Published online by Cambridge University Press: 25 February 2011
A model reaction is proposed which can totally explain formation of the defects detected in SiO2: GeO2 glasses such as E', NBOHC, T-T, bonding, peroxy linkages, and T=O or T(II) species, where T is Si or Ge. The initial reaction is radical decomposition of T-O bonds at high temperatures and the defects are products of the secondary reaction between the initial radical species. The net reaction is expressed as 2TO2⇄2TO+O2, which predicts the dependence of concentration of the radical species on PO2 during processing.