• Title/Summary/Keyword: Raman spectroscopy

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Aggregation of Polyynes on Metal Nanoparticles

  • Kim, Kuk-Ki;Shin, Seung-Keun;Park, Seung-Min
    • Bulletin of the Korean Chemical Society
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    • v.33 no.2
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    • pp.625-628
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    • 2012
  • We investigated the interaction between polyynes (linear carbon chains) and various metal nanoparticles (Ag, Au, and Cu) to provide insight into the optical properties of metal-polyynes systems prepared by different experimental techniques. Polyynes were produced by laser ablation in deionized water, metal nanoparticles solutions, and copper chloride solution. Metal nanoparticles complexes with polyynes were analyzed by Raman, surface-enhanced Raman scattering, and UV-vis spectroscopy.

Interfacial Charge and Mass Transfer at Graphene-SiO2 Substrates: Raman Spectroscopic Studies

  • Ryu, Sun-Min
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.115.1-115.1
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    • 2014
  • Atom-thick 2-dimensional materials such as graphene, h-BN and MoS2 hold substantial potential for applications in future molecular-scale integrated electronics, transparent conducting membranes, nanocomposites, etc. From a fundamental point of view, 2-dim crystal-solid substrates can also serve as a unique system to study various physicochemical phenomena occurring at low dimensions or interfaces. In this talk, I will present our recent Raman spectroscopy studies on the surface science problems of graphene: interfacial charge transfer, molecular diffusion in confined space and structural deformation.

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The Effect of Laser on Silicon thin film measurement in Raman spectroscopy

  • Lee, Yeong-Ju;Park, Seong-Gyu;Gwon, Jeong-Dae;Kim, Dong-Ho;Jeong, Yong-Su
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2012.05a
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    • pp.249-250
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    • 2012
  • Raman spectroscopy는 미세결정질 실리콘 박막의 분석에 널리 사용되고 있으며 특히, 측정 자료를 통해 미세결정질 분율을 알아낼 수 있다. Raman 측정 시 조사되는 laser의 특성에 따라 박막시편 측정값에 일련의 변화가 나타나는 것을 알 수 있었다.

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The Study of Two-dimensional Chemical Distribution about Soil using Laser Spectroscopy (레이저 분광법을 활용한 토양 2차원 화학적 분포도 검출 연구)

  • Yang, Jun-Ho;Yoh, Jai-Ick
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.45 no.6
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    • pp.523-530
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    • 2017
  • Laser-Induced Breakdown Spectroscopy (LIBS) which a plasma is irradiated at a specific wavelength depending on the material when a high-energy laser is irradiated, and a Raman spectroscopy which measures rotation and vibration in molecules as light-scattering phenomