STRUCTURAL AND MICROSTRUCTURAL STUDY OF GLASSES IN THE LI2O-TIO2-SIO2SYSTEM

Glasses from the Li2O-TiO2-SiO2 system with TiO2 content ranging betwe en 5 and 20 mol % were prepared. The glasses studied have an opal appe arance and when their microstructure is studied through transmission e lectron microscopy, a strong phase separation in droplet form is obser ved, with the size of the droplets depending on the TiO2 and the Li2O content. X-ray diffraction showed that these glasses are non-crystalli ne and identified the crystalline phases which take place after the co rresponding thermal treatment to enhance liquid immiscibility. A struc tural study of the samples prepared was carried out through infrared s pectroscopy. Titanium oxide is incorporated into glasses as a network modifier, so that titanium atoms place themselves in octahedral positi ons [TiO6]. This is attributed to the presence of Li2O which breaks up the glass network, favouring the hexacoordination of titanium atoms.