• 제목/요약/키워드: Ferroelectric properties Dielectric properties

검색결과 318건 처리시간 0.031초

Eu 첨가에 따른 PZT 박막의 강유전 특성 (Ferroelectirc Properties of Eu-doped PZT Thin Films)

  • 김창일;손영훈;김경태;김동표;이병기
    • 한국전기전자재료학회논문지
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    • 제16권7호
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    • pp.611-615
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    • 2003
  • Eu-doped lead zirconate titanate(Pb$\sub$1.1/(Zr$\sub$0.6/Ti$\sub$0.4/)O$_3$; PZT) thin films on the Pt/Ti/SiO$_2$/Si substrates prepared by a sol-gel method. The effect on structural and electrical properties of PZT thin films measured according to the Eu content. Eu-doping altered significantly dielectric and ferroelectric properties. The remanent polarization and the coercive field decreased with the increasing Eu content. The dielectric constant and the dielectric loss of PZT thin films decreased with the increasing Eu content. The 0.5 mol% of Eu-doped PZT thin film showed improved fatigue characteristic comparing to the undoped PZT thin film.

Dielectric and Magnetic Properties of BaTiO3-LaMnO3 Composites

  • Kim, N.G.;Koo, Y.S.;Jung, J.H.
    • Journal of Magnetics
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    • 제11권4호
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    • pp.164-166
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    • 2006
  • We have investigated the dielectric and magnetic properties of ferroelectric-antiferromagnetic $BaTiO_{3}-LaMnO_{3}$ composite with changing relative mole percents. Due to high sintering temperature, i.e. $1150^{\circ}C$, the Ba ion in $BaTiO_{3}$ seems to diffuse into $LaMnO_{3}$; resulting in $BaTiO_{3}-(La,Ba)MnO_{3}$ ferroelectric-ferromagnetic composite. At room temperature, $0.9BaTiO_{3}-0.1LaMnO_{3}$ composite exhibits considerable magnetization (${\sim}0.7\;emu/g\;at\;2000\;Oe$) and low coercive field (${\sim}5\;Oe$). Also it exhibits high dielectric constant (${\sim}560$) and low loss (${\sim}0.08$) at 10 kHz. This result may imply that $BaTiO_{3}-LaMnO_{3}$ could be suitable for a low leakage multiferroic composite.

BT/BNT 이종층 후막의 전기적 특성 (Electrical Properties of Heterolayered BT/BNT Thick Films)

  • 남성필;이승환;이성갑;배선기;이영희
    • 전기학회논문지
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    • 제58권12호
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    • pp.2431-2435
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    • 2009
  • The heterolayered BT/BNT thick films were fabricated by screen printing techniques on alumina substrates electrodes with Pt. We report the improved ferroelectric and dielectric properties in the heterolayered tetragonal/rhombohedral structure composed of the BT and the BNT thick films. We investigated the effects of deposition conditions on the structural and electrical properties of the heterolayered BT/BNT thick films. The dielectric properties of the heterolayered BT/BNT thick films were superior to those of single composition BNT, and those values for the heterolayered BT/BNT thick films were 1455, 0.025 and $12.63 {\mu}C/cm^2$.

Relaxation Characteristic of the Disordered Lead Scandium Niobate

  • Kim, Yeon Jung
    • Applied Science and Convergence Technology
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    • 제24권3호
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    • pp.47-52
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    • 2015
  • The correlation between admittance and dielectric spectroscopy of dielectric relaxation in lead scandium noibate, have been investigated. Lead scandium niobate, with composition $PbSc_{0.5}Nb_{0.5}O_3$, was prepared by conventional solid state synthesis. Conductance Y'(G), susceptance Y"(B) and capacitance C of lead scandium niobate as a function of frequency and temperature were measured. From the temperature-dependence of RLC circuit, insight into physical significance of the dielectric properties of lead scandium niobate is obtained. The relative strong frequency dependent of dielectric properties in lead scandium niobate is observed, and the phase transition occurred at a broad temperature region. Also, the value of critical exponent ${\gamma}$=1.6 showed on heating process. The long relaxation times part enlarged diffuse by conductivity effects with increasing temperature, and the ordering between $Sc^{3+}$ and $Nb^{5+}$ in PSN influences complex admittance and dielectric properties. Confirmed the typical characteristic of lead-type relaxor in the Raman spectra of lead scandium niobate and major ranges are between 400 and $900cm^{-1}$.

