• 제목/요약/키워드: X-Ray crystal structure

검색결과 1,355건 처리시간 0.027초

X선의 초고속 결정구조 측정법 (Survey on ultrafast time resolved X-ray diffraction measurements of crystal structure)

  • 구영덕;김영철;오창섭
    • 에너지공학
    • /
    • 제23권3호
    • /
    • pp.13-16
    • /
    • 2014
  • 무기단결정을 광 펄스로 여기 한 격자에서 광학이나 음향포논을 이용하여 광 여기 반도체가 서브피코초로 관측하고 있다. 다수의 회절 점으로 결정구조를 파악하는 것으로써 광 여기에 의한 분자결정 구조변화를 관측하는 것이 보고되고 있고 또한 반응이 진행되고 있는 중에 분자구조를 하나하나 영상으로 관측하는 것이 연구되고 있다. 단백질 분자구조의 시간에 따른 변화와 용액 중 분자의 광반응에 따른 구조변화를 파악하고 있는데 이것은 시스템에 따라 펨토 초에서 초 단위까지 다양하고 광범위하게 고도의 시간분해능으로 계측할 수 있는 X선 측정기술이다.

데칸술폰이 삽입된 니켈 화합물의 층상 구조의 열적 성질 (Thermal behavior of the layered structure of decanesulfonate intercalated into the hydrated nickel compound)

  • 허영덕;전태현;박용준
    • 한국결정성장학회지
    • /
    • 제9권6호
    • /
    • pp.580-584
    • /
    • 1999
  • 수화된 니켈에 데칸술폰이 층간 삽입된 화합물을 합성한 후 성질을 확인하였다. 화합물의 층상구조는 고온 X-선 회절 데이터로 확인하였다. 온도가 증가하면 층간 삽입된 니켈화합물의 구조가 변하는 것과 동시에 화합물의 층 거리가 24.7 $\AA$에서 30.5 $\AA$가지 증가하였다. X-선 회절 데이터와 데칸술폰의 크기로부터 니켈 층에 결합된 데칸술폰의 공간배열을 결정하였다. 이중 층 구조를 가진 데칸술폰의 분자 축은 니켈 층에 경사진 각도로 수직하게 배열되어있다.

  • PDF

Correlation between composition and structure of PtxNiy alloy nanodendrites

  • Lee, Young-Woo;Kwak, Da-Hee;Park, Kyung-Won
    • 한국결정성장학회지
    • /
    • 제26권5호
    • /
    • pp.165-170
    • /
    • 2016
  • We have synthesized $Pt_xNi_y$ alloy nanodendrites by a thermal decomposition method. The structure and composition of the as-prepared samples were characterized by field-emission transmission electron microscopy (FE-TEM), energy dispersive X-ray (EDX) spectroscopy, and X-ray diffraction (XRD). The growth mode of the $Pt_xNi_y$ alloy samples synthesized as a function of an intended atomic fraction of Ni was likely to be strongly affected by and reduction (or oxidation) potentials and surface energy.

X-ray Scattering Studies for Phase Separated Composite Organic Films

  • Choi, H.;Eom, K.E.;Wang, Q.;Kumar, S.;Kim, J.H.;Shin, S.T.
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
    • /
    • pp.1229-1232
    • /
    • 2004
  • The ratio of optimized concentration on optical characteristics for phase-separated composite organic films (PSCOF) liquid crystal display is 30% of pre-polymer (NOA65) and 70% of ferroelectric liquid crystal (Felix). The layer structure in ferroelectric liquid crystal cell made by 30% NOA65 and 70% Felix materials is tilt-bookshelf layer structure. The angle of tilt-bookshelf structure are 17$^{\circ}$, 12$^{\circ}$ which are almost same of tilt angle of ferroelectric liquid crystal in Sm $C^{\ast}$ phase. We know that this result is from compensating the layer buckling. In this paper, we will discuss the effect of layer structure in PSCOF cell on ratio of concentration between pre-polymer and liquid crystal by x-ray measurements. We believe that technology of PSCOF is a good solution to solve the problems of align-defect and mechanical shock for future TV application and plastic LCD.

  • PDF

Crystal Structure Analysis of 3-(4-ethylphenyl)-3H-chromeno[4,3-c]isoxazole-3a(4H)-carbonitrile

  • Malathy, P.;Ganapathy, Jagadeesan;Srinivasan, J.;Manickam, Bakthadoss
    • 통합자연과학논문집
    • /
    • 제8권4호
    • /
    • pp.250-257
    • /
    • 2015
  • The crystal structure of the potential active 3-(4-ethylphenyl)-3H-chromeno[4,3-c]isoxazole-3a(4H)-carbonitrile ($C_{19}H_{16}N_2O_2$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group $P2_1/c$ with unit cell dimension a=6.6869 (8) ${\AA}$, b=15.8326 (19) ${\AA}$ and c= 15.237 (2) ${\AA}$ [${\alpha}=90^{\circ}$, ${\beta}=100.663^{\circ}$ and ${\gamma}=90^{\circ}$]. In the structure chromene, isoxazole and carboxylate are almost coplanar each other. All geometrical parameters revelled that chromene ring of pyran ring adopt sofa conformation. The crystal packing is stabilized by intermolecular C-H...N and C-H...O hydrogen bond interaction.

