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Galeener, F. L.; Leadbetter, A. J.; Stringfellow, M. W.

doi:10.1103/physrevb.27.1052

Cited by 408 publications

(180 citation statements)

References 61 publications

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“…This band is attributed to the bending vibration of the Si-O-Si bonds with the oxygen oscillating along the axis bisecting the angle of this bond. 13,18 According to Galeener et al 19 the frequency of this vibrational mode is given by With the shift of this band to 816 cm −1 , due to poling, the angle should have decreased to ϳ128°, according to Eq. ͑3͒.…”

Section: Discussionmentioning

confidence: 99%

Compositional and structural changes at the anodic surface of thermally poled soda-lime float glass

Ziemath¹,

Araújo²,

Escanhoela³

2008

Journal of Applied Physics

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Applying high dc electric fields at elevated temperatures on silicate glasses results in displacement of ions, causing compositional and structural changes in the anodic surface. In this work, the ionic displacement was accompanied by electric current measurements during poling. The thickness of the Na + depletion layer calculated from the current curves agrees with the thickness measured by EDS only if displacement of Ca 2+ and O − are also taken into account. A depletion of Ca 2+ in the anodic surface has in fact been observed. Structural changes were confirmed by infrared diffuse and specular reflectance spectroscopies. A narrowing of the band at about 1070 cm −1 can be attributed to an increase in the structural ordering degree. Refractive index measurements confirm compositional changes and contact angle measurements indicate the existence of a negative charge density at the anodic surface.

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Section: Discussionmentioning

confidence: 99%

Compositional and structural changes at the anodic surface of thermally poled soda-lime float glass

Ziemath¹,

Araújo²,

Escanhoela³

2008

Journal of Applied Physics

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“…One of the earliest is that of Kaiser et al [80] while more recent studies have tended to use IR in high-pressure studies [81] for investigating the onset of amorphous to amorphous phase transitions (see below). The IR spectrum of GeO 2 glass exhibits two peaks at 560 cm −1 and one at ≃ 870 cm −1 with a shoulder at ≃ 1000 cm −1 although the relative intensities for these two bands are reversed in the spectra of Galeener et al [82]. The low frequency band at 560 cm −1 is the IR equivalent of the LO bending mode observed in the Raman spectrum at ≃ 595 cm −1 while the bands at 870 cm −1 and ≃ 1000 cm −1 are the IR equivalent TO (870 cm −1 ) and LO split asymmetric stretching of the bridging oxygens [82].…”

Section: Infra Red (Ir) Spectroscopymentioning

confidence: 99%

“…The IR spectrum of GeO 2 glass exhibits two peaks at 560 cm −1 and one at ≃ 870 cm −1 with a shoulder at ≃ 1000 cm −1 although the relative intensities for these two bands are reversed in the spectra of Galeener et al [82]. The low frequency band at 560 cm −1 is the IR equivalent of the LO bending mode observed in the Raman spectrum at ≃ 595 cm −1 while the bands at 870 cm −1 and ≃ 1000 cm −1 are the IR equivalent TO (870 cm −1 ) and LO split asymmetric stretching of the bridging oxygens [82]. The data of Galeener et al [82] also show a peak in their IR reflectance spectrum at ≃ 340 cm −1 which is the equivalent of the 347 cm −1 Raman band.…”

