• Title/Summary/Keyword: dielectric polarization

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Ferroelectirc Properties of Sm-doped PZT Thin films (Sm이 첨가된 PZT 박막의 강유전 특성)

  • 손영훈;김경태;김창일;이병기;장의구
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.2
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    • pp.178-183
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    • 2004
  • PBT thin film was known to be a representative for the FeRAM devices because of its good ferroelectric proporties and the ease in fabricating the thin film. However, there have been several problems such as polarization fatigue and leakage current in memory devices with a PZT thin film. In this study, Sm-dolled PZT thin films were fabricated by the so1-gel method, and their ferroelectric and dielectric proportrics were compared as a function of Sm content. We investigated the effect of the Sm dopant on structural and electrical properties of PZT film. Sm-doped PZT thin films on the Pt/Ti/SiO$_2$/Si substrates have been prepared by a sol-gel method. The remanent polarization and coercive field decreased with increasing the concentration of Sm. The dielectric constant and dielectric loss decreased with Increasing Sm content. Sm-doped PZT thin films showed improved fatigue characteristics compared to the undoped PZT thin film.

Electrical Properties of Pb(Mg1/3 Nb2/3)O3 Ceramics (Pb(Mg1/3 Nb2/3)O3 세라믹스의 전기적 특성)

  • 강동헌;윤기현
    • Journal of the Korean Ceramic Society
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    • v.26 no.5
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    • pp.712-718
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    • 1989
  • PMN ceramics with excess MgO addition in the range of 0 to 70m/o were prepared, and their electrical properties, such as dielectric constant, tan$\delta$, diffuseness coefficient, remanent polarization, coercive field and electrical conductivity were measured. Dielectric constant and remanent polarization increased with up to 5m/o excess MgO and then decreased presumely due to the precipitation of second phase, etc. Electrical conductivity slightly increased with the addition of excess MgO.

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Correlation Between Arrhenius Equation and Binding Energy by X-ray Photoelectron Spectroscopy

  • Oh, Teresa
    • Transactions on Electrical and Electronic Materials
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    • v.14 no.6
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    • pp.329-333
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    • 2013
  • SiOC films were prepared by capacitively coupled plasma chemical vapor deposition, and the correlation between the binding energy by X-ray photoelectron spectroscopy and Arrhenius equation for ionization energy was studied. The ionization energy decreased with increase of the potential barrier, and then the dielectric constant also decreased. The binding energy decreased with increase of the potential barrier. The dielectric constant and electrical characteristic of SiOC film was obtained by Arrhenius equation. The dielectric constant of SiOC film was decreased by lowering the polarization, which was made from the recombination between opposite polar sites, and the dissociation energy during the deposition. The SiOC film with the lowest dielectric constant had a flat surface, which depended on how carbocations recombined with other broken bonds of precursor molecules, and it became a fine cross-linked structure with low ionization energy, which contributed to decreasing the binding energy by Si 2p, C 1s electron orbital spectra and O 1s electron orbital spectra. The dielectric constant after annealing decreased, owing to the extraction of the $H_2O$ group, and lowering of the polarity.

Dielectric Properties depending on Frequency in ITO/$Alq_3$/Al (ITO/$Alq_3$/Al의 주파수 변화에 따른 유전 특성)

  • Oh, Y.C.;Lee, D.K.;Kim, J.S.;Shin, C.G.;Lee, S.I.;Kim, C.H.;Kim, T.W.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.292-293
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    • 2006
  • We have Investigated dielectric properties depending on bias voltage in organic lightemitting diodes using 8-hydroxyquinoline aluminum($Alq_3$) as an electron transport and emissive material. We analyzed the dielectric properties of organic light emitting diodes using impedance characteristics measurement by the auto-balancing bridge technique and equivalent cirrcuit of ITO/$Alq_3$/Al. Impedance characteristics was measured complex impedance Z and phase ${\theta}$ in the frequency range of 40 [Hz] to $10^8$ [Hz]. We obtained complex electrical conductivity, dielectric constant, and loss tangent ($tan{\delta}$) of the device at room temperature. From these analyses, we are able to interpret a conduction mechanism and dielectric properties contributed by an interfacial and orientational polarization.

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Dielectric Properties depending on Frequency in Organic Light-emitting Diodes using $Alq_3$ (Alq3를 이용한 유기 발광 소자의 주파수에 변화에 따른 유전 특성)

  • Oh, Y.C.;Lee, D.K.;Chung, D.H.;Lee, H.S.;Park, G.H.;Kim, T.W.;Lee, J.U.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.11a
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    • pp.293-294
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    • 2005
  • We have investigated dielectric properties depending on frequency in organic light -emitting diodes using 8-hydroxyquinoline aluminum ($Alq_3$) as an electron transport and emissive material. We analyzed the dielectric properties of organic light-emitting diodes using impedance of characteristics. impedance characteristics was measured complex impedance Z and phase $\Theta$ in the frequency range of 40 Hz to $10^8$ Hz. We obtained complex electrical conductivity, dielectric constant, and loss tangent (tan$\delta$) of the device at room temperature. From these analyses, we are able to interpret a conduction mechanism and dielectric properties contributed by an interfacial and orientational polarization.

