• Title/Summary/Keyword: electrical anisotropy

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Anisotropy Electrical Conduction Characteristics of Maleate Copolymer LB Films (말레에이트계 공중합체 LB초박막의 이방성 전기전도 특성)

  • Kim, Do-Kyun;Lee, Eul-Sik;Choi, Yong-Sung;Chang, Jeong-Soo;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 1997.07d
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    • pp.1525-1527
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    • 1997
  • We deposited maleate copolymer films by using Langmuir-Blodgrtt(LB) method. The deposition status of LB films were verified by the measurement of capacitance which was increased with the number of layers. And, we have investigated anisotropy electrical conduction characteristics of maleate copolymer LB films by I-V measurement for perpendicular direction and horizontal direction.

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Study on electro-optic characteristics of FFS mode using a positive LC (양의 액정을 이용한 Fringe Field Switching mode의 전기-광학 특성 연구)

  • Woo, Chang-Woo;Ha, Kyung-Su;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.171-171
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    • 2010
  • Electro-optic characteristics of liquid crystal display using fringe field switching(FFS) device depend on many parameters such as cell retardation, electrode structure, rubbing angle, cell gap and dielectric anisotropy. In this paper, the light efficiency of FFS mode will be analyzed to confirm the electro-optic characteristics according to positive dielectric anisotropy such as transmittance, operating voltage and response time.

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Characteristics of the photoinduced anisotropy(PA) in Ag/AsGeSeS multilayer thin films (Ag/AsGeSeS 다층박막의 광유기 이방성(PA) 특성)

  • Park, Jong-Hwa;Na, Sun-Woong;Yeo, Cheol-Ho;Park, Jeong-Il;Lee, Young-Jong;Chung, Hong-Bay
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.362-365
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    • 2001
  • The chalcogenide glasses of thin films have the superior property of photoinduced anisotrophy(PA). In this study, we observed the linear dichroism(D) using the irradiation with polarized He-Ne laser light, in the $Ag/As_{40}Ge_{10}Se_{15}S_{35}$ multi-layer. Mutilayer structures formed by alternating metal(Ag) a chalcogenide$(As_{40}Ge_{10}Se_{15}S_{35})$. Such multilayer structures have a greater sensitivity to illumination am larger dichroism in comparison the conventional double layer structure. Also new phenomena are discovered. These results will be show a capability of new method that suggested more improvement of photoinduced anisotropy property.

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Simulations of Ferromagnetic Resonance Spectra Excited in Magnetic Bilayers (이층 자성막에서 여기되는 강자성 공명신호의 모의실험)

  • 김약연;한기평;유성초
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.3
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    • pp.238-246
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    • 2003
  • We have performed the simulation of ferromagnetic resonance spectra on the exchange coupled bilayer thin films at perpendicular configuration. Variables considered in spectrum calculation were the interfacial exchange constants per unit area, the layer thickness, and the surface anisotropy constants. In case of antiferromagnetic coupling, variation of exchange constant gave a great effect to the absorption spectra of the low and the high magnetization layer. Variation of thickness in low magnetization layer did nt nearly influenced the resonated field of the high magnetization layer. Also, the increase of negative surface anisotropy increased the resonance field of the low and the high magnetization layer.

Analysis of the Three-Phase Transformer Considering the Non-Linear and Anisotropic Properties using the Transmission Line Modeling Method and FEM (이방성과 비선형성을 고려한 삼상 변압기의 TLM-FEM해석)

  • Im, Chang-Hwan;Kim, Hong-Gyu;Lee, Chang-Hwan;Jeong, Hyeon-Gyo
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.48 no.10
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    • pp.523-529
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    • 1999
  • In the case of the large power transformer, the grain-oriented material is usually used. So, to obtain more accurate results, anisotropy and non-linearity of the material must be considered. The Newton-Raphson(NR) method is generally used for analyzing these non-linear properties, but it consumes so much time, especially when the number of nodes is large or the shape of the model is complex. The transmission line modeling (TLM) method is successfully adopted to the analysis of non-linear properties with FEM, but it has not been adopted to the analysis of the anisotropic material. In this paper, the formulation of the TLM method considering anisotropy is developed and the adoption to the 3-phase transformer is presented.

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Characteristics of the photoinduced anisotropy(PA) in Ag/AsGeSeS multilayer thin films (Ag/AsGeSeS 다층박막의 광유기 이방성(PA) 특성)

  • 박종화;나선웅;여철호;박정일;이영종;정홍배
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.362-365
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    • 2001
  • The chalcogenide glasses of thin films have the superior property of photoinduced anisotrophy(PA). In this study, we observed the linear dichroism(D) using the irradiation with polarized He-Ne laser light, in the Ag/As$\sub$40/Ge$\sub$10/Se$\sub$15/S$\sub$35/ multi-layer. Mutilayer structures farmed by alternating metal(Ag) a chalcogenide(As$\sub$40/Ge$\sub$10/Se$\sub$15/S$\sub$35/). Such multilayer structures have a greater sensitivity to illumination and larger dichroism in comparison the conventional double layer structure. Also new phenomena are discovered. These results will be show a capability of new method that suggested more improvement of photoinduced anisotropy property.

