• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.1
• /
• pp.390-395
• /
• 2011

In order to develope piezoelectric transformer for the ballast of fluorescent lamp, the composition of piezoelectric ceramics was 0.95Pb($Zr_xTi_{1-x}$)O3+yPb($Mn_{1/3}Nb_{2/3}$)$O_3$+(0.05-y)Pb($Sb_{1/2}Nb_{1/2}$)$O_3$. PMN compound was selected to improve mechanical quality factor and PSN to prevent the decrease of dielectric constant and electromechanical coupling coefficient. Dielectric and piezoelectric characteristics in the region of MPB of 0.95Pb($Zr_xTi_{1-x}$)$O_3$+yPb($Mn_{1/3}Nb_{2/3}$)$O_3$+(0.05-y)Pb($Sb_{1/2}Nb_{1/2}$)$O_3$ ceramics was discussed both quantatively and qualitatively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.296-297
• /
• 2007

PMN-PZT 단층 및 다층 후막을 알루미나 기판위에 켄티레버 형태로 제작하여, 외부의 미소 진동에 의한 마이크로 발전 특성을 고찰하였다. 미소 변위에 의한 마이크로 발전 특성은 켄티레버의 무게(load), 진동수, 켄티레버의 길이 등에 밀접한 영향을 미치므로 이에 준한 요소를 고려하여 여러 가지 변수로 실험하였다. 연구 결과 서로 다른 소재의 기판과 발전체의 계면 분리 현상, 전극과 발전체의 분리 현상, 소결 온도 등이 소재 측면의 문제점으로 크게 대두되었으며, $5{\times}20mm$ 기판위에 형성된 발전체의 특성은 $1.1k{\Omega}{\sim}1M{\Omega}$의 부하에 따른 전압변동이 0.01V에서 3.6V로 큰 차이가 났다. 켄티레버의 로드의 변화에 대한 피크 전압은 $1.9{\sim}{\pm}2.8V$로 조사되었으며, 출력은 $0.45{\sim}4{\mu}W$로 측정되었다. 그러나 이런 외부 조건 보다 압전체의 공진 특성과 진동수는 가장 중요한 요인으로 나타났으며, 몇몇 문제가 해결될 경우 마이크로 발전소자로의 활용 가능성이 있는 것으로 조사되었다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.19 no.1
• /
• pp.35-39
• /
• 2006

In this study, in order to develop the multilayer piezoelectric actuator and ultrasonic resonator, PMN-PNN-PZT ceramics were fabricated by sintering with $Li_2CO_3-Na_2CO_3$ as sintering aids at $950^{\circ}C$ and their piezoelectric and dielectric characteristics were investigated as a function of PNN substitution. With increasing PNN substitution, dielectric constant(${\epsilon}_r$), electromechanical coupling factor(kp), and piezoelectric d constant($d_{33}$) were increased to $12 mol\%$ PNN substitution and then showed a tendency to decrease rapidly With increasing PNN substitution, crystal structure changed from tetragonal to rhombohedral at $12 mol\%$ PNN substitution and then secondary phase was appeared and its intensity was increased. At the $12 mol\%$ PNN substituted PMN-PZT composition ceramic sintered at $950^{\circ}C$, density, kp, $d_{33}$ and Qm showed the optimum value of $7.79 g/cm^3$, 0.599, 419 pC/N, and 894, respectively for multilayer piezoelectric actuator application.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.36 no.2
• /
• pp.191-196
• /
• 2023

In this paper, for the application of ultrasonic cleaners for cleaning dentures and transparent braces, Pb(Mn_1/3Nb_2/3)O₃-Pb(Ni_1/3 Nb_2/3)O₃-Pb(Zr,Ti)O₃ [PMN-PNN-PZT] system ceramics were manufactured and their dielectric and piezoelectric properties were investigated. Overall the best properties suitable for the device applications such as ultrasonic cleaner were obtained from the ceramics sintered at 920℃: bulk density of 7.8 g/cm³, the dielectric constant (ε_r) of 1,689, piezoelectric charge constant (d₃₃) of 433 pC/N, planar electromechanical coupling factor (k_p) of 0.64, mechanical quality factor (Qm) of 835, S₁₁^E of 13.37 (10^-12 N/m²), and Curie temperature of 315℃ By using the physical properties of this composition, the ultrasonic cleaner was designed and simulated using the commercial ATILA software. For the three-layered ceramics with the dimension of 25 mm × 25 mm × 2.5mm, an excellent displacement of 8.998 10^-3 m) and the sound pressure of 147.68 dB were recorded.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1999.11a
• /
• pp.269-272
• /
• 1999

In this study, electrical properties and TCFr of Pb(Sb$_{1}$2/Nb$_{1}$2/)O$_3$-Pb(Mn $_{1}$3/Nb$_{2}$3/)O$_3$-Pb(zr, Ti)O$_3$ composition ceramics were investigated wish the Zr/Ti ratio and the additions of Y2O3. and Fe$_2$O$_3$ Electromechanical coupling factor(Kp) showed the highest value of 0.555 in the Zr/Ti=0.50/0.50 ratio ,however, dielectric constant showed the highest value of 1,217 in the Zr/Ti = 0.49/0.51 ratio. Excellent TCFr vague of 421ppm/$^{\circ}C$] at-30~9O$^{\circ}C$ was appeared in the Zr/Ti=0.50/0.50 ratio and electro-mechanical coupling factor(Kp) , mechanical quility factor(Qm) and dielectric constant was 0.496, 1,286 and 1,085 ,respectively ,in the composition ceramics of lwt%Y$_2$O$_3$ and 0.3wt%Fe$_2$O$_3$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.59-61
• /
• 2005

