• 제목/요약/키워드: Excess PbO

검색결과 77건 처리시간 0.032초

$Nd^{3+}$로 치환된 $Pb(Mg^{1/3}Nb^{2/3})O_3$$PbTiO_3$ 첨가에 따른 유전특성과 PbO 휘발 (Effects of $PbTiO_3$ Addition on Dielectric Properties and Extent of PbO Loss in Nd-Doped $Pb(Mg^{1/3}Nb^{2/3})O_3$ System)

  • 김성열;이응상
    • 한국세라믹학회지
    • /
    • 제30권8호
    • /
    • pp.671-677
    • /
    • 1993
  • Effects of PbTiO3 addition on dielectric properties and extent of PbO loss in Nd-doped Pb(Mg1/3Nb2/3)O3 system were investigated. As the proportion of dopping increased, the phase transition temperature shifted to low region, and the dielectric constant at room temperature decreased rapidly. But as the proportion of PbTiO3 increased, the phase transition temperature shifted to high retion, and the dielectric constant at room temperature increased. The substitution of Nd3+ for Pb2+ decreased the amount of PbO evaporation, therefore the sample sintered well in case of only 1 mole% adding excess PbO.

  • PDF

Sputtering법으로 성장한 PZT 박막의 Target의 Pb Excess에 따른 전기적 특성에 관한 연구 (Electrical characteristic of PZT thin film deposit by Rf-magnetron sputtering as Pb excess ratio of target)

  • 이규일;강현일;박영;박기엽;송준태
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
    • /
    • pp.570-573
    • /
    • 2002
  • Pb(Zr0.52Ti0.48)O3 (PZT) thin films were deposited on the Pt/Ti bottom electrode by rf magnetron sputtering method from target containing 5%, 25% and 50% Pb excess for applying ferroelectric random access memory (FRAM). PZT films were deposited at $300^{\circ}C$ and then they were crystallized by rapid thermal annealing (RTA) at $700^{\circ}C$. After RTA treatment, our results showed that all PZT films indicated perovskite polycrystalline structure with preferred orientation (110) and no pyrochlore phase was observed by X-ray diffraction (XRD) and by Scanning electron microscopy (SEM). A well-fabricated PZT film of excess Pb 25% capacitor showed a leakage current density in the order of $2.63{\times}10^{-7}A/cm^2$ at 100kV/cm, a remanent polarization of $3.385{\mu}C/cm^2$ and a coercive field of 41.32 kV/cm. The results showed that Pb excess of target affects to electrical properties of PZT thin film.

  • PDF

Rf-sputtering법으로 증착한 PZT박막의 타겟의 Pb 함량에 따른 전기적 특성에 관한 연구 (Electrical Characteristics of PZT Thin film Deposited by Rf-magnetron Sputtering as Pb Excess Content of Target)

  • 이규일;강현일;박영;박기엽;송준태
    • 한국전기전자재료학회논문지
    • /
    • 제16권3호
    • /
    • pp.186-189
    • /
    • 2003
  • The role of excess Pb about the crystallization behavior and electrical properties in b(Zr$\sub$0.52/Ti$\sub$0.48/)O3(PZT) thin films has not been precisely defined. In this work, the effect of excess Pb content on the ferroelectric properties of these films was investigated. To analyze the effect, PZT films containing various amounts of excess Pb were Prepared. PZT thin films were deposited on the Pt/Ti bottom electrode by rf magnetron sputtering method and then they were crystallized by rapid thermal annealing (RTA). The experiment showed that all PZT films indicated perovskite polycrystalline structure with preferred orientation (111) and no pyrochlore phase was observed. As higher excess Pb was included, the films showed that value of leakage current shift from 2.03${\times}$10$\^$-6/ to 6.63 ${\times}$ 10$\^$-8/A/cm$^2$ at 100kV/cm, and value of remanent polarization shift from 8.587 ${\mu}$C /cm$^2$ to 4.256 ${\mu}$C/ cm$^2$. Electrical properties of PZT thin film affected by Pb excess content of target were explained to be caused of defect among space charges and defect grain boundaries.

