Influence of dopants on the crystallization of borosilicate glass

The effects of TiO2 nucleating agent and CeO2, ZrO2, La2O3 and Y2O3 network modifiers on crystallization and structure of borosilicate glasses were systematically investigated. It was found that the nucleating Ti4+ ions entered [TiO6] Octahedron, participated in network formation and promoted glass crystallization, while the network modifiers induced alpha-quartz formation, favoring its crystallization as major crystal phase, which positively affected thermal expansion coefficient of the glass-ceramics. Network modifiers allowed strengthening glass network and conduced alpha-quartz-like structure, which was helpful for alpha-quartz crystallization. (c) 2009 Elsevier Ltd and Techna Group S.r.l. All rights reserved.