Stability of E' centers induced by 4.7eV laser radiation in SiO2
Abstract
The kinetics of E' centers (silicon dangling bonds) induced by 4.7eV pulsed laser irradiation in dry fused silica was investigated by in situ optical absorption spectroscopy. The stability of the defects, conditioned by reaction with mobile hydrogen of radiolytic origin, is discussed and compared to results of similar experiments performed on wet fused silica. A portion of E' and hydrogen are most likely generated by laser-induced breaking of Si-H precursors, while an additional fraction of the paramagnetic centers arise from another formation mechanism. Both typologies of E' participate to the reaction with H_2 leading to the post-irradiation decay of the defects. This annealing process is slowed down on decreasing temperature and is frozen at T=200K, consistently with the diffusion properties of H_2 in silica.
Keywords
Cite
@article{arxiv.cond-mat/0703066,
title = {Stability of E' centers induced by 4.7eV laser radiation in SiO2},
author = {F. Messina and M. Cannas},
journal= {arXiv preprint arXiv:cond-mat/0703066},
year = {2009}
}
Comments
12 pages, 3 figures, in press on J. Non cryst. solids (2007)