• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.190-193
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• 2003

Sm-doped lead zirconate titanate($Pb_{1.1}(Zr_{0.6}Ti_{0.4})O_3$; PZT) thin films on the Pt(111)/Ti/$SiO_2$/Si(100) substrates prepared by a sol-gel method. The effect on structural and electrical properties of PZT thin films measured according to the Sm content. Sm-doping altered significantly dielectric and ferroelectric properties. The remanent polarization and the coercive field decreased with the increasing Sm content. The dielectric constant and the dielectric loss of PZT thin films decreased with the increasing Sm content. At 100 kHz, the dielectric constant and the dielectric loss of. the 0.3 mol% of Sm-doped PZT thin film were 1200 and 0.12 respectively. The remanent polarization (2Pr) of the 0.3 mol% of Sm-doped PZT thin film was $52.13{\mu}C/cm^2$ and the coercive field was 94.01 kV/cm. The 0.3 mol% of Sm-doped PZT thin film showed an improved fatigue characteristic comparing to the undoped PZT thin film.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1301-1302
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• 2007

The multilayered $Pb_{1.1}(Zr_{0.4}Ti_{0.6})O_{3}$/$Pb_{1.1}(Zr_{0.6}Ti_{0.4})O_{3}/Pb_{1.1}(Zr_{0.4}Ti_{0.6})O_{3}$[PZT(4060)/(6040)/(4060)] thin films were deposited by RF sputtering method on the Pt/TiO2/SiO2/Si substrate. We investigated the effects of deposition conditions on the structural and electrical properties of the multilayered PZT thin films. All the multilayered PZT thin films showed dense and homogeneous structure without the presence of the rosette structure. The dielectric properties such as dielectric constant, loss, remanent polarization of the multilayered PZT thin film were superior to those of single composition PZT(4060) and PZT(6040) films, and those values for the multilayered PZT(10/20/10) thin film were 903, 1.01% and $25.60{\mu}C/cm^2$. This study suggests that the design of the multilayered PZT thin films capacitor with tetragonal and rhombohedral phase should be an effective method to enhance the dielectric and ferroelectric performance in devices.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.885-888
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• 2000

The effects of deposition temperature and post annealing process of ferroelectric PbZr$\sub$0.52/Ti$\sub$0.48/O$_3$(PZT) thin films by pulsed laser deposition (PLD) were investigated. The PZT thin films were deposited at 400, 450, 500, and 550$^{\circ}C$, with/without post annealing at 650$^{\circ}C$ for 30 min. The PZT thin films deposited above 500$^{\circ}C$ without post annealing were crystallized into peroveskite phase, but the PZT thin films deposited below 450$^{\circ}C$ had pyrochlore phase. The PZT thin films deposited below 450$^{\circ}C$ with post annealing also crystallized into pure perovskite. Compared to the PZT thin films which were deposited at 450$^{\circ}C$ and post annealed, the films deposited at 550$^{\circ}C$ have a columnar microstructure and high remnant polarization 28 (${\mu}$C/cm$^2$). With in-situ annealing at oxygen ambient, the PZT thin films reduced oxygen vacancies and increased retained polarization.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.66-66
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• 2007

Lead zirconate titanate (PZT) is one of the most attractive perovskite-type materials for ferroelectric random access memory (FRAM) due to its higher remanant polarization and the ability to withstand higher coercive fields. We first applied the damascene process using chemical mechanical polishing (CMP) to fabricate the PZT thin film capacitor to solve the problems of plasma etching including low etching profile and ion charging. The $0.8{\times}0.8\;{\mu}m$ square patterns of silicon dioxide on Pt/Ti/$SiO_2$/Si substrate were coated by sol-gel method with the precursor solution of PZT. Damascene process by CMP was performed to pattern the PZT thin film with the vertical sidewall and no plasma damage. The polarization-voltage (P-V) characteristics of PZT capacitors and the current-voltage characteristics (I-V) were examined by change of process parameters. To examine the CMP induced damage to PZT capacitor, the domain structure of the polished PZT thin film was also investigated by piezoresponse force microscopy (PFM).

