• Title/Summary/Keyword: switching field

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Effect of Domain Switching on Crack Growth in Ferroelectric Ceramics (분역회전이 강유전체 세라믹내의 균열성장에 미치는 영향)

  • 정경문;박재연;범현규
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.11
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    • pp.142-149
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    • 2003
  • Domain switching effect on crack growth in ferroelectric ceramics under combined electric and mechanical loading is investigated. The shape and size of the switching zone is shown to depend strongly on the relative magnitude between the applied electric field and stress field as well as on the ratio of the coercive electric field to the yield electric field. The toughening mechanism is thought to be ferroelectric domain switching leading to the development of a process zone around the crack. Crack-tip stress intensity factor induced by domain switching for the steady state crack growth is numerically obtained.

Variation of the Switching Field of Composite Nanowires with Different Widths

  • Kim, Seung-Ho;Lee, Han-Seok;Lee, Seung-Hyun;Lee, Woo-Young;Lee, J.
    • Journal of Magnetics
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    • v.13 no.4
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    • pp.167-169
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    • 2008
  • The switching field of a 300 nm wide nanowire has been controlled by attaching a wide wire to it. The width of the wide wires varies from 700 nm to 2000 nm. While the connection of the two wires does not affect the switching field of the wide wires, it strongly affects the 300 nm-wire, resulting in a decrease of the switching field of the isolated wire from 175 Oe to 54 Oe when the 2000 nm-wire is connected to it. This result clearly shows that the switching field of the nanowire can be engineered by attaching a nucleation pad that has a different magnetic anisotropy.

Surface Driven Switching in Liquid Crystal Displays

  • Komitov, Lachezar
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.14-16
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    • 2009
  • Surface driven switching of the liquid crystal bulk arising from the coupling between an applied electric field and a polarized state of a nematic liquid crystal, both localized at the substrate surface, is reported. Fast switching is demonstrated in a hybrid aligned nematic cell with a fringe electric field generated by comb-like electrode structure.

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Electro-Optic Characteristics according to Distance between Pixel Electrodes in Fringe In-plane field Switching mode (화소 전극 간 거리가 Fringe In-plane field Switching mode의 전기 광학 특성에 미치는 영향)

  • Kim, Min-Su;Park, Ji-Woong;Jung, Jun-Ho;Ha, Kyung-Su;Lim, Young-Jin;Lee, Myong-Hoon;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.337-338
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    • 2008
  • We have studied electro-optic characteristics of a high performance liquid crystal display using Fringe In-plane field Switching (FIS) mode. The strong electric fields cause more liquid crystals to reorient almost in plane above and between the pixel electrodes. As a result, the operation voltage is lower and transmittance is higher than those of Fringe Field Switching (FFS) and In-Plane Switching (IPS) modes. Apparently, the transmittance depends on voltage applied at the configurations of FIS mode which are proposed. Therefore, we have studied certain length of between electrodes for maximum transmittance and light intensity.

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Study on Electro-optic Characteristics of Fringe-field Switching Twisted Nematic Mode using a Liquid Crystal with Negative Dielectric Anisotropy (유전율 이방성이 음인 액정을 이용한 Fringe-field Switching Twisted Hematic 모드의 전기광학 특성 연구)

  • 송일섭;신성식;이종문;이승희
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.5
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    • pp.530-535
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    • 2004
  • We have studied 90$^{\circ}$ twisted nematic mode switching by fringe electric field(F-TN mode) using a liquid crystal (LC) with negative dielectric anisotropy. In the device, two polarizers are parallel each other, electrodes exist only on bottom substrate, and one of rubbing direction is coincident with polarizer axis. Therefore, the cell shows a black state before a voltage is applied. With a bias voltage generating fringe-electric field, the LC twists perpendicular to fringe electric field such that the LCs are almost homogeneously aligned except near the bottom surface since the negative type of the LC is used. Consequently, the new device exhibits much wider viewing angle than that of the conventional TN mode due to in-plane switching and relatively high transmittance since the LC director above whole electrode area aligns parallel to the polarizer axis.

