Solid-state NMR investigations of sodium–cesium mixed-alkali phosphate glasses

Prabakar, S.; Mueller, Karl T.

doi:10.1016/j.jnoncrysol.2004.08.253

Cited by 18 publications

(12 citation statements)

References 52 publications

(111 reference statements)

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“…57 Moreover it is known that different alkali ions occupy dissimilar sites in phosphate glasses, but by the current techniques it has not been possible to specify the differences in short range order. 53,60,61 Therefore, the suggested characteristic structures cannot fully describe the glassy network but may still serve as a basis for a topological model, as they agree well with the structural data presented in Sec. III.…”

Section: Topologysupporting

confidence: 63%

A model for phosphate glass topology considering the modifying ion sub-network

Hermansen

Mauro

Yue

2014

The Journal of Chemical Physics

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In the present paper we establish a temperature dependent constraint model of alkali phosphate glasses considering the structural and topological role of the modifying ion sub-network constituted by alkali ions and their non-bonding oxygen coordination spheres. The model is consistent with available structural data by NMR and molecular dynamics simulations and with dynamic data such glass transition temperature (T g ) and liquid fragility (m). Alkali phosphate glasses are exemplary systems for developing constraint model since the modifying cation network plays an important role besides the primary phosphate network. The proposed topological model predicts the changing trend of the T g and m with increasing alkali oxide content for alkali phosphate glasses, including an anomalous minimum at around 20 mol.% alkali oxide content. We find that the minimum in T g and m is caused by increased connectivity of the modifying ion sub-network, as the alkali ions must share non-bonding oxygen to satisfy their coordination requirements at higher alkali oxide contents. We argue that the systematically decreasing the T g values of alkali phosphate glasses from Li 2 O to Na 2 O to Cs 2 O could be caused by a weakening of the modifying ion sub-network and can be accounted for by lower constraint onset temperatures.

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Section: Topologysupporting

confidence: 63%

A model for phosphate glass topology considering the modifying ion sub-network

Hermansen

Mauro

Yue

2014

The Journal of Chemical Physics

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“…lithium). Inspection of a large body of chemical shift trends in various mixed-alkali glasses suggests that these structural readjustments are rather universal [59][60][61][62][63][64][65][66][67][68][69][70][71][72][73][74]: substitution of an alkali ion A by larger homologue B always leads to a slight compression of the A site and an expansion of the B site, compared to the situation in the corresponding single-alkali glass. Based on this evidence for site modification, we have suggested an additional ("secondary") mismatch effect as a fundamental principle underlying the MAE, which seems particularly relevant in the dilute foreign ion limit (see Fig.…”

Section: Site Modifications and Secondary Mismatch Effectsmentioning

confidence: 99%

Short and Medium Range Order in Ion-Conducting Glasses Studied by Modern Solid State NMR Techniques

Eckert¹

2010

Zeitschrift Für Physikalische Chemie

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Glass Structure / Solid State NMR Spectroscopy / Structure-Property RelationsGlassy ionic conductors have attained considerable importance in the solid state battery technology field. To understand the influence of composition on ionic mobility and transport, information about the local and dynamic environments of the mobile ions in glasses is required. Solid state NMR spectroscopy is one of the most powerful tools for addressing these questions. Our research effort in this area comprises (1) the development of efficient techniques and strategies for the study of disordered materials, (2) the detailed application of optimized measurement and data analysis protocols to different glass systems under systematic compositional variation, and (3) the comprehensive interpretation of the results obtained in the overall literature context. This article attempts to convey a concise overview of our contribution to this field over the period from 2004 to 2010, to describe the most significant insights obtained and to place them into the overall field of Solid State Ionics.

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“…Thus far, various structural models have been proposed to explain the MAE on the basis of a homogeneous spatial cation distribution using nuclear magnetic resonance (NMR) spectroscopy [5][6][7][8][9][10], extended X-ray absorption fine structure (EXAFS) analysis [11], and so on. For instance, Ingram et al reported that the MAE is caused by the disturbance created when one type of alkali ion moves to a site that was previously occupied by another type of alkali ion [12].…”

Section: Introductionmentioning

confidence: 99%

Structural analysis of alkali cations in mixed alkali silicate glasses by ²³Na and ¹³³Cs MAS NMR

Minami

Tokuda

Masai

et al. 2014

Journal of Asian Ceramic Societies

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We report the structural analysis of Na + and Cs + in sodium cesium silicate glasses by using 23 Na and 133 Cs magic-angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy. In the NMR spectra of cesium silicate crystals, the peak position shifted to higher magnetic field for structures with larger Cs + coordination numbers and to lower magnetic field for smaller Cs + coordination numbers. The MAS NMR spectra of xNa 2 O-yCs 2 O-2SiO 2 (x = 0, 0.2, 0.33, 0.5, 0.66, 0.8, 1.0; x + y = 1) glass reveal that the average coordination number of both the alkali cations decreases with increasing Cs + /(Na + + Cs +) ratio. In addition, the coordination number of Na + in xNa 2 O-yCs 2 O-2SiO 2 glass is smaller than that of Cs +. This difference between the average coordination numbers of the alkali cations is considered to be one structural reason of the mixed alkali effect.

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Solid-state NMR investigations of sodium–cesium mixed-alkali phosphate glasses

Cited by 18 publications

References 52 publications

A model for phosphate glass topology considering the modifying ion sub-network

A model for phosphate glass topology considering the modifying ion sub-network

Short and Medium Range Order in Ion-Conducting Glasses Studied by Modern Solid State NMR Techniques

Structural analysis of alkali cations in mixed alkali silicate glasses by ²³Na and ¹³³Cs MAS NMR

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Solid-state NMR investigations of sodium–cesium mixed-alkali phosphate glasses

Cited by 18 publications

References 52 publications

A model for phosphate glass topology considering the modifying ion sub-network

A model for phosphate glass topology considering the modifying ion sub-network

Short and Medium Range Order in Ion-Conducting Glasses Studied by Modern Solid State NMR Techniques

Structural analysis of alkali cations in mixed alkali silicate glasses by 23Na and 133Cs MAS NMR

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Structural analysis of alkali cations in mixed alkali silicate glasses by ²³Na and ¹³³Cs MAS NMR