• Title/Summary/Keyword: the polarization constant

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Correlation between Dielectric Constant and Electronic Polarization by the Reflective Index (굴절률에 의한 유전상수와 전자에 의한 분극에 대한 상관성)

  • Oh, Teresa
    • Journal of the Korean Vacuum Society
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    • v.18 no.1
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    • pp.24-29
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    • 2009
  • The SiOC film as inter layer insulator was researched the reason of the decreasing the dielectric constant by the ionic polarization and electronic polarization, respectively. The dielectric constant was measured using the conventional C-V measurement system, and the reflective index owing to the electronic polarization. Two kinds of dielectric constants were compared and then induced the origin of low-k materials. The chemical properties of the SiOC film were analyzed by the FTIR spectra, and the carbon content was obtained by the deconvoluted data of FTIR spectra. The variation of the carbon content tended to similar to the trend of reflective index, but was in inverse proportion to the dielectric constant. The effect of the electronic polarization did not affect the decreasing the dielectric constant, however the ionic polarization decreased effectively the dielectric constant of the SiOC film.

A Study on the Dielectric Polarization of $ITO/Alq_3/Al$ Structure Organic Light-emitting Diodes ($ITO/Alq_3/Al$ 구조 유기 발광 소자의 유전분극 현상의 연구)

  • Oh, Yong-Cheul;Shin, Cheol-Gi;Kim, Chung-Hyeak
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.1
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    • pp.73-77
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    • 2008
  • We have investigated dielectric polarization in organic light-emitting diodes using 8-hydroxyquinoline aluminum($Alq_3$) as an electron transport and emissive material. We analyzed the dielectric polarization of organic light-emitting diodes using characteristics of impedance and equivalent circuit of $ITO/Alq_3/Al$. Impedance characteristics was measured complex impedance Z and phase ${\theta}$ in the frequency range of $1{\times}40Hz\;to\;1{\times}10^8Hz$. We obtained complex electrical conductivity, dielectric constant, and loss tangent(tan${\delta}$) of the device at room temperature. And, we obtained the equivalent circuit of $ITO/Alq_3/Al$ through analyzing dielectric constant and dielectric loss tangent. From these analyses, we could interpret a conduction mechanism and dielectric polarization.

Complex Dielectric Constant of Soil Contaminated by Landfill Leachate with Measured Frequency (매립지 침출수로 오염된 토양의 측정주파수에 따른 유전특성 변화)

  • Oh Myoung-Hak;Bang Sun-Young;Park Jun-Boum;Lee Ju-Hyung;Lee Seock-Heon;Ahn Kyu-Hong
    • Journal of Soil and Groundwater Environment
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    • v.9 no.3
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    • pp.1-11
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    • 2004
  • To evaluate the applicability of dielectric constant measurement method on the geoenvironmental investigation of subsurface contaminated by landfill leachate, the analysis on dielectric characteristics of sand containing contaminated pore water by landfill leachate was performed. The separate real and imaginary parts of dielectric constant were investigated in the frequency range of 75kHz to 12MHz. The real part of dielectric constant increased at the lower frequency wherea the real part of dielectric constant decreased at the higher frequency as the concentration of leachate increased. These results can be explained by the frequency dependence of space charge polarization and orientation polarization. The imaginary part of dielectric constant on the contaminated sand with leachate increased with their concentration for whole frequency range. These results are caused by the increase of energy loss due to the enhancement of conduction in soil with leachate concentration. The results in this study indicate that the dielectric constant measurement method has potential in evaluating the contaminated soil and pore water by landfill leachate.

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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Origin of Decreasing the Dielectric Constant and the Effect of Ionic Polarization (유전상수가 낮아지는 원인과 이온 분극의 효과)

  • Oh, Teresa
    • Journal of the Korean Vacuum Society
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    • v.18 no.6
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    • pp.453-458
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    • 2009
  • SiOC film was deposited by the chemical vapor deposition using BTMSM and oxygen mixed precursor. The characteristic of SiOC film varied with increasing of the gas flow rate ratios. The dielectric constant was obtained by C-V measurement using the structure of metal/SiOC film/Si. The space effect due to the steric hindrance between alkyl group at terminal bond of Si-$CH_3$ made the pores, and increased the thickness. However, the SiOC film due to the lowering of the polarization decreased the thickness and then decreased the dielectric constant. After annealing process, the dielectric constant decreased because of the evaporation of the OH or $H_2O$ sites. The thickness was related to the lowering of the dielectric constant by the reduction of the polarization and the thickness decreased with the decrease of the dielectric constant. The refractive index was in inverse proportion to thickness. The trends of the thickness and refractive index did not change after annealing.

