Influence of CoO Addition on Structural and Dielectric Properties of Strontium Titanate Glass Ceramics

Abstract

The effect of small amount of CoO addition on alkali oxide containing borosilicate glass ceramics has been discussed in order to see the influence on the crystalline phase constitution, microstructure and dielectric behavior. The glasses were crystallized in the temperature range 725–950°C. The lower crystallization temperature results in the formation of Sr₂B₂O₅ and Sr₃Ti₂O₇ as major phase while higher crystallization temperature results in the formation of perovskite SrTiO₃ phase in major amount. The micrographs depict well inter-linked, oriented and elongated crystallites of Sr₂B₂O₅ phase at lower crystallization temperature whereas the aggregates of small crystallites of SrTiO₃ phase were observed at higher crystallization temperature. The value of dielectric constant and dissipation factor is found to be very small and show temperature independent characteristics, which is highly desirable for devices where thermally stable dielectric behavior is required and also may be proposed for high frequency capacitor applications.

Keywords:

• Borosilicate glass
• crystallization
• glass ceramics
• perovskite
• dielectric constant

Notes

Note:^* = Trace amount, SB = Sr₂B₂O₅, ST = Sr₃Ti₂O₇, R = TiO₂ (rutile) and P = SrTiO₃ etc.