• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.223-223
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• 1999

PZT(PbZr1-xTixO3) 박막은 고유전율과 같은 remanent polarization을 가져서 고집적 소자의 커패시터 유전율층 또는 비휘발성 메모리 소자의 제조에 이용되고 있으나, fatigue 와 aging 문제로 인하여 새로운 물질의 개발이 필요한데, 그 대표적으로 연구되고 있는 것이 PMN-PT(Pb(Mg1/3Nb2/3)O-PbTiO3) 이다. 본 실험에서는 sol-gel 법에 의하여 제조된 PMN-PT막을 ICP(Inductively coupled plasma)에 의하여 식각하였고 mask층으로는 PR을 사용하였다. 식각 가스로는 Ar, Cl, BCl를 단독 또는 혼합하여 사용하였으며, 식각 특성을 보기 위하여 RF Power, Substrate bias, Operation pressure, Substrate temperature를 변화시켰다. 식각속도는 stylus profiler를 이용하여 측정하였고, 단면 profile은 scanning electron microscopy (SEM)를 이용하여 관찰하였다. 식각 메커니즘을 규명하고자 식각된 박막의 표면을 X-ray photoelectron spectroscopy (XPS)로 관찰하였고, optical emission spectroscopy (OES)로 플라즈마 특성을 규명하고자 하였다. 식각속도는 Ar 또는 Cl2 플라즈마에 BCl3 가스를 혼합하였을 경우 증가되었고, BCl3 가스를 단독으로 사용하여도 높은 식각속도를 나타내었으며, BCl3의 첨가량이 늘어날수록 PR의 식각속도는 감소하여 높은 선택비를 보였다. 90% BCl3/10%Cl2 플라즈마에서 2800$\AA$/min의 식각속도 그리고 1.37:1의 PR 선택비를 얻을 수 있었다. Power나 기판 bias 증가에 따라 식각속도는 증가하였으나 기판 온도변화에는 민감하지 않았다. BCl3 rich에서의 식각속도 증가와 선택비 증가는 B2O3의 형성에 의한 것으로 생각된다.

• Journal of Sensor Science and Technology
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• v.6 no.5
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• pp.392-399
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• 1997

In this study, the effect of the sintering temperature on the dielectric and piezoelectric properties of 0.5 wt% $MnO_{2}$-doped $0.125Pb(Mg_{1/2}Nb_{2/3})O_{3}-0.435PbTiO_{3}-0.44PbZrO_{3}$ ceramics were investigated aiming at ultrasonic motor applications. From experimental result, it was found that the optimal sintering temperature condition was at $1270^{\circ}C$. The sample sintered at $1270^{\circ}C$ had density of $7.72\;g/cm^{3}$, dielectric constant of 570, dielectric loss of 0.82%, remanent polarization of $19.18{\mu}C/cm^{2}$, coercive field of 9.63 kV/cm, electromechanical coupling factor of radial mode of 55.1%, mechanical quality factor of 886. Temperature and frequency dependence of dielectric constant and dielectric loss of the sintered sample at $1270^{\circ}C$ was also investigated.

• Analytical Science and Technology
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• v.10 no.6
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• pp.439-444
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• 1997

Twelve kinds (1set) standard materials of chemical ingredients of lead zirconate titanate[$Pb(ZrTi)O_3$] have been developed in order to determine fast and accurate measurement of X-ray fluorescence spectrometry. Especially, we used diluted(ahout sixteen times) filling compound($Li_2B_4O_7/LiBO_2=4/1$) to consider removal effect of matrix, storage convenience, and homogenous characteristics. As a result from the four different laboratories, we obtained extremly good agreement about the standard curve on twelve standard materials which containing eleven elements, PbO, $ZrO_2$, $TiO_2$, SrO, $WO_3$, $La_2O_3$, $Cr_2O_3$, MgO, $Nb_2O_5$, and $MnO_2$. The correlation factor of standard curve was over 0.998. However, ZnO has relatively low correlation factor, 0.977, because the concentration was 10ppm lower than other original materials. This analysis reveals that ZnO has shown the poor linearity as well as low fluorescence intensity. In present work, XRF standard materials are useful for determining a rapid and accurate results for major and minor elements concentration among PZT.

