| Autor: |
Redkov, Alexey V., Melehin, Vladimir G., Lipovskii, Andrey A. |
| Zdroj: |
The Journal of Physical Chemistry - Part C; July 2015, Vol. 119 Issue: 30 p17298-17307, 10p |
| Abstrakt: |
Thermal poling of glasses induces structural and compositional modification and breaks central symmetry of these initially isotropic media. In spite of numerous experimental data accumulated, little is known about the processes occurring in soft glasses under this processing. We use micro-Raman technique to study the formation of interstitial molecular oxygen and structural modification of the subsurface layer of a soda-lime silicate glass in the course of thermal poling. The presence of O2is demonstrated in cation-depleted subanodic region of the glass, the thickness of which depends on the charge passed during the poling procedure and, in our experiments, reaches one micron. O2concentration in this layer is independent of the charge passed and is on the order of 3 × 1020cm–3being maximal in anodic surface craters arising because of poling current nonuniformities. O2generation is accompanied by an increase in the concentration of three-membered Si–O rings in the modified region of the glass matrix. The ways of nonbridging oxygen recombination are discussed and proposed as the main mechanism of the interstitial O2formation. |
| Databáze: |
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