Contribution of 43Ca MAS NMR for probing the structural configuration of calcium in glass

Angeli, Frédéric; Gaillard, Marina; Jollivet, Patrick; Charpentier, Thibault

doi:10.1016/j.cplett.2007.04.036

Cited by 85 publications

(127 citation statements)

References 23 publications

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“…Since the coordination of aluminum does not change, part of aluminum groups must be charge compensated by other cations than sodium, here calcium. As a consequence, an increase of the quadrupolar splitting and thus the linewidth of the 27 Al MAS spectra is expected, 47,48 as actually observed here. Therefore, rather than compensate the charges of BO 4 and AlO 4 groups, part of the sodium ions in the as-received fibers acts as additional network modifiers, probably forming non-bridging oxygen bonds with silicon groups and adopting a less homogeneous distribution.…”

Section: Discussionsupporting

confidence: 80%

Effect of thermally induced structural disorder on the chemical durability of International Simple Glass

et al. 2018

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While the influence of silicate oxide glass composition on its chemical durability is increasingly known, the contribution of structure only is less well understood, yet is crucial for an accurate description of aqueous alteration mechanisms. The effect of structural disorder can be investigated by varying the thermal history of the glass. Furthermore, the structural changes generated by selfirradiation in nuclear glasses can be compared with those induced by fast quenching. In the context of deep geological disposal of vitreous matrices, it is then challenging to address the structural impact on glass durability. Here, a borosilicate glass, the International Simple Glass, was fiberized to obtain a rapidly quenched sample. The quenching rate and fictive temperature were evaluated from in situ Raman and Brillouin spectroscopies. Multinuclear nuclear magnetic resonance was used to obtain insight into the effect of quenching on the pristine and altered glass structure. Higher bond angle distribution and lower mixing of alkalis were observed in the fast quenched glass. Some of AlO 4 groups are then Ca-compensated, while a part of BO 4 is transformed into BO 3 units. The structural modifications increase the hydrolysis of the silicate network occurring in the forward rate regime at 90°C by a factor of 1.4-1.8 depending on the pH value. Residual rate regime is similarly affected, more significantly at the beginning of the experiments conducted in silica saturated solutions. These findings prove that the reactivity of glass remains controlled by its structure under the various alteration regimes.

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Section: Discussionsupporting

confidence: 80%

Effect of thermally induced structural disorder on the chemical durability of International Simple Glass

et al. 2018

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“…In such glasses calcium changes its role from charge compensating the (AlO 4 ) to acting as a network modifier being associated with non-bridging oxygens. The change of iso and Q gave clear discrimination of the different sites, allowing such changes in a series of glasses to be followed [73].…”

Section: Half-integer Spin Low-quadrupolar Nucleimentioning

confidence: 99%

“…Nuclei in this group include 25 Mg, 33 S, 35,37 Cl, 43 Ca, 47,49 Ti, 73 Ge, 91 Zr, 95,97 Mo and 135,137 Ba. Examples of developments of all these nuclei can be found in the literature in the last decade, but a few illustrative cases will be given here.…”

Section: Half-integer Spin Low-quadrupolar Nucleimentioning

confidence: 99%

“…7(d) such that spectra have to be interpreted carefully even at high magnetic field [61]. An example of a nucleus which is now observable really for the first time because of the better availability of high magnetic field is 73 Ge. From the two forms of crystalline GeO 2 , GeO 4 units had a much smaller Q than GeO 6 and a shift difference of ~200 ppm [62].…”

Section: Half-integer Spin Low-quadrupolar Nucleimentioning

confidence: 99%

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Recent technique developments and applications of solid state NMR in characterising inorganic materials

Hanna

Smith

2010

Solid State Nuclear Magnetic Resonance

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A broad overview is given of some key recent developments in solid state NMR techniques that have driven enhanced applications to inorganic materials science. Reference is made to advances in hardware, pulse sequences and associated computational methods (e.g. first principles calculations, spectral simulation), along with their combination to provide more information about solid phases. The resulting methodology has allowed more nuclei to be observed and more structural information to be extracted. Cross referencing between experimental parameters and their calculation from the structure has seen an added dimension to NMR as a characterisation probe of materials. Emphasis is placed on the progress made in the last decade especially from those nuclei that were little studied previously. The general points about technique development and the increased range of nuclei observed are illustrated through a range of specific exemplars from inorganic materials science.