A study of the effect of the temperature on the As Te Ge Si amorphous semiconductor (As Te Ge Si 무정형 반도체의 온도영향)

  • 박창엽
    • 전기의세계
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    • v.23 no.6
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    • pp.49-55
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    • 1974
  • Amorphous semiconductor from As 30 Te 48 Ge 10 Si 12 was prepared, and studied electron microscopy, X-ray analysis and resistivity measurement. It's resistivity is 1.56*10$^{6}$ .ohm.-cm when small ampule is used for preparing sample it is found that no phase separation has occurced by electron microscopy, and that phase transition temperature is 232.deg. C by differential Thermal Analysis. The specimen showed threshold switching that the low resistance state occur at critical electric field and the resistance recover at low applied field. Critical electric field of the switching is 10$^{5}$ V/cm at room temperature. Threshold voltage secreace exponentially with increasing ambient temperature and at that each voltage resistance of the switching device increase exponentially. According to the series resistance and applied vottage current slope on the V-I curve is varied. When applied voltage is decreased after switching, the resistance of the switching device is increased. By this result the origin of the switching is the Joule's heating.

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Electro-optic characteristics of carbon nanotube-doped liquid crystal cell driven by in-plane switching and fringe-field switching

  • Shin, Seung-Hwan;Jeong, Seok-Jin;Jo, Eun-Mi;Lee, Seung-Hee;Kang, Hoon;Kim, Kyeong-Jin;Baik, In-Su;Jeong, Seok-Ho;Lee, Young-Hee;Lee, Hee-Kyu;Lee, Seung-Eun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.556-559
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    • 2007
  • Effects of carbon nanotube (CNT) on the in-plain switching (IPS) and fringe-field switching (FFS) modes were investigated. The studies show that the CNT-doped LC cells exhibit lower transmittance but faster response time than those in the pure LC cell. Interestingly, the CNT-doped IPS and FFS modes show different characteristic in effects of operating voltage.

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Investigation on the Free Layer Switching behavior of a Spin-valve MTJ Device with 2 Dimensional Magnetic Field (2차원 자기장에 의한 spin-valve 터널링 자기저항 소자의 자유층 반전 거동에 관한 연구)

  • Lee, Young-Woo;Kim, Cheol-Gi;Kim, Chong-Oh
    • Korean Journal of Materials Research
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    • v.13 no.6
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    • pp.394-397
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    • 2003
  • MTJ devices are fabricated using metal shadow masks and switching characteristics are investigated under 2 dimensional magnetic field. When the hard axis field is less than $\pm$ 16 Oe, switching behavior is similar to that based on the Stoner-Wohlfarth model. As the hard axis field is larger than $\pm$ 16 Oe, deviation from the expectation by Stoner-Wohlfarth model is observed. These phenomena are induced by the generation of multi-domain and inhomogeneous magnetization reversal.

A High Quality Fringe-Field Switching Display for Transmissive and Reflective Type

  • Lee, Seung-Hee;Choi, Soo-Han
    • 한국정보디스플레이학회:학술대회논문집
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    • 2000.01a
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    • pp.5-6
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    • 2000
  • Fringe-field switching (FFS) technology exhibiting a high image quality has been developed. In this paper, one pixel concept, manufacturing process, materials, and electro-optic characteristics of FFS mode comparing with conventional in-plane switching mode, and its possible application to reflective type will be discussed.

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Viewing Angle Switching using Hybrid Aligned Nematic Liquid Crystal Display Driven by a Fringe-Field

  • Chin, Mi-Hyung;Jeong, Eun;Lim, Young-Jin;Kim, Jin-Ho;Srivastava, Anoop Kumar;Lee, Seung-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1386-1389
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    • 2008
  • Conventional viewing angle switching electrode requires pixel division and additional liquid crystal panel. Hence the conventional viewing angle switching has low aperture ratio and high thickness. In this paper we proposed new viewing angle switching using hybrid aligned nematic mode by fringe-field electrode field (named HAN-FFS) with single liquid crystal panel. The fringe-field switching electrode is located at the bottom, and the additional common electrode is located at the top of the cell to control viewing angle. The proposed device is free from additional liquid crystal panel and pixel division. Consequently, the suggested structure has not only high aperture ratio but also show an excellent potential for viewing angle switching.

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