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.102.1-102
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• 2003

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.873-876
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• 2000

Characteristics of piezoelectric thick films prepared by screen printing method were investigated. The piezoelectric thick films were printed using Pb(Mg,Nb)O$_3$-Pb(Zr,Ti)O$_3$system. The lower electrodes were coated with various thickness of Ag-Pd by screen printing to investigate the effect as a diffusion barrier and deposited with Pt by sputtering on Ag-Pd. The ceramic paste was prepared by mixing powder and binder with various ratios using three roll miller. The fabricated thick films were burned out at 650$^{\circ}C$ and sintered at 950$^{\circ}C$ in the O$_2$condition for each 20, 60min after printing with 350mesh screen. The thickness of piezoelectric thick film was 15∼20 $\mu\textrm{m}$ and the Ag-Pd electrode acted as a diffusion barrier above 3 $\mu\textrm{m}$ thickness. When the lower electrode Ag-Pd was 6 $\mu\textrm{m}$ and the piezoelectric thick films were sintered by 2nd step (650$^{\circ}C$/20min and 950$^{\circ}C$/1h) using paste mixed Pb(Mg,Nb)O$_3$-Pb(Zr,Ti)O$_3$$.$ MnO$_2$+ Bi$_2$O$_3$. V$_2$O$\_$5/ and binder in the ratio of 70:30, the remnant polarization of thick film was 9.1 ${\mu}$C /cm$^2$.

• Transactions on Electrical and Electronic Materials
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• v.12 no.6
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• pp.249-252
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• 2011

We investigated the low firing of $Li_2CO_3$ added $0.2Pb(Mg_{1/3}Nb_{2/3})O_3$ - 0.3Pb($Fe_{1/2}Nb_{1/2}$) - $0.5Pb(Zr_{0.475}Ti_{0.525})O_3$ (PMN-PFN-PZT) ceramics and multilayer actuators (MLAs) using Ag inner electrodes. It was found that 0.1 wt% $Li_2CO_3$ was quite effective in lowering the sintering temperature of PMN-PFN-PZT ceramics from $1,100^{\circ}C$ down to $900^{\circ}C$ without deteriorating their piezoelectric ceramics ($d_{33}$ = 425 pC/N and $k_p$ = 61.9%). However, excess $Li_2CO_3$ up to 0.3 wt% brings about unwanted problems such as the formation of a $LiPbO_2$ secondary phase and subsequent degradation in the piezoelectric properties. Using 0.1 wt% $Li_2CO_3$ added PMN-PFN-PZT ceramics, MLAs with Ag inner electrodes were successfully fabricated, resulting in a normalized strain of 580 pm/V at an electric field of 1.5 kV/mm.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.1
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• pp.12-19
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• 2001

In this study, the physical properties of the piezoelectric sounder with metal-piezoelectric ceramics were analyzed. The dielectric and piezoeletric 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 acoustic characteristics of a thin circular disc-type with metal-piezoceramics have been investigated. Also, the acoustic characteristics for the geometrical form of case were investigated. The piezoelectric sounder with 200kHz resonant frequency and 20kHz bandwidth was designed by considering the sharp directivity and the sound pressure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.283-286
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• 2000

In this study, the acoustic transducer of a thin circular disc-type with PZT/Metal was manufactured. The piezoelectric transducer with 200kHz resonance frequency was designed by considering the sharp directivity and the sound pressure. The dielectric and piezoelectric properties of 0.5 weight percent $MnO_2$ and NiO doped $0.1Pb(Mg_{1/3}Nb_{2/3})O_3-0.45PbTiO_3-0.42PbZrO_3$ ceramics were investigated aiming at acoustic transducer applications. Also, the acoustic characteristics of a thin circular disc-type with metal-piezoceramics have been Investigated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.711-714
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• 2000

In this study, the physical properties of the acoustic element and case with metal-piezoelectric ceramics were analyzed. The dielectric and piezoelectric properties of 0.5 wt% MnO$_2$and NiO doped 0.1Pb(Mg$\_$1/3Nb$\_$2/3)O$_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. Also, the acoustic characteristics for the geometrical form of case have been investigated. The design and fabrication method worked in this paper can be utilized in development of actuator and acoustic device.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.413-416
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• 2000

In this study, the physical properties of the acoustic element and case with metal-piezoelectric ceramics were analyzed. The dielectric and piezoelectric properties of 0.5 wt% 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. Also, the acoustic characteristics for the geometrical form of case have been investigated. The design and fabrication method worked in this paper can be utilized in development of actuator and acoustic device.