Hydrogen release in SiO2: Source sites and release mechanisms

R. M. Van Ginhoven, H. P. Hjalmarson, A. H. Edwards, Blair Richard Tuttle

Research output: Contribution to journalArticlepeer-review

15 Scopus citations

Abstract

We investigate molecular scale mechanisms for radiation-induced release of hydrogen from precursor sites using density functional theory applied to a fully periodic model of SiO2. We focus on proton release from H-decorated oxygen vacancies in the bulk oxide. After hole-capture at the vacancy, a proton can hop to an energetically favorable bound state at a neighboring oxygen atom. In α-quartz, this release mechanism has an activation energy of about 1.2 eV. In amorphous silica, this hop has a range of low barriers, from 0.1 to 0.5 eV. Furthermore, another proton release mechanism involves cracking of H2 molecules by a reaction with an isolated, positively charged Si-dangling bond.

Original languageEnglish (US)
Pages (from-to)274-278
Number of pages5
JournalNuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Volume250
Issue number1-2 SPEC. ISS.
DOIs
StatePublished - Sep 1 2006

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Instrumentation

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