이종접합 SrBi$_2Ta_2O_9$/Pb(Zr,Ti)O$_3$박막 케패시터의 강유전 특성 (Ferroelectric Properties of Hetero-Junction SrBi$_2Ta_2O_9$/Pb(Zr,Ti)O$_3$)

  • 이광배;김종탁
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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    • pp.217-221
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    • 1997
  • We have investigated the ferroelectric properties of multi-layered SrBi$_2$Ta$_2$$O_{9}$Pb(Zr,Ti)O$_3$, SBT/PZT, thin film capacitors. Specimens were prepared onto Pt-coated Si wafer by sol-gel method. Ferroelectric properties of these finns could be obtained only for thin SBT layers below 50nm in thickness. The values of dielectric constant and remnant polarization depend mainly on the thickness of SBT layer, which arises from the paraelectric interface layer between SBT and PZT due to the thermal diffusion of Pb. The value of remnant poarization of PZT/SBT is greater than that of SBT, and the plarization fatigue behaviors of PZT/SBT/Pt capacitors are somewhat improved as compared with those of PZT/Pt.t.

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희토류원소(Y, Nd, Sm, Gd)의 치환에 의한 $Bi_4Ti_3O_{12}$의 결정화학 및 유전물성 (Crystal Chemistry and Dielectric Properties of $Bi_4Ti_3O_{12}$ by the Substitution of Rare Earth Elements (Y, Nd, Sm, Gd))

  • 고태경;방규석
    • 한국세라믹학회지
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    • 제32권10호
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    • pp.1178-1188
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    • 1995
  • Bi4Ti3O12 (BIT) and its rare earth (Y, Nd, Sm, Gd)-substituted derivatives were synthesized using a sol-gel method to investigate their microstructures, cystal structures and electrical properties depending on the subsituted elemetns. Nd- or Sm-substitution into BIT appeared to be favorable, while Y- or Gd-substitution occurred with a pyrochlore phase. This suggests that a smaller trivalent rare earth ion may not be favorable in the structure of BIT. The rare earth derivatives showed that their particle sizes and shapes were considerably different depending on the kinds of substituted elements. Y-substitution resulted in developing a relatively even particle size and a dense microstructure. In structure, they may be similar to the pseudo-orthorhombic BIT but close to a paraelectric tetragonal phase. Their a (or b) axes were shortened, compared to the one of BIT. Such a distortion may result a decrease in the tilting of TiO6. BIT and the derivatives showed that their dielectric constants and losses were 40~120 and less than 0.03, respectively in the frequency range of 1~10 MHz. The dielectric loss of Y-substituted derivative was the lowest one and changed a little to frequency. Curie points were observed in all the derivatives like BIT to suggest that they would be ferroelectric. The temperature stability of the delectric properties of the derivatives below the Curie points were relatively better than the one of BIT.

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스크린 프린팅법으로 제작한 PZT후막의 강유전 특성 (The Ferroelectric properties of PZT thick film by preparation Screen Printing)

  • 강정민;조현무;이성갑;이상헌;이영희;배선기
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.656-658
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    • 2004
  • Pb$(Zr_{0.8}Ti_{0.2})TiO_3$ powder were prepared by the sol-gel method using a solution of Pb-acetate, Zr n-propoxide and Ti iso-propoxide. PZT thick film were fabricated by the screen printing method, and the structural and ferroelectric properties asafunting of the sintering temperature were studied. PZT film thickness, obtained by four screen printing, was approximately $70\sim90{\mu}m$. The relative dielectric constant and the dielectric loss of the PZT thick film sintered at $1050^{\circ}C$t were approximately 676 and 1.4%, respectively. The remanent polarization and the coercive field of the PZT thick film sintered at $1050^{\circ}C$ were $21.15{\mu}C/cm^2$ and 10.1 kV/cm, mapetively

