• Title/Summary/Keyword: Lead titanate

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The Effects of Process Parameters on the Composition and Microstructure of Lead Titanate Thin Films deposited by ECR PECVD (ECR PECVD법으로 증착된 lead titanate박막의 조성과 미세구조에 대한 증착변수의 영향)

  • Chung, Su-Ock;Chung, Seong-Ung;Lee, Won-Jong
    • Korean Journal of Materials Research
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    • v.7 no.2
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    • pp.93-101
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    • 1997
  • Lead titanate박막을 $Pt/Ti/SiO_{2}/Si(Pt/Ti기판)와\;Pt/Ta/SiO_{2}/SiO_{2}$Si(Pt/Ta 기판) 위에서 전자 사이크로트론 공명플라즈마 화학증착법(ECR PECVD)으로 증착하였다. 증착온도, 산소유입량, MO source유입비등의 증착변수에 따른 lead titanate박막의 조성과 미세구조를 주사전자현미경(SEM), 투과전자현미경(TEM), X선 회절법(XRD)으로 조사하였다. 산소유입량이 적을 경우,Tisource와 Pb source의 산소화의 반응성 차이 때문에 Pb 농도가 부족한 화학양론비가 잘 맞는 박막이 증착되었다. Pt/ti기판은 lead titanate박막증착도중 기판의 Ti층과 Pt층의 확산으로 기판변형이 발생하는 반면, Pt/Ta기판은 기판변형이 일어나지 않았다. Pt/Ta기판에서 페롭스카이트 화학양론비를 갖는 매우 평탄한 lead titanate박막을 증착 하였는데, 산소유입량이 lead titanate박막의 결정성을 크게 지배하였다.

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Microwave Hydrothermal Sythesis of PbTiO$_3$ and PMN Ceramic Powders (마이크로파 수열법에 의한 PbTiO$_3$ PMN 세라믹분말의 합성)

  • Bai, Kang
    • Journal of the Korean Ceramic Society
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    • v.35 no.5
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    • pp.465-471
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    • 1998
  • Lead titanate(PT) and lead magnesium niobate(PMN) ceramic powders were prepared by microwave hy-drothermal method using teflon bomb. Raw materials were Pb(NO3)2 and TiO2 for lead titanate and Pb(NO3)2 Nb2O5 and Mg(NO)3.6H2O for PMN with NaOH as mineralizer in both cases. in lead titanate synthsis rate of microwave hydrothermal method was faster three times than one f conventional hydrothermal methods In lead magnesium niobate synthsis the mixture of perovskite and pyrochlore phases was obtained by single step technique and the PMN was not obtained by double step technique due to low temperature limitation of teflon bomb.

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Effects of Two-Step Annealing Process on the Pulsed Laser Ablated Lead Zirconate Titanate Thin Films

  • Rhie, Dong-Hee
    • KIEE International Transactions on Electrophysics and Applications
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    • v.3C no.2
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    • pp.43-47
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    • 2003
  • Lead zirconate titanate (PZT) thin films were fabricated by the pulsed laser ablation deposition (PLAD) method onto Pt/Ti/SiO$_2$/Si substrates. Crystalline phases as well as preferred orientations in PZT films were investigated by X-ray diffraction analysis (XRD). The well-crystallized perovskite phase and the (101) preferred orientation were obtained by two-step annealing at the conditions of $650^{\circ}C$, 1 hour. It was found that the temperature for the pulsed laser ablated PZT films annealed via a two-step annealing process can be reduced 20$0^{\circ}C$ compared to that of the conventional three-step annealing temperature profile for enhancing the transformation of the perovskite phase. The remanent polarization and the coercive field of this film were about 20 $\mu$C/$\textrm{cm}^2$ and 46 kV/cm, while the dielectric constant and loss values measured at 1 KHz were approximately 860 and 0.04, respectively. The interesting phenomena of this film, such as vertical shift in hysteresis curve, are also discussed.

Effect of Nd Doping on the Electrical Conductivity and Lattice Parameters of barium-Lead Titanate (Nd첨가가 Barium-Lead Titanate의 전기전도도와 격자상수에 미치는 영향)

  • Tadashi NAKANO;;Hiroaki YANAGIDA
    • Journal of the Korean Ceramic Society
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    • v.22 no.4
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    • pp.15-20
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    • 1985
  • $(Ba_{0.5} Pb_{0.5})_{1-x} Nd_x TiO_3$ 중의 $_x(Nd$의 양)를 변화시키면서 격자상수와 전기전도도를 측정하였다 c축과 a축의 비(c/a) 의 극대값은 실온에 있어서 전기전도도의 극대값과 일치하였다. 이것은 Nd원자의 치환위치와 강유 전성의 변화에 의한 것으로 고찰되었다 Curie 온도이하에서는 Nd 첨가량의 증가에 따라 전기전도도의 활성화에너지가 증가하는 경향을 나타내었다 이것은 입경의 감소에 따른 Spontaneous polarization의 저하가 원인으로 고찰되었다 첨가량의 역학을 입계의 potential barrier의 높이와 관련지어 논하였다.

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Electrical Properties of $PbTiO_3$ Thin Films Fabricated by CVD (화학증착법에 의해 제조된 $PbTiO_3$ 박막의 전기적 특성에 관한 연구)

  • Yoon, Soon-Gil;Kim, Ho-Gi
    • Proceedings of the KIEE Conference
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    • 1989.07a
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    • pp.329-332
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    • 1989
  • Lead titanate thin films were deposited on titanium substrates by a chemical vapour deposition(CVD) process involving the application of vapour mixtures of Pb, ethyl titanate( Ti($C_2H_5O_4$)), and oxygen. The lead titanate having a stoichiometric composition has a dc conductivity of $3.2{\times}10^{-12}{\Omega}^{-1}{\cdot}cm^{-1}$ at room temperature. The nonsaturating loops observed in present investigation may be attributed to the $TiO_2$ and TiO layers between the conductive substrate and the $PbTiO_3$ ferroelectric film. The ferroelectric properties of the stoichiometric $PbTiO_3$ film included a remanent polarization of 14.1 ${\mu}C/cm^2$ and a coercive field of 20.16 kV/cm.

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Fabrication of 1 ㎛ Thickness Lead Zirconium Titanate Films Using Poly(N-vinylpyrrolidone) Added Sol-gel Method

  • Oh, Seung-Min;Kang, Min-Gyu;Do, Young-Ho;Kang, Chong-Yun;Yoon, Seok-Jin;Nahm, Sahn
    • Transactions on Electrical and Electronic Materials
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    • v.12 no.5
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    • pp.222-225
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    • 2011
  • Lead zirconate titanate (PZT) films were fabricated on Pt/Ti/$SiO_2$/Si substrate by the sol-gel method using a sol containing poly(N-vinylpyrrolidone) (PVP). PVP in alkoxide solutions can suppress the condensation reaction in gel films during heat treatment, and increase the viscosity of alkoxide solutions. Single-phase PZT films as thick as 1 ${\mu}m$ were deposited by repetitive coating with successive third-step heat treatments at 150$^{\circ}C$, 350$^{\circ}C$ and 650$^{\circ}C$. After heat treatment, the films were crack free, and optically transparent. As a result, we demonstrated a PZT film with a PVP molar ratio of 0.5, which has a permittivity of 734, a dielectric loss of 0.042, a $P_r$ of 40.5 ${\mu}C/cm^2$ and an $E_c$ of 156 kV/cm.

Deposition and XPS Study of Pb, Zr, and Ti Films

  • Choi, Sujin;Park, Juyun;Jeong, Eunkang;Kim, Beob Jun;Son, Seo Yoon;Lee, Jeong Min;Lee, Jin Seong;Jo, Hee Jin;Park, Jihun;Kang, Yong-Cheol
    • Journal of Integrative Natural Science
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    • v.7 no.3
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    • pp.183-187
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    • 2014
  • Lead zirconate titanate (PZT) is significant material in electrical and optical devices for their ferroelectric, piezoelectric and dielectric properties. In this research, PZT films were fabricated by reactive RF co-sputtering method using Pb, Zr, and Ti targets. From XPS study, lead, zirconium, and titanium are successfully deposited on Si(100) substrate. Thickness of PZT films was measured with a surface profiler and the thickness was decreased as the oxygen gas ratio increased in the sputter gas.

Crystallization of $PbTiO_3$ Prepared by Wet-Chemical Methods (습식 화학법으로 제조된 $PbTiO_3$의 결정화)

  • 최병철;이문호
    • Journal of the Korean Ceramic Society
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    • v.28 no.11
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    • pp.892-896
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    • 1991
  • The cyrstallization behavior of lead titanate powders prepared by sol-gel and coprecipitation techniques was investigated. The lead titanate precursors were derived from a mixed solution of lead nitrate and titanium tetrachloride at 4$0^{\circ}C$ to 43$^{\circ}C$ and pH of 9.00 to 9.75. The X-ray diffraction patterns of the dried gel and coprecipitated powders showed it to be amorphous. DTA runs of the powders indicated crystallization to occur at 475~48$0^{\circ}C$. However, the amorphous powders were partially crystallized at 400~45$0^{\circ}C$ with sufficient annealing time. The room temperature Raman spectra from heat-treated powders changed continuously from amorphous to crystalline state with increasing heat-treating temperature. By annealing coprecipitated powders, a dramatic change in the Raman spectra due to the structural relaxation as the annealing temperatures increased, was clearly visible. i.e., coprecipitated, gel, and crystalline structure, in turn.

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Preparation of Lead Titanate Powders from Oxalates (수산에타놀법에 의한 $PbTiO_3$ 말의 합성)

  • Choi, Hee-Lark;Lee, Bong;Moon, Chang-Kwan
    • Journal of Ocean Engineering and Technology
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    • v.14 no.1
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    • pp.37-43
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    • 2000
  • $PbTiO_3$ was prepared by addition of lead-tltanium mixed aqueous solution to an ethanol solution of oxalic acid. The influence of various ripening factors was invesigated. On the basis of the results in the mono-component system we studied the foramtion of $PbTiO_3$ phase with various ripening conditions. The $PbTiO_3$ phase formation was accelerated with the ripening time temperature and ultrasonic irradiation.

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