Oxidation and diffusion process in the ferrous iron-bearing glass fibres near glass temperature

The Fe2+ oxidation and the network modifier diffusion in the Fe2+-bearing glass fibers are studied using differential scanning calorimetry (DSC), thermogravimetry (TG), and secondary neutral mass spectrometry (SNMS). The results show two couplings: 1) between the Fe2+ oxidation and the network modifier diffusion; 2) between the oxidation process and the glass transition. Based on these couplings, a phenomenological equation is proposed, which describes both kinetics and dynamics of the oxidation process of the Fe2+-bearing glass fibers. The equation can be used to predict the degree of oxidation of the Fe2+-bearing fibers with an average diameter of 3.5 m by knowing the heat-treatment conditions and vice versa