Volumetric Changes Between Different Conformations of Two SiOH Groups in SiO2 Glass

M. Mlejnek; S. Kuchinsky

doi:10.4028/www.scientific.net/AMR.39-40.89

Paper Titles

Glass Formation and Structure of the Glasses in the MoO₃-Nd₂O₃-Bi₂O₃ System
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Silicon Oxycarbide Glasses from Gel Hybrid Structures
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The Effect of CaO and MgO on Physical Properties of MgO-CaO-B₂O₃-Al₂O₃-SiO₂ Glasses with Composition Close to the E-Glass Fibers
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First Principles Molecular Simulations of Soda-Lime-Silica Glass
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Volumetric Changes Between Different Conformations of Two SiOH Groups in SiO₂ Glass
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The Yttria-Alumina Glasses - MD and TD Models
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Zinc Borophosphate Glasses Doped with Molybdenum Oxide
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The Structure-Property Relationship in Oxide Glasses: A Thermodynamic Approach
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Transport and Relaxation Study of Ionic Phosphate Glasses
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HomeAdvanced Materials ResearchAdvanced Materials Research Vols. 39-40Volumetric Changes Between Different Conformations...

Volumetric Changes Between Different Conformations of Two SiOH Groups in SiO₂ Glass

Abstract:

We present numerical studies of possible modifications of SiOH groups in “wet” SiO2 glass with 193 nm laser irradiation. We focus on structural changes associated with two conformations: (i) two nearby hydrogen bonded SiOH groups, and (ii) oxygen triclusters, i.e. bridging oxygen forming a third covalent bond with a hydrogen atom. The energies of these two systems and the activation barrier of thermal relaxation between them identify the latter conformation as a candidate for a product formed under 193 nm laser exposure, when we consider the former conformation as an initial state. We investigate the effects of local volume changes associated with the changes in conformation and find it has non-negligible effect on the index of refraction. These conformational changes thus appear able to contribute to the permanent changes in index of refraction and absorption of the glass after UV irradiation.