In this paper, in order to develop the low temperature sintering ceramics for multilayer piezoelectric transformer, $Pb[(Mn_{1/3},Nb_{2/3})_{0.07}(Zn_{1/3}Nb_{2/3})_a(Zr_{0.48}Ti_{0.52})_{1-0.07-a}O_3]$ ceramics were manufactured with the variations of PZN from 2 to 14mol% and their dielectric and piezoelectric properties were investigated. Sintering temperature was varied from 910 to $1000^{\circ}C$. At 8mol% PZN substituted specimen sintered at $970^{\circ}C$, electromechanical coupling factor(kp), mechanical quality factor(Qm), dielectric constant and peizoelectric constant($d_{33}$) showed the optimal values of 0.536, 1803, 1551 and 328[pC/N), respectively, for multilayer piezoelectric transformer application.

• Journal of the Korean Ceramic Society
• /
• v.42 no.10 s.281
• /
• pp.698-702
• /
• 2005

Dielectric and Piezoelectric properties of complex perovskite 0.92Pb($Zr_{1/2}Ti_{1/2})O_{3}-(0.08-x)Pb(Cu_{1/3}Nb_{2/3})O_{3}-xPb(Mn_{1/3}Nb_{2/3})O_{3}(0{\leq}x{\leq}0.080$) (PZT-PCN-PMN) system were investigated as a function of PMN content. With the increase of PMN content of the sintered specimens, tetragonal phase was coexisted with rhombohedral phase, the dielectric constant was decreased, mechanical quality factor ($Q_{m}$) was inceased, and optimal sintering temperature was increased up to 1050$^{\circ}C$. For the composition of x = 0.064 sintered at 1050$^{\circ}C$ for 2 h, 1939 of maximum mechanical quality factor ($Q_{m}$), 57$\%$ of electromechanical coupling factor ($k_{p}$), and 1100$^{\circ}C$ of dielectric constant, 0.37$\% $ of dielectric loss (tan $\delta$) were obtained.

• Journal of the Korean Ceramic Society
• /
• v.39 no.9
• /
• pp.846-850
• /
• 2002

A PMN-PT-BT/Ag composite was prepared by surface modification with MgO sol with hoping to suppress silver's migration during sintering. The mixture of PbO, $N_2O_5,\;TiO_2\;with\;Mg(NO_3)_2$ instead of MgO was ball milled, the solvent was removed and then the dried powders were calcined at 950$^{\circ}C$/1h. The calcined powder were treated with 3.0 mol% $Ag_2O$ and 1.0 wt% MgO sol and calcined at 550$^{\circ}C$/1h. The dielectrics sintered at 1000$^{\circ}C$/4h under a flowing oxygen showed the density of 7.84g/$cm^3$, the room temperature dielectric constant of 18400, the dielectric loss of 2.4%, the specific resistivity of $0.24{\times}10^{12}{\Omega}{\cdot}cm$. It also showed the bending strength of $120.7{\pm}11.26$ MPa and the fracture toughness of $0.87{\pm}0.002\;MPam^{1/2}$ which were comparable to commercial PZT. The microstructure sonsisted of grains of ∼4${\mu}m$. SEM and SIMS analysis showed that Ag grew as ∼1${\mu}m$ and excess MgO as ∼0.5${\mu}m$.

• Proceedings of the KIEE Conference
• /
• 1999.07d
• /
• pp.1541-1543
• /
• 1999

Screen printing에 의해 압전 후막을 제조하기 위하여 약 $0.6{\mu}m$의 평균 입자 크기를 갖는 PMN-PZT와 PAN-PZT 분말을 산화물 혼합법에 의해 제조하였다. 치밀한 후막의 제조를 위한 분말과 유기물의 비율은 분산이 가능한 범위에서 80:20 (분말:유기물)의 중량비를 나타내었다 사용된 기판과 하부전극은 각각 $SiO_2$/Si와 AgPd 였으며, 후막 제조시 박리 및 균열현상은 발생되지 않았다. 프린트된 후막은 건조온도와 무관한 미세구조를 나타내었으며, 보다 치밀한 구조를 갖는 후막의 제조를 이해 입자의 분산 및 열처리 조건 그리고 기판과의 매칭에 대해 연구가 계속되어야 할 것으로 생각된다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.07a
• /
• pp.198-202
• /
• 2001

In this study, contour vibration mode piezoelectric transformer with size of 27.5${\times}$27.5${\times}$2.6mm$^3$ using PNW-PMN-PZT ceramic was fabricated. And the piezoelectric transformer was adopted to fluorescent lamp ballast circuit. Electrical characteristics of the piezoelectric transformer were investigated for fluorescent lamp ballast application. The electrical properties and characteristic temperature rise were measured using oscilloscope and infrared temperature sensor. A 28W fluorescent lamp was successfully driven by the fabricated ballast circuit. After driving the lamp using ballast circuit for 24 min, the output power, efficiency and characteristic temperature rise of piezoelectric transformer showed the appropriate values of 28.85[W], 86.3[%] and 15[$^{\circ}C$], respectively.