Section: Infra Red (Ir) Spectroscopymentioning

confidence: 99%

The structure of amorphous, crystalline and liquid GeO₂

Micoulaut

Cormier

Henderson

2006

J. Phys.: Condens. Matter

229

252

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Abstract. Germanium dioxide (GeO 2 ) is a chemical analogue of SiO 2 . Furthermore, it is also to some extent a structural analogue, as the low and high-pressure short-range order (tetrahedral and octahedral) is the same. However, a number of differences exist. For example, the GeO 2 phase diagram exhibits a smaller number of polymorphs, and all three GeO 2 phases (crystalline, glass, liquid) have an increased sensitivity to pressure, undergoing pressure induced changes at much lower pressures than their equivalent SiO 2 analogues. In addition, differences exist in GeO 2 glass in the medium range order, resulting in the glass transition temperature of germania being much lower than for silica. This review highlights the structure of amorphous GeO 2 by different experimental (e.g., Raman and NMR spectroscopy, neutron and x-ray diffraction) and theoretical methods (e.g., classical molecular dynamics, ab initio calculations). It also addresses the structure of liquid and crystalline GeO 2 that have received much less attention. Furthermore, we compare and contrast the structural differences between GeO 2 and SiO 2 , as well as, along the GeO 2 − SiO 2 join. It is probably a very timely review as interest in this compound, that can be investigated in the liquid state at relatively low temperatures and pressures, continues to increase.

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“…In both cases, Al as well as Si are tetrahedrally coordinated. Therefore, the shift of the SiO asymmetric stretching vibration might be attributed to contributions of smaller Si-O-Si bond angles in the bond angle distribution in the glass [45,51,52,53]. In crystalline -spodumene, rings of 5, 6, and 7 tetrahedra exist in the network [28].…”

Section: Al Mas Nmr and Ir Spectroscopymentioning

confidence: 99%

Li Ion Diffusion in Nanocrystalline and Nanoglassy LiAlSi₂O₆ and LiBO₂ - Structure-Dynamics Relations in Two Glass Forming Compounds

Kuhn¹,

Tobschall²,

Heitjans³

2009

Zeitschrift Für Physikalische Chemie

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In the present study the Li diffusivity in nanostructured samples of two glass forming model systems, spodumene (LiAlSi 2 O 6 ) and lithium metaborate (LiBO 2 ), was examined using 7 Li nuclear magnetic resonance (NMR) spin-lattice relaxometry and dc conductivity measurements. The nanostructured samples were prepared by high-energy ball milling of the respective crystalline starting material on the one hand and the corresponding glass on the other hand. The diffusivity of the glass exceeds that of the crystalline sample for both systems. However, when the crystalline samples are mechanically treated by ball milling the diffusivity is enhanced. Nevertheless, the diffusivity of these nanocrystalline samples remains lower than that of the corresponding glass. Surprisingly, when the glassy samples are treated in the same way the diffusivity decreases. After sufficiently long milling times the diffusivity of these nanoglassy samples approaches that of the nanocrystalline samples. This convergence effect seems to be due to structural relaxation processes as is suggested by supplementary infrared spectroscopy and 27 Al, 12B magic angle spinning NMR measurements.

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Comparison of the neutron, Raman, and infrared vibrational spectra of vitreous SiO2, GeO2

Cited by 408 publications

References 61 publications

Compositional and structural changes at the anodic surface of thermally poled soda-lime float glass

Compositional and structural changes at the anodic surface of thermally poled soda-lime float glass

The structure of amorphous, crystalline and liquid GeO₂

Li Ion Diffusion in Nanocrystalline and Nanoglassy LiAlSi₂O₆ and LiBO₂ - Structure-Dynamics Relations in Two Glass Forming Compounds

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Comparison of the neutron, Raman, and infrared vibrational spectra of vitreous SiO2, GeO2

Cited by 408 publications

References 61 publications

Compositional and structural changes at the anodic surface of thermally poled soda-lime float glass

Compositional and structural changes at the anodic surface of thermally poled soda-lime float glass

The structure of amorphous, crystalline and liquid GeO2

Li Ion Diffusion in Nanocrystalline and Nanoglassy LiAlSi2O6 and LiBO2 - Structure-Dynamics Relations in Two Glass Forming Compounds

Contact Info

Product

Resources

About

The structure of amorphous, crystalline and liquid GeO₂

Li Ion Diffusion in Nanocrystalline and Nanoglassy LiAlSi₂O₆ and LiBO₂ - Structure-Dynamics Relations in Two Glass Forming Compounds