Crystallization behavior and dielectric properties of BaO–ZnO–SrO–CaO–Nd 2O 3–TiO 2–B 2O 3–SiO 2 glass–ceramics

Abstract

The effects of heating rate on the crystallization and sintering behaviors of glass–ceramics (BaO–ZnO–SrO–CaO–Nd 2O 3–TiO 2–B 2O 3–SiO 2) were investigated in this study. The results showed that the onset of glass shrinkage occurred at around the glass transition temperature. The first crystalline phase, Nd 2Ti 4O 11 was observed at around 775–800 °C. Fully densified glass can be obtained via glass viscous flow before the occurrence of the second crystalline phase, Nd 0.66TiO 3. With increasing heating rate, the glass transition temperature and crystallization temperature both shift to higher temperature. Sintering at a higher heating rate can retard the Nd 0.667TiO 3 crystallization of the glass, and thus improves the sintering densification via glass viscous flow during the firing process. The Ba–Zn–Sr–Ca–Nd–Ti–B–Si glass–ceramics sintered at 900 °C with a heating rate of 20 °C/min exhibited a high dielectric constant of 25 and a quality factor of about 1460, which provided a promising candidate for LTCC applications.