Determination of the structure of GeO2-SiO2 glasses by EXAFS and X-ray scattering

Greegor, R.B.; Lytle, F. W.; Kortright, J. B.; Fischer-Colbrie, A.

doi:10.1016/s0022-3093(87)80274-0

Cited by 18 publications

(21 citation statements)

References 20 publications

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“…These structural parameters remain identical whatever the composition, and point out a slightly distorted GeO 4 tetrahedron, with a mean Ge-O bond length of 1.73 Å and a Debye-Waller factor of 0.051 Å at 12 K. The Ge-O distances are similar to those found in earlier studies [4,11].…”

Section: Low Temperature Ge K-edge Xas Spectrasupporting

confidence: 82%

“…Though the presence of Ge atoms is suspected to modify the atomic structure of silica and to cause both permanent and photo-induced variation of the refractive index, the microscopic origin of the original properties of germanosilicate optical fibers and glasses is still poorly constrained. An earlier EXAFS study of silica-rich compositions [4] has shown a local structure based on a continuous network of interconnected SiO 4 and GeO 4 tetrahedra. This model has been confirmed by molecular dynamics [5], although high energy X-ray diffraction measurements on a mixed glass with Si/Ge = 2.4 question the continuous nature of this random network [6].…”

Section: Introductionmentioning

confidence: 94%

“…The region between 850 and 1250 cm À1 encompasses several bands assigned to the asymmetric stretching motion of the binding oxygen (m as (T-O-T)). This region contains information about the mixing of the SiO 4 Fig. 5 focuses on the 700-1300 cm À1 range.…”

Section: Raman Spectramentioning

confidence: 99%

See 2 more Smart Citations

The structure of SiO2–GeO2 glasses: A spectroscopic study

Majérus¹,

Cormier²,

Neuville³

et al. 2008

Journal of Non-Crystalline Solids

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Section: Low Temperature Ge K-edge Xas Spectrasupporting

confidence: 82%

Section: Introductionmentioning

confidence: 94%

See 1 more Smart Citation

The structure of SiO2–GeO2 glasses: A spectroscopic study

Majérus¹,

Cormier²,

Neuville³

et al. 2008

Journal of Non-Crystalline Solids

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“…A more extensive study using a combination of Ge K-edge X-ray absorption and wide angle X-ray scattering (WAXS) experiments were carried out on GeO 2 − SiO 2 glasses containing 16 − 36 mol% GeO 2 [100]. They showed that the XANES spectra are similar with increasing GeO 2 content and that EXAFS-derived distances are 1.72 ± 0.02Å for Ge − O.…”

Section: Exafs and X-ray Scatteringmentioning

confidence: 99%

The structure of amorphous, crystalline and liquid GeO₂

Micoulaut

Cormier

Henderson

2006

J. Phys.: Condens. Matter

228

256

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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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“…When germanium is introduced into the material, it substitutes randomly for silicon atoms in the SiO 2 network, with little germanium clustering, as has been demonstrated by EXAFS and X-ray scattering experiments [22]. The Raman spectra of Ge-doped silica have been studied before [22][23][24][25].…”

Section: Discussionmentioning

confidence: 99%