Quantification of the disorder in network-modified silicate glasses

Farnan, Ian; Grandinetti, Philip J.; Baltisberger, Jay H.; Stebbins, Jonathan F.; Werner, Ulrike; Eastman, Margaret A.; Pines, Alexander

doi:10.1038/358031a0

Cited by 254 publications

(311 citation statements)

References 26 publications

Supporting

Mentioning

279

Contrasting

Unclassified

Order By: Relevance

“…At ordinary density, the angle shows a broad distribution between 120 • and 180 • and centered at 153 • (see also Fig. 6a), compared to the 142 • experimental value from NMR 45,46 . This difference was also observed by previous simulations, as reviewed in 19 and is consistent with the over estimated value of the Si-Si distance.…”

Section: Bond-angle Distributionsmentioning

confidence: 99%

Structural, vibrational, and thermal properties of densified silicates: Insights from molecular dynamics

Bauchy

2012

The Journal of Chemical Physics

View full text Add to dashboard Cite

Structural, vibrational and thermal properties of densified sodium silicate (NS2) are investigated with classical molecular dynamics simulations of the glass and the liquid state. A systematic investigation of the glass structure with respect to density was performed. We observe a repolymerization of the network manifested by a transition from a tetrahedral to an octahedral silicon environment, the decrease of the amount of non-bridging oxygen atoms and the appearance of three-fold coordinated oxygen atoms (triclusters). Anomalous changes in the medium range order are observed, the first sharp diffraction peak showing a minimum of its full-width at half maximum according to density. The previously reported vibrational trends in densified glasses are observed, such as the shift of the Boson peak intensity to higher frequencies and the decrease of its intensity. Finally, we show that the thermal behavior of the liquid can be reproduced by the Birch-Murnaghan equation of states, thus allowing us to compute the isothermal compressibility.

show abstract

Section: Bond-angle Distributionsmentioning

confidence: 99%

Structural, vibrational, and thermal properties of densified silicates: Insights from molecular dynamics

Bauchy

2012

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…A wide distribution of the Si-O-Si angle from ~120° to 180° is consistent with the reported results. 38,39) According to previous studies, 43,48) the introduction of a modifier will cause the decrease of the Si-O-Si angle in the silicate network. The average angle of the Si-O-Si, listed in Table 5, slightly decreases from ~155° to 151° with increasing the V 2 O 3 content, this may be an indication that V 2 O 3 act as a modifier in this tetrahedral network.…”

Section: Local Structure Of the Meltsmentioning

confidence: 99%

Structural Characterization of FeO–SiO2–V2O3 Slags Using Molecular Dynamics Simulations and FT-IR Spectroscopy

et al. 2016

View full text Add to dashboard Cite

The structure of FeO-SiO 2 -V 2 O 3 slags with compositions of (1-x)(1.5FeO·SiO 2 )·xV 2 O 3 (x = 0-20% mole fraction) was investigated in the molten and quenched states by using molecular dynamics (MD) simulations and Fourier transform infrared (FT-IR) spectroscopy. An empirical potential for the multi-component system has been developed in this work for performing MD simulations. The local atomic structures and the micro-heterogeneity in the molten slag have been systematically investigated using MD simulations. The bond length of V-O varies from 1.92 to 1.96 Å and the averaged coordination number of V (CN V-O ) increases from 4.50 to 4.96 with the addition of V 2 O 3 . The simulation results revealed that the average Si-O-Si bond angle and the degree of polymerization both decrease with increasing amount of V 2 O 3 , implying that V 2 O 3 may behave as a network-modifying basic oxide in the FeO-SiO 2 -V 2 O 3 system. This was further confirmed by the FT-IR spectrum analysis, which shows that the silicate network dissociates with the presence of V 2 O 3 .

show abstract

“…This can be converted to a distribution function, X(␤), of the secants of all Si-O-Si bond angles, where ␤ = sec ␣. This distribution is then used to calculate V(␣) via Dupree & Pettifer (1984) and Farnan et al (1992) used this method to determine the Si-O-Si bond-angle distribution. The model of Dupree & Pettifer (1984) that gave the best agreement with experiment has a broad, symmetric V(␣) distribution with nearly constant probability over 140-155°, whereas Farnan et al (1992) obtained a V(␣) distribution from ~130 to 180° for glass of K 2 Si 4 O 9 composition, with a maximum at 143° consistent with the data obtained by Mozzi & Warren (1969) for SiO 2 glass.…”

Section: The Sio 4 Tetrahedron (Short-range Order)mentioning

confidence: 99%

“…This distribution is then used to calculate V(␣) via Dupree & Pettifer (1984) and Farnan et al (1992) used this method to determine the Si-O-Si bond-angle distribution. The model of Dupree & Pettifer (1984) that gave the best agreement with experiment has a broad, symmetric V(␣) distribution with nearly constant probability over 140-155°, whereas Farnan et al (1992) obtained a V(␣) distribution from ~130 to 180° for glass of K 2 Si 4 O 9 composition, with a maximum at 143° consistent with the data obtained by Mozzi & Warren (1969) for SiO 2 glass. However, Mauri et al (2000) showed that the average Si-O-Si angle calculated from NMR spectra is not consistent with the distribution of Mozzi & Warren (1969), but closer to a mean of 151°.…”

Section: The Sio 4 Tetrahedron (Short-range Order)mentioning

confidence: 99%

The Structure of Silicate Melts: A Glass Perspective

Henderson

2005

The Canadian Mineralogist

126

View full text Add to dashboard Cite

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...

show abstract

Quantification of the disorder in network-modified silicate glasses

Cited by 254 publications

References 26 publications

Structural, vibrational, and thermal properties of densified silicates: Insights from molecular dynamics

Structural, vibrational, and thermal properties of densified silicates: Insights from molecular dynamics

Structural Characterization of FeO–SiO<sub>2</sub>–V<sub>2</sub>O<sub>3</sub> Slags Using Molecular Dynamics Simulations and FT-IR Spectroscopy

The Structure of Silicate Melts: A Glass Perspective

Contact Info

Product

Resources

About