• Title, Summary, Keyword: micro raman

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Application Study of Raman Micro-Spectroscopy for Analysis on Corrosion Compound of Iron Artifacts (철제유물 부식화합물 분석의 표준데이터 확보를 위한 라만 분광법 적용성 연구)

  • Park, Hyung Ho;Lee, Jae Sung;Yu, Jae Eun
    • 보존과학연구
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    • pp.89-98
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    • 2011
  • It is quite difficult to identify its corrosion compound because they have a wide variety of crystal structures and they are mixed with two component. This study was conducted with the standard iron corrosion compounds through the analysis by Raman Micro-Spectroscopy, which aims to obtain standard Raman Data. To assess the reliability of standard iron corrosion compounds, SEM-EDS analysis and XRD analysis were conducted. Through SEM-EDS analysis, the elements of corrosion compound matched with those of standards iron corrosion compounds except Goethite. XRD analysis showed that the structures of corrosion compounds were identical to those of standard iron corrosion compounds, however, it was identified that Iron sulfate ($FeSO_4{\cdot}6H_2O$) is the Rozenite ($FeSO_4{\cdot}4H_2O$). Through Raman Micro-Spectroscopy analysis, the new peak was detected from the wavenumbers of hydroxide and iron oxide. It is considered that it is due to changes in the wavelength of the laser. As the wavenumbers of iron chloride and iron sulfate have been identified, eight kinds of Raman Data were obtained. It can be considered to contribute to cultral heritage for iron objects that Raman Micro-Spectroscopy analysis which is relatively easy to compare material properties and structures can be highly applicable to the research on cultural heritage with the limited amount of samples.

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Micro-Raman Spectroscopy and Cathodoluminescence Study of Cross-section of Diamond Film

  • Wang, Chun-Lei;Akimitsu Hatta;Jaihyung Won;Jaihyung Won;Nan Jinang;Toshimichi Ito;Takatomo Sasaki;Akio Hiraki;Zengsun Jin
    • The Korean Journal of Ceramics
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    • v.3 no.1
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    • pp.1-4
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    • 1997
  • Diamond film (24$\mu\textrm{m}$) were prepared by Microwave Plasma Chemical Vapor Deposition method from a reactive CO/H$_2$ mixtures. Micro-Raman spectroscopy and micro-cathodoluminescence study were carried out along the crosssection and correlated to SEM observation. CL image of cross-section was also investigated. Peak position, FWHM of Raman spectrum were determined using Lorentzing fit. The stress in this sample is 0.4~0.7 GPa compressive stress, and along the distance the compressive stress reduced. The Raman peak broadening is dominated by phonon life time reduction at grain boundaries and defect sites. Defects and impurities were mainly present inside the film, not at Silicon/Diamond interface.

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Microstructural Analysis of Slags using Raman Micro Spectroscope

  • Park, Su Kyoung;Kwon, In Cheol;Lee, Su Jeong;Huh, Il Kwon;Cho, Nam Chul
    • Journal of Conservation Science
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    • v.35 no.2
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    • pp.145-152
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    • 2019
  • The metal-manufacturing method and smelting temperature of ancient metal-production processes have been studied by analyzing the principal elements and microstructures of slag. However, the microstructure of slag varies according to the solidification cooling rate and types and relative amounts of various oxides contained within the smelting materials. Hence, there is a need for accurate analysis methods that allow slag to be distinguished by more than its composition or microstructure. In this study, the microstructures of slag discharged as a result of smelting iron sands collected from Pohang and Gyeongju, as well as the slag excavated from the Ungyo site in Wanju, were analyzed by using metalloscopy, scanning election microscopy-energy dispersine X-ray spectroscopy(SEM-EDS) and wavelength dispersive X-ray fluorenscence(WD-XRF). Furthermore, the microcrystals were accurately characterized by performing Raman micro-spectroscopy, which is a technique that can be used to identify the microcrystals of slags. SEM-EDS analysis of Pohang slag indicated that its white polygonal crystals could be Magnetite; however, Raman micro-spectroscopy revealed that these crystals were actually $ulv{\ddot{o}}spinel$. Raman micro-spectroscopy and SEM-EDS were also used to verify that the coarse white dendritic structures observed in the Gyeongju-slag were $W{\ddot{u}}stites$. Additionally, the Wanju slag was observed to have a glassy matrix, which was confirmed by Raman micro-spectroscopy to be Augite. Thus, we have demonstrated that Raman micro-spectroscopy can accurately identify slag microcrystals, which are otherwise difficult to distinguish as solely based on their chemical composition and crystal morphology. Therefore, we conclude that it has excellent potential as a slag analysis technique.

