• Title/Summary/Keyword: BaTiO$_3$

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Effect of Nd Doping on the Electrical Conductivity and Lattice Parameters of barium-Lead Titanate (Nd첨가가 Barium-Lead Titanate의 전기전도도와 격자상수에 미치는 영향)

  • Tadashi NAKANO;;Hiroaki YANAGIDA
    • Journal of the Korean Ceramic Society
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    • v.22 no.4
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    • pp.15-20
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    • 1985
  • $(Ba_{0.5} Pb_{0.5})_{1-x} Nd_x TiO_3$ 중의 $_x(Nd$의 양)를 변화시키면서 격자상수와 전기전도도를 측정하였다 c축과 a축의 비(c/a) 의 극대값은 실온에 있어서 전기전도도의 극대값과 일치하였다. 이것은 Nd원자의 치환위치와 강유 전성의 변화에 의한 것으로 고찰되었다 Curie 온도이하에서는 Nd 첨가량의 증가에 따라 전기전도도의 활성화에너지가 증가하는 경향을 나타내었다 이것은 입경의 감소에 따른 Spontaneous polarization의 저하가 원인으로 고찰되었다 첨가량의 역학을 입계의 potential barrier의 높이와 관련지어 논하였다.

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Intensity Dependence of Mutually Pumped Phase Conjugator in Photorefractive Crystal (광굴절결정에서 인코히어런트한 두 빔에 의해 발생되는 위상공액파의 광세기 의존성)

  • 박서연;곽종훈;김천민
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.2
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    • pp.41-46
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    • 1992
  • Mutually pumped phase conjugator(MPPC) is experimentally investigated and analyzed in terms of fanning gratings of a photorefractive BaTiO$_3$ crystal. As considering the intensity-dependent absorption and coupling cofficients in photorefractive two wave mixing, the dependence of phase conjugate reflectivites on the incident angle, beam ratio, and total intensity in MPPC is analyzed.

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A Study on the Optical Digital paralle Processor using Phase Conjugate Mirror (위상 공액경을 이용한 광 디지틀 병렬 연산기에 관한 연구)

  • 은재정;최평석
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.9
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    • pp.135-141
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    • 1995
  • An optical digital parallel processor using Self-Pumped Phase Conjugate Mirror and liquid crystal spatial light modulator is presented and experimentally implemented. To use self-pumped PCM as memory, the mechanism for phase conjugation in two coupled interaction regions with the photorefractive crystal BaTiO$_{3}$ is investigated, especially the temporal behavior and effects of incident beam position. The optical design and implementation of matrix-vector multiplication using LCSLM and PCM memory is presented.

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Powder EL device with 7-segment type and Driving Circuit (7-segment형 후막 EL소자와 구동회로)

  • 이종찬;박대희
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2000.11a
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    • pp.60-63
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    • 2000
  • In this paper, 7-segment was implemented using AC powder EL. ZnS:Cu and BaTiO3 was used as a phosphor and dielectric respectively. The preparation of phosphor and dielectric layer was performed with screen printing. The implemented system of 7-segment was divided as following; EL display, driving circuit, software for driving. The properties of fabricated devices was measured with EL spectrum and brightness.

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Flexible Information Display using Powder Electroluminescent Device (후막 전계 발광 소자를 이용한 정보 표시형 Flexible Display)

  • Lee, Jong-Chan;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 2000.11c
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    • pp.428-430
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    • 2000
  • In this paper, the Flexible information display was implemented using AC powder electroluminescent device. ZnS:Cu and $BaTiO_3$ was used as a phosphor and dielectric respectively. The preparation of phosphor and dielectric layer was performed with screen printing. The implemented system of the Flexible information display was divided as following; EL display, driving circuit, software for driving. The properties of fabricated devices was measured with EL spectrum and brightness.

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All-Optical Implementation of Volume Holographic Associative Memory (부피격자형 연상메모리의 광학적 구현)

  • 오창석;이권연;박한규
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.9
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    • pp.1102-1107
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    • 1988
  • We describe a volume holographic associative memory using photorefractive material and conventional planar mirror. Multiple hologram is generated with two angular multiplexed writing beams and Fourier transformed object beam in Ba Ti O3 crystal at 0.6328 um. Complete image can be recalled successfully by partial input of the original stored image without any additional thresholding and optical feedback process. It is proved that our system is useful for optical implementation of real-time associative memory and location addressable memory.

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Remote Controlled PTC Thermistor by YAG Laser Irradiation (YAG 레이저를 이용한 PTC 서미스터의 원격작동)

  • 박용동
    • Journal of the Microelectronics and Packaging Society
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    • v.4 no.2
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    • pp.41-46
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    • 1997
  • 지향성이 좋고 에너지밀도가 높고 집광성이 뛰어난 Nd:YAG레이저를 이용해서 원거 리 레이저 조사를 통한 서미스터의 PTCR 특성을 관찰하여 원격 제어를 시도를하였다. 1064nm의 Nd:YAG레이저 광선을 BaTiO3 서미터 표면에 1m 거리에서 5mm2 빔 사이즈로 50~200mJ/pulse, 10Hz의 조건에서 조사하였을 때 서미스터의 전기저항변화는 약 103 정도 로 레이저 조사에 의하여 원격으로 PTCR 특성을 제어 할수 있었다.

Current-voltage Characteristics of PTC Ceramics by Changing Donor Concentration and Specimen Thickness (Donor 첨가량과 시편두께에 따른 PTC 세라믹스의 전류-전압 특성)

  • 한응학;강영석;박순자
    • Journal of the Korean Ceramic Society
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    • v.28 no.8
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    • pp.619-625
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    • 1991
  • The current-voltage characteristics of the semiconducting BaTiO3 ceramics are measured in the range of 0.01∼100 Volt. Non ohmic behavior was observed above Tc. This behavior is not dependent on specimen thickness and is not observed at the incomplete semiconducting sepcimen. From this experiment, non-ohmic behavior of PTC is attributed to Heywang's potential barrier not to space change limited current. In the low voltage range, current-voltage characteristics of PTC ceramics can be explained by Heywang model.

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