Comparison of dielectric response deduced from infrared reflectivity and Raman spectra of silicate glasses

Gervais, F.; Lagrange, Ch.; Blin, Annie; Aliari, M.; Hauret, G.; Coutures, J.P.; Leroux, M.

doi:10.1016/0022-3093(90)90243-f

Cited by 21 publications

(6 citation statements)

References 20 publications

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“…The projection of VDOS for Ca and Mg was computed in this work by direct diagonalization of the dynamic matrix by using the GULP code with the same energy setting as for elastic property calculations. The results obtained, shown in Figure , are consistent with vibrational frequencies deduced from infrared reflectivity spectroscopy measurements , and Raman studies . VDOS of Ca and Mg are similar to the frequencies of the latter being shifted to higher values.…”

Section: Resultssupporting

confidence: 92%

Role of Magnesium in Soda-Lime Glasses: Insight into Structural, Transport, and Mechanical Properties through Computer Simulations

et al. 2008

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The role of Mg in soda-lime glasses was elucidated by classical molecular dynamics (MD) simulations. The effect of the replacement of CaO for MgO on the structure, transport, and elastic properties of a series of glasses with compositions 15Na 2 O • (10x)CaO • xMgO • 75SiO 2 (x ) 0, 5, and 10 mol) was studied. Different structural roles were found for the Ca and Mg ions. The former, coordinated by six oxygen atoms, acts as a network modifier, while the latter, four-fold coordinated, participates in the silica network. Consequently, Na ion diffusion is favored by the replacement of MgO for CaO in these glasses, as shown by variation in the computed diffusion coefficients and activation energy of the process in the series of glasses studied. Moreover, the consequences of these structural modifications on the elastic properties (Young's modulus, shear modulus, bulk modulus, Poisson's ratio, and compressibility) of the glasses were evaluated by means of energy minimization techniques carried out on the structures obtained by MD simulations.

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Section: Resultssupporting

confidence: 92%

Role of Magnesium in Soda-Lime Glasses: Insight into Structural, Transport, and Mechanical Properties through Computer Simulations

et al. 2008

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“…The observed broadening of the NMS2 glass spectrum and the shift of the apparent maxima are attributed to the appearance of new structural Q n units (mainly Q 1 , Q 2 , and in a lesser extent Q 3 ), where NBOs would be charge balanced by Mg 2+ , Mg 2+ and Na + , and not by Na + only. The broadening of Raman spectra or the appearance of new vibration bands has also been noticed for ternary glasses in the system Na 2 OCaOSiO 2 when replacing Na + by Ca 2+ 17, 35, 38–40 and in the system Na 2 OLa 2 O 3 SiO 2 while replacing Na + by La 3+ 41. The low wavenumber region of the Raman spectrum is continuously modified as magnesium replaces sodium and the 634 cm −1 line shifts to 660 cm −1 for the MS glass (Table 2).…”

Section: Resultsmentioning

confidence: 68%

Structural study of Mg‐bearing sodosilicate glasses by Raman spectroscopy

Trcera

Rossano

Tarrida

2011

J Raman Spectroscopy

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The presence of magnesium in glasses of geological, medical, and technological interests influences their physicochemical and durability properties. However, the understanding of the role of magnesium is dependent on the combined knowledge of the structural environment of magnesium in the glass or melt and of the silicate network connectivity of the studied systems. In this article, we present a Raman spectroscopic study of the network connectivity of 10 ternary silicate glasses in the system Na 2 O-MgO-SiO 2 and one Mg-free binary silicate glass Na 2 O-SiO 2 . Results obtained at constant polymerization suggest the existence of various Q n units according to the nature of the modifying cation. As polymerization decreases for Na 2 O-MgO-αSiO 2 glasses (labeled as NMSα with α decreasing from 10 to 2), the band associated with Si-O-Si bending in fully polymerized region disappears being gradually replaced by a band attributed to Si-O-Si bending in region containing mainly Q 2 and Q 3 species. For highly polymerized glasses (NMS10-NMS4), the coexistence of these two bands suggests the presence of two interconnected networks. Concomitantly, the signal associated with Q 3 species first increases. For a further decrease of the polymerization, the high wavenumber part of the signal associated with Q 3 species decreases, while the intensity of the high wavenumber part of the band related to Q 2 species increases. This result strongly suggests that magnesium charge-balances preferentially Q 2 species rather than Q 3 species.

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“…1 and 2, the polar lattice dynamics are very sensitive to the CaO amount included in the glass. A comparison with the infrared spectra of pure silica [24,[27][28][29] shows that the wide reflection band below 350 cm À1 , that strengthens with increasing CaO content, is due to lattice vibrations involving the calcium cations. The low frequency limit (20 cm À1 ) of the experimental measurements is clearly sufficient to capture the low wavenumber absorption profiles because all the glasses become semitransparent below 50 cm À1 (see Fig.…”

Section: Resultsmentioning

confidence: 96%