NMR Studies of the Structure of Glass

Bray, P. J.; Dell, W.J.

doi:10.1051/jphyscol:1982926

Cited by 3 publications

(8 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These glasses were made up to R values exceeding 8 and K values from 2 to 6. Using the 29 Si MAS NMR spectra, they were able to examine directly and, for the first time, the exact nature of the silicon speciation into the various Si i species, where i is the number of BOs on the Si atoms, as a function of both R and K. Combining both the 11 B NMR spectra of similar sodium borosilicate (SBS) glasses from the previous work of Bray et al, 50,51,55 Wu et al, 62 and Zhang et al, 63 with their 29 1. Now, using these values for the equivalent R 0 → y 0 values, where up to the mole fraction of y 0 all of Na 2 O is used to create B 4 units, Figure 3 shows the composition dependence of the y 0 values that could be calculated from the available data.…”

Section: ■ Introductionmentioning

confidence: 99%

“…While there are many models of the structure of alkali borosilicate glasses, those due to Bray et al, − ,, Stebbins et al, and Feller et al − have examined perhaps the widest range of glass compositions and gained the most interest and acceptance. However, all of these studies have focused on glass compositions in the series R M 2 O + B 2 O 3 + K SiO 2 , where K is fixed and the different K series of glasses are studied as a function of R .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

New Interpretation of Na⁺-Ion Conduction in and the Structures and Properties of Sodium Borosilicate Mixed Glass Former Glasses

et al. 2019

View full text Add to dashboard Cite

A new study has been made of the well-known sodium borosilicate glass system to improve the overall and detailed understanding of both the atomic level structures in these glasses and the correlation of these structures to their physical properties. The specific intent is to examine the isocompositional, Na 2 O content, variation of the Na + -ion conductivity with the mixing ratio x of the amounts of B 2 O 3 and 2SiO 2 (Si 2 O 4 , which keeps the number of glass former cations constant across this series) in these glasses. This study deepens our ongoing examination of the mixed glass former effect (MGFE) on the Na + ion conductivity in these glasses. In doing so, we also report and examine the MGFE on the density, the mechanical moduli, and the glass-transition temperature, T g . The most significant structural change that occurs in these glasses is the formation of large fractions of tetrahedral borons, B 4 , that leads to densification and strengthening of the glass structure and, as a result, causes what appears to the very first negative MGFE in the alkali-ion conductivity in an oxide glass. Until this study, all studies of the MGFE in oxide glasses have shown that the alkali-ion conductivity is a positive function of the mixing ratio of the two glass formers. The weak negative effect reported here appears to be a direct result of the positive MGFEs observed in the density, the T g , and all of the mechanical moduli of these glasses. Weak negative MGFE in the Na + -ion conductivity appears to be consistent with an increasing strain energy to Na + conduction caused by the densification of the structure, leading to the increased mechanical energy necessary to force the dilation of the volume necessary to accommodate the Na + -ion motion between sites. This negative MGFE in the volumetric strain energy appears therefore to overcome a slight reduction in the coulombic binding energy between the Na + ion and its counter anions caused by the formation of weakly basic B 4 anion sites. An improved model for ion conduction in solid electrolyte glasses is developed as a result of modeling the composition dependence of the Na + -ion conductivity in these glasses.

show abstract

Section: ■ Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

New Interpretation of Na⁺-Ion Conduction in and the Structures and Properties of Sodium Borosilicate Mixed Glass Former Glasses

et al. 2019

View full text Add to dashboard Cite

show abstract

“…15 It is known that a binary liquid mixture below T c orders through small amplitude long-wavelength fluctuations knows as spinodal decomposition. Its late time phase ordering dynamics 16,17 is characterized by a single length scale specifying a measure of the domain size of each component. The main result of this paper is the observation of an echo diffraction pattern in these media which corresponds to the dominant length scale alluded to above.…”

Section: Numerical Simulationmentioning

confidence: 99%

“…That the tail of the structure factor ϳk Ϫ(dϩn) has some universal features which are independent of microscopic details has been discussed in detail by Bray. 17 We have checked that for the two-dimensional porous media considered here, for kRӷ1, S(k)ϳk Ϫ3 . Sen et al also found the same result in three-dimensional porous media ͑constructed out of spherical beads͒, where s(k)ϳk Ϫ4 .…”

Section: B 2d Porous Mediamentioning

confidence: 99%

Spin echo diffraction in disordered media with single length scales

Bhattacharya

Mahanti

1997

Phys. Rev. B

View full text Add to dashboard Cite

The spin echo diffraction observed in a pulsed field gradient NMR experiment is studied by simulation in computer generated two-dimensional disordered porous media characterized by a single length scale such as their mean pore diameter. In the propagator formulation of the pulsed field gradient experiments carried out in fluids confined inside porous media one expects to see a diffraction pattern characterizing the above length scale. We have explored the possibility of using this echo diffraction technique as a practical noninvasive tool to extract information about the pore geometries. It turns out that even for a disordered medium, the echodiffraction pattern picks up the dominant length scale. ͓S0163-1829͑97͒12417-1͔

show abstract

“…(5). Since the bonding environment of B 4 SRO units is symmetric, the asymmetry parameter, η, describing the magnitude of the quadrupolar broadening of the B resonance peak, is very small 76,77 .…”

Section: B Mas-nmr Spectramentioning

confidence: 99%

Mixed glass former effect in borate and thioborate sodium-ion conducting glass systems

Curtis¹

View full text Add to dashboard Cite

NMR Studies of the Structure of Glass

Cited by 3 publications

References 0 publications

New Interpretation of Na⁺-Ion Conduction in and the Structures and Properties of Sodium Borosilicate Mixed Glass Former Glasses

New Interpretation of Na⁺-Ion Conduction in and the Structures and Properties of Sodium Borosilicate Mixed Glass Former Glasses

Spin echo diffraction in disordered media with single length scales

Mixed glass former effect in borate and thioborate sodium-ion conducting glass systems

Contact Info

Product

Resources

About

NMR Studies of the Structure of Glass

Cited by 3 publications

References 0 publications

New Interpretation of Na+-Ion Conduction in and the Structures and Properties of Sodium Borosilicate Mixed Glass Former Glasses

New Interpretation of Na+-Ion Conduction in and the Structures and Properties of Sodium Borosilicate Mixed Glass Former Glasses

Spin echo diffraction in disordered media with single length scales

Mixed glass former effect in borate and thioborate sodium-ion conducting glass systems

Contact Info

Product

Resources

About

New Interpretation of Na⁺-Ion Conduction in and the Structures and Properties of Sodium Borosilicate Mixed Glass Former Glasses

New Interpretation of Na⁺-Ion Conduction in and the Structures and Properties of Sodium Borosilicate Mixed Glass Former Glasses