• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1242-1244
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• 1995

The dielectric and polarizable properties of $0.9Pb_{1-x}La_x({Mg}_{1/3}Nb_{2/3})O_3-0.1PbTiO_3$ (x=0,1,2,3,4,5) have been investigated. The temperature-dependant electrostictive characteristics of 0.9PMN-0.1PT relaxor ferroelectric system were improved by enhencing the extent of the diffuse phase transition(DPT). This was achieved using PMN-PTceramics by the partial substitution of La at the Pb site. The curie temperature and the maximum dielectric permittivity decreased by substituting La and the electric field-related hysteresis phenomena decreased with increasing La substitution amount.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.293-295
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• 1991

In this study, we investigated the possibilty that $Pb(Mg_{1/3}Nb_{2/3})O_3-PbTiO_3-PbZrO_3$ ceramics with strontium substitutions could be used for piezoelectric sounders. Piezoelectric buzzer is one of them. By partially substituting Sr for Ph, dielectric constants had values greater than 2000, the value proper piezoelectric buzzer, piezoelectric constant($d_{31}$) had a maximum value, 298 $[10^{-12}C/N]$, at the Sr 5 mol % substitution. Sound level of piezoelectric buzzer had the highest value of 91 dB at the Sr 5 mol % substitution.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.107-109
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• 2003

This paper was to measure the structure, piezoelectric properties of $0.03Pb(Mg_{0.5}W_{0.5})O_3$ - $0.12Pb(Sb_{0.5}Nb_{0.5})O_3$ - $0.85Pb(Zr_{0.52}Ti_{0.48})O_3$ + $0.5[wt%]MnO_2$ ceramics dropped with additive CuO after manufacturing the specimens with a general method. It is shown that X-ray diffraction pattern variation of lines (211) have tendency to move minutely by addition of additive CuO. According to dropping with Cu, the dielectric constant at 20[$^{\circ}C$] reduced to CuO 3.0[wt%]. In case of sintering at 1050[$^{\circ}C$], dielectric constant was maximum value 623.59 at CuO 1.0[wt%]. Dielectric loss was maximum value 2.7[%] at Cu 2.0[wt%] in case of sintering at 1050[$^{\circ}C$].

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.85-85
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• 2009

본 연구에서는 압전 세라믹과 고분자를 혼합한 복합체를 제작하고 이러한 재료로부터 발생될 수 있는 미소 전력량을 조사하였다. 압전 세라믹으로는 0.2(PbMg1/3Nb2/3O3)-0.8(PbZr0.475Ti0.525O3)와 고분자는 PVPF-TrFE (6:4)를 사용하였다. 고분자와 압전 세라믹 분율을 1%, 5%, 10%, 30%, 50%로 변화하였으며, 구조는 0-3 복합재료 및 1-3 재료를 제작하였다. 제작한 결과 0.3 복합재료에서는 분율이 10%에서 가장 큰 전력량이 발생되었고, 1-3 복합재료에서는 분율이 30%에서 최대 값을 나타내었다. 이러한 결과들을 간단한 식을 이용하여 분석을 하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.11
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• pp.921-925
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• 2000

Characteristics of Pb(Mg, Nb)O$_3$-Pb(Zr, Ti)O$_3$system thick films fabricated by a screen printing method were investigated. The buffer layer were coated with various thickness of Ag-Pd by screen printing to investigate the effect as a diffusion barrier and deposited Pt as a electrode by sputtering on Ag-Pb layer. The printed thick films were burned out at 650$\^{C}$ and sintered at 950$\^{C}$ in O$_2$condition for each 20, 60min after printing with 350mesh screen. The thickness of piezoelectric thick film was 15∼20㎛ and Ag-Pb layer acted as a diffusion barrier above 3㎛ thickness. The PMN-PZT thick films were screen printed on Pt/Ag-Pb(6m) and sintered by 2nd step (650$\^{C}$/20min and 950$\^{C}$/1h) using paste mixed PMN-PZT and binder in the ratio of 70:30, and the remnant polarization of thick film was 9.1$\mu$C/㎠ in this conditions.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.275-278
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• 2000

In this study, the acoustic transducer of a thin circular disc-type with PZT/Metal was designed. The dielectric and piezoelectric properties of $0.5wt\%$ $MnO_2$ and NiO doped 0.1Pb($Mg_{1/3}$$Nb_{2/3}$)$O_3$-$0.45PbTiO_3$-$0.45PbZrO_3$ ceramics were investigated aiming at acoustic transducer applications. The vibration characteristics for the laminated circular plate was analyzed for the various thickness and diameter of the piezoceramic layer and metal layer. The acoustic characteristics which is radiated from the acoustic transducer within the finite space was simulated using the finite element method. It has been observed that the characteristics of the sound pressure ard impedance response calculated for the various models of the size and geometry of acoustic transducer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.131-134
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• 2001

In this paper, the piezoelectric and dielectric properties as a function of x and a in $aPbZr_xTi_{1-x}O_3-(1-a)Pb(Mn_{1/3}Nb_{2/3})O_3$ + ywt%MgO is investigated. As a results, when a is 0.95 and x is 0.505, electromechanical coupling factor$(k_p)$, permittivity${\varepsilon}_33^T/{\varepsilon}_0$, piezoelectric strain constant$(d_{33})$ and mechanical quality factor$(Q_m)$ are 58 %, 1520, 272 pC/N and 1550, respectively. From XRD analysis, when x is 0.505, it is MPB which present rhombohedral and tetragonal phase in same quantity. Also, From SEM observation, when sintering temperature is $1150^{\circ}C$, grain size is about $2\;{\mu}m$. As a results added MgO dopant in the ternary piezoelectric ceramic, when MgO content is 0.1 wt%, $k_p$ increases to 63[%].

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1400-1401
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• 2006

In this study, in order to develop low temperature sintering piezoelectric ceramics for multilayer piezoelectric actuator, $PbSr(Mn_{1/3}Nb_{2/3})O_3-(Mg_{1/3}Nb_{2/3})O_3-(ZrTi)O_3$ ceramics were fabricated using $Na_{2}CO_{3}-Li_{2}CO_{3}$ as sintering aids and their piezoelectric and dielectric characteristics were investigated according to the sintering tempo rature. At the sintering temperature of $900^{\circ}C$, the density, electrom echanical coupling factor(kp), mechanical quality factor(Qm) and dielectric constant(${\varepsilon}r$) of specimen showed the optimum value of $7.730[g/cm^2]$, 0.552, 1134, 1492 and 330[pC/N], respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.68-69
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• 2005

Low temperature ($\leq900^{\circ}C$) sintering piezoelectric ceramics $0.01Pb(Mg_{1/2}W_{1/2})O_3$-0.41Pb$(Ni_{1/3}Nb_{2/3})O_3-0.35PbTiO_3-0.23PbZrO_3+0.1wt%Y_2O_3+xwt%ZnO$ $(0{\leq}x{\leq}2.5)$ have been developed and investigated. The electromechanical coupling coefficient ($k_p$), piezoelectric constant ($d_{33}$), and mechanical quality factor ($Q_m$) have been measured to characterize the piezoelectric materials system. When 2.0 wt% ZnO is added, the properties of the system, $d_{33}$ = 559 pC/N, $k_p$ = 55.0 % and $Q_m$ = 73.4 are obtained which are very suitable for piezoelectric actuators. A bending mode multilayer actuator has been also developed using the materials which size is $27(L)\times9(W)\times1.07(t)mm^3$. The actuators are fabricated by multilayer ceramic (MLC) process and consist of24 layers and each layer thickness is $35{\mu}m$. At this time, the displacement of actuator was $100{\mu}m$ at 28V.

• Korean Journal of Materials Research
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• v.7 no.7
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• pp.547-558
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• 1997

Pb(Mg$_{1}$3/Nb$_{2}$3)O$_{3}$[PMN]-PbTiO$_{3}$[PT]계 고용체의 상경계조성(MPB)영역에 대해 La을 첨가하여 변성시킨 La변성 (1-x)PMN-xPT(x=0.35) 고용체를 만들어 온도-유전율 특성, 전계유기 분극특성 및 변위특성을 조사하였다. PMN-PT의 상경영역의 조성인 x=0.35에 대해 La함량을 0-10at%까지 변화시켰다. PMN-PT계 고용체에서 PT 의 함량이 증가함에 따라 전계유기변위 및 히스테리시스 특성이 모두 증가하였다. 전계유기변위 값 $\varepsilon$ 는 능면정과 정방정의 공존영역인 MPB(x=0.35)조성에서 가장 높은 값($\varepsilon$ = 2 x $10^{-3}$)을 보여 주었다. MPB조성에 대해 La을 첨가한 계의 전계유기변위를 조사한 결과 La의 첨가량이 적을 때 (La=0-5at%)는 La의 함량이 증가함에 따라 히스테리시스 특성이 감소하였고 $\varepsilon$ 은 증가하여 고성능의 액튜에이터 재료에 적합한 조성물로 기대된다.