• 제목/요약/키워드: Crystallography

검색결과 578건 처리시간 0.023초

trans-Bis(tert-butylamine)dichloropalladium(II), trans-[$PdCl_2(t-BuNH_2)_2$의 합성 및 구조 (Preparation and Structure of trans-Bis(tert-butylamine)dichloropalladium(II), trans-[$PdCl_2(t-BuNH_2)_2$])

  • 김혜진;한원석;이순원
    • 한국결정학회지
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    • 제12권1호
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    • pp.10-13
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    • 2001
  • Compound PdCl₂(PhCN)₂(1) reacted with tert-butylamine(t-BuNH₂) to give trans-[PdCl₂(t-BuNH₂)₂] (2) Compound 2 was characterized by spectroscopy (¹H-NMR, /sup 13/C{¹H}-NMR, and IR) and X-ray diffraction. Crystallographic data for f2: monoclinic space group p2₁/c, a=6.298(1)Å, b=20.740(2)Å, c=10.731(1)Å, β=92.58(1)°, Z=4, R(wR₂)=0.0207(0.0543).

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완화형 가유전체에서 전계인가에 따른 격자왜곡과 강유전물성의 상관관계 (Electric-Field-Induced Lattice Distortion and Related Properties in Relaxor Ferroelectrics)

  • 박재환;박재관;김윤호
    • 한국결정학회지
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    • 제12권1호
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    • pp.14-19
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    • 2001
  • Effects of electric-field-induced lattice distortion on the polarization and strain were investigated in Pb(Mg/sub 1/3/Nb/sub 2/3)O₃ relaxor ferroelectric ceramics in the temperature range of -50℃∼90℃. The ratio of residual strain and polarization (S/sub r//P/sub r/ rarely depends on the temperature. However, the ratio of the electric field included strain and polarization (S/sub induced//P/sub induced/) increased as the temperature decreases below phase transition temperature. To explain these experimental results, a simple rigid ion model concentrating on only Bo/sub 6/ octahedron was suggested.

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$TiO_2$ 코팅에 의한 흑연의 전기적 특성연구 (Study on the Electrical Properties of Graphite by $TiO_2$ Coating)

  • 최승도;문흥수;박병규;이태근;김철진;이석근
    • 한국결정학회지
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    • 제10권1호
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    • pp.9-12
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    • 1999
  • TiO2로 수열코팅하여 표면 개질한 흑연의 미세구조 및 전기적 특성에 관하여 연구하였다. 수열합성에 의해 코팅된 TiO2는 rutile 상이였고, 흑연의 소결정을 증대하였다. 온도에 따라 흑연의 소결성 및 밀도는 증가하였고, 코팅된 TiO2에 의한 흑연의 산화로 저항은 증가하였고 1100℃ 이상에서는 포화되었다.

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쵸크랄스키법에 의한 $Bi_4Ge_3O_{12}$ 단결정 육성 및 화학조성이 광학적 성질에 미치는 영향 ($Bi_4Ge_3O_{12}$ Crystal Growth by Czochralski Method and the Effect of Composition on Optical Properties)

  • 배인국;황진명
    • 한국결정학회지
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    • 제10권1호
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    • pp.39-44
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    • 1999
  • 주파수 무선센서에 의한 자동직경제어방식으로 쵸크랄스키법에 의해 Bi4Ge3O12 단결정을 육성하였다. Bi4Ge3O12의 화학양론적 조성으로부터 Bi2O3와 GeO2의 조성비를 변화시키면서 단결정을 육성하였다. 광학적인 투과도 조사결과, 화학양론적 조성에서 가장 우수한 투과도를 나타내었고 과잉의 Bi2O3에서는 투과도가 현저히 낮아졌다. 또한 육성된 단결정의 결함밀도는 ∼1×103/cm2이었다.

