MENG Zheng, LIU Shujiang, SHEN Jianxing, GAO Bin
（Key Laboratory of Processing and Testing Technology of Glass and Functional Ceramics, Shandong Institute of Light Industry, Jinan 250353）
Abstract:CaO -Al2O3 -SiO2 -AlF3 (series A) and CaO -Al2O3 -SiO2 -CaF2 (series C) glasses were prepared by means of conventional melt quenching technology. When SiO2＞45mol%, Ca/Al＞1(mol), F/Al<1(mol), we got the value of the volume of AlO3F tetrahedron from series A and series C of CaO-Al2O3-SiO2-F system glasses by using Doweidar Density Model which can be regarded as a constant VAl -f=57.82×10-24cm-3 and without relation to the dopant (CaF2 or AlF3) and stoichiometric concentration. It is also found that the volume of [AlO3F] tetrahedron is bigger than [AlO4] tetrahedron (VAl-f>VAl-o); the reason is that the bonding force at the mass point was changed (fAl-f <f Al-0). The smaller the bonding force, the bigger the distance between mass points. There was a satisfactory agreement between the calculated densities and the measured densities of CaO-Al2O3-SiO2 system glasses with the error less than 0.03%.
Keywords:CaO-Al2O3-SiO2-F system glasses, density, structure