• 제목/요약/키워드: X-ray diffraction (XRD)

검색결과 2,660건 처리시간 0.039초

수중의 철 제거 시 생기는 산화철의 결정구조에 관한 연구 (On the Crystalline Structures of Iron Oxides formed During Removal Process of Iron in Water)

  • 조봉연
    • 대한토목학회논문집
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    • 제26권1B호
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    • pp.107-111
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    • 2006
  • 2종류의 제철 반응조에 있어서, 각종의 반응조건 하에 생성한 산화철을 x-ray회절과 M$\ddot{o}$ssbauer spectroscopy실험으로 철산화 물질을 동정한 결과, 여재 표면에 부착한 철 산화물의 결정은 pH 조건에 관계없이 Ferrihydrite($Fe_5HO_8{\cdot}4H_2O$)이었으며, Batch(회분) 실험에서 생긴 철 산화 물질은 가수분해에 의해 생긴 것으로, Microcrystalline Goethite 이었다.

해산 이매패류 패각의 CaCO3 결정 구조에 대한 X-ray 회절 분석 (Analysis of CaCO3 structure of marine bivalves using X-ray diffraction)

  • 남기웅;이승우;송재희;정희도;박경일
    • 한국패류학회지
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    • 제31권4호
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    • pp.279-283
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    • 2015
  • 본 연구는 해산 이매패 8종에 대해 패각 결정 (結晶)에 대한 분광학적 특성을 XRD 기법을 이용하여 조사하고 종간 근연관계에 대해 기존의 조사와 비교하였다. XRD분석을 수행한 결과, 바지락, 백합, 꼬막, 새조개의 패각은 $CaCO_3$의 orthorhombic 결정형인 aragonite였으며, 가리비와 굴의 패각은 trigonal-rhombohedral 결정형인 calcite였다. 담치와 키조개의 경우 aragonite와 calcite가 혼합된 결정으로 분석되었다. XRD를 이용하여 측정된 패각의 x-선 회절정보는 패류별 특이성을 나타내었으며, 이러한 특성을 이용한 과 (Family) 간 근연관계를 조사한 결과 현재 알려진 분류체계를 잘 대변하고 있었다. 결론적으로 패각 결정 (結晶)에 대한 분광학적 특성은 조사된 패류의 과 (Family) 수준에서 특이성을 잘 나타내며, 향후 종수준의 연구를 통한 종 동정을 위한 추가 연구가 필요함을 시사하였다. 또한 이러한 기술은 소량의 패각을 이용하므로 미확인 소량 절편의 패류 종 파악에 유용하게 이용될 수 있을 것으로 기대된다.

Structural and Electronic Properties of Cu-doped ZnO Thin Films by RF Sputtering Method

  • 이익재;성낙언;유청종;이한구;신현준;윤영덕
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.103-103
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    • 2011
  • The epitaxial Cu-doped ZnO and pure ZnO thin films were grown on Al2O3 (0001) substrates by RF sputtering method. The structures and crystallographic orientations were investigated using X-ray diffraction (XRD) and X-ray absorption spectroscopy. From the XRD pattern, it is observed that peak positions shift towards higher $2{\theta}$ value with Cu doping. The ${\omega}$-scan measurements at the (0002) diffraction peak for these samples reveal that the full-widths at half-maxima (FWHMs) are about $0.017-0.019^{\circ}$, which indicate a good c-axis orientation of the Zn1-xCuxO films. From phi-scan, all of the Zn1-xCuxO films were epitaxially grown. EXAFS measurements also demonstrated that Cu incorporated into a Zn-atom position substitutionally. All the results confirmed that copper ion were well incorporated into the ZnO lattices by substituting Zn sites without changing the wurtzite structure and no secondary phase existed in Cu-doped ZnO thin films.

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X-선 회절 패턴 측정과 투과 전자 현미경을 이용한 구리 나노분말의 수소 환원 처리 시 발생하는 미세조직 변화 및 치밀화 시편의 물성 분석 (Analysis of the Change in Microstructures of Nano Copper Powders During the Hydrogen Reduction using X-ray Diffraction Patterns and Transmission Electron Microscope, and the Mechanical Property of Compacted Powders)

  • 안동현;이동준;김우열;박이주;김형섭
    • 한국분말재료학회지
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    • 제21권3호
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    • pp.207-214
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    • 2014
  • In this study, nano-scale copper powders were reduction treated in a hydrogen atmosphere at the relatively high temperature of $350^{\circ}C$ in order to eliminate surface oxide layers, which are the main obstacles for fabricating a nano/ultrafine grained bulk parts from the nano-scale powders. The changes in composition and microstructure before and after the hydrogen reduction treatment were evaluated by analyzing X-ray diffraction (XRD) line profile patterns using the convolutional multiple whole profile (CMWP) procedure. In order to confirm the result from the XRD line profile analysis, transmitted electron microscope observations were performed on the specimen of the hydrogen reduction treated powders fabricated using a focused ion beam process. A quasi-statically compacted specimen from the nano-scale powders was produced and Vickers micro-hardness was measured to verify the potential of the powders as the basis for a bulk nano/ultrafine grained material. Although the bonding between particles and the growth in size of the particles occurred, crystallites retained their nano-scale size evaluated using the XRD results. The hardness results demonstrate the usefulness of the powders for a nano/ultrafine grained material, once a good consolidation of powders is achieved.

