Influence of rare earth oxides on structure, dielectric properties and viscosity of alkali-free aluminoborosilicate glasses

• Published in: Journal of non-crystalline solids 2020-03, Vol.532, p.119886, Article 119886
• Main Authors: Zhang, Lulu, Qu, Ya, Wan, Xiangrong, Zhao, Jiling, Zhao, Jingang, Yue, Yunlong, Kang, Junfeng
• Format: Article
• Language: English
• Subjects: Alkali-free aluminoborosilicate glasses; Dielectric properties; Rare earth oxides; Viscosity
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2020.119886

•The dielectric properties of the alkali-free aluminoborosilicate glass can be optimized by doping rare earth oxides (La2O3, Pr2O3, Gd2O3, Yb2O3), and the dielectric constant of the sample doped with 1.5 mol% Yb2O3 has a low value of 4.52.•The viscosity of alkali-free aluminoborosilicate glass reduced by the addition of rare earth oxides, and decrease in the order: La1.5 > Pr1.5 > Yb1.5 > Gd1.5.•The addition of rare earth oxides can reduce CTE of the alkali-free aluminoborosilicate glass, and the sequence of the reduced CTE ability of alkali-free aluminoborosilicate glass is Yb3+ > Gd3+ > Pr3+ > La3+. The effect of rare earth oxides (La2O3, Pr2O3, Gd2O3, and Yb2O3) on the structure, dielectric properties, and viscosity of alkali-free aluminoborosilicate glasses was systematic studied. The results showed that rare earth oxides as modifiers can provide free oxygen to promote the formation of [AlO4] and [BO4] on the one hand and the increase of non-bridging oxygen (Qn) in [SiO4] on the other hand. The addition of rare earth oxides to alkali-free aluminoborosilicate glass reduced the dielectric constant from 4.96 to 4.52–4.62, which could optimize the dielectric properties of the glass. The coefficient of thermal expansion (CTE) decreased, while glass transition temperature (Tg) and glass expansion softening point (Td) increased with the addition of rare earth oxides. The introduction of rare earth oxides in this work all decreased the viscosity, fiber drawing temperature and melting temperature, and narrow the working temperature range of alkali-free aluminoborosilicate glass, which is beneficial to the glass fiber melting and drawing process. The Figure shows that the dielectric constant decreased due to the doped La2O3, Pr2O3, Gd2O3, and Yb2O3, and decrease with the increases of the atomic number on the whole. Among them, the dielectric constant of the sample doped with 1.5 mol% Yb2O3 has a low value of 4.52. [Display omitted]