6533b82afe1ef96bd128b652

RESEARCH PRODUCT

Oxygen-excess amorphous SiO2 with 18O-labeled interstitial oxygen molecules

Masahiro HiranoHideo HosonoKoichi KajiharaKoichi KajiharaLinards SkujaLinards Skuja

subject

PhotoluminescenceChemistryDiffusionAnalytical chemistryMineralogychemistry.chemical_elementFraction (chemistry)Condensed Matter PhysicsOxygenElectronic Optical and Magnetic MaterialsAmorphous solidChemical bondMaterials ChemistryCeramics and CompositesMoleculeOxygen excess

description

Abstract Exchange between oxygen molecules embedded in amorphous SiO 2 (interstitial O 2 ) and oxygen atoms in the a -SiO 2 network is found to be remarkably slow at 500 °C. Thermal loading of 18 O 2 at this temperature yields a -SiO 2 containing 18 O-labeled interstitial O 2 whose 18 O fraction is as high as ~ 90%. The 18 O fraction of interstitial O 2 in this sample is quickly decreased by thermal annealing at or above 700 °C because of the oxygen exchange accompanied by the release of 16 O from the a -SiO 2 network. This finding indicates that the oxygen exchange starts at much lower temperatures than indicated by previous works, based on monitoring of the isotopic composition of oxygen atoms in the a -SiO 2 network.

yearjournalcountryeditionlanguage
2011-04-01Journal of Non-Crystalline Solids
https://doi.org/10.1016/j.jnoncrysol.2010.11.116