초미세 크기의 과염소산암모늄 결정체 제조 (Preparation of Ultra Fine Ammonium Perchlorate Crystals)

  • 김준형;임유진
    • 한국추진공학회지
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    • 제8권1호
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    • pp.1-7
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    • 2004
  • 과염소산암모늄(AP)의 N-메틸피롤리돈(NMP) 용액으로부터 초미세 크기를 갖는 과염소산암모늄(UFAP) 결정의 결정화 연구를 수행하였고, 침전된 결정들의 특성들을 scanning electron micrograph(SEM)와 X-ray diffraction(XRD) 그리고 thermogravimetric analysis(TGA)를 사용하여 분석하였다. 침전용매로 클로로포름, 염화메틸렌 그리고 톨루엔이 사용되었을 경우, 2$\mu\textrm{m}$ 이하의 크기를 갖는 결정들이 제조되었다. 제조된 UFAP의 결정학적 특성과 열분해 거동은 상용으로 사용되는 AP와 거의 유사하였다.

Bacteria를 이용한 연약한 흙의 고결화 가능성 (Possibility of cementation of soft soil using Bacteria)

  • 김대현;김호철;박경호
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 추계 학술발표회
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    • pp.379-391
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    • 2010
  • In order to understand the mechanism of cementation of soft soils treated with bacteria, three types of specimens(untreated, normal bacteria concentration treated, and high bacteria concentration treated) were made. Scanning Electron Microscope(SEM), EDX and X-ray diffraction(XRD) analyses were performed on the soft silt and loose sand specimens. Compared with the untreated specimen, a clearer cementation between particles was observed in the high bacteria concentration treated specimen. Based on the scanning electron microscope(SEM) EDX analyses, more calcium carbonate was observed in the specimen treated with high bacteria concentration than other specimens. On the basis of the preliminary results, it appears that microbial cementation can occur in the soft soil. Further study on the cementation of soils using bacteria is necessary to validate this result.

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PLD증착 변수에 따른 II-VI족 화합물 ZnO 반도체 박막의 발광 특성 연구 (Correlation Between Deposition Parameters and Photoluminescence of ZnO Semiconducting Thin Films by Pulsed laser Deposition)

  • 배상혁;윤일구;서대식;명재민;이상렬
    • 한국전기전자재료학회논문지
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    • 제14권3호
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    • pp.246-250
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    • 2001
  • ZnO thin films for light emission device have been deposited on sapphire and silicon substrates by pulsed laser deposition technique(PLD). A Nd:YAG laser was used with the wavelength of355 nm. In order to investigate the emission properties of ZnO thin films, Pl measurements with an Ar ion laser a light source using an excitation wavelength of 351 nm and a power of 100 mW are used. All spectra were taken at room temperature by using a grating spectrometer and a photomultiplier detector. ZnO exhibited Pl bands centers around 390, 510 and 640 nm, labeled near ultra-violet(UV), green and orange bands. Structural properties of ZnO thin films are analyzed with X-ray diffraction(XRD).

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Study on Improvement of Diamond Deposition on Al2O3 Ceramic Substrates by a DC Arc Plasmatron

  • Kang, In-Je;Joa, Sang-Beom;Chun, Se-Min;Lee, Heon-Ju
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.457-457
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    • 2012
  • We presented plasma processing using a DC Arc Plasmatron for diamond deposition on Al2O3 ceramic substrates. Plasma surface treatments were conducted to improve deposition condition before processing for diamond deposition. The Al2O3 ceramic substrates deposited, $5{\times}15mm^2$, were investigated by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD). Properties of diamond (111), (220) and (311) peaks were shown in XRD. We identified nanocrystalline diamond films on substrates. The results showed that deposition rate was approximately $2.2{\mu}m/h$ after plasma surface treatments. Comparing the above result with a common processing, deposition rate was improved. Also, the surface condition was improved more than a common processing for diamond deposition on Al2O3 ceramic substrates.

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스퍼터링을 이용한 $YMnO_3$/Si(100) 구조의 제작 (Fabrication of $YMnO_3$/Si(100) Structures by RF Magnetron Sputtering)

  • 김진규;김채규;정순원;김용성;이남열;김광호;유병곤;이원재;유인규
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 추계학술대회 논문집
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    • pp.429-432
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    • 1999
  • The growth of $\textrm{YMnO}_3$ films directly on Si(100) substrates by RF magnetron sputtering system has been performed. The structural properties of $\textrm{YMnO}_3$ films on Si(100) by rapid thermal annealing(RTA) analysed by XRD(X-ray diffraction). The c-axis oriented $\textrm{YMnO}_3$ peaks were observed deposited in $\textrm{YMnO}_3$/Si(100) structure at RF power of 100W and at a temperature range of $840^{\circ}C$~$870^{\circ}C$ in oxygen ambient.

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펄스 레이저 증착법으로 제작한 ZnO 박막의 발광 특성 (Light emission properties of ZnO thin films grown by pulsed laser deposition)

  • 배상혁;이상렬
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.539-542
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    • 2000
  • ZnO thin films for light emission device have been deposited on sapphire and silicon substrates by pulsed laser deposition technique(PLD). A Nd:YAG laser was used with the wavelength of 355 nm. In order to investigate the emission properties of ZnO thin films, PL measurements with an Ar ion laser as a light source using an excitation wavelength of 351 nm and a power of 100 mW are used. All spectra were taken at room temperature by using a grating spectrometer and a photomultiplier detector. ZnO exhibited PL bands centered around 390, 510 and 640 nm, labeled near ultra-violet (UV), green and orange bands. Structural properties of ZnO thin films are analized with X-ray diffraction (XRD).

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