PZT 요업체의 소결과정 중 승온속도가 미세조직에 미치는 영향 (Effect of heating Rate on the Microstructural Evolution during Sintering of PZT Ceramics)

  • 박은태;김정주;조상희;김도연
    • 한국세라믹학회지
    • /
    • 제27권8호
    • /
    • pp.1020-1026
    • /
    • 1990
  • The effect of heating rate on the microstructural evolution during sintering of PZT ceramics has been investigated. In case of PZT powder compacts containing excess of PbO, fast heating caused incomplete rearrangement of solid grains in a liquid, resulting in lower density and inhomogeneous pore shape ; on contrary, slow heating resulted in better densification. In contrast, in case of compacts without excess PbO, the densification was enhanced by fast heating due to suppression of the grain growth.

  • PDF

Thermodynamic Assessment of the PbO-ZrO2 System

  • Koo, Bon-Keup;Ping Liang;Hans Jiirgen Seifert;Fritz Aldinger
    • The Korean Journal of Ceramics
    • /
    • 제5권3호
    • /
    • pp.205-210
    • /
    • 1999
  • The thermodynamic properties and phase diagram of the$ PbO-ZrO_2$ system have been critically assessed using the Thermo-Calc program. Excess Gibbs energies were expressed by Redlich-Kister polynomials for the solid phases, by the two-sublattice ionic liquid model for the liquid phase and by the compound energy model for the solid solution phase. All solid phases were treated as stoichimetric compounds.

  • PDF

Pb 함량에 따른 PZT 박막의 식각 및 유전특성에 관한 연구 (A study on the Etching and Dielectric Properties of PZT Thin Films with Excess Pb Contents)

  • 김경태;이성갑;김창일;이영희
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2000년도 춘계학술대회 논문집 전자세라믹스 센서 및 박막재료 반도체재료 일렉트렛트 및 응용기술
    • /
    • pp.56-59
    • /
    • 2000
  • In this study, Ferroelectric $Pb(Zr_x,Ti_{1-x})O_3$(x=0.53) thin films were fabricated by the spin-coating on the Pt/Ti/$SiO_2$/Si substrate using the PZT metal alkoxide solutions with various excess Pb contents. Etching of PZT film was performed using planar inductively coupled Ar(20)$/Cl_2/BCl_3$ plasma. The etch rate of PZT film was 2450 ${\AA}/min$ at Ar(20)$/BCl_3$(80) gas mixing ratio and substrate temperature of $80^{\circ}C$. The leakage current densities of before etching and after etching PZT thin film were $6.25\times10^{-8}A/cm^2$, $8.74\times10^{-7}A/cm^2$ with electric field of 0.07MV/em, respectively.

  • PDF

CuO의 첨가가 PMN-PT 세라믹스의 유전특성에 미치는 영향 (Effects of CuO Addition on the Dielectric Properties of $Pb(Mg_{1/3}Nb_{2/3})O_3-PbTiO_3$ Ceramics)

  • 김효태;변재동;김인태;김윤호
    • 한국세라믹학회지
    • /
    • 제32권9호
    • /
    • pp.1056-1064
    • /
    • 1995
  • 95Pb(Mg1/3Nb2/3)O3-5PbTiO3 (hereinafter designated as 95PMN-5PT) system was prepared by the columbite-precursor method with 2 mol% excess PbO to compensate the PbO loss during thermal process. The amount of CuO was 1~10 mol%, and the effects of CuO addition on the dielectric properties of this system have been investigated. From the microstructures, XRD analysis and dielectric measurements, the solubility limit of CuO in 95PMN-5PT was found to be around 3 mol%. Lattice parameter and Curie temperature were found to be decreased as the amount of CuO increased up to the solubility limit. This result confirmed that the Cu2+-ions substituted the Pb2+-ions. It was revealed that the addition of CuO on 95PMN-5PT promoted the sinterability and properties. The room temperature dielectric constant, the loss factor and the specific resistivity of the specimens processed with optimum conditions were 23000, 1%, and 8$\times$1011Ω.cm, respectively.

  • PDF