Nuclear Magnetic Resonance Studies of B11 in Crystalline Borates

Bray, P. J.; Edwards, John O.; O'Keefe, J. G.; Ross, Virginia; Tatsuzaki, Itaru

doi:10.1063/1.1731947

Cited by 95 publications

(40 citation statements)

References 26 publications

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“…The 11 B quadrupole coupling constant e 2 qQ calculated from the BO 3 component is 2.53 MHz, which is in good agreement with values previously reported for crystals and glasses containing trigonal and tetrahedral groups (6). However it is lower than those found for materials containing only the BO 3 entity.…”

Section: Iii1 Structural Investigation By Nmr Spectroscopysupporting

confidence: 90%

See 1 more Smart Citation

Photoluminescence of Ce3+, Tb3+, and Mn2+in Glasses of Base Composition LaMgB5O10

Jouhari

Parent

Flem

1996

Journal of Solid State Chemistry

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Section: Iii1 Structural Investigation By Nmr Spectroscopysupporting

confidence: 90%

“…The time evolution of the donor emission intensity is given by [6] where z ϭ t/ 0 exp Ͳ, g(z) is the Taylor series expansion…”

Section: V1 Theoretical Aspectmentioning

confidence: 99%

Photoluminescence of Ce3+, Tb3+, and Mn2+in Glasses of Base Composition LaMgB5O10

Jouhari

Parent

Flem

1996

Journal of Solid State Chemistry

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“…Borax has been shown by X-ray crystallography to contain equal amounts of trigonally and tetrahedrally coordinated boron atoms. 25 Chemical shifts were reported relative to 85% phosphoric acid, H 3 PO 4 Figure 6 and are comparable to spectra found in the literature for similar glasses. 18,26−30 Due to the stronger Raman scattering cross section of the phosphate SRO structural units than the borate SRO structural units, the Raman spectra of sodium borophosphate glasses show Raman bands that are far more intense for the modes arising from the phosphate structural units than the modes arising from the borate structural units.…”

Section: Experimental Methodssupporting

confidence: 83%

Structural Studies of Mixed Glass Former 0.35Na₂O + 0.65[xB₂O₃ + (1 – x)P₂O₅] Glasses by Raman and ¹¹B and ³¹P Magic Angle Spinning Nuclear Magnetic Resonance Spectroscopies

2013

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The mixed glass former (MGF) effect (MGFE) is defined as a nonlinear and nonadditive change in the ionic conductivity with changing glass former composition at constant modifier composition. In this study, sodium borophosphate 0.35Na2O + 0.65[xB2O3 + (1 -x)P2O5], 0 ≤ x≤ 1, glasses which have been shown to exhibit a positive MGFE have been prepared and examined using Raman and 11B and 31P magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopies. Through examination of the short-range order (SRO) structures found in the ternary glasses, it was determined that the minority glass former, B for 0.1 ≤ x ≤ 0.7 and P for 0.7 ≤ x ≤ 0.9, is "overmodified" and contains more Na+ ions than would be expected from simple linear mixing of the binary sodium borate, x = 1, and sodium phosphate, x = 0, glasses, respectively. Changes in the intermediate range order (IRO) structures were suggested by changes in the NMR spectral chemical shifts and Raman spectra wavenumber shifts over the full composition range x in the Raman and MAS NMR spectra. The changes observed in the chemical shifts of 31P MAS NMR spectra with x are found to be too large to be caused solely by changing sodium modification of the phosphate SRO structural groups, and this indicates that internetwork bonding between phosphorus and boron through bridging oxygens (BOs), P-O-B, must be a major contributor to the IRO structure of these glasses. While not fully developed, a firstorder thermodynamic analysis based upon the Gibbs free energies of formation of the various SRO structural units in this system has been developed and can be used to account for the preferential formation of tetrahedral boron groups, B4, by the reaction of B3 with P2 groups to form B4 and P3 groups, respectively, where the superscript denotes the number of BOs on these units, in these glasses. This preference for B4 units appears to be a predominate cause of the changing modifier to glass former ratio with composition x in these ternary MGF glasses and appears to be associated with the large negative value of the Gibbs free energy of formation of this group. Disciplines Materials Science and Engineering | Physical Chemistry CommentsReprinted with permission from The Journal of Physical Chemistry B 117 (2013) P magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopies. Through examination of the short-range order (SRO) structures found in the ternary glasses, it was determined that the minority glass former, B for 0.1 ≤ x ≤ 0.7 and P for 0.7 ≤ x ≤ 0.9, is "overmodified" and contains more Na + ions than would be expected from simple linear mixing of the binary sodium borate, x = 1, and sodium phosphate, x = 0, glasses, respectively. Changes in the intermediate range order (IRO) structures were suggested by changes in the NMR spectral chemical shifts and Raman spectra wavenumber shifts over the full composition range x in the Raman and MAS NMR spectra. The changes observed in the chemical shifts of 31 P MAS NMR spectra with x are found to be too large to be ...

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“…5). The two groups of lines (16.7-6.4 and 10.8-3.4 ppm) observed on the spectrum are characteristic of trigonal borons located in two different environments (20,21). The small peaks which appear around 47.2, 38.0, and !14.…”

Section: Nmrmentioning

confidence: 89%

“…6. It is obvious that YBO contains mainly BO tetrahedra (20). However, the presence of a shoulder (denoted A) on Fig.…”

Section: Nmrmentioning

confidence: 98%

Revised Structure of the Orthoborate YBO3

Chadeyron

El‐Ghozzi

Mahiou

et al. 1997

Journal of Solid State Chemistry

205

101

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Nuclear Magnetic Resonance Studies of B11 in Crystalline Borates

Cited by 95 publications

References 26 publications

Photoluminescence of Ce3+, Tb3+, and Mn2+in Glasses of Base Composition LaMgB5O10

Photoluminescence of Ce3+, Tb3+, and Mn2+in Glasses of Base Composition LaMgB5O10

Structural Studies of Mixed Glass Former 0.35Na₂O + 0.65[xB₂O₃ + (1 – x)P₂O₅] Glasses by Raman and ¹¹B and ³¹P Magic Angle Spinning Nuclear Magnetic Resonance Spectroscopies

Revised Structure of the Orthoborate YBO3

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Nuclear Magnetic Resonance Studies of B11 in Crystalline Borates

Cited by 95 publications

References 26 publications

Photoluminescence of Ce3+, Tb3+, and Mn2+in Glasses of Base Composition LaMgB5O10

Photoluminescence of Ce3+, Tb3+, and Mn2+in Glasses of Base Composition LaMgB5O10

Structural Studies of Mixed Glass Former 0.35Na2O + 0.65[xB2O3 + (1 – x)P2O5] Glasses by Raman and 11B and 31P Magic Angle Spinning Nuclear Magnetic Resonance Spectroscopies

Revised Structure of the Orthoborate YBO3

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Structural Studies of Mixed Glass Former 0.35Na₂O + 0.65[xB₂O₃ + (1 – x)P₂O₅] Glasses by Raman and ¹¹B and ³¹P Magic Angle Spinning Nuclear Magnetic Resonance Spectroscopies