Identification for the Vivid Yellow Diamonds (비비드 옐로우 다이아몬드의 감별 방안 연구)

  • Song, Jeongho;Yun, Yury;Song, Ohsung
    • Journal of the Korean Ceramic Society
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    • v.49 no.6
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    • pp.493-497
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    • 2012
  • We propose a new reliable, fast, and low cost identification method for similarly looking 0.3ct vivid yellow color of natural, HPHT treated, and synthesized diamonds. Conventional optical microscopy as well as low temperature PL(photoluminescence), FT-IR, UV-VIS-NIR, micro-Raman spectroscopy, and vibrating sample magnetometry(VSM) characterization were executed. We could not distinguish the natural diamonds from the treated or the synthesized stones with an optical microscopy, PL, FT-IR, and UV-VIS-NIR spectroscopy. However, we could identify the treated diamond with micro-Raman spectroscopy due to unique $1440cm^{-1}$ peak appearance. VSM revealed easily the synthesized diamond because of its ferromagnetic behavior. Our preliminary propose on employing the Micro-Raman spectroscopy and VSM might be suitable for identification of the similar looking vivid yellow colored diamonds.

Fabrication of micro carbon structures using laser-induced chemical vapor deposition and Raman spectroscopic analysis (레이저 국소증착에 의한 탄소 미세 구조물 제조 및 분광분석)

  • ;;J. Senthil Selvan
    • Journal of Korean Society of Laser Processing
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    • v.5 no.2
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    • pp.17-22
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    • 2002
  • Characteristics of micro carbon structures fabricated with laser-induced chemical vapor deposition (LCVD) are investigated. An argon ion laser (λ=514.5nm) and ethylene gas were utilized as the energy source and precursor, respectively. The laser beam was focused onto a graphite substrate to produce carbon deposit through thermal decomposition of the precursor. Average growth rate of a carbon rod increased for increasing laser power and pressure. Micro carbon rods with good surface quality were obtained at near the threshold condition. Micro carbon rods with aspect ratio of about 100 and micro tubular structures were fabricated to demonstrate the possible application of this method to the fabrication of three-dimensional microstructures. Laser Raman spectroscopic analysis of the micro carbon structures revealed that the carbon rods are consisting of amorphous carbon.

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Proton-Conducting Electrolyte $CsH_2PO_4$ for Intermediate-Temperature Fuel Cell

  • Park, Chi-Yeong;Lee, Su-Yeon;Jeon, Min-Hyeon;Lee, Gwang-Se;Kim, Jae-Hyeong;Kim, Jeong-Bae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.218-218
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    • 2007
  • 고체 전해질로서 $CsH_2PO_4$결정은 $230^{\circ}C$ 이상에서 전기전도도가 $10^{-2}\;{\Omega}^{-1}cm^{-1}$의 값에 도달하는 초양성자(Superprotonic) 상태로 상전이를 한다. 이러한 이유로 $CsH_2PO_4$ 결정은 $230^{\circ}C$ 부근에서 사용할 수 있는 연료전지로 개발되어왔다. 실용적인 면에서 단결정의 경우보다 다결정의 물성 및 응용 연구가 많았는데, 입자 크기에 따른 체계적인 연구는 잘 이루어지지 않았다. 본 발표에서는 $CsH_2PO_4$ 다결정을 합성하여 SEM 및 micro Raman spectra를 조사하였다. SEM의 결과 입자들의 평균 크기는 100 nm 이었으며, micro Raman spectra는 Bulk $CsH_2PO_4$의 spectra 와 큰 차이를 보이지 않았다. $PO_4$의 내부진동은 거의 같은 주파수대를 보여주나, $300\;cm^{-1}$이하의 저주파 수 영역에서는 광학적 포논의 픽이 잘 보이지 않았다. 그 원인이 micro Raman 장치의 측정 특성인지, 물리적 변화인지는 확실치 않다.

