High-frequency dielectric properties of BSTO ceramic prepared with hydrothermal synthesized SrTiO3 and BaTiO3 powders
✍ Scribed by Yonghui Xing; Hui Liang; Xiaolei Li; Liuqi Si
- Publisher
- Elsevier
- Year
- 2009
- Tongue
- English
- Weight
- 891 KB
- Volume
- 7
- Category
- Article
- ISSN
- 1674-2001
No coin nor oath required. For personal study only.
✦ Synopsis
BSTO dielectric ceramic was prepared from SrTiO 3 and BaTiO 3 powders synthesized by hydrothermal method, as well as from Ba 0.6 Sr 0.4 TiO 3 powder synthesized by conventional solid-state reaction. The former can be sintered at a relatively low temperature of 1120 • C. Characterization by SEM showed that the grain shapes of both ceramics are cubical, though the grain size of the former is much smaller. Dielectric constants measured at 20 • C were shown to vary with frequency in the range from 1 kHz to 2 MHz and dc bias field, and further that the dielectric loss of the former to be less than 2 × 10 -3 in the frequency range of 20 kHz to 1 MHz, much smaller than that of the latter sample. For the former, temperature dependence of dielectric constant is much flatter and there exists an extended phase transition diffusion covering a wide temperature range of Curie temperature T c . The smaller grain size of the former depresses the dc bias electrical field dependence of dielectric constant. The tunability is 7% under a bias field of 0.6 kV/mm dc.