Structural, vibrational, and elastic properties of a calcium aluminosilicate glass from molecular dynamics simulations: The role of the potential

Bauchy, Mathieu

doi:10.1063/1.4886421

Cited by 145 publications

(183 citation statements)

References 55 publications

(111 reference statements)

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“…However, this enumeration under-estimates n c as a small fraction of overcoordinated three-fold oxygen tricluster and five-fold aluminum species are found 29,30 . Hence, the rigidity of the aluminosilicate glasses was evaluated by a careful analysis of their structure, as predicted by the molecular dynamics (MD) simulations.…”

Section: A Dissolution Ratesmentioning

confidence: 99%

“…Na cations then act as charge compensators around Al IV cations 29 and are, therefore, not considered any further in the constraints enumeration. Note that the tetrahedral angular environment of Al cations is not as well defined as that of Si, so that the O-Al-O angles are considered unconstrained 30 . Consequently, the number of constraints per atom for (Na…”

Section: A Dissolution Ratesmentioning

confidence: 99%

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Topological Control on Silicates’ Dissolution Kinetics

et al. 2016

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Like many others, silicate solids dissolve when placed in contact with water. In a given aqueous environment, the dissolution rate depends highly on the composition and the structure of the solid, and can span several orders of magnitude. Although the kinetics of dissolution depends on the complexities of both the dissolving solid and the solvent, a clear understanding of which critical structural descriptors of the solid control its dissolution rate is lacking. Through pioneering dissolution experiments and atomistic simulations, we correlate the dissolution rates -ranging over four orders of magnitude -of a selection of silicate glasses and crystals, to the number of chemical topological constraints acting between the atoms of the dissolving solid. The number of such constraints serves as an indicator of the effective activation energy, which arises from steric effects, and prevents the network from reorganizing locally to accommodate intermediate units forming over the course of the dissolution.

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Section: A Dissolution Ratesmentioning

confidence: 99%

Section: A Dissolution Ratesmentioning

confidence: 99%

Topological Control on Silicates’ Dissolution Kinetics

et al. 2016

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“…After the initial formation of the two Si III , they can relax away from the vacancy and form small rings with the nearby silicon tetrahedra. This involves the formation of three member Si-O rings, as well as three-fold coordinated oxygen atoms, or tricluster oxygen, which are found to exist in some silicate glasses [31]. An example is shown in Fig.…”

Section: A Structural Damagementioning

confidence: 99%

Nature of radiation-induced defects in quartz

Wang

Pignatelli

et al. 2015

The Journal of Chemical Physics

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Although quartz (α-form) is a mineral used in numerous applications wherein radiation exposure is an issue, the nature of the atomistic defects formed during radiation-induced damage have not been fully clarified. Especially, the extent of oxygen vacancy formation is still debated, which is an issue of primary importance as optical techniques based on charged oxygen vacancies have been utilized to assess the level of radiation damage in quartz. In this paper, molecular dynamics (MD) simulations are applied to study the effects of ballistic impacts on the atomic network of quartz. We show that the defects that are formed mainly consist of over-coordinated Si and O, as well as Si-O connectivity defects, e.g., small Si-O rings and edge-sharing Si tetrahedra. Oxygen vacancies, on the contrary, are found in relatively low abundance, suggesting that characterizations based on E centers do not adequately capture radiation-induced structural damage in quartz. Finally, we evaluate the dependence on the incident energy, of the amount of each type of the point defects formed, and quantify unambiguously the threshold displacement energies for both O and Si atoms. These results provide a comprehensive basis to assess the nature and extent of radiation damage in quartz.

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“…The composition of the simulated systems was restricted to the following oxides: SiO 2 and Al 2 O 3 (network forming species), and CaO, MgO, Na 2 O, and K 2 O (network modifying species). MD simulations of the glasses were then performed utilizing the conventional melt-quenching method at zero pressure in the NPT ensemble as follows: (1) heating the system to 4000 K to remove any memory of its initial atomic configuration, (2) cooling to 300 K at a rate of 1 K/ps, (3) relaxing the structure at 300 K for an additional 100 ps, and (4) equilibrating the structure for an additional 100 ps in the NVT ensemble for statistical averaging [47]. The simulations were performed with a time step of 1 fs using the interatomic potential parametrized by Teter [48].…”

Section: Molecular Dynamics (Md) Simulations For Assessing the Networmentioning

confidence: 99%

Rate controls on silicate dissolution in cementitious environments

Oey¹,

Hsiao²,

Callagon³

et al. 2017

RILEM Tech Lett

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The dissolution rate of silicate minerals and glasses in alkaline environments is of importance in cementitious systems due to its influences on: (a) earlyage reactivity that affects the rate of strength gain and microstructure formation, and/or, (b) chemical durability of aggregates; compromises in which can result deleterious processes such as alkali-silica reaction (ASR). In spite of decades of study, quantitative linkages between the atomic structure of silicates and their dissolution rate in aqueous media (i.e., chemical reactivity) has remained elusive. Recently, via pioneering applications of molecular dynamics simulations and nanoscale-resolved measurements of dissolution rates using vertical scanning interferometry, a quantitative basis has been established to link silicate dissolution rates to the topology (rigidity) of their atomic networks. Specifically, an Arrhenius-like expression is noted to capture the dependence between silicate dissolution rates and the average number of constraints placed on a central atom in a network (n c , i.e., an indicator of the network's rigidity). This finding is demonstrated by: (i) ordering fly ashes spanning Ca-rich/poor variants in terms of their reactivity, and, (ii) assessing alterations in the reactivity of albite, and quartz following irradiation due to their potential to induce ASR in concrete exposed to radiation, e.g., in nuclear power plants.

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Structural, vibrational, and elastic properties of a calcium aluminosilicate glass from molecular dynamics simulations: The role of the potential

Cited by 145 publications

References 55 publications

Topological Control on Silicates’ Dissolution Kinetics

Topological Control on Silicates’ Dissolution Kinetics

Nature of radiation-induced defects in quartz

Rate controls on silicate dissolution in cementitious environments

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