Effects of changing the oxygen partial pressure in cooling after deposition of PZT thin films by reactive sputtering (Reactive sputtering법에 의한 PZT 박막 증착후 냉각시 산소분압의 영향에 관한 연구)

  • 이희수;오근호
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.6 no.3
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    • pp.406-414
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    • 1996
  • We studied the phase formation and the effect of electrical properties of PZT thin films with changing the oxygen partial pressure in cooling after deposition of PZT thin film by reactive sputtering method. The roughness of thin film increased with decreasing the oxygen partial pressure in cooling due to the evaporation on the surface ofthin films and the grain size was not changed very much. The hysteresis property of PZT thin film was improved toward having a good squareness with increasing the cooling oxygen partial pressure. We observed the decrease of remanent polarization, retained polarization and coercive field with decreasing the oxygen partial pressure. Dielectric constant decreased gradually and internal bias field increased in the measurement of dielectric constant-voltage property with decreasing cooling oxygen partial pressure. We observed the increase of nonswitched polarization in the measurement of field accelerated retention and the decrease of nonswitched polarization with increasing the bias time.

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Polarization behavior of polyvinylidene fluoride films with the addition of reduced graphene oxide

  • Lee, Junwoo;Lim, Sangwoo
    • Journal of Industrial and Engineering Chemistry
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    • v.67
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    • pp.478-485
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    • 2018
  • The effect of reduced graphene oxide (RGO) addition on the dielectric and piezoelectric behavior of the polyvinylidene fluoride (PVDF) films was studied. Dielectric constant increased by four times and piezoelectric coefficient also increased twice by the addition of RGO in the PVDF films. Based on capacitance-voltage and ellipsometry measurements and the Kramers-Kronig transformation, it is concluded that the enhanced dielectric and piezoelectric properties of the PVDF/RGO films resulted from the increased orientational polarization due to a phase transition from nonpolar crystalline ${\alpha}$ phase to polar crystalline ${\beta}$ phase in the PVDF structure.

A Study on the Dielectric Constant Measurement of PBDG Organic Ultra Thin Film (PBDG 유기초박막의 유전율 측정에 관한 연구)

  • Song, Jin-Won;Lee, Kyung-Sup
    • Proceedings of the KIEE Conference
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    • 2002.11a
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    • pp.150-152
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    • 2002
  • This paper, experiment manufactures device of Metal/Poly-$\gamma-Benzyl\;_D-Glutamate$ Organic Films/Metal structure using PBDG and I-V properties and C-F properties. The I-V characteristic is measured that approve voltage from 0 to +2[V] of device and the distance between electrode is larger, could know that small current flow and thin film could know that had insulation property. C-F characteristic has each other affinity between the polarization amount and frequency. Dielectric constant of MIM device could know by dipole that is voluntary polarization of LB film that polarization is happened. The capacitor properties of a thin film is better as the distance between electrodes is smaller.

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Microstructure and Ferroelectric Properties of Low Temperature Sintering PMN-PNN-PZT Ceramics with Sintering Temperature (저온소결 PMN-PNN-PZT세라믹스의 소결온도에 따른 미세구조 및 강유전특성)

  • Yoo, Ju-Hyun;Lee, Hyun-Seok;Lee, Sang-Ho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.12
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    • pp.1118-1122
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    • 2006
  • In this study, in order to develop the low temperature sintering multilayer piezoelectric actuator, PMN-PNN-PZT system ceramics were manufactured and their microstructure, ferroelectric and piezoelectric properties were investigated. By increasing sintering temperature, remanent polarization$(P_r)$ was increased due to the increase of sinterability and grain size. However, coercive $field(E_c)$ showed an opposite tendency to remanent polarization owing to the feasibility of domain wall motion. At the sintering temperature of $900^{\circ}C$, dielectric $constant({\varepsilon}_r)$, electromechanical coupling $factor(k_p)$, piezoelectric $constant(d_{33})$ and mechanical quality $factor(Q_m)$ showed the optimal value of 1095, 0.60, 363 and 1055, respectively, for multilayer piezoelectric actuator application.