Structural studies of germanium doped silica glasses: the role of the fictive temperature

We studied the influence of germanium atom introduction into the silica network and the influence of heat treatements on the glass structure by doing Raman and infra-red spectra of vitreous germanium doped silica (5% wt GeO2, 95% wt SiO2). Germanium incorporates into the network by substituting Si atoms and consequently, we observed band shifts and broadening of defect peaks D-1 and D-2. The peak positions are directly correlated with the structural state characterized by the glass fictive temperature T-F of the different samples. (C) 2003 Elsevier B.V. All rights reserved.