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“…[65] The total distribution is given by the product shown in [Eq. (9)] in which the Gaussian isotropic (or Czjzek) model PA C H T U N G T R E N N U N G (C Q ,h Q ) was used for the EFG interaction parameters, [66,67] and a normal (or Gaussian) distribution model GA C H T U N G T R E N N U N G (d iso ) was used for the isotropic chemical shift.…”

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confidence: 99%

A ⁹³Nb Solid‐State NMR and Density Functional Theory Study of Four‐ and Six‐Coordinate Niobate Systems

Hanna¹,

Pike²,

Charpentier³

et al. 2010

Chemistry A European J

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A variable B(0) field static (broadline) NMR study of a large suite of niobate materials has enabled the elucidation of high-precision measurement of (93)Nb NMR interaction parameters such as the isotropic chemical shift (delta(iso)), quadrupole coupling constant and asymmetry parameter (C(Q) and eta(Q)), chemical shift span/anisotropy and skew/asymmetry (Omega/Deltadelta and kappa/eta(delta)) and Euler angles (alpha, beta, gamma) describing the relative orientation of the quadrupolar and chemical shift tensorial frames. These measurements have been augmented with ab initio DFT calculations by using WIEN2k and NMR-CASTEP codes, which corroborate these reported values. Unlike previous assertions made about the inability to detect CSA (chemical shift anisotropy) contributions from Nb(V) in most oxo environments, this study emphasises that a thorough variable B(0) approach coupled with the VOCS (variable offset cumulative spectroscopy) technique for the acquisition of undistorted broad (-1/2<-->+1/2) central transition resonances facilitates the unambiguous observation of both quadrupolar and CSA contributions within these (93)Nb broadline data. These measurements reveal that the (93)Nb electric field gradient tensor is a particularly sensitive measure of the immediate and extended environments of the Nb(V) positions, with C(Q) values in the 0 to >80 MHz range being measured; similarly, the delta(iso) (covering an approximately 250 ppm range) and Omega values (covering a 0 to approximately 800 ppm range) characteristic of these niobate systems are also sensitive to structural disposition. However, their systematic rationalisation in terms of the Nb-O bond angles and distances defining the immediate Nb(V) oxo environment is complicated by longer-range influences that usually involve other heavy elements comprising the structure. It has also been established in this study that the best computational method(s) of analysis for the (93)Nb NMR interaction parameters generated here are the all-electron WIEN2k and the gauge included projector augmented wave (GIPAW) NMR-CASTEP DFT approaches, which account for the short- and long-range symmetries, periodicities and interaction-potential characteristics for all elements (and particularly the heavy elements) in comparison with Gaussian 03 methods, which focus on terminated portions of the total structure.

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Contribution of 43Ca MAS NMR for probing the structural configuration of calcium in glass

Cited by 85 publications

References 23 publications

Effect of thermally induced structural disorder on the chemical durability of International Simple Glass

Effect of thermally induced structural disorder on the chemical durability of International Simple Glass

Recent technique developments and applications of solid state NMR in characterising inorganic materials

A ⁹³Nb Solid‐State NMR and Density Functional Theory Study of Four‐ and Six‐Coordinate Niobate Systems

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Contribution of 43Ca MAS NMR for probing the structural configuration of calcium in glass

Cited by 85 publications

References 23 publications

Effect of thermally induced structural disorder on the chemical durability of International Simple Glass

Effect of thermally induced structural disorder on the chemical durability of International Simple Glass

Recent technique developments and applications of solid state NMR in characterising inorganic materials

A 93Nb Solid‐State NMR and Density Functional Theory Study of Four‐ and Six‐Coordinate Niobate Systems

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A ⁹³Nb Solid‐State NMR and Density Functional Theory Study of Four‐ and Six‐Coordinate Niobate Systems