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[FeH(CN)$(dppe)_2$ 착물의 합성 및 구조 (Synthesis and Structure of trans-Bis[bis(diphenylphosphino)ethane]cyanohydridoiron(II), trans[FeH(CN)$(dppe)_2$](dppe=$Ph_2PCH_2CH_2PPh_2)$)

  • 이재경;최남선;이순원
    • 한국결정학회지
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    • 제10권1호
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    • pp.45-50
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    • 1999
  • Ar 기류하에서 trans-[FeH(NCCH2CH2CH2Cl)(dppe)2][BF4], 1과 KCN이 반응하여 trans-[FeH(CN)(dppe)2], 2가 생성되었다. 이 화합물의 구조가 NMR, IR, 원소분석, 그리고 X-ray 회절법으로 규명되었다. 착물 2의 결정학 자료: 단사정계 공간군 p21/c, a=13.580(1) b=20.178(2) , c=17.592(3) , β=92.22(1)o, Z=4,(wR2)=0.0659(0.1692).

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Crystallization and Preliminary Crystallographic Study of 26kDa Clonorchis sinensis glutathione S-transferase Complexed with Inhibitors

  • Chung, Yong-Hak;Chung, Yong-Je
    • 한국결정학회지
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    • 제11권4호
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    • pp.238-240
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    • 2000
  • A helminth glutathione S-transfease, 26 kDa isozyme from Clonorchis sinensis was cocrystallized with inhibitors by the hanging-drop method with monomethylether 550 as a precipitant. The crystals, grown in the presence of S-methylglutathione or trans-4-phenyl-3-buten-2-one, suitable for X-ray analysis, belong to the hexagonal space group P6₂(or P6₄), with unit cell parameters a= b= 97.6Å, c=117.4Å. X-ray diffraction data were collected with 2.5Å resolution.

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Ni/Au와 Au/Al 전극 증착에 의한 GaN의 전기적 특성 연구 (Electrical Behavior of Ni/Ti and Au/Al Contact Metallization on GaN)

  • 이태근;최종운;허재근
    • 한국결정학회지
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    • 제14권2호
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    • pp.105-109
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    • 2003
  • Electrical properties of Ni/Au/p-GaN and optical properties of epitaxial GaN MQW LED on sapphire were characterized. At 20 mA forward bias, GaN MQW emitted in the blue at 470 nm. Current-voltage (I-V) characteristics were decreased linearly with the annealing temperature. The resistivity of Ni/Au contacts was found by TLM measurements to be of device quality (2×10/sup -1/Ωㆍcm).

The Symmetry of Aurivillius Ceramics

  • Fuentes, Luis;Fuentes, Maria E.;Camacho, Hector
    • 한국결정학회지
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    • 제12권4호
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    • pp.227-232
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    • 2001
  • Structure-physical properties relationships for Aurivillius ceramics are discussed, with empha-sis in symmetry considerations. Single-crystal materials and polycrystal ceramics are analysed. Electric and magnetic coupling properties are considered. Colour Symmetry Groups and Texture Analysis tool are emploed. Symmetry conditions for polarisation vectors and inverse pole figures related to Aurivillius phases are given. The influence of crystallographic texture of the physical properties of polycrystalline Aurivillius ceramics is evaluated.

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Co-Silicide Device Characteristics in Embedded DRAM

  • Kim, Jong-Chae;Kim, Yeong-Cheol;Kim, Byung-Kook
    • 한국결정학회지
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    • 제12권3호
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    • pp.162-165
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    • 2001
  • The EDL (Embedded DRAM and Logic) technologies with stack cell capacitors based on NO dielectric and Co-silicided source/drain junctions using a Ti capping material, were successfully implemented. The employed Co-silicided film exhibited junction leakage characteristics comparable to those of non-silicided junctions. Improved device characteristics without degradation of I/sub off/ was also achieved.

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참오동나무 줄기의 성분 연구 (The Constituents of Paulownia tomentosa Stem)

  • 박유미;장성기;김연수;김박광
    • 약학회지
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    • 제35권4호
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    • pp.301-307
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    • 1991
  • A benzofuran substance was isolated from the methanol extract of Pauownia tomentosa stem which has been used to treat against gonorrhoea and contusion etc. in the oriental traditional medicine. Its structure was elucidated as methyl-5-hydroxy-[1, 4]naphthoquino-[2, 3-b]benzo-[I, 2-g] benzofuran-6-carboxylate by X-ray crystallography and various spectroscopic evidences and also other three known compounds, paulownin, sesamin, $\beta$-sitosteryl-3-O-$\beta$-D-glucopyranoside, were obtained.

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