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Surface Graphite Formation of the Brown Colored Type I Diamonds During High Pressure Annealing (갈색 Type I 다이아몬드의 고압 열처리에 따른 표면 흑연화 생성 연구)

  • Song, Jeongho;Song, Ohsung
    • Journal of the Korean Ceramic Society
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    • v.49 no.6
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    • pp.614-619
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    • 2012
  • We investigated color and graphite layer formation on the surface of Type I tinted brown diamonds exposed for 5 minutes under a high-pressure high-temperature (HPHT) condition in a stable graphite regime. We executed the HPHT processes of Process I, varying the temperature from $1600^{\circ}C$ to $2300^{\circ}C$ under 5.2 GPa pressure for 5 minutes, and Process II, varying the pressure from 4.2 to 5.7 GPa at $2150^{\circ}C$ for 5 minutes. Optical microscopy and micro-Raman spectroscopy were used to check the microstructure and surface layer phase evolution. For Process I, we observed a color change to vivid yellow and greenish yellow and the growth of a graphite layer as the temperature increased. For Process II, the graphite layer thickness increased as the pressure decreased. We also confirmed by 531 nm micro-Raman spectroscopy that all diamonds showed a $1440cm^{-1}$ characteristic peak, which remained even after HPHT annealing. The results implied that HPHT-treated colored diamonds can be distinguished from natural stones by checking for the existence of the $1440cm^{-1}$ peak with 531 nm micro-Raman spectroscopy.

Ageing assessment of zirconia implant prostheses by three different quantitative assessment techniques

  • Kyaw, Phyu Phyu;Pongprueksa, Pong;Anuchitolarn, Warangkana;Sirinukunwatta, Krongkarn;Suputtamongkol, Kallaya
    • The Journal of Advanced Prosthodontics
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    • v.11 no.5
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    • pp.253-261
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    • 2019
  • PURPOSE. To evaluate the influence of cyclic loading on phase transformation of zirconia abutments and to compare the effectiveness of three different quantitative ageing assessment techniques. MATERIALS AND METHODS. Thirty two Y-TZP prostheses fabricated from two brands, InCoris ZI and Ceramill ZI, were cemented to titanium bases and equally divided into two subgroups (n=8): control group without any treatment and aged group with cyclic loading between 20 N and 98 N for 100,000 cycles at 4 Hz in distilled water at $37^{\circ}C$. The tetragonal-to-monoclinic phase transformation was assessed by (i) conventional x-ray diffraction (XRD), (ii) micro x-ray diffraction (${\mu}XRD$), and (iii) micro-Raman spectroscopy. The monoclinic-phase fractions (M%) were compared by two-way ANOVA. RESULTS. InCoris Zi presented significantly higher M% than Ceramill Zi in both control and aged groups (P<.001). Both materials exhibited significant phase transformation with monoclinicphase of 1 to 3% more in aged groups than controls for all three assessment techniques. The comparable M% was quantified by both ${\mu}XRD$ and XRD. The highest M% was assessed with micro-Raman. CONCLUSION. Cyclic loading produced significant phase transformation in tested Y-TZP prostheses. The micro-Raman spectroscopy could be used as an alternative to XRD and ${\mu}XRD$.

Tailoring and Control of The Micro (Nano) Structure of Functional CMSs and MMCs

  • Colomban
    • The Korean Journal of Ceramics
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    • v.5 no.1
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    • pp.55-72
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    • 1999
  • A cheallenge in the aerospace field is to design new composites satisfying specific and sometimes conflicting properties. The key steps are ⅰ)the understanding and the control of the reaction between the reinforcement and the embedding matrix, ⅱ) the achievement of a coherent and robust matrix. The problems encountered to prepare particulate, 1D, 2D and 3D reinforced composites using polymeric are discussed. Emphasis is given to the control of the micro/nanostructure using Raman microspectrometry and depth-sensing microindentation, in order to get information on the micromechanics and fiber structure simultaneously, within ceramic (CMC's) and metal matrix (MMC's) composites.

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Micro Raman Spectroscopic Analysis of Local Stress on Silicon Surface in Semiconductor Fabrication Process (반도체 제조 공정에서 실리콘 표면에 유입된 Stress의 마이크로 Raman 분광분석)

  • Son, Min Young;Jung, Jae Kyung;Park, Jin Seong;Kang, Sung Chul
    • Analytical Science and Technology
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    • v.5 no.4
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    • pp.359-366
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    • 1992
  • Using micro-Raman spectrometer, we investigated the evaluation of microstress on silicon surface after the local thermal oxidation. The induced stress of silicon surface after local thermal oxidation shows maximum value at the interface of silicon oxide and active area. The smaller the size of active area, the larger stress. From the evaluation of three other device isolation processes, A, B and moB, whose active size has $0.45{\mu}m$ in length, moB process is turned out to have the lowest stress value and the smallest bird's beak effect.

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