• Title/Summary/Keyword: XRD Diffraction

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Asbestos Determination of Some Domestic Building-Materials Using X-ray diffraction (국내 건축자재에 함유된 석면의 함량에 대한 X-선회절분석 연구)

  • Hwang, Jin-Yeon;Lee, Hyo-Min;Oh, Ji-Ho;Park, Gi-Nam
    • Journal of the Mineralogical Society of Korea
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    • v.24 no.2
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    • pp.119-131
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    • 2011
  • The asbestos contents in some representative building materials were analyzed using JIS (Japanese Industrial Standard) X-ray diffraction (XRD) method. The changes in mineral composition during analysis process and problems in JIS method were also examined. XRD analysis of some representative domestic building materials used for roof, wall, ceiling, and floor indicates that slate have the highest asbestos content having 6.87~6.93% of chrysotile. Other building materials analyzed in this study also have 1.35~3.98% of chrysotile contents. The XRD analysis results of asbestos contents in some domestic building materials are presented in this study. This method is very effective for the asbestos content evaluation of building materials according to newly modified asbestos content regulation (Law of Industrial Safety and Health, 2007-26) that limits asbestos content less than 0.1% by Ministry of Employment and Labor. Small amount of tremolite as well as chrysotile were also observed in some samples. With consideration of crystal shape, contents and geological occurrence, it is considered that tremolite is an associated mineral of chrysotile and is not intentionally added. Complemental analyses with optical microscope and SEM/EDS are also necessary because XRD method cannot distinguish asbestiform from non-asbestiform. The XRD method applied in this study is very effective in the asbestos content analysis of building materials, specially building materials showing high asbestos concentration in residues due to the high loss rate with ashing and acid dissolution procedure.

마이크로볼로미터를 위한 VOx-ZnO 다층 박막의 XRD 특성 연구

  • Mun, Su-Bin;Han, Seok-Man;Kim, Dae-Hyeon;Kim, Hyo-Jin;Sin, Jae-Cheol;Jang, Won-Geun;Han, Myeong-Su
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.234-234
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    • 2013
  • VOx 박막은 마이크로볼로미터 적외선 센서의 감지재료로 주로 사용된다. 일반적으로 VOx 박막은 RF sputtering 방법으로 증착이 되며, 이 때 저항 값은 수 kohm~수 Mohm, TCR 값은 -1.5~-2.0%/K까지 다양하게 변화되어 나타난다. 이는 산소의 phase가 여러가지로 변화되기 때문에 재현성이 떨어지는 단점이 있으며, 결정성있는 박막을 증착하기 어려운 문제들이 있다. 본 연구에서는 VOx 박막의 재현성 및 재료의 안정성을 위해 ZnO 물질을 첨가하여 sandwich 구조의 나노박막을 증착하여 산소 열처리를 통해 산소의 phase가 어떻게 변화되는가를 XRD 측정을 통해 조사하였다. ZnO 나노박막을 첨가함으로써 갓 증착되었을 때의 XRD는 V2O5 주된 상을 이루고 있었으며, 산소열처리에 의해 VO2상이 나타남을 알 수 있었다. 또한 V2O5 phase가 표면쪽의 얇은 층에서 주로 나타나고, 중간층은 V2O5와 VO2 phase 가 혼합된 형태로 존재함을 X-ray diffraction 분석을 통해 알 수 있었다. 또한 GIXRD 측정을 통해 깊이에 따른 혼합 phase가 주로 VO2에 의해 형성된 것임을 확인할 수 있었다. 또한 산소열처리의 온도 및 시간에 따라 XRD 특성을 조사하였으며, 최적의 열처리 조건을 XRD 피크를 통해 찾고자 하였다.