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Surface Flatness Improvement in Si Anisotropy Etching Process Utilizing Ultrasonic Wave Technology (초음파 기술을 이용한 실리콘 이방성 식각 공정에서의 표면 평탄화 향상 연구)

  • Yun, Eui-Jung;Kim, Jwa-Yeon;Lee, Kang-Won;Lee, Seok-Tae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.416-417
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    • 2005
  • In this study, we optimized the process of Si anisotropy etching by combing tetramethyl ammonium hydroxide (TMAH) etching process with ultrasonic wave technology. New ultrasonic TMAH etching apparatus was developed and it was used for fabricating a $20{\mu}m$ thick diaphragm for Si piezoresistive pressure sensors. Based on comparison study on etch rate and surface flatness, it was observed that the Si anisotropy etching methode with new ultrasonic TMAH etching apparatus (at 40 kHz/ 500 watt) was superior to conventional etching methods with TMAH or TMAH+ammonium persulfate(AP) solutions.

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Electro-optic Characteristics of the fringe-field Driven Reflective Hybrid Aligned Nematic Liquid Crystal Cell using a Liquid Crystal with Positive Dielectric Anisotropy (유전율 이방성이 양인 액정을 이용한 fringe-Field 구동형 반사형 Hybrid Aligned Nematic 액정 디스플레이의 전기-광학 특성)

  • Song, Je-Hoon;Choi, Min-Oh;Lim, Young-Jin;Lee, Seung-Hee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.8
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    • pp.724-728
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    • 2005
  • Electro-optic characteristics of reflective hybrid aligned liquid crystal (LC) cell driven by fringe field using a nematic LC with positive dielectric anisotropy have been studied. Optimized optical configurations are achieved by using a single polarizer, half-wave film and a cell with quarter-wave retardation. The simulation results shows an optimum cell retardation of $0.30{\mu}m$. This value may allow a practical cell gap larger than $3{\mu}m$, which makes it easy to control in the manufacturing process. Furthermore, this LC cell with optimized cell parameters shows low wavelength dispersion and the contrast ratio greater than 5 over exists about $100{\circ}$ in vertical direction and $160{\circ}$ in horizontal direction. Also, when using the LC with positive dielectric anisotropy rather than negative dielectric anisotropy, the display shows low power consumption and fast response time.

Electro-Optic Characteristics of Fringe-Field Switching (FFS) according to Magnitude of Dielectric Anisotropy of Liquid Crystal (Fringe-Field Switching (FFS)모드의 액정 물성과 셀 파라미터에 따른 전기-광학 특성 연구)

  • Jung, Jun-Ho;Ha, Kyung-Su;Kim, Min-Su;Lee, Hee-Kyu;Lee, Seung-Eun;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.04a
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    • pp.61-62
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    • 2009
  • Electro-optical properties of liquid crystal display (LCD) using fringe-field switching (FFS) devices depend on many parameters such as cell retardation, electrode structure, magnitude and sign of dielectric anisotropy, rubbing angle and cell gap. In this paper, the light efficiency of FFS device depending on magnitude of positive dielectric anisotropy with other cell parameters such as rubbing angle and angle and cell gap have been explored compared with FFS device using LC with negative dielectric anisotropy.

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Origin of the Initial Permeabiliy of Ni0.8-xZn0.2CoxFe2O4+δ Ferrite (Ni0.8-xZn0.2CoxFe2O4+δ조성 페라이트의 투자율 변화 기구)

  • 안용운;김종령;오영우
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.1
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    • pp.46-51
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    • 2004
  • The cause for the variation of the initial permeability according to the Co substitution of Ni-Zn ferrite used in the LC resonance filter for the power line communication is studied. The initial permeability decreases as the quantity of Co diminishes, and the saturation magnetization increases as the quantity increases. Because the sintering density and the microstructure of ferrite show little change, the variation of the initial permeability can't be explained by the density, microstructure nor the saturation magnetization factor. The magnetocrystalline anisotropy increases, similar with the saturation magnetization, as the quantity of Co increases. The increase of magnetocrystalline anisotropy value makes the domain wall energy grow, which leads to the decrease of the initial permeability, because there's linear law between the magnetocrystalline anisotropy and the domain wall energy. The resonance frequency to Co substitution moved to high frequency band, due to the close relationship with domain wall energy, Initial permeability decreaed a little with an increase of Co contents, but resonace frequency moved to high frequency band. as a result of that, when Co was added 0.05 mol, initial permeability and resonace frequency was 75 and 25 MHz respectively.