Volume 82, Number 5, June 2008
|Number of page(s)||6|
|Section||Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties|
|Published online||26 May 2008|
On the nature of native defects in high OH-content silica glasses: A first-principles study
CEMES - 29 rue Jeanne Marvig, BP 94347, 1055 Toulouse Cedex 4, France, EU
2 AREVA NP GmbH - Paul-Gossen-Str. 100, 91058 Erlangen, Germany, EU
3 LCVN, CNRS UMR 5587 and Université Montpellier II - 34095 Montpellier, France, EU
Corresponding author: email@example.com
Accepted: 10 April 2008
First-principles simulations based on the density functional theory are used in order to generate silica glasses containing 3.84 wt % water molecules employing different quench protocols. Using the Kohn-Sham density of states we find localized states in the band gap that can be associated with doubly occupied Si-O dangling bond (DB) which are negatively charged and are compensated by positively charged threefold coordinated oxygens. The position of these states above the O 2p valence band depends on the local environment of the dangling bonds, in particular on the presence of other defects in their neighborhood, and on the hydrogen bond length. These native defects, which could exist in optical fibers for instance, are compatible with the optical absorption and photoluminescence bands observed in amorphous silica and their dependence in the OH content. If present, these pre-existing defects would play a significant role as precursors in the laser-induced defect formation process.
PACS: 71.23.-k – Electronic structure of disordered solids / 71.15.Pd – Molecular dynamics calculations (Car-Parrinello) and other numerical simulations / 61.43.Fs – Glasses
© EPLA, 2008
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.