Author/Authors :
Schlenz، نويسنده , , H. and Kirfel، نويسنده , , A. and Schulmeister، نويسنده , , K. and Wartner، نويسنده , , N. and Mader، نويسنده , , W. and Raberg، نويسنده , , W. and Wandelt، نويسنده , , K. and Oligschleger، نويسنده , , C. and Bender، نويسنده , , S. and Franke، نويسنده , , R. and Hormes، نويسنده , , J. and Hoffbauer، نويسنده , , W. and Lansmann، نويسنده , , V. and Jansen، نويسنده , , M. and Zotov، نويسنده , , N. and Marian، نويسنده , , C. and Putz، نويسنده , , H. and Neuefeind، نويسنده , , J.، نويسنده ,
Abstract :
The structures of four different Ba-silicate glasses were analysed applying a broad spectrum of diffraction and spectroscopic methods, atomic force microscopy and computer simulations. This collaborative study offers new insights into the influence of the network modifier BaO. 3 at.% carbon were incorporated into two of the glasses with the intention to obtain additional information about the effect of partial substitution of carbon for oxygen on the considered structures. A structure model for Ba-silicate glasses with compositions close to BaSi2O5 is discussed that differs with respect to other models proposed in previous studies. We propose that [SiO4] tetrahedra do not exclusively form six-membered rings, but also considerable numbers of smaller rings arranged in (slightly) folded layers which alternate with barium layers and/or barium chains. Additionally, the occurrence of tetrahedral chains, possibly isolated rings and of regions in which the [SiO4] tetrahedra form a silica-like network is assumed.