• Tribology and Lubricants
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• v.19 no.3
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• pp.133-138
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• 2003

The characteristics for bimorph PZT cantilever of laboratory-fabricated have been evaluated experimentally. The deflections of cantilever with PZT are result from a capillary force between a water drop and a tip of cantilever. The output voltage due to deflect cantilever are depend on the tip shape and thickness of cantilever. We applied a bimorph PZT cantilever to oil thickness measurement. This reasonable concept is that the output voltage be caused by different defected characteristics between oil and surface. Experimental results demonstrated that the high measurement accuracy of the oil film thickness is obtained from the probe.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.250-253
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• 2004

This study deals with the microvalve, which is composed of the multilayer bender type PZT actuator, actuator controller and microvalve body. The object of this study is to develope the microvalve with multilayer bender type PZT actuator. In order to achieve this object, prototype PZT actuator and microvalve were suggested and manufactured. Also, the performance of this model was evaluated through the experiments.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1618-1620
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• 2004

The $Pb(Zr_{0.4}Ti_{0.6})O_3/Pb(Zr_{0.6}Ti_{0.4})O_3$ [PZT(4060)/(6040)] multilayered thin films were deposited by RF Sputtering method on the Pt/Ti/$SiO_2$/Si substrate. This procedure was repeated several times to form PZT(4060)/(6040) heterolayerd thin films. The effects on the structural and dielectric properties of PZT multilayered thin films were investigated. The MFM(Metal Ferroelectric Metal) type capacitors were made using the PZT(4060)/(6040) multilayered thin films deposited with optimum deposition condition. An enhanced dielectric property was observed in the PZT(4060)/(6040) multilayered thin films. The relative dielectric constant and dielectric loss at 100Hz of the PZT(4060)/(6040)-5 multilayered thin films were about 1106 and 0.016, respectively.

• Smart Structures and Systems
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• v.15 no.2
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• pp.375-393
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• 2015

In this study, local dynamic characteristics of mountable PZT interfaces are numerically analyzed to verify their feasibility on impedance monitoring of the prestress-loss in tendon anchorage subsystems. Firstly, a prestressed tendon-anchorage system with mountable PZT interfaces is described. Two types of mountable interfaces which are different in geometric and boundary conditions are designed for impedance monitoring in the tendon-anchorage subsystems. Secondly, laboratory experiments are performed to evaluate the impedance monitoring via the two mountable PZT interfaces placed on the tendon-anchorage under the variation of prestress forces. Impedance features such as frequency-shifts and root-mean-square-deviations are quantified for the two PZT interfaces. Finally, local dynamic characteristics of the two PZT interfaces are numerically analyzed to verify their performances on impedance monitoring at the tendon-anchorage system. For the two PZT interfaces, the relationships between structural parameters and local vibration responses are examined by modal sensitivity analyses.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.05a
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• pp.192-195
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• 1995

PZT powders were prepared by the molten salt synthesis method. The porous PZT was prepared from a mixture of PZT an polyvinylacohol(PVA) powders by BURPS(Burnout Plastic Sphere) technique. The piezolectirc and acoustic properties with various PVA wt% were studied, Piezoelectric coefficient d$\sub$33/ of porous PZT ceramics was almost same to that of single phase PZT ceramics, The thickness mode coupling factor k$\sub$t/ was 0.53~0.59 in comparable with the single phase PZT ceramics(k$\sub$t/=0.7)

• Journal of the Korean Ceramic Society
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• v.38 no.8
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• pp.724-731
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• 2001

스크린 인쇄법에 의해 Si 기판에 PZT 후막의 제조에 있어서 주요 문제점은 낮은 소결밀도 및 PZT 후막과 Si 기판과의 반응현상이다. 이러한 현상을 억제하기 위해 본 연구에서는 스크린 인쇄법 및 PZT sol-gel 처리법의 혼합된 방법을 채택하여 Pt/TiO$_2$/YSZ/SiO$_2$/Si(100) 기판에 Zr/Ti 비가 52/48인 PZT 후막을 제조하였으며, 소결온도에 따른 잔류분극(P$_{r}$), 유전상수($\varepsilon$$_{r}$) 및 압전상수(d$_{33}$)를 측정하였다. 인쇄된 PZT 후막에 졸 처리함으로써 단순히 인쇄된 후막에 비해 전기적 특성이 증진된 결과를 얻었다.다.