• 제목/요약/키워드: spin-structure

검색결과 727건 처리시간 0.029초

대형과제 기획시 계층분석적 의사결정기법을 적용한 전략적 에너지기술 R&D 프로그램 선정 (Selecting Strategic Energy Technology R&D Programs Applied to the AHP Approach as Planning a Big-sized Energy R&D Program)

  • 이성곤;겐토 모기;김종욱
    • 신재생에너지
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    • 제4권1호
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    • pp.25-30
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    • 2008
  • The R&D budget of energy technology development has increased in the sector of korean energy technology development continuously. In addition to that, KIER, the government invested research institute and unique energy technology R&D research institute, is trying to plan for a big-sized energy R&D program for the well focused R&D and excellent research outcomes. In the phase of R&D process, the planning is one of the most important sectors because it drives the direction of R&D. In this study, we suggest the assessment criteria to select a strategic energy technology R&D programs by the analytic hierarchy process, which is one of multi-criteria decision making method (MCDM)We structure 2 tiers of hierarchy for assessing a big-sized R&D program and also establish 6 criteria in the level 1, which are energy environment, economic spin-off, technical spin-off, marketability, KIER mission, and cost. We allocate the relative weights of criteria by checking the values of consistency ratio as making pairwise comparisons. The result of this research will provide the decision makers as they select a right well focused R&D program.

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Molecular Motions of [N(C2H5)4]+ and [N(CH3)4]+ ions by 1H Nuclear Magnetic Resonance Relaxation in [N(C2H5)4]2CoCl4 and [N(CH3)4]2CoCl4 Single Crystals

  • Yoon, Su-A;Lim, Ae-Ran
    • 한국자기공명학회논문지
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    • 제15권2호
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    • pp.146-156
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    • 2011
  • The line widths and spin-lattice relaxation times of protons in $[N(C_2H_5)_4]_2CoCl_4$ and $[N(CH_3)_4]_2CoCl_4$ single crystals were investigated in the temperature range 160-400 K. The temperature dependences of the spin-lattice relaxation times are attributed to the molecular motions of the ethyl and methyl groups in the $[N(C_2H_5)_4]^+$ and $[N(CH_3)_4]^+$ ions respectively. The NMR line widths indicate that the ethyl groups in $[N(C_2H_5)_4]_2CoCl_4$ have one more degree of freedom than the methyl groups in $[N(CH_3)_4]_2CoCl_4$. The experimental results are interpreted in terms of the reorientations of the methyl and ethyl groups.

코팅 횟수에 따른 $Ba_{0.7}Sr_{0.3}TiO_{3}$ 박막의 전기적 특성 (The Electric Characteristics of $Ba_{0.7}Sr_{0.3}TiO_{3}$ by Coating Numbers)

  • 홍경진;민용기;기현철;조재철
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 춘계학술대회 논문집 반도체재료
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    • pp.42-45
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    • 2001
  • The high permittivity are applied to DRAM and FRAM. (Ba,Sr)$TiO_3$ (EST) thin films were prepared by Sol-Gel method. BST solution was made and spin-coated on $Pt/SiO_2/Si$ substrate at 4000 [rpm] for 10 seconds in a time coating. Coated specimens were dried at $90[^{\circ}C]$ for 5 minutes. Coating process was repeated from 3 times to 5 times and then sintered at $750[^{\circ}C]$ for 30 minutes. Each specimen was analyzed structure and electrical characteristics. Thickness of BST ceramics thin films are about 2600-2800[$\AA$] in 3 times. Dielectric constant of thin films was little decreased at 1[KHz]~1[MHz]. Dielectric constant and loss to frequency were 250 and 0.02 in BST3. The property of leakage current was stable When the applied voltage was 0~3[V] Leakage current was $10^{9}\sim10^{11}$[A] at 0~3[V].

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(Bi,La)FeO3-PbTiO3 세라믹스의 자전효과 (Magnetoelectric Effects in (Bi,La)FeO3-PbTiO3 Ceramics)

  • 이은구;이종국;장우양;김선재;이재갑
    • 한국재료학회지
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    • 제15권2호
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    • pp.121-125
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    • 2005
  • Magnetoelectric (ME) effects for lanthanum modified $BiFeO_3-PbTiO_3\;(BE-_xPT)$ solid solutions have been investigated. The value of magnetoelectric polarization coefficient, up is 10 times greater than that of $Cr_2O_3$. The results also show that up is due to a linear coupling between polarization and magnetization, and that up is independent of do magnetic bias and ac magnetic field. The ME effect is believed to be significantly enhanced due to breaking of the cycloidal spin state of a long-period spiral spin structure, via randomly distributed charged imperfections.

P3HT를 이용한 유기 박막 트랜지스터에 관한 연구 (Investigation on the P3HT-based Organic Thin Film Transistors)

  • 김영훈;박성규;한정인;문대규;김원근;이찬재
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 춘계학술대회 논문집 디스플레이 광소자 분야
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    • pp.45-48
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    • 2002
  • Poly(3-hexylthiophene) or P3HT based organic thin film transistor (OTFT) array was fabricated on flexible poly carbonate substrates and the electrical characteristics were investigated. As the gate dielectric, a dual layer structure of polyimide-$SiO_2$ was used to improve the roughness of $SiO_2$ surface and further enhancing the device performance and also source-drain electrodes were $O_2$ plasma treated for improvement of the electrical properties, such as drain current and field effect mobility. For the active layer, polymer semiconductor, P3HT layer was printed by contact-printing and spin-coating method. The electrical properties of OTFT devices printed by both methods were evaluated for the comparison. Based on the experiments, P3HT-based OTFT array with field effect mobility of 0.02~0.025 $cm^{2}/V{\cdot}s$ and current modulation (or $I_{on}/I_{off}$ ratio) of $10^{3}\sim10^{4}$ was fabricated.

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TWO-COLOR CCD PHOTOMETRY OF THE INTERMEDIATE POLAR 1RXS J180340.0+401214

  • Andronov, Ivan L.;Kim, Yong-Gi;Yoon, Joh-Na;Breus, Vitalii V.;Smecker-Hane, Tammy A.;Chinarova, Lidia L.;Han, Won-Yong
    • 천문학회지
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    • 제44권3호
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    • pp.89-96
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    • 2011
  • We present results of two-color VR photometry of the intermediate polar RXS J1803. The data were aquired using the Korean 1-m telescope located at Mt. Lemmon, USA. Different "high" and "low" luminosity states, similar to other intermediate polars, were discovered. No statistically significant variability of the color index with varying luminosity was detected. The orbital variability was found to be not statistically significant. Spin maxima timings were determined, as well as the photometric ephemeris for the time interval of our observations. The spin period variations, caused by interaction of the accretion structure with the rotating magnetic white dwarf, were also detected. These variations are of complicated character, and their study requires further observations. We determine the color transformation coefficients for our photometric systems, and improve on the secondary photometric standards.

대형과제 기획시 계층분석적 의사결정기법을 적용한 전략적 에너지기술 R&D 프로그램 선정 (Selecting strategic energy technology R&D programs applied to the AHP approach as planning a big-sized energy R&D program)

  • 이성곤
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2007년도 추계학술대회 논문집
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    • pp.690-693
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    • 2007
  • The R&D budget of energy technology development has increased in the sector of Korean energy technology development continuously. In addition to that, KIER, the government invested research institute and unique energy technology R&D research institute, is trying to plan for a big-sized energy R&D program for the well focused R&D and excellent research outcomes. In the phase of R&D process, the planning is one of the most important sectors because it drives the direction of R&D. In this study, we suggest the assessment criteria to select a strategic energy technology R&D programs by the analytic hierarchy process, which is one of multi-criteria decision making method (MCDM). We structure 2 tiers of hierarchy for assessing a big-sized R&D program and also establish 6 criteria in the level 1, which are energy environment, economic spin-off, technical spin-off, marketability, KIER mission, and cost. We allocate the relative weights of criteria by checking the values of consistency ratio as making pairwise comparisons. The result of this research will provide the decision makers as they select a right well focused R&D program.

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4f spin dynamics in TbNi$_2$B$_2$C by $^{11}$B NMR

  • Lee, K.H.;Seo, S.W.;Kim, D.H.;Khang, K.H.;Seo, H.S.;Hwang, C.S.;Hong, K.S.;Cho, B.K.;Lee, W.C.;Lee, Moo-Hee
    • 한국초전도학회:학술대회논문집
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    • 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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    • pp.61-64
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    • 2000
  • $^{11}$B NMR measurements have been performed to investigate local electronic structure and 4f spin dynamics for TbNi$_2$B$_2$C single crystal. $^{11}$B NMR spectra show three resonance peaks due to the quadrupolar interaction. Shift and linewidth are huge and strongly temperature-dependent. In addition, both are proportional to magnetic susceptibility, indicating that the hyperfine field at the boron site originates from the 4f spins of Tb. $^{11}$B NMR shift and relaxation rates show high anisotropy for field parallel and perpendicular to the c-axis. Anisotropy of the shift and the relaxation rates suggests that the hyperfine field perpendicular to the c-axis is larger.

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Fabrication of SOI FinFET Devices using Arsenic Solid-phase-diffusion

  • Cho, Won-Ju;Koo, Hyun-Mo;Lee, Woo-Hyun;Koo, Sang-Mo;Chung, Hong-Bay
    • 한국전기전자재료학회논문지
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    • 제20권5호
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    • pp.394-398
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    • 2007
  • A simple doping method to fabricate a very thin channel body of the nano-scaled n-type fin field-effect-transistor (FinFET) by arsenic solid-Phase-diffusion (SPD) process is presented. Using the As-doped spin-on-glass films and the rapid thermal annealing for shallow junction, the n-type source-drain extensions with a three-dimensional structure of the FinFET devices were doped. The junction properties of arsenic doped regions were investigated by using the $n^+$-p junction diodes which showed excellent electrical characteristics. The n-type FinFET devices with a gate length of 20-100 nm were fabricated by As-SPD and revealed superior device scalability.

회전코팅법을 이용한 BST 박막의 제조 및 전기적 특성에 관한 연구 (The Preparation and Electrical Characteristics of BST Thin Film by Spin-Coating Method)

  • 기현철;김덕근;이승우;홍경진;이진;김태성
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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    • pp.918-920
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    • 1999
  • Recently, the ceramics of high permittivity are applied to DRAM and FRAM. In this study, (Ba, Sr)$TiO_3$ (BST) ceramics thin films were prepared by Sol-Gel method. BST solution was made and spin-coated on Pt/$SiO_2$/Si substrate at 4000[rpm] for 10 seconds. Coating process was repeated 3 times and then sintered at $750[^{\circ}C]$ for 30 minutes. Each specimen was analyzed structure and electrical characteristics. Thickness of BST ceramics thin films are about $2000[\AA]$. Dielectric constant and loss of thin films was little decreased at $1[kHz]{\sim}1[MHz]$. Dielectric constant and loss to frequency were 250 and 0.02 in BST3. In accordance with applied voltage, property of leakage current was stability when the was $0{\sim}3$[V]. According to voltage, leakage current was increased exponentially at $4{\sim}7$[V].

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