• 제목/요약/키워드: solid dielectric

검색결과 327건 처리시간 0.037초

$CaTiO_3-LaAIO_3$계 세라믹스의 마이크로파 유전특성 (Microwave dielectric properties of $CaTiO_3-LaAIO_3$ ceramics)

  • 여동훈;김현재;송준태
    • E2M - 전기 전자와 첨단 소재
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    • 제9권4호
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    • pp.379-384
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    • 1996
  • The microwave dielectric properties of (I-x)CaTiO$_{3}$-xLaAIO$_{3}$ were investigated. The solid solution of (1-x)CaTiO$_{3}$-xLaAIO$_{3}$ had the perovskite structure in the range of all compositions. The crystal system of (1-x)CaTiO$_{3}$-xLaAIO$_{3}$ was transformed to orthorhombic(x.leq.0.4), psudo-cubic(x=0.5), and rhombohedral (x.geq.0.7) in turn, as the amount of LaAIO$_{3}$ increased. The dielectric constant and temperature coefficient of resonant frequency of solid solution were decreased with the content of LaAIO$_{3}$, whereas, the value of Q . f$_{o}$ was increased. The microwave dielectric material having Q . f$_{o}$ = 32, 500, .epsilon.$_{r}$ = 42, and .tau.$_{f}$ = 5 ppm/.deg. C was obtained from the 0.35CaTiO$_{3}$-0.65LaAIO$_{3}$ composition sintered at 1600.deg. C for 4hrs.hrs.hrs.

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용융 블랜드법에 의한 에폭시 수지의 전기 절연특성에 관한 연구 (Electrical Insulating Characteristics of Epoxy Resin by the Fusion Blend Method)

  • 홍경진;정우성;구할본;김태성
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1990년도 하계학술대회 논문집
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    • pp.275-278
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    • 1990
  • This study investigated electrical characteristics of solid and liquid epoxy rosins by measuring dielectric breakdown and dielectric loss when epoxy resins were exposed to a mixing cure, i.e., Fusion Blend Method. It was found that mixing epoxy resins were superior to dielectric breakdown and has shorter curing time compare with those of pure liquid epoxy resins.

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PNN-PZN-PZT계 세라믹의 압전 및 유전특성 (Dielectric and Electric Properties of Ceramics PNN-PZV-PZT)

  • 이수호;손무헌;사공건
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 하계학술대회 논문집 C
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    • pp.1271-1273
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    • 1994
  • In the field of the optics, precise machine, semiconducting processing, the micro-positioning actuators are required for the control of position in the submicron range. In this study, PNN-PZN-PZT ceramics were fabricated by solid state reaction. The structural, dielectric and electric properties were investigated for sintering condition. The specimen sintered for 1hr at 1,150($^{\circ}C$), had the highest density and dielectric contant.

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ZnO Thin Film Transistor Prepared from ALD with an Organic Gate Dielectric

  • Choi, Woon-Seop
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.543-545
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    • 2009
  • With injection-type source delivery system of atomic layer deposition (ALD), bottom-contact and bottom-gate thin-film transistors (TFTs) were fabricated with a poly-4-vinyphenol polymeric dielectric for the first time. The properties of the ZnO TFT were greatly influenced by the device structure and the process conditions. The zinc oxide TFTs exhibited a channel mobility of 0.43 $cm^2$/Vs, a threshold voltage of 0.85 V, a subthreshold slope of 3.30 V/dec, and an on-to-off current ratio of above $10^6$ with solid saturation.

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Fabrication and Characterization of (1-x)BiFeO3-xBaTiO3 Ceramics Prepared by a Solid State Reaction Method

  • Chandarak, S.;Unruan, M.;Sareein, T.;Ngamjarurojana, A.;Maensiri, S.;Laoratanakul, P.;Ananta, S.;Yimnirun, R.
    • Journal of Magnetics
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    • 제14권3호
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    • pp.120-123
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    • 2009
  • In this study, BiFe$O_3$-BaTi$O_3$ ceramics have been fabricated by a solid-state reaction method. The effects of BaTi$O_3$ content in the (1-x)BiFe$O_3$-xBaTi$O_3$ (x = 0.1, 0.2, 0.25, 0.3, 0.4, 0.5) system on crystal structure and magnetic, dielectric, and ferroelectric properties were investigated. Perovskite BiFe$O_3$ was stabilized through the formation of a solid solution with BaTi$O_3$. Rhombohedrally distorted structure (1-x)BiFe$O_3$-xBaTi$O_3$ ceramics showed strong ferromagnetism at x = 0.5. Dielectric and ferroelectric properties of the BiFe$O_3$-BaTi$O_3$ system also changed significantly upon addition of BaTi$O_3$. It was found that the maximum dielectric and ferroelectric properties were exhibited in the (1-x)BiFe$O_3$-xBaTi$O_3$ system at x = 0.25. This suggested the morphotropic phase boundary (MPB) with the coexistence of both rhombohedral and cubic phases of the (1-x)BiFe$O_3$-xBaTi$O_3$ system at x = 0.25.

$CaTiO_3-La(Zn_{1/2}Ti_{1/2})O_3$ 마이크로파 유전체의 소결거동 및 유전특성 (Sontering behavior and dielectric properties $CaTiO_3-La(Zn_{1/2}Ti_{1/2})O_3$ microwave dielectrics)

  • 김영신;윤상옥;박상엽;김경용
    • 한국결정성장학회지
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    • 제8권3호
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    • pp.503-507
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    • 1998
  • 마이크로파 유전체로 응용되는 $xCaTiO_3-La(Zn_{1/2}Ti_{1/2})O_3$계의 소결시 고용조성 변화(x=0.4-0.6) 및 소결거동에 따른 유전특성에 조사하였다. 소결밀도가 감소함에 따라 유전상수는 감소하였으며 품질계수(Q)는 증가하다 일정한 값을 유지하였다. 고용체형의 경우 유전상수는 $CaTiO_3$조성 증가에 따라 증가하였다. $0.5\;CaTIO_3\;0.5\;La(Zn_{1/2}Ti_{1/2})O_3$의 경우 유전상수 48, 온도계수는 $-1ppm/^{\circ}C$를 나타내었다.

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유전체 보호층을 이용한 NFR 미디어 커버층의 표면 특성 향상 (Enhancement of cover-layer surface properties using dielectric protective layer)

  • 김진홍;임정식;이준석;서정교
    • 정보저장시스템학회논문집
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    • 제4권1호
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    • pp.13-18
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    • 2008
  • Scratches are observed on a polymer cover-layer of near-field recording (NFR) media after a servo test with rotating disc. The scratches are formed by the collision of a solid immersion lens (SIL)-media. One of the possible ways to avoid the scratch problem is to coat a dielectric protective film on the polymer cover-layer which enhances the hardness of the surface. The surface with hard characteristics in the surface reduces the scratch problem in the cover-layer. Not only the mechanical properties but also the optical properties should be controlled. Specifically, the refractive index of the dielectric protective film should be matched with the polymer cover-layer not to lose light at the interface due to the difference of the refractive index. The refractive index of the dielectric film can be tailored by controlling process parameters during sputtering and matched with that of the polymer cover-layer.

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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 $900cm^{-1}$.