Compositionally-dependent structural variations in glassy chalcogenides: The case of binary AsSe system

Shpotyuk, O.; Hyla, M.; Boyko, V.

doi:10.1016/j.commatsci.2015.08.015

Cited by 18 publications

(21 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast, a slight increase in the FSDP width Δ Q 1 for As x Se 100 − x with 20 ≤ x ≤ 40 can be ascribed to reduction in the correlation length L due to defects generated under MM, which disturb the FSDP‐responsible inter‐planar correlations due to mechanically built‐in stresses. This range in As‐Se system is known to be full of some instabilities, tending to local decomposition on As‐ and Se‐rich fragments and/or global separation on As 2 Se 3 ‐ and Se‐rich arsenoselenide phases, occurring fragmentation effect on the correlation length L of the FSDP‐responsible quasi‐periodicity.…”

Section: Resultsmentioning

confidence: 99%

Effect of high‐energy mechanical milling on the medium‐range ordering in glassy As‐Se

et al. 2019

View full text Add to dashboard Cite

Effect of high‐energy mechanical milling on glassy AsxSe100 − x (5 ≤ x ≤ 75) is recognized with X‐ray powder diffraction analysis applied to their diffuse halos ascribed to intermediate—and extended‐range structural ordering, which are revealed respectively in the first sharp diffraction peak (FSDP) and principal diffraction peak (PDP). Straightforward interpretation of the results is developed within modified microcrystalline approach, treating diffuse halos as superposition of broadened Bragg‐diffraction reflexes from remnants of inter‐planar correlations, supplemented by inter‐atomic Ehrenfest‐diffraction reflexes from most prominent inter‐atomic and inter‐molecular correlations between cage‐like molecules (such As4Se4 and/or As4Se3). Milling is shown to be ineffective in glassy arsenoselenides near Se (x < 20), while causing increase in the FSDP width for glasses with 20 ≤ x ≤ 40 due to destroyed inter‐planar ordering. Remnants of cage‐like molecules in over‐stoichiometric As‐rich AsxSe100 − x glasses (40 ≤ x ≤ 75) disappear under milling, promoting formation of higher polymerized structural network. This milling‐driven reamorphization results in a drastic increase in the FSDP position and fragmentation impact on the correlation length of the FSDP‐responsible entities. Breakdown in intermediate‐range ordering in these glasses is accompanied by changes in their extended‐range ordering revealed in high‐angular shift and broadening of the PDP. This effect is concomitant with the disappearance of distant inter‐atomic correlations between quasi‐crystalline planes in the milled arsenoselenide glasses at a cost of prolonged correlations dominating in their extended‐range ordering.

show abstract

Section: Resultsmentioning

confidence: 99%

Effect of high‐energy mechanical milling on the medium‐range ordering in glassy As‐Se

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The average CFE for As 2 S m NFC ( m = 3 ÷ 9) in As–S system are gathered in Table 1 along with previously calculated data for As 2 Se m NFC ( m = 3 ÷ 7) in As–Se ChG system [30]. Numerical values of CFE for geometrically optimized AsSe 3/2 ( E f = −72.309 kcal/mol) and AsS 3/2 ( E f = −79.404 kcal/mol) pyramids were taken as reference points for respective ChG.…”

Section: Resultsmentioning

confidence: 99%

“…In calculations concerning decomposition of stoichiometric As 2 S 3 , the CFE of geometrically optimized As 2 S 4/2 NFC ( m = 2) based on bridging homonuclear As–As chemical bonds ( E f = −77.683 kcal/mol) was taken into account. To estimate an energetic preference of global chemical decomposition due to reaction (2), the CFE for geometry-optimized S m−3 and Se m−3 nanoclusters were taken from [30, 33]. The corresponding compositional dependencies of energetic barriers Δ E (1) and Δ E (2) for best geometrically optimized NFC in As–Se/S ChG are depicted in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Within most generalized approach, atomic clusters of As 2 (S/Se) m chemical compositions which represented themselves as trigonal As(S/Se) 3/2 pyramids linked by (S/Se) m–3 chains are principal network-forming clusters (NFC) in Ch-rich ChG of As–(S/Se) systems [25, 26, 30]. This simplification allows usage a simple simulation route for relatively small atomic entities and available software like Hyper Chem Release 7.5 program [31, 32], instead of complicated and time-consuming modeling procedures for multi-atomic glassy networks evolved hundreds or even thousands of atoms.…”

