Densification and microwave dielectric properties of CaO-B2O3-SiO2 system glass-ceramics
Journal
Ceramics International
Journal Volume
34
Journal Issue
3
Pages
599-604
Date Issued
2008
Author(s)
Abstract
In order to relieve the narrow processing window and poor material compatibility in practical applications as well as understand the microwave dielectric properties, investigation on the formulations of CaO/B2O3/SiO2 glasses on their structure, thermal properties, and microwave properties were performed in this study. Six glasses with different molar ratios of CaO/B2O3/SiO2 (designed as CBS-3, CBS-5, CBS-7, CBS-8, CBS-9, and CBS-10) were prepared and pulverized. Results indicate that most softening points of glasses are ranging from 680 to 710 °C. They were sintered at different temperatures to reach maximum densification. Among various glass formulations, CBS-9 glass-ceramic containing the largest amount of SiO2 has the lowest CTE. The dielectric constants can be divided into two groups including around 4-5 and 7-8, and the dielectric losses (tan δ) are all below 0.005 in the frequency of ≈10 GHz. The dielectric constants and dielectric losses are generally frequency dependent. For CBS-9 glass-ceramic, the dielectric constant and dielectric loss at 4.7 and 18.6 GHz are 4.13 and 0.0018, and 4.20 and 0.0063, respectively. © 2007 Elsevier Ltd and Techna Group S.r.l.
Type
journal article