The structures of pyrope (Mg3Al2Si3O12) and grossular (Ca3Al2Si3O12) glasses at 300 K have been analyzed by molecular dynamics (MD) simulation techniques. The calculated glass structures have been compared with the structures obtained by the X-ray diffraction method. The averaged structures are in good agreement with the results of X-ray analyses, indicating that these MD-derived structures represent well the real glass structures. The calculated pair correlation functions of SiO and AlO pairs for pyrope glass show broader peaks than those of grossular glass, which may indicate that Mg2+ ions give a larger effect on the network structure of SiO4 and AlO4 tetrahedra. The calculated structures include AlOAl arrangements, which indicate that these structures do not well obey the aluminum avoidance principle. Numbers of AlO4 tetrahedra in these glasses show the presence of Q4 species greater than SiO4 tetrahedra. In these glasses, the O (Si + Al) ratios are 2.4. Therefore, it is expected that some Al3+ ions work as network modifier ions in these glasses.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry