• Proceedings of the KIEE Conference
• /
• 2001.11a
• /
• pp.134-136
• /
• 2001

In this paper, we investigated the electrical and piezoelectric characteristics of $Pb(Sb,Nb)O_3-Pb(Zr,Ti)O_3$ for piezoelectric transformer and actuator etc. Effect of $WO_3$ addition($0\;wt%{\sim}0.6\;wt%$) on the PSN-PZT ceramic was investigated. Anisotropic properties of electromechanical coupling factor and piezoelectric properties were proved to be varied with amount of $WO_3$ impurity and sintering temperature($1100{\sim}1300^{\circ}C$). The electromechanical coupling factor $k_p$ of 0.41 and the mechanical quality factor am of 1243 were obtained from the specimen with 0.6 wt% $WO_3$ addition sintered at $1100^{\circ}C$ Experimental results indicated that the PZT-PSN ceramics with $WO_3$ impurity can be effectively used for piezoelectric transformer and actuator. etc.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.222-223
• /
• 2008

Recently, piezoelectric transformer is applied to wide fields. Multi layer piezoelectric transformer has the advantage of high step up ratio, high electromechanical coupling coefficient(Kp) and high mechanical quality factor(Qm), however it shows the peeling-phenomenon of electrode, and high price due to high sintering temperature. Therefore this study focus on the method for fabrication of high power rosen type piezoelectric transformers. The composition of $0.01Pb(Ni_{1/3}Nb_{2/3)O_3$ - 0.08Pb$(Mn_{1/3}Nb_{2/3})O_3$-0.91Pb$(Zr_{0.505}Ti_{0.495})O_3$(abbreviated as PNN-PMN-PZT) ceramics is employed for this study.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.5
• /
• pp.481-485
• /
• 2004

0.91 (PSN-PZT) －0.05BF －0.04PNW＋0.3wt%MnO$_2$＋0.6wt%CuO＋xwt%CeO$_2$ ceramics were fabricated with the variations of CeO$_2$addition at the sintering temperature of 95$0^{\circ}C$ and their microstructure, dielectric and piezoelectric characteristics were investigated. As the amount of CeO$_2$ addition increased, the grain size, density and electromechanical coupling factor(k$_{p}$) were increased and the mechanical quality factor(Q$_{m}$ ) was decreased. At the 0.3 wt% CeO$_2$, the density, grain size, electromechanical coupling factor(k$_{p}$), and pizoelectric constants(d$_{33}$, g$_{33}$) showed the maximum value of 7.87 g/㎤, 3.22 $\mu\textrm{m}$, 0.5, 289 pC/N, and 22.2 ㎷ㆍm/N, respectively. However, mechanical quality factor(Q$_{m}$ ) showed the minimum value of 807 at the 0.5 wt% CeO$_2$.$.EX>.EX>.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.27 no.1
• /
• pp.27-32
• /
• 2014

In this paper, PZT piezoelectric ceramic specimens with 4 compositions (Zr/Ti=50/50, 53/47, 56/44, 58/42) in $Pb(Zr,Ti)O_3$ system were fabricated. We studied effects of poling strength and thermal aging on the temperature characteristics of eletromechanical coupling factor k31 of the specimens, which were poled with the DC electric fields, 1.5, 2.5 and 3.5 kV/mm respectively and thermally aged for an hour at $200^{\circ}C$. The eletromechanical coupling factor k31 of the specimen with the composition Zr/Ti= 53/47, nearest to the morphotropic phase boundary decreased the most greatly, irrelevant to the intensity of poling field, due to 1st thermal aging. And the temperature coefficient of eletromechanical coupling factor k31 was (-) in the tetragonal phase composition and (+) in the rhombohedral phase composition, which is reverse in the temperature coefficient of resonance frequency. It is interesting that eletromechanical coupling factor k31 of PZT ceramics is shown to be able to increase as temperature increase in the interval $-20{\sim}80^{\circ}C$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.11a
• /
• pp.181-182
• /
• 2005

In this study, in order to develop multilayer piezoelectric transformer, PMN-PZT ceramics were fabricated according to PFW substitution using $Li_2CO_3-CaCO_3$ as sintering aids and their dielectric and piezoelectric characteristics were investigated. As increasing the amount of PFW substitution, density was slightly increased due to the increased sinterability. At the 1[mol%] PFW substituted PMN-PZT ceramic sintered at 950[$^{\circ}C$], density, dielectric constant $\varepsilon_r$, electromechanical coupling factor kp, mechanical quality factor Qm and piezoelectric $d_{33}$ constant showed the optimum value of 7.761[$g/cm^3$], 1251, 0.479, 1425 and 282[pC/N], respectively.

