• Title/Summary/Keyword: X-ray diffraction(XRD)

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

  • Nam, Ki-Woong;Lee, Seng-Woo;Song, Jae-Hee;Jeung, Hee-Do;Park, Kyung-Il
    • The Korean Journal of Malacology
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    • v.31 no.4
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    • pp.279-283
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    • 2015
  • This study investigated spectroscopic characteristics of shell crystals of eight marine bivalve species using X-ray diffraction (XRD) analysis; moreover, the Family level relatedness of shellfish was investigated. In XRD analysis, the shells of Ruditapes philippinarum, Meretrix lusoria, Anadara granosa, and Fulvia mutica were found to have orthorhombic aragonite $CaCO_3$ crystals, while shells of Patinopecten yessoensis and Crassostrea gigas had trigonal-rhombohedral calcite crystals. The shells of Mytilus coruscus and Atrina pectinata were determined to have a mixture of aragonite and calcite crystals. XRD information revealed the Family level-specific characteristics of shellfish; the results agreed with the current taxonomic system. In conclusion, spectroscopic characteristics of shell crystals indicated Family-level characteristics of shellfish and suggested a more intense species-level investigation; this technology may be useful in identifying shellfish species using small quantities of shells.

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

  • Lee, Ik-Jae;Seong, Nak-Eon;Yu, Cheong-Jong;Lee, Han-Gu;Sin, Hyeon-Jun;Yun, Yeong-Deok
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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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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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 (X-선 회절 패턴 측정과 투과 전자 현미경을 이용한 구리 나노분말의 수소 환원 처리 시 발생하는 미세조직 변화 및 치밀화 시편의 물성 분석)

  • Ahn, Dong-Hyun;Lee, Dong Jun;Kim, Wooyeol;Park, Lee Ju;Kim, Hyoung Seop
    • Journal of Powder Materials
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    • v.21 no.3
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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.

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

  • 김준형;임유진
    • Journal of the Korean Society of Propulsion Engineers
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    • v.8 no.1
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    • pp.1-7
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    • 2004
  • The precipitation of ultra fine ammonium perchlorate(UFAP) crystals from the N-methyl pyrrolidone(NMP) solutions of ammonium perchlorate(AP) was studied. The characteristics of the precipitated crystals were investigated by means of scanning electron micrograph(SEM), X-ray diffraction(XRD), and thermogravimetric analysis(TGA). When chloroform, methylene chloride and toluene were the precipitants, the product crystals had a mean particle size less than 2$\mu\textrm{m}$. The crystallographical property and thermal decomposition behavior of the prepared UFAP were almost the same as those of the commercial AP.

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

  • Kim, Dae-Hyeon;Kim, Ho-Chul;Park, Kyoung-Ho
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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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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Correlation Between Deposition Parameters and Photoluminescence of ZnO Semiconducting Thin Films by Pulsed laser Deposition (PLD증착 변수에 따른 II-VI족 화합물 ZnO 반도체 박막의 발광 특성 연구)

  • 배상혁;윤일구;서대식;명재민;이상렬
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.3
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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
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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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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Fabrication of $YMnO_3$/Si(100) Structures by RF Magnetron Sputtering (스퍼터링을 이용한 $YMnO_3$/Si(100) 구조의 제작)

  • 김진규;김채규;정순원;김용성;이남열;김광호;유병곤;이원재;유인규
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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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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Light emission properties of ZnO thin films grown by pulsed laser deposition (펄스 레이저 증착법으로 제작한 ZnO 박막의 발광 특성)

  • 배상혁;이상렬
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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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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RF Power dependence in $YMnO_3$/Si(100) Structures ($YMnO_3$/Si(100) 구조의 RF Power 의존성)

  • 김진규;정순원;김용성;이남열;정상현;김광호;유병곤;이원재;유인규
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.755-758
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    • 2000
  • YMnO$_3$films have been deposited with different Rf powers of 60W, 80W, 100W, and 120W. The structural properties of YMnO$_3$films on Si(100) were analysed by XRD(X-ray diffraction). The c-axis oriented peaks of YMnO$_3$were observed deposited in YMnO$_3$/Si(100) structure of RF power at 87$0^{\circ}C$ in oxygen ambient, and the peaks were enlarged by increasing The RF powers. The dielectric constant of the film deposited at 100W and 120W of RF power were about 19, 20 respectively.

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