Structural changes between soda-lime silicate glass and melt

Neutron diffraction has been used to study the structure of a glass and melt of composition 75SiO(2)-15Na(2)O-10CaO. RMC modeling of the neutron and X-ray diffraction data for the glass allowed the determination of the Na and Ca environment. The structure has been investigated at 300K, just below the glass transition at 823 K and in the melt at 1273 K The short range order does not present important modifications with temperature while significant reorganization appears at the medium range order. These latter changes can be associated with the Si and O pairs and indicate the relaxation of the silicate network. This indicates that the glass formation involved structural rearrangement during cooling. (C) 2010 Elsevier B.V. All rights reserved.