• Journal of the Korean Ceramic Society
• /
• v.50 no.6
• /
• pp.466-469
• /
• 2013

Currently, piezoelectric ceramics are being applied in various fields, such as ultrasonic sensors, vibration devices, sound filters, and various energy conversion devices. Flexible piezoelectric ceramics are widely studied in an effort to mitigate the disadvantages of their brittle and inductile properties. Structural damage to piezoelectric fibers is much less than that to thin films when piezoelectric fibers are twisted or bent. Therefore, stretchable devices can be fabricated if piezoelectric fibers are obtained using an elongated substrate. In this study, sintering processes of PZT ($Pb(Zr_{0.53}Ti_{0.47})O_3$) fibers prepared by electrospinning were optimized through the TGA and XRD analyses. The crystal structure and microstructure of the piezoelectric fibers were investigated by XRD, FE-SEM and TEM.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.11a
• /
• pp.300-303
• /
• 2003

[ $0.91(PSN-PZT)-0.05BF-0.04PNW+0.3wt%MnO_2+0.6wt%CuO+xwt%CeO_2$ ] ceramics were fabricated with the variations of $CeO_2$ addition at the sintering temperature of $950^{\circ}C$ and their microstructure and dielectric and piezoelectric characteristics were investigated. As the amount of $CeO_2$ addition increased, the grain size, density and electromechanical coupling factor(kp) were increased and the mechanical quality factor(Qm) was decreased. At the $0.3wt%CeO_2$, density, grain size and electromechanical factor(kp) showed the maximum value of $7.87g/cm^3$, $3.22{\mu}m$ and 0.5, respectively. However, mechanical quality factor(Qm) showed the minimum value of 807 at the $0.5wt%CeO_2$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.332-333
• /
• 2005

In this study, in order to develop low temperature sintering piezoelectric actuator, $Pb(Mg_{1/2}W_{1/2})_{0.03}(Ni_{1/3}Nb_{2/3})_x(Zr_{0.50},Ti_{0.50})_{1-x-0.03}$ (PMW-PNN-PZT) ceramic systems were fabricated using $CaCO_3-Li_2CO_3$ sintering aid and their dielectric and piezoelectric properties were investigated with the variation of PNN substitution. The piezoelectric actuator requires high piezoelectric constant $d_{33}$ and high electromechanical coupling factor kp. At the PMW-PNN-PZT ceramics with 9mol% PNN substitution sintered at $900^{\circ}C$, the density, electromechanical coupling factor kp, dielectric constant, piezoelectric constant $d_{33}$ and mechanical quality factor Qm showed the excellent values of 7.86 [$g/cm^3$], 0.584, 1881, 485 [pC/N] and 76, respectively for piezoelectric actuator application.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.66-67
• /
• 2005

In this study, in order to develop multilayer piezoelectric actuator, PMN-PNN-PZT ceramics were fabricated using $Li_2CO_3-Na_2CO_3$ as sintering aids and their piezoelectric and dielectric characteristics were investigated with the function of PNN substitution. With increasing PNN substitution, dielectric constant(${\varepsilon}r$), electromechanical coupling factor(kp), and piezoelectric d constant($d_{33}$) were increased at 10~12[mol%] PNN substitution and then decreased at all sintering temperature. With increasing PNN substitution, phase changed from tetragonal to rhombohedral at [10~12mol%] PNN substitution. At the 12[mol%] PNN substituted PMN-PZT composition ceramic sintered at 950[$^{\circ}C$], density, ${\varepsilon}r$, kp, $d_{33}$ and Qm showed the optimum value of 7.79[$g/cm^3$], 1160, 0.599, 419[pC/N) and 894, respectively for multilayer piezoelectric actuator application.

• Proceedings of the KIEE Conference
• /
• 1992.07b
• /
• pp.730-732
• /
• 1992

In this study, piezoceramics/polymer composites with 3-3 connectivity were made by BURPS(Burnout Plastic Sphere) technique with PZT ceramics and PMMA sphere(50 - 80${\mu}m$). And the dielectric and piezoelectric properties dependent on the PZT vol.% were investigated. The dielectric constant($K_{33}$) of 3-3 composites is increased almost linearly with increasing the PZT vol.%, while piezoelectric coefficient($d_{33}$) is slightly increased.