Dielectric Properties of Mg-Doped Ba_0.6Sr_0.4TiO₃ Ceramic Sintered at a Low Temperature with Li₂O Additve

Abstract

Dielectric properties of Mg-doped Ba_0.6Sr_0.4TiO₃ ceramics with the aid of Li₂O have been investigated. 3.0wt% Li₂O additive samples can be sintered at 900°C for 4h and sintering temperature remarkably decrease. Phase and microstructure of these samples were analyzed using XRD and SEM. Results show no obvious secondary phase and decreased grain-size as MgO content increased. Dielectric constant is decreased and the Curie temperature is shifted to low temperature and the peaks are suppressed and broaden with the increase of MgO. Tunability is decreased from about 30% to 15% with MgO content increasing from 0.15wt% to 5.0wt% under applied electric field of 40 kV/cm.

Keywords:

• Barium strontium titanium
• doping
• low-temperature sintering
• dielectric properties
• tunability

Acknowledgment

This research was supported by the Ministry of Sciences and Technology of China through 973-project under grant 2002CB613304, Shanghai Foundation Project under grant 06JC14070, Program for New Century Excellent Talents in University (NCET-04-0378) and Shanghai Pujiang Program.