Crystal Structure Analysis of Methyl-3-phenyl-3H-chromeno[4,3-c]isoxazole-3a(4H)-carboxylate

  • Ganapathy, Jagadeesan;Srinivasan, J.;Manickam, Bakthadoss
    • 통합자연과학논문집
    • /
    • 제8권3호
    • /
    • pp.184-191
    • /
    • 2015
  • The crystal structure of the potential active methyl-3-phenyl-3H-chromeno[4,3-c]isoxazole-3a(4H)-carboxylate ($C_{18}H_{15}NO_4$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the orthorombic space group $P2_12_12_1$ with unit cell dimension $a=9.8320(17){\AA}$, $b=9.9890(18){\AA}$ and $c=15.588(3){\AA}$ [${\alpha}=90^{\circ}$, ${\beta}=90^{\circ}$ and ${\gamma}=90^{\circ}$]. In the structure chromene, isoxazole and carboxylate are almost coplanar each other. All geometrical parameters revelled that chromene ring of pyran ring adopt sofa conformation. The crystal packing is stabilized by intermolecular C-H...O and C-H...N hydrogen bond interaction.

X-線 廻折法을 利用한 벤지딘過鹽素酸鹽의 結晶構造에 關한 硏究 (II)結晶構造의 解析 (Studies on the Crystal Structure of Benzidine Perchlorate by X-ray Diffraction method (II) Crystal Structure Analysis)

  • 구정회;신현소;강만형
    • 대한화학회지
    • /
    • 제14권1호
    • /
    • pp.123-126
    • /
    • 1970
  • The approximate crystal structure of benzidine monoperchlorate has been determined by single crystal X-Ray diffraction technique and patterson method. As the molecule has a center of symmetry in it and location of perchlorate ion is symmetrically on the mirror plane in the unit cell, perchlorate ion is forming hydrogen bond with two -$NH_2$ groups in the different molecule. Thus, one molecule of benzidine and perchloric acid combines 1:1 by mole ratio.

  • PDF

The Crystal Structure of Fenbufen, 3-(4-biphenylylcarbonyl)propionic acid ($C_{16}H_{14}O_3$), A Non-steroidal Antiinflammatory Agent

  • Kim, Yang-Bae;Park, Il-Yeong;Park, Yang-Hwan
    • Archives of Pharmacal Research
    • /
    • 제11권2호
    • /
    • pp.127-133
    • /
    • 1988
  • The crystal structure of fenbufen was determined by X-ray diffraction techniuques. The compound was recrystallized in orthorhombic crystal system, space group $Pca2_1$ a = 31. 918(10), b = 5.550 (2), c = 15.078 (9) ${\AA}, D_m$= $1.26, {\D_x$= 1.264 g/$\textrm{cm}^3$, and Z = 8. The structure was solved by direct methods and refined by least squares procedure to the final R value of 0.051 for 1780 independent reflections. Two molecules in the asymmetric unit are related by a pseudo center of symmetry and dimerized via O-H...O hydrogen bonds. The carbonyl group attached to the phenyl ring is nearly coplanar to the ring. In the crystal the molecules are arranged in paralle stacks in the a direction.

  • PDF

반도체 HgCdTe의 전자 밀도 분포와 결정 구조 (The electron density distribution and the structure of semiconductor HgCdTe)

  • Kook-Sang Park;Ky-Am Lee
    • 한국결정성장학회지
    • /
    • 제4권4호
    • /
    • pp.388-394
    • /
    • 1994
  • 단결정 Hg(1-x)Cd(x)Te (MCT,X=0,21)가 특수 제작된 고압로에서 Traveling Heater Method(THM)으로 성장되었다.X-선 회절 실험으로 MCT는 입방ZnS 구조임을 확인하였다. 측정된 격자상수는 $6.464 {\AA}$이엇으며, J.C.Wooley가 측정한 값과 비교하여 얻은 MCT의 성분비는 0.21이었다.MCT의 결정 구조를 분석하기 위하여 X-선 회절 강도로 부터 전자 밀도를 계산하였다.전자 분포 밀도도로 부터 MCT는 주로 공유 결합을 하고 있으며, 인접 원자들 상에는 사면체 구조를 이루고 있음을 알 수 있다. 격자 상수가 Vegard line으로 부터 편이 되는 원인은 성분비x가 증가될 때 원자간 거리 변화의 비선형적 증가로 판단되며, 이것은 결합 에너지와 관련될 것으로 추축된다.

  • PDF

Crystal Structure Analysis of 6-Ethoxy-3-phenyl-5a,9a-dihydro-3H-chromen[4,3-c][1,2]oxazole-3a(4H)-carbonitrile

  • Malathy, P.;Sharmila, P.;Srinivasan, J.;Manickam, Bakthadoss;Aravindhan, S.
    • 통합자연과학논문집
    • /
    • 제9권2호
    • /
    • pp.94-102
    • /
    • 2016
  • The crystal structure of the potential active 6-ethoxy-3-phenyl-5a,9a-dihydro-3H-chromen[4,3-c][1,2]oxazole-3a(4H)-carbonitrile ($C_{19}H_{15}N_2O_3$) has been determined from single crystal X-ray diffraction technique. The title compound crystallizes in the monoclinic space group C2/c with unit cell dimension a= 29.3026(9) ${\AA}$, b= 6.7695(2) ${\AA}$ and c= 19.7597(6) ${\AA}$ [${\alpha}= 90^{\circ}$, ${\beta}= 125.709(10)^{\circ}$ and ${\gamma}= 90^{\circ}$]. Single crystals suitable for X-ray diffraction were obtained by slow evaporation method, the isoxazole and six membered pyran rings adopts envelope conformation. The crystal packing of the molecules is stabilized by the weak $C-H{\ldots}N$ hydrogen bond interaction.