| 학회 |
한국재료학회 |
| 학술대회 |
2021년 봄 (05/12 ~ 05/14, 광주 김대중컨벤션센터) |
| 권호 |
27권 1호 |
| 발표분야 |
A. 전자/반도체 재료 분과 |
| 제목 |
Dependence of dielectric properties and structural characteristics on Ca2+ substitution for Ba-/Sr-site of (Ba0.7Sr0.3)(Ti0.9Zr0.1)O3-based ceramics |
| 초록 |
For various applications of MLCC(Multi-layered ceramic capacitor), the dielectric constant (εr) and breakdown voltage (Vb) of BaTiO3-based ceramics should be improved. Dielectric properties of the (Ba0.7Sr0.3)(Ti0.9Zr0.1)O3 ceramics were investigated by the substitution of Ca2+ ions for either Ba2+ and/or Sr2+ ions, and evaluated based on the quantitative crystal structure characteristics by RIR(Rietveld refinement) method from XRD results. With the increase of Ca2+ contents, the specimens of both (Ba0.7Sr0.3-xCax)(Ti0.9Zr0.1)O3 (BSCTZ) and (Ba0.7-yCaySr0.3)(Ti0.9Zr0.1)O3 (BCSTZ) (0 ≤ x, y ≤ 0.2) ceramics sintered at 1550℃ for 6h showed the decrease of unit cell volume due to the smaller ionic size of Ca2+ ions than Ba2+ and/or Sr2+ ions, and the diffuse phase transition of tetragonal (P4mm) and the cubic (Pm3 ̅m) phase was detected over the entire range of compositions. The cubic phase fraction of BSCTZ ceramics decreased, while that of BCSTZ ceramics increased with Ca2+ ion substitution. These results can be attributed to the A-site cation size-variance effect and steric effect, respectively. And also, the dielectric constants (εr) of both compositions were decreased, while the breakdown voltage (Vb) was increased with increasing of average B-site bond valence. Optimization of the dielectric properties of (Ba0.7Sr0.3)(Ti0.9Zr0.1)O3-based ceramics were also discussed. |
| 저자 |
Eung Soo Kim1, Nak Beom Jo2
|
| 소속 |
1Department of Materials Engineering, 2Kyonggi Univ. |
| 키워드 |
BaTiO<SUB>3</SUB>-based ceramics; Dielectric properties; Bond valence; Rietveld refinement; MLCC
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| E-Mail |
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