A neutron diffraction, isotopic substitution study of the structure of Li2O·2SiO2 glass

Zhao, Jianyu; Gaskell, Philip; Cluckie, M.M.; Soper, A. K.

doi:10.1016/s0022-3093(98)00554-7

Cited by 57 publications

(55 citation statements)

References 15 publications

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“…Rb + (Vessal et al, 1992) and Cs + (Greaves et al, 1991) cations have been reported to have a CN of 5-6, apart from the study of Stefanovsky and Purans (2012) in nuclear waste glasses where Cs + was found to have CNs of 6-12. Finally, similar versatility is found in literature for Li + , with CN of 3-4 (Uhlig et al, 1996;Zhao et al, 1998) and 3-6 (Xu and Stebbins, 1995). As can be seen in Table 4, the effects of the CN differences for the alkalis are not as strong as for the noble metal ions.…”

Section: Methodssupporting

confidence: 85%

Trends in Effective Diffusion Coefficients for Ion-Exchange Strengthening of Soda-Lime-Silicate Glasses

et al. 2017

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Monovalent cations enable efficient ion-exchange processes due to their high mobility in silicate glasses. Numerous properties can be modified in this way, e.g., mechanical, optical, electrical, or chemical performance. In particular, alkali cation exchange has received significant attention, primarily with respect to introducing compressive stress into the surface region of a glass, which increases mechanical durability. However, most of the present applications rely on specifically tailored matrix compositions in which the cation mobility is enhanced. This largely excludes the major area of soda-lime-silicates (SLS) such as are commodity in almost all large-scale applications of glasses. Basic understanding of the relations between structural parameters and the effective diffusion coefficients may help to improve ion-exchanged SLS glass products, on the one hand in terms of obtainable strength and on the other in terms of cost. In the present paper, we discuss the trends in the effective diffusion coefficients when exchanging Na + for various monovalent cations (K + , Cu + , Ag + , Rb + , and Cs + ) by drawing relations to physicochemical properties. Correlations of effective diffusion coefficients were found for the bond dissociation energy and the electronic cation polarizability, indicating that localization and rupture of bonds are of importance for the ion-exchange rate.

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Section: Methodssupporting

confidence: 85%

Trends in Effective Diffusion Coefficients for Ion-Exchange Strengthening of Soda-Lime-Silicate Glasses

et al. 2017

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“…Following this, Hannon et al (1992) interpreted the lithium silicate glass structure to consist of a pairing of lithium ions that are immediately surrounded by two non-bridging oxygen atoms, thus satisfying charge neutrality. However, Zhao et al (1998) determined a higher coordination of Li for glasses of Li 2 Si 2 O 5 composition with lithium in four-fold coordination with oxygen. Hannon et al (1992) also concluded that in comparison to potassium, lithium occupies a distinctly different position in the alkali silicates.…”

Section: The Structure Of Other Alkali Silicate Glassesmentioning

confidence: 95%

The Structure of Silicate Melts: A Glass Perspective

Henderson

2005

The Canadian Mineralogist

125

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Glasses are widely used as analogues for the study of silicate melts. Although they are solid materials, their structure is inherently complex and diffi cult to study. However, progress has been made in elucidating this structure, its relationship to composition, and how it behaves at high temperatures and pressures. Recent research has brought to light some new fi ndings with important implications for natural melts. These include the observation that the structure is dependent upon the type and size of alkali or alkaline-earth cations incorporated into the glass network, with Li behaving very differently than other alkali cations. In addition, the presence of more than one type of alkali cation can cause non-linear physical behavior. Elements such as Al, Ti and Fe, which play important roles in petrological phenomena, can exhibit coordination environments (e.g., 5-fold) or polyhedral arrangements (e.g., triclusters) that are not common in crystalline phases. Furthermore, polyamorphic phase-transitions may occur at high temperature and pressures; the application of new theoretical models like mean fi eld-constraint hypothesis suggests that several glass phenomena, and probably melt phenomena as well, may be related to stress-rigid to fl oppy transitions. The state of understanding of glass structure, although still rudimentary relative to crystalline materials, has grown exponentially over the last few decades, often with geological researchers at the forefront.Keywords: melts, structure, glasses, petrology, spectroscopy, behavior, model. SOMMAIREOn se sert couramment des verres pour étudier les bains fondus silicatés. Quoiqu'ils sont des matériaux solides, leur structure est naturellement complexe et diffi cile à étudier. Toutefois, des progrès ont été faits dans l'étude de cette structure, sa relation à la composition, et son comportement à températures et pressions élevées. Les projets de recherche récents font ressortir les implications importantes aux bains fondus naturels. A titre d'exemple, la structure dépendrait de la sorte et la taille d'ion alcalin ou alcalino-terreux qui se trouve incorporé dans le réseau du verre. Le Li se comporte de façon très différente des autres alcalins. De plus, la présence de plus d'une sorte d'alcalin peut causer des comportements physiques non-linéaires. Les élements tels Al, Ti et Fe, dont l'importance pétrologique est évidente, peuvent adopter une coordinence inhabituelle, cinq par exemple, et un arrangement polyédrique, des groupements par trois, par exemple, qui ne sont pas communs dans les phases cristallines. De plus, des transitions de phases polyamorphiques pourraient avoir lieu à températures et à pressions élevées. L'application de nouveaux modèles théoriques, par exemple le modèle de contrainte moyenne du champ, fait penser que plusieurs phénomènes impliquant les verres, et tout probablement les bains fondus, pourraient résulter de transitions de matériau rigide face aux contraintes à maté-riau déformable. Quoique les connaissances de la structure du ve...

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“…According to the very large average Debye-Waller factor (0.115Å), this site is highly distorted with two broad components at 1.97 and 2.03Å. Similarly, Li atoms occur in distorted tetrahedral sites in Lialuminosilicate [42] and Li-disilicate glasses [43], with mean Li-O distances of 2.10 and 2.02Å, respectively. The Li environment obtained by molecular dynamics (MD) simulations on Li borate glasses consists of various distorted sites with 4-8 oxygen neighbors [44].…”

Section: Discussionmentioning

confidence: 99%

Thermoluminescence of B2O3–Li2O glass system doped with MgO

Elkholy

2010

Journal of Luminescence

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A neutron diffraction, isotopic substitution study of the structure of Li2O·2SiO2 glass

Cited by 57 publications

References 15 publications

Trends in Effective Diffusion Coefficients for Ion-Exchange Strengthening of Soda-Lime-Silicate Glasses

Trends in Effective Diffusion Coefficients for Ion-Exchange Strengthening of Soda-Lime-Silicate Glasses

The Structure of Silicate Melts: A Glass Perspective

Thermoluminescence of B2O3–Li2O glass system doped with MgO

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