Section: Methodsmentioning

confidence: 99%

“…This approach applied recently to As–Se ChG based on As 2 Se m NFC [30] shows instability onset near Z = 2.25, where these glasses demonstrate strong tendency towards both global phase separation due to reaction (2) and local chemical decomposition due to reaction (1). In this work, the same CINCA simulation procedure will be applied to As 2 S m NFC ( m = 3 ÷ 9), which serves as a basis for S-rich ChG of binary As–S system.…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Network-Forming Nanoclusters in Binary As–S/Se Glasses: From Ab Initio Quantum Chemical Modeling to Experimental Evidences

Hyla

2017

Nanoscale Res Lett

Self Cite

View full text Add to dashboard Cite

Network-forming As2(S/Se)m nanoclusters are employed to recognize expected variations in a vicinity of some remarkable compositions in binary As–Se/S glassy systems accepted as signatures of optimally constrained intermediate topological phases in earlier temperature-modulated differential scanning calorimetry experiments. The ab initio quantum chemical calculations performed using the cation-interlinking network cluster approach show similar oscillating character in tendency to local chemical decomposition but obvious step-like behavior in preference to global phase separation on boundary chemical compounds (pure chalcogen and stoichiometric arsenic chalcogenides). The onsets of stability are defined for chalcogen-rich glasses, these being connected with As2Se5 (Z = 2.29) and As2S6 (Z = 2.25) nanoclusters for As–Se and As–S glasses, respectively. The physical aging effects result preferentially from global phase separation in As–S glass system due to high localization of covalent bonding and local demixing on neighboring As2Sem+1 and As2Sem−1 nanoclusters in As–Se system. These nanoclusters well explain the lower limits of reversibility windows in temperature-modulated differential scanning calorimetry, but they cannot be accepted as signatures of topological phase transitions in respect to the rigidity theory.

show abstract

Cluster Modeling of Network-Forming Amorphization Pathways in AsxS100−x Arsenicals (50 ≤ x ≤ 57) Diven by Nanomilling

et al. 2021

View full text Add to dashboard Cite

Complete hierarchy of network amorphization scenarios initiated in AsxS100-x nanoarsenicals within As4S4-As4S3 cut-Sect. (50 ≤ x ≤ 57) is reconstructed employing materials-computational approach based on ab-initio quantum-chemical modeling code (CINCA). Under nanostructurization due to high-energy mechanical milling, the inter-crystalline transformations to nanoscopic β-As4S4 phase accompanied by appearance of covalent-network amorphous matrix are activated. General amorphization trend under nanomilling obeys tending from molecular cage-like structures to optimally-constrained covalent-bonded networks compositionally invariant with parent arsenical. The contribution of amorphization paths in nanoarsenicals is defined by their chemistry with higher molecular-to-network barriers proper to As4S3-rich alloys. The generated amorphous phase is intrinsically decomposed, possessing double-Tg relaxation due to stoichiometric (x = 40) and non-stoichiometric (x > 40) sub-networks, which are built of AsS3/2 pyramids and As-rich arrangement keeping (i) two separated As-As bonds derived from realgar-type molecules, (ii) two neighboring As-As bonds derived from pararealgar-type molecules or (iii) three neighboring As-As bonds in triangle-like geometry derived from dimorphite-type molecules. Compositional invariance of nanoamorphous phase is ensured by growing sequence of network-forming clusters with average coordination numbers Z in the row (As2S4/2,Z = 2.50) – (As3S5/2, Z = 2.55) – (As3S3/2, Z = 2.67). Diversity of main molecular-to-network amorphizing pathways in nanoarsenicals is reflected on the unified potential energy landscape specified for boundary As4S4 and As4S3 components.

show abstract

Compositionally-dependent structural variations in glassy chalcogenides: The case of binary AsSe system

Cited by 18 publications

References 30 publications

Effect of high‐energy mechanical milling on the medium‐range ordering in glassy As‐Se

Effect of high‐energy mechanical milling on the medium‐range ordering in glassy As‐Se

Network-Forming Nanoclusters in Binary As–S/Se Glasses: From Ab Initio Quantum Chemical Modeling to Experimental Evidences

Cluster Modeling of Network-Forming Amorphization Pathways in AsxS100−x Arsenicals (50 ≤ x ≤ 57) Diven by Nanomilling

Contact Info

Product

Resources

About