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스크린 프린팅법으로 제작한 BSCT 후막의 구조적 특성과 유전적 특성 (Structural and dielectric properties of the BSCT thick films fabricated by the screen printing method)

  • 노현지;이성갑;이창공;남성필;이영희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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    • pp.167-167
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    • 2008
  • The barium strontium calcium titanate powders were prepared by sol-gel method. Ferroelectric $(Ba_{0.54}Sr_{0.36}Ca_{0.1})TiO_3$(BSCT) thick films were fabricated by the screen-printing method on alumina substrate. And we investigated the structural and dielectric properties of BSCT thick films with the variation of sintering temperature. As a result of thermal analysis, BSCT polycrystalline perovskite phase was formed at around $660^{\circ}C$. The results of X-ray diffraction analysis were showed a cubic perovskite structure without presence of the second phase in all BSCT thick films. The average grain size and the thickness of the specimen sintered at $1450^{\circ}C$ were about 1.6 mm and 45 mm, respectively. The relative dielectric constant increased and the dielectric loss decreased with increasing the sintering temperature, the values of the BSCT thick films sintered at $1450^{\circ}C$ were 5641 and 0.4% at 1kHz, respectively.

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SrRuO3 전극 박막 위에 증착된 PZT 박막의 구조 및 강유전 특성 (Structural and Ferroelectric Properties of PZT Thin Films Deposited on SrRuO3 Electrode Films)

  • 이명복
    • 한국전기전자재료학회논문지
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    • 제29권10호
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    • pp.620-624
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    • 2016
  • Ferroelectric $Pb(Zr_{0.52}Ti_{0.48})O_3$ (PZT) films were deposited on SrTiO3(100) substrate by using conductive $SrRuO_3$ films as underlayer and their structural and ferroelectric properties were investigated. PZT films were grown in (00l) orientation on well lattice-matched pseudo-cubic $SrRuO_3$ films. Thickness dependence of ferroelectric and electrical properties of PZT films was investigated. PZT film with 400 nm thickness showed a remanent polarization ($P_r$) of $29.0{\mu}C/cm^2$ and coercive field ($E_c$) of 83 kV/cm, and $P_r$ decreased and $E_c$ increased with thickness reduction. The dielectric constant for PZT films showed gradual decrease with thickness reduction. Breakdown field of PZT films did not show the thickness dependence and displayed as high value as 1 MV/cm.

PLD를 이용한 강유전체(PZT, PST, PT)/YBCO 박막 구조의 제작과 전기적인 특성에 관한 연구 (Electrical Properties and Fabrication of Ferroelectric (PZT)

  • 김정환;이재형;문병무
    • 한국전기전자재료학회논문지
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    • 제11권7호
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    • pp.541-545
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    • 1998
  • (PZT, PST, PT)/ YBCO structured have been grown on single crystal $LaAlO_3$ using in-situ Nb:YAG pulsed laser deposition technique. The optimum conditions of fabrication for high quality films have been established under various oxygen pressure. TBCO was used as a metallic electrode for polarizing ferroelectric thin fillms. Lattice mismatch of these materials were found to be with in 3%. As a result XRD patterns and rocking curves, (PZT, PST, PT)/ YBCO multiayered thin films on $LaAlO_3$ substrates showed preferred orientation to c-axis. For invastigation on electrical properties of ferroelectric thin films, remanent polaiztion $P_r$ and coercive field $E_c$ were measured for three samples. At each optimum condition, they showed the values of P_r=60 \mu C/cm^2 and E_c=240kV/ cm for PT, 30\mu C/cm^2 and 105kV/cm for PZT, 1.5\mu C/cm^2$ and 15kV/cm for PST. Frequency dependence of dielectric properties of ferroelectric thin fillms was also investigated. As a result, it showed the frequency dependence was relatively small in the range of 10Hz~10kHz.

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