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Microwave Dielectric Properties of $(Pb_{1-x}Ca_x)ZrO_3$ and $(Pb_{0.63},Ca_{0.37-x}M_x)ZrO_3$ (M = Mg, Sr) Ceramics ($(Pb_{1-x}Ca_x)ZrO_3$$(Pb_{0.63},Ca_{0.37-x}M_x)ZrO_3$ 세라믹스의 고주파 유전 특성)

  • 윤중락;이헌용
    • Electrical & Electronic Materials
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    • v.10 no.6
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    • pp.533-540
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    • 1997
  • The microwave dielectric properties of ((P $b_{1-x}$ C $a_{x}$)Zr $O_3$ and (P $b_{0.63}$,C $a_{0.37-x}$ $M_{x}$)Zr $O_3$(M=Mg,Sr) ceramics were investigated. In (P $b_{1-x}$ C $a_{x}$)Zr $O_3$ (X=0.33~0.40) ceramics, high quality factor and small temperature coefficient of resonant frequency were obtain in (P $b_{0.63}$C $a_{0.37}$)Zr $O_3$with perovskite structure. In the case of (P $b_{0.63}$C $a_{0.37-x}$M $g_{x}$)Zr $O_3$ dielectric constant temperature coefficient of resonant frequency increased and quality factor decreased due to increase of polarization of A-O bonding. When replacing Ca ion with Sr ion with large ion radius, polarization decreased with increased of bonding length and thus dielectric constant and temperature coefficient of resonant frequency decreased.decreased.creased.

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Ferroelectric properties of Sm-doped PZT thin films (Sm 첨가에 따른 PZT 박막의 유전 특성)

  • Son, Young-Hoon;Kim, Kyoung-Tae;Kim, Chang-Il;Lee, Byoung-Ki
    • 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.

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Dielectric Properties Depending on Temperature in Organic Light-emitting Diodes(ITO/$AIq_3$/AI) (유기 발광 다이오드(ITO/$AIq_3$/AI)의 온도 변화에 따른 유전 특성)

  • Oh, Y.C.;Lee, D.K.;Cho, C.N.;Ahn, J.H.;Jeong, Dong-Hui;Lee, S.I.;Kim, G.Y.;Kim, T.W.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.04a
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    • pp.74-75
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    • 2006
  • We have investigated dielectric properties depending on temperature in organic light-emitting diodes using 8-hydroxyquinoline aluminum ($Alq_3$) as an electron transport and emissive material. We analyzed the dielectric properties of organic light-emitting diodes using characteristics of impedance. he Impedance characteristics was measured complex impedance Z and phase $\theta$ in the temperature range of 10 K to 300 K. We obtained complex electrical conductivity, dielectric constant and loss tangent ($tan{\delta}$) of the device at room temperature. From these analyses, we are able to interpret a conduction mechanism and dielectric properties contributed by an interfacial and orientational polarization.

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Study on Dielectric Dispersion of Epoxy/SiO2 Nanocomposites using High Voltage Generator (중전기기용 Epoxy/SiO2 나노복합재료의 유전분산 연구)

  • Ahn, Joon-Ho;Park, Jae-Jun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.4
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    • pp.348-351
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    • 2007
  • Recently, Nanotechnology becomes a major issue in most part of industries. Nanotechnology is expected to develop various application products due to nano material mired composites is improved physical and electrical properties compared to conventional composites materials. Dielectric and insulation materials need to develop and improve like other field about nanotechnology. In this paper, we reported dielectric dispersion by size(no filler, $1.2{\mu}m$, 500 nm, 10 nm), frequencies(60, 120, 1 kHz), and temperatures($30{\sim}170^{\circ}C$). Dielectric constant of composites materials with filler shows higher than composites materials without filler and increased depending on rising temperatures in low frequency region. It was the effect that nano-filler and impurities in composites contributed to electrical conductivity. And dielectric properties depending on temperatures shows to change in low frequency region dramatically We analyzed interfacial polarization in low frequency region($10^{-2}$ Hz) and oriented polarization in high frequency region($10^{-5{\sim}6}$ Hz) on composites materials.

Design of a Simply Structured High-efficiency Polarization-independent Multilayer Dielectric Grating for Spectral Beam Combining (SBC 시스템 구성을 위한 단순한 구조를 가지는 고효율 무편광 유전체 다층박막 회절격자 설계)

  • Cho, Hyun-Ju;Kim, Gwan-Ha;Kim, Dong Hwan;Lee, Yong-Soo;Kim, Sang-In;Cho, Joonyoung;Kim, Hyun Tae;Kwak, Young-seop
    • Korean Journal of Optics and Photonics
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    • v.31 no.4
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    • pp.169-175
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    • 2020
  • We design a polarization-independent dielectric multilayer thin-film diffraction grating for a spectral-beam-combining (SBC) system with a simple grating structure and low aspect ratio. To maintain the high quality of the SBC beam, we propose a multilayer mirror structure in which the wavefront distortion due to stress accumulation is minimized. Moreover, to prevent light absorption from contamination, an optimized design to minimize the grating thickness was performed. The optimally designed diffraction grating has 99.36% diffraction efficiency for -1st-order polarization-independent light, for incidence at the Littrow angle and 1055-nm wavelength. It is confirmed that the designed diffraction grating has sufficient process margin to secure a polarization-independent diffraction efficiency of 96% or greater.