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The application of a chemical assessment of archaeological animal bone by Fourier transform infrared spectroscopy and x-ray diffraction (FTIR과 XRD를 이용한 출토 동물뼈의 화학적 평가 적용)

  • Kang, Soyeong;Cho, Eun Min;Kim, Sue Hoon;Kim, Yun-Ji;Lee, Jeongwon
    • Analytical Science and Technology
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    • v.27 no.6
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    • pp.300-307
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    • 2014
  • For the application of chemical assessment standards by the extent of diagenetic alteration, we investigated three archaeological animal bones and a modern animal bone using Fourier transform infrared-attenuated total reflection (FTIR-ATR) spectroscopy and x-ray diffraction (XRD) analysis. The calculating results of crystallinity index (CI), carbonate-to-phosphate (C/P) and carbonate-to-carbonate (C/C) using FTIR-ATR spectra showed differences CI and C/P according to the preservative condition of animal bones. By comparison of the crystallinity contents using XRD patterns, the states of animal bones were distinguished to the range of $30^{\circ}-35^{\circ}$. As results of FTIR-ATR and XRD analysis, it is suggested that Mongolian large mammals bone presents the best preservative condition, and cattle bone from Naju site, and Haman site followed. In addition, those were correlated with the results of histological index. The results suggested that the chemical assessment standards may contribute to application of predictions of the states of animal bones discovered from Korea.

Detail analysis of the peak disappearance of minor phase in mechanically alloyed samples(II) (기계적 합금화 시료에서 미소상 피이크의 소멸현상 해석(II))

  • Kim, Hye-Sung
    • Journal of the Korean Society of Industry Convergence
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    • v.4 no.1
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    • pp.27-34
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    • 2001
  • Refining of powder particles and their dissolution into the Al matrix during mechanical alloying(MA) were investigated by using X-ray diffraction(XRD) transmission electron microscopy (TEM) functions of alloy composition, milling time and ball to powder ratio(BPR). It is found that Ti particles less than 20nm are observed in a dark field image of mechanically alloyed Al-10wt%Ti whose XHD pattern exhibits no Ti peak. The observed change of lattice constant of AI indicates that about 1 wt%Ti can he solved in Al after MA for a long time, independent of alloy composition, milling time and BPR, suggesting that most of Ti particles arc retained in the Al matrix. It is concluded that the disappearance of XRD peaks in mechanically alloyed Al-10wt%Ti is not simply attributable to the dissolution of Ti into Al, but associated mainly with extreme refining and/or heavy straining of Ti Particles.

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Study on the Evaluation for the Property of Mo-Si Multilayers (Mo/Si 다층박막의 특성 평가에 관한 연구)

  • 허성민;김형준;이동현;이승윤;이영태
    • Journal of the Microelectronics and Packaging Society
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    • v.8 no.2
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    • pp.15-18
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    • 2001
  • The Mo/si multilayer for EUV lithography was deposited using magnetron sputtering system. The multilayers were characterized using the cross-sectional transmission electron microscope (TEM) and low/high angle X-ray diffraction (XRD). The microstructure of Mo and Si was highly textured structure and amorphous, respectively. The well-defined low angle XRD peaks implies a well-defined multilayer structure. The interfacial layer of Mo-on-Si was thicker than Si-on-Mo interfacial layer.

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XRD and Image Analyis of Low Carbon Type Recycled Cement Using Waste Concrete Powder (폐콘크리트 미분말을 이용하여 제조한 저탄소형 클링커의 XRD 및 영상분석)

  • Shin, Hyeon-Uk;Song, Hun;Chu, Yong-Sik;Lee, Jong-Kyu;Park, Dong-Cheon
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.252-253
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    • 2014
  • This study is to XRD and image analysis of low carbon type recycled cement from waste concrete powder and cement raw materials. Waste concrete powder possible to low carbon type recycled cement in small part of additive materials. Also, low carbon type recycled cement using waste concrete powder is suitable for ordinary portland cement.

