glasses Ag-As bonding was observed [34]. The comparison of As K-edge EXAFS spectra of AsS 2 -Ag glasses (Fig.…”