STRUCTURE OF NA2O.2TIO2 GLASS

X-ray radial distribution analysis and Raman spectroscopic measurement were carried out on Na2O.2TiO2 glass prepared by twin-roller quenching method. It is found that four-coordinated Ti4+ ions may be predominant over six-coordinated ones in the present glass. It is also found that the fraction of six-coordinated Ti4+ ions is larger in the present glass than in K2O.2TiO2 and Cs2O.2TiO2 glasses. Poorer glass-forming ability of the Na2O-TiO2 system compared with the K2O-TiO2 and Cs2O-TiO2 systems is ascribed to a larger fraction of TiO6 octahedron for the former system.