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Structural Evolution and Medium Range Order in Permanently Densified VitreousSiO2
- Source :
- Physical Review Letters. 112
- Publication Year :
- 2014
- Publisher :
- American Physical Society (APS), 2014.
-
Abstract
- Positron annihilation lifetime spectroscopy is employed to measure the size of the interstitial void spaces characterizing the structure of a set of permanently densified ${\mathrm{SiO}}_{2}$ glasses. The average volume of the voids is markedly affected by the densification process and linearly shrinks by almost an order of magnitude after a relative density variation of 22%. In addition, x-ray diffraction shows that this change of density does not modify appreciably the short range order, which remains organized in ${\mathrm{SiO}}_{4}$ tetrahedra. These results strongly suggest a porous medium description for $v\text{\ensuremath{-}}{\mathrm{SiO}}_{2}$ glasses where the compressibility and the medium range order are dominated by the density variation of the voids volume up to densities close to that of $\ensuremath{\alpha}$-quartz.
Details
- ISSN :
- 10797114 and 00319007
- Volume :
- 112
- Database :
- OpenAIRE
- Journal :
- Physical Review Letters
- Accession number :
- edsair.doi...........e161d2e81708bd9612108d899973e91a