• Title/Summary/Keyword: X-ray diffraction patterns

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

  • Kook-Sang Park;Ky-Am Lee
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.4 no.4
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    • pp.388-394
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    • 1994
  • A Hg(0.79)Cd(0.21)Te single crystal has been grown by the Traveling Heater Method(THM). Its zinc blend cubic structure is identified from the X-ray diffraction patterns and its lattice constant is determined to be $6.464 {\AA}$ using the least-square method of Cohen. From the values of the lattice constant, the composition x is determined to be 0.21. The electron density is calculated from the relative intensities of the scattered X-ray and compared with the theoretically calculated values. From the electron density distribution, it is shown that the crystal binding of Hg(1-x)Cd(x)Te(MCT) is mainly covalent and has tetrahedron bonds between adjacent atoms.

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Effects of Superstructure on Electronic Properties of Polyethylene (Polyethylene의 전자물성(電子物性)에 미치는 고차구조(高次構造)의 효과(效果))

  • Park, Dae-Hee;Kim, Dong-Wook;Kang, Sung-Hwa;Lee, Kee-Joe
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1993.05a
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    • pp.55-58
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    • 1993
  • In this paper, the relationship between trap properties and the molecular orientation owing to elongation was investigation from TSC, electrical conductivity and X-ray diffraction was investgated. The changes of the stretching direction, from an a-axis orientation(at low elongation) to a c-axis orientation(at high elongation), as the elongation increases. were determined from X-my diffraction patterns. These results suggest that the tendency for a decrease in the trap density at a higher elongation is consistent with a continuous change of the reorientation from the a-axis to the c-axis as the elongation increases.

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Effect of Cu substitution on Superconductivity in $(Ru_{1-x}Cu_x)Sr_2(Eu_{1.34}Ce_{0.66})Cu_2O_z$ System (Cu 치환에 따른 $(Ru_{1-x}Cu_x)Sr_2(Eu_{1.34}Ce_{0.66})Cu_2O_z$ 계의 초전도 특성)

  • Lee, H.K.
    • Progress in Superconductivity
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    • v.11 no.1
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    • pp.67-71
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    • 2009
  • The effect of Cu substitution on the structural and superconducting properties of the $(Ru_{1-x}Cu_x)Sr_2(Eu_{1.34{\cdot}}Ce_{0.66})Cu_2O_z$ system with x = 0, 0.25 and 0.5 prepared under ambient pressure have been investigated. The X-ray diffraction patterns indicated that the Ru ions are replaced by the Cu ions. It is found that the Cu substitution for Ru significantly reduces the ferromagnetic component of field-cooled magnetic susceptibility, but results in a small change in diamagnetic onset transition temperature of zero-field-cooled magnetic susceptibility. In contrast to the Ru $Sr_2(Eu_{1.34{\cdot}}Ce_{0.66})Cu_2O_z$, bulk Meissner effect is observed in the field-cooled magnetization measurements of the Cu doped samples. The experimental results are discussed in connection with the spontaneous vortex phase interpretation.

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Physicochemical Properties of Cross-linked Apios Starch (가교결합 아피오스 전분의 이화학적 특성)

  • Park, Mi Hye;Kim, Meera
    • Journal of the East Asian Society of Dietary Life
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    • v.24 no.3
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    • pp.400-406
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    • 2014
  • Apios (Apios americana Medikus) belongs to Leguminosae and is called 'American groundnut', 'Potato bean', and 'wild bean'. Apios is native to the Northern United States but is not widely distributed in Korea. In this study, cross-linked apios starch was prepared by reaction with epichlorohydrin, followed by characterization. FT-IR spectroscopy confirmed the degree of cross-linking of apios starch. X-ray diffraction patterns of native apios showed typical 'A' type as peaks at 15.1, 17.1, 17.9 and $23.2^{\circ}$, and cross-linking did not affect relative crystallinity and X-ray diffraction patterns of the starch. Scanning electron micrographs showed that apios starch granules were smooth with a globular shape, and there was little damage to starch granules after cross-linking. The lightness value of cross-linked apios starch was lower than that of native apios starch, whereas the redness value was not significantly different between cross-linked apios starch and native apios starch. Blue value showed that cross-linking of starch did not affect the iodine reaction of starch.

Deposition Characteristics of AlN Thin Films Prepared by RF Magnetron Sputtering (RF 마그네트론 스퍼터링에 의해 제조된 AlN 박막의 증착 특성)

  • Song, Jong-Han;Chun, Myoung-Pyo;Choi, Duck-Kyun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.12
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    • pp.969-973
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    • 2012
  • AlN thin films were deposited on p-type Si(100) substrates by RF magnetron sputtering method. This study showed the change of the preferential orientation of AlN thin films deposition with the change of the deposition conditions such as sputtering pressure and Ar/N2 gas ratio in chamber. It was identified by X-ray diffraction patterns that AlN thin film deposited at low sputtering pressure has a (002) orientation, however its preferred orientation was changed from the (002) to the (100) orientation with increasing sputtering pressure. Also, it was observed that the properties of AlN thin films such as thickness, grain size and surface roughness were largely dependent on Ar/$N_2$ gas ratio and a high quality thin film could be prepared at lower nitrogen concentration. AlN thin films were investigated relationship between preferential orientation and deposition condition by using XRD, FE-SEM and PFM.

The Austempering Transformation Behavior of Fe-0.7wt.%C-2.3wt.%Si-0.3wt.%Mn Steel (Fe-0.7wt.%C-2.3wt.%Si-0.3wt.%Mn 강의 오스템퍼링 변태 거동)

  • Shin, Sang-Yun;Lee, Do-Hoon;Kim, Seo-Eun;Ye, Byung-Joon
    • Journal of Korea Foundry Society
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    • v.34 no.1
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    • pp.1-5
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    • 2014
  • The austempering transformation behavior in Fe-0.7wt.%C-2.3wt.%Si-0.3wt.%Mn steel is investigated. Each specimen was austenitized for 60 min at $900^{\circ}C$, and austempered at $380^{\circ}C$ for different time periods varying from 2 min to 256 min. After the austempering heat treatment, the Stage I and II evolutions are performed using optical metallography, X-ray diffraction and image analyses. Variations in the X-ray diffraction patterns and lattice parameters of the ferrite and austenite demonstrate that the residual austenite decomposes into ferrite and carbide during the Stage II evolution; moreover the amount of ferrite increases during the Stage I evolution. While the amount of austenite increases during Stage I, it dicreases during Stage II. Overall, the variations in the volume fractions of the microstructure and carbide formation in stages I and II meet high temperature austempering reaction of the ausferrite microstructure.

Structural characterization of Pt/Co modulated films by X-ray diffraction (X선회절에 의한 Pt/Co 인공격자 다층막의 구조평가)

  • 김찬욱;조남웅
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.7 no.2
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    • pp.341-348
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    • 1997
  • X-ray diffraction patterns of Pt/Co modulated films prepared by RF comagnetron sputtering method was investigated. Modulated films ([$Pt10.7\AA/Co2.8{\AA}{\times}{12}$]) were deposited on glass substrate with various sputtering conditions : sputtering with variations of gas pressures, sputtering with Xe instead Ar gas, and etching of the buffer layers. In order to obtain the structural information of Pt/Co modulated films, the structural model was constructed and calculated data of the model were compared with experimental ones. Comparison results showed that there were good agreements in satellite peak position and its intensity between them. This suggests that the realistic Pt/Co modulated film can be reproduced by our structure model.

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Copper, aluminum based metallization for display applications (표시소자 응용을 위한 copper, aluminum 박막의 성장과 특성)

  • 김형택;배선기
    • Electrical & Electronic Materials
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    • v.8 no.3
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    • pp.340-351
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    • 1995
  • Electrical, physical and optical properties of Aluminum(Al), Copper(Cu) thin films were investigated in order to establish the optimum sputtering parameters in Liquid Crystal Display (LCD) panel applications. DC-magnetron sputtered film on coming 7059 samples were fabricated with variations of deposition power densities, deposition pressures and substrate temperatures. Low resistivity films(AI;2.80 .mu..ohm.-cm, Cu:1.84 .mu..ohm-cm),which lower than the reported values, were obtained under sputtering parameters of power density(250W), substrate temperature(450-530.deg. C) and 5*10$\^$-3/ Torr deposition pressure. Expected columnar growth and stable grain growth of both films was observed through the Scanning Electron Microscope(SEM) micrographs. Dependency of the applicable defect-free film density upon depositon power and temperature was also characterized. Not too noticable variations in X-ray diffraction patterns were remarked under the alterations of sputtering parameters. High optical reflectivities of Al, Cu films, approximately 70-90 %, showed high degree of surface flatness.

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Crystal Structure and Optical Absorption of ZnO Thin Films Grown by Electrodeposition (전착법에 의한 ZnO 박막의 결정구조 및 광흡수 특성)

  • Choi, C.T.;Seo, J.N.
    • Journal of Sensor Science and Technology
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    • v.9 no.6
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    • pp.455-460
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    • 2000
  • Zinc oxide(ZnO) thin films were cathodically deposited on ITO glass from an aqueous zinc nitrate electrolyte. Three main fabrication parameters were taken into account : deposition potential, solution concentration and growth temperature. Different layers of ZnO thin films grown by varying the three parameters were studied by X-ray diffraction, scanning electron microscope and optical absorption spectroscopy. The prepared ZnO thin films were shown as a hexagonal wurtzite structure on the X-ray diffraction patterns and the good quality of ZnO thin films were obtained by potentiostatic cathodic deposition at -0.7V vs. Ag/AgCl reference electrode onto ITO glass from aqueous 0.1 mol/liter zinc nitrate electrolyte at $60^{\circ}C$.

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Distribution of Pr ions in $Y(Ba_{1-Xn}Pr_{Xn})_2Cu_3O_y$

  • Ha, Dong-Han;Lee, Kyu-Won;Kim, Jin-Tae;Park, Yong-Ki;Park, Jong-Chul
    • Progress in Superconductivity
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    • v.1 no.2
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    • pp.135-140
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    • 2000
  • Distribution of Pr ions between Y- and Ba-site of the $Y(Ba_{1-Xn}Pr_{Xn})_2Cu_3O_y$ ($0{\leq}Xn{\leq}{0.3}$, Xn : nominal composition) material prepared by the solid state reaction method was studied. Although the samples have narrow superconducting transition, tiny peaks of $Y_2BaCuO_5$ impurity phase are included in the x-ray diffraction patterns suggesting that some of the Pr ions are entered into the Y-site. The distribution of Pr ions between Y- and Ba-site was determined by measuring the mass fraction of YBCO and $Y_2BaCuO_5$ phase for each sample through the Rietveld analysis of the x-ray diffraction data. About 60 % of Pr ions occupy the Y-site regardless of the Pr content. Various superconducting parameters such as the oxygen content and the hole concentration etc. are compared before and after the impurity correction.

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