• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.228-231
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• 2003

In this sturdy, piezoelectric transformer using PNW-PMN-PZT ceramics was fabricated with the size of $1{\times}16{\times}5mm^3$ for LCD backlight inverter application of PDA. And its electrical characteristics were investigated with load resistance and driving frequency. At the frequency of 212.6kHz, CCFL for PDA was driven stably, and input voltage of 8.83V and output voltage of 305V were shown.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.232-235
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• 2003

In this study, in order to develop the low temperature sintering ceramics for multilayer piezoelectric transformer, dielectric and piezoelectric properties of PSN-PZT ceramics were investigated as a function of CuO addition, At the 0.6wt% CuO added specimen sintered at $920^{\circ}C$, the most excellent mechanical quality factor and electromechanical coupling factor were obtained.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.5
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• pp.453-457
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• 2008

In this thesis, piezoelectric properties and sintering properties of PCW-PNN-PZT+0.5 wt%$MnO_2$ ceramics adding $B_2O_3$ after creating the specimens with a general method. The lattice constant from the analysis of crystal structure showed that the crystal structure of ceramic features both rhombohdral and tetragonal structures and that the pychlore structure was decreased with the increase of the sintering temperature. The electromechanical coupling coefficient showed its maximum of 31 % in the sintered specimens at $1050^{\circ}C$, and its minimum of 20 % in the sintered specimens at $1150^{\circ}C$. The mechanical quality coefficient marked the maximum of 139 at the sintering temperature of $1150^{\circ}C$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.253-254
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• 2007

In this study, in order to develop low temperature sintering multilayer piezoelectric actuator, PMN-PNN-PZT system ceramics were fabricated using $Li_2CO_3-Bi_2O_3$-CuO as sintering aids and their piezoelectric and dielectric characteristics were investigated as a function of heating rate. At sintering temperature of $900^{\circ}C$, with increasing heating rate, electromechanical coupling factor(kp), mechanical quality factor(Qm) and dielectric constant $({\varepsilon}_r)$ were increased.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1110-1112
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• 1993

Optical and quadratic electrooptic properties were studied for some compositions(BLN/PZ/PT=9.0/70/30,9.0/65/35,8.5/70/30,8.5/65/35) of the two-stage sintered BLN-PZT ceramics. Effective birefringences(${\Delta}n$), quadratic electrooptic coefficients(R) and half-wave voltages($V_{\pi}$) were measured with electric field and temperature. Also, switching times and contrast ratios were measured.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.332-335
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• 2003

Particle size and piezoelectric characteristics of PNW-PMN-PZT ceramics with the variations in attrition milling conditions were investigated for the piezoelectric transformer application. Particle size and distribution were decreased with increasing milling time. Dielectric constant (${\varepsilon}r$), electromechanical coupling factor (kp), mechanical quality factor (Qm) and density showed the optimum value of 1563, 0.53, 2342, 7.63, respectively at 7h milling time.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.3
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• pp.152-156
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• 2017

In this paper, $Pb(Mn_{1/3}Nb_{2/3})_{0.07}(Ni_{1/3}Nb_{2/3})_{0.10}(Zr_{0.5}Ti_{0.5})_{0.83}O_3$ ceramics were fabricated by the conventional solid state method to obtain excellent dielectric properties for ultrasonic generators. The effects of 2nd calcination temperature on their microstructure and piezoelectric properties were systematically investigated. The tetragonality increased in the ceramics when 2nd calcination temperature increased to the optimized temperature at $750^{\circ}C$. At that temperature, excellent physical properties ($d_{33}=352\;pC/N$, ${\varepsilon}_r=1,687$, $k_p=0.570$, $Q_m=1,640$) were obtained for ultrasonic generator application.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.3
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• pp.243-247
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• 2005

In this study, in order to develop low temperature sintering ceramics for ultrasonic vibrator application, PNW-PMN-PZT system ceramics were manufactured according to the amount of CaCO$_3$ addition, and their piezoelectric, dielectric and microstructural characteristics were investigated. The ceramic specimens could be sintered at sintering temperature below 1000 $^{\circ}C$ due to the effect of Li$_2$CO$_3$-CaCO$_3$ liquid phase produced by the reaction of Li$_2$CO$_3$ and CaCO$_3$. At 0.2 wt% Li$_2$CO$_3$ and 0.25 wt％ CaCO$_3$ added specimen sintered at 920 $^{\circ}C$, the density, electromechanical coupling factor(k$_{p}$), mechanical quality factor(Q$_{m}$) and dielectric constant showed the optimal value of 7.78 g/㎤, 0.49, 1396, and 1300, respectively, for ultrasonic vibrator application.ion.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.214-216
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• 2006

In this study, in order to develop the composition ceramics for low loss and low temperature sintering multilayer piezoelectric actuator, PMN-PZN-PZT ceramics were fabricated using two stage calcination method and $Li_2CO_3$, $Bi_2O_3$ and CuO as sintering aids and their piezoelectric characteristics were investigated according to the 2nd calcination and sintering temperature. At the calcination temperature of $750^{\circ}C$ and sintering temperature of $930^{\circ}C$, density, electromechanical coupling factor ($k_p$), mechanical quality factor ($Q_m$), Dielectric constant (${\varepsilon}_r$) and piezoelectric constant ($d_{33}$) of specimen showed the optimum value of $7.94g/cm^2$ 0.581, 1554, 1555 and 356pC/N, respectively for multilayer piezoelectric actuator application.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.425-430
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• 2004

In this paper, in order to develop the low temperature sintering ceramics for multilayer piezoelectric transformer, PMN-PZT ceramics were manufactured with the variations of sintering times, and their microstructural, piezoelectric and dielectric properties were investigated. To manufacture multilayer piezoelectric transformer, the low temperature sintering composition is need, hence, $Li_2CO_3$ and $Bi_2O_3$ were used as sintering aids and the specimens were sintered during 30, 60, 90, 120, 150 and 180 minutes, respectively. At the specimen sintered during 90 minute, mechanical quality factor(Qm), electromechanical coupling factor(kp) and dielectric constant were showed the optimum values of 2356, 0.504 and 1266, respectively. All the specimens showed tetragonality phase, and pyrochlore phase was not shown.