Intermediate- and short-range order in phosphorus-selenium glasses

Bytchkov, Aleksei; Miloshova, Mariana; Бычков, Е.; Kohara, Shinji; Hennet, Louis; Price, David L.

doi:10.1103/physrevb.83.144201

Cited by 14 publications

(7 citation statements)

References 27 publications

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“…In addition, this absence of a repeating unit cell has often limited to short-range order the detailed structural information gathered from standard experimental techniques. Still, diffraction methods provide a partial characterization of the intermediate range order [1][2][3][4][5][6] with a particular emphasis on the low wave-vector region revealing a first sharp diffraction peak (FSDP) in the structure factor and particular correlations in reciprocal space [7][8][9][10][11] that can be even related to a species dependence using isotopic substitution [12][13][14]. However, there is only a limited number of cases where the structural groupings, essentially ring structures, of the glass structure can be unambiguously analysed and characterized from their explicit spectroscopic signature using Raman or Nuclear Magnetic Resonance (NMR) spectroscopy [15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Concepts and applications of rigidity in non-crystalline solids: a review on new developments and directions

Micoulaut

2016

Advances in Physics: X

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Section: Introductionmentioning

confidence: 99%

Concepts and applications of rigidity in non-crystalline solids: a review on new developments and directions

Micoulaut

2016

Advances in Physics: X

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“…Although FSDP has been a subject of extended interest in the last three decades, its origin is still debated [20][21][22][23][24][25]. It is clear that FSDP can arise for various reasons in different systems [20,23,25], but in general it reflects features of the glass network at both the MRO and SRO length scales, for example, homopolar bonds, cage molecules, random/nonrandom distribution of the network-forming clusters, prevailing structural motif, etc. [3,23,25].…”

Section: Introductionmentioning

confidence: 99%

“…It is clear that FSDP can arise for various reasons in different systems [20,23,25], but in general it reflects features of the glass network at both the MRO and SRO length scales, for example, homopolar bonds, cage molecules, random/nonrandom distribution of the network-forming clusters, prevailing structural motif, etc. [3,23,25]. A characteristic length scale associated with the FSDP position typically implies 2-4 interatomic distances (~3.5-10 Å), which correspond to the intermediate MRO.…”

Section: Introductionmentioning

confidence: 99%

Medium range order and structural relaxation in As–Se network glasses through FSDP analysis

Golovchak

Lucas

Oelgoetz

et al. 2015

Materials Chemistry and Physics

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Synchrotron X-ray diffraction and neutron scattering studies are performed on As-Se glasses in two states: as-prepared (rejuvenated) and aged for ~23 years. The first sharp diffraction peak (FSDP) obtained from the structure factor data as a function of composition and temperature indicates that the cooperative processes that are responsible for structural relaxation do not affect FSDP. The results are correlated with the composition dependence of the complex heat capacity of the glasses and concentration of different structural fragments in the glass network. The comparison of structural information shows that density fluctuations, which were thought previously to have a significant contribution to FSDP, have much smaller contribution than the cation-cation correlations, presence of ordered structural fragments or cage molecules.

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“…2d). This result suggests that the densification mechanism in this pressure range is dominated by increased molecular packing 14 . The rate of this pressure-induced shift in the peak positions abruptly changes with a slower rate of decrease at pressures above 6.3 GPa.…”

Section: Resultsmentioning

confidence: 81%

Unravelling the mechanism of pressure induced polyamorphic transition in an inorganic molecular glass

Kalkan

Okay

Aitken

et al. 2020

Sci Rep

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The atomic structure of a germanium doped phosphorous selenide glass of composition Ge 2.8 p 57.7 Se 39.5 is determined as a function of pressure from ambient to 24 GPa using Monte-Carlo simulations constrained by high energy x-ray scattering data. The ambient pressure structure consists primarily of p 4 Se 3 molecules and planar edge shared phosphorus rings, reminiscent of those found in red phosphorous as well as a small fraction of locally clustered corner-sharing GeSe 4 tetrahedra. This low-density amorphous phase transforms into a high-density amorphous phase at ~6.3 GPa. The highpressure phase is characterized by an extended network structure. The polyamorphic transformation between these two phases involves opening of the p 3 ring at the base of the p 4 Se 3 molecules and subsequent reaction with red phosphorus type moieties to produce a cross linked structure. The compression mechanism of the low-density phase involves increased molecular packing, whereas that of the high pressure phase involves an increase in the nearest-neighbor coordination number while the bond angle distributions broaden and shift to smaller angles. The entropy and volume changes associated with this polyamorphic transformation are positive and negative, respectively, and consequently the corresponding Clapeyron slope for this transition would be negative. This result has far reaching implications in our current understanding of the thermodynamics of polyamorphic transitions in glasses and glass-forming liquids. The existence and the nature of polyamorphic phase transitions in the glassy or liquid state between structurally and thermodynamically distinct phases of the same composition remain controversial issues in the fields of condensed matter physics and chemistry 1. The most extensively studied case of polyamorphism in the literature pertains to the transitions between the low-and high-density phases of H 2 O in the supercooled liquid state 2-4. The low-density phase is characterized by an open, hydrogen-bonded tetrahedral "molecular" structure with low entropy, which transforms under pressure into a high-density network structure with high entropy 4. This inverse relation between volume and entropy implies a negative slope in the P-T space for this polyamorphic transition. However, the structural complexity of water has made the experimental determination of the atomistic mechanism of this structural transformation rather difficult. On the other hand, structurally simple van der Waals-bonded molecular liquids may prove to be more tractable systems for studying the atomistic mechanisms of molecular-to-network polyamorphic transformations. A handful of inorganic crystals are known to be molecular and consist of nearly spherical cage-like molecules held together by the van der Waals force; examples include As 4 S 3 , P 4 S 3 , P 4 Se 3 and C 60. It has been demonstrated in the literature that, amongst these compositions, As 4 S 3 and P 4 Se 3 can be glass-forming if the liquid is stabilized against crystallization by the addition o...

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Intermediate- and short-range order in phosphorus-selenium glasses

Cited by 14 publications

References 27 publications

Concepts and applications of rigidity in non-crystalline solids: a review on new developments and directions

Concepts and applications of rigidity in non-crystalline solids: a review on new developments and directions

Medium range order and structural relaxation in As–Se network glasses through FSDP analysis

Unravelling the mechanism of pressure induced polyamorphic transition in an inorganic molecular glass

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