The effects of La3+ substitution for Sr2+-site on the crystal structure and the dielectric properties of (Ba0.7Sr0.3-3x/2Lax) (Ti0.9Zr0.1)O3 (BSLTZ) (0.005 ≤ x ≤ 0.02) ceramics were investigated. The structural characteristics of the BSLTZ ceramics were quantitatively evaluated using the Rietveld refinement method from X-ray diffraction (XRD) data. For the specimens sintered at 1,550 °C for 6 h, a single phase with a perovskite structure and homogeneous microstructure were observed for the entire range of compositions. With increasing La3+ substitution (x), the unit cell volume decreased because the ionic size of La3+ (1.36 Å) ions is smaller than that of Sr2+ (1.44 Å) ions. With increasing La3+ substitution (x), the tetragonal phase fraction increased due to the A-site cation size mismatch effect. Dielectric constant (εr) increased with the La3+ substitution (x) due to the increase in tetragonality (c/a) and the average B-site bond valence of the ABO3 perovskite. The BSLTZ ceramics showed a higher dielectric loss due to the smaller grain size than that of (Ba0.7Sr0.3)(Ti0.9Zr0.1)O3 ceramics. BSLTZ (x = 0.02) ceramics met the X7R specification proposed by the Electronic Industries Association (EIA).

1. 서 론
2. 실험 방법
3. 결과 및 고찰
    3.1. (Ba0.7Sr0.3-3x/2Lax)(Ti0.9Zr0.1)O3 세라믹스의 물리적 특성
    3.2. (Ba0.7Sr0.3-3x/2Lax)(Ti0.9Zr0.1)O3 세라믹스의 유전특성
4. 결 론
Acknowledgement

• 김시현(경기대학교 신소재공학과 학생) | Si Hyun Kim (Department of Advanced Materials Engineering, Kyonggi University, Suwon 16227, Republic of Korea)
• 김주혜(경기대학교 신소재공학과 학생) | Ju Hye Kim (Department of Advanced Materials Engineering, Kyonggi University, Suwon 16227, Republic of Korea)
• 김응수(경기대학교 신소재공학과 교수) | Eung Soo Kim (Department of Advanced Materials Engineering, Kyonggi University, Suwon 16227, Republic of Korea) Corresponding Author