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Determination of temperature and flux variations during ultra-thin InGaN quantum well growth on a 2" wafer for GaN Green LED

  • Kim, Hyo-Jeong;Kim, Min-Ho;Jeong, Hun-Yeong;Lee, Hyeon-Hwi
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.149-149
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    • 2010
  • The origin of the inhomogeneous distribution of photoluminescence (PL) peak wavelength on a commercial 2" GaN wafer for green light emitting diode has been investigated by wide momentum transfer (Q) range x-ray diffraction (XRD) profile of InGaN/GaN multiple quantum wells. Near the GaN (0004) Bragg peak, wide-Q range XRD (${\Delta}Q$ > $1.4{\AA}-1$) was measured along the growth direction. Wide-Q XRD gives precise and direct information of ultra-thin InGaN quantum well structure. Based on the QW structural information, the variation of PL spectra can be explained by the combined effect of temperature gradient and slightly uneven flow of atomic sources during the QW growth. In narrow variations of indium composition and thickness of QW, an effective indium composition can be a good character to match structural data to PL spectra.

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Activation energy for the loss of substitutional carbon in $Si_{0.984}C_{0.016}$ grown by solid phase epitaxy

  • Kim, Yong-Jeong;Kim, Tae-Joon;Park, Byungwoo;Song, Jong-Han
    • Journal of Korean Vacuum Science & Technology
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    • v.4 no.2
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    • pp.50-54
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    • 2000
  • We studied the synthesis of S $i_{1-x}$ Cx (x=0.016) epitaxial layer using ion implantation and solid phase epitaxy (SPE). The activation energy Ea was obtained for the loss of substitutional carbon using fourier transform-infrared spectroscopy (FTIR) and high-resolution x-ray diffraction (HR-XRD). In FTIR analysis, the integrated peak intensity was used to quantify the loss of carbon atoms from substitutional to interstitial sites during annealing. The substitutional carbon contents in S $i_{0.984}$ $C_{0.016}$ were also measured using HR-XRD. By dynamic simulations of x-ray rocking curves, the fraction of substitutional carbon was obtained. The effects of annealing temperature and time were also studied by comparing vacuum furnace annealing with rapid thermal annealing (RTA))))))

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Analysis of crystalline structure of autogenous tooth bone graft material: X-Ray diffraction analysis (자가치아골이식재의 결정구조 분석: X선 회절 분석)

  • Kim, Gyung-Wook;Yeo, In-Sung;Kim, Su-Gwan;Um, In-Woong;Kim, Young-Kyun
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.37 no.3
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    • pp.225-228
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    • 2011
  • This study evaluated the mineral crystalline structure of an autogenous tooth bone graft material. The crystalline structures of the autogenous tooth bone graft material enamel (AutoBT E+), dentin (AutoBT D+), xenograft (BioOss), alloplastic material (MBCP), allograft (ICB) and autogenous mandibular cortical bone were compared using XRD. The XRD pattern of AutoBT dentin and ICB was similar to that of autogenous bone.

Facile Hydrothermal Synthesis and Characterization of the $CeO_2$ Nanorings

  • Arul, N. Sabari;Kim, Tae Whan;Mangalaraj, Devanesan
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.455-455
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    • 2013
  • $CeO_2$ nanorings were synthesized by using a surfactant free hydrothermal method. The surface morphology, structural and optical properties of the synthesized $CeO_2$ was investigated by using scanning electron microscopy (SEM), X-ray diffraction (XRD), and ultraviolet-visible (UV) spectroscopy measurements. SEM images showed that the surface morphology of the formed $CeO_2$ appeared as nanorings. The XRD pattern of $CeO_2$ nanorings showed the presence of the polycrystalline $CeO_2$ phase readily indexed to the cubic fluorite structure of the $CeO_2$. The mean crystallite size of the $CeO_2$ was calculated using the Scherrer equation from the XRD line broadening of the (111) planes of the cubic $CeO_2$. The UV-Visible spectroscopy spectrum of the $CeO_2$ nanorings exhibited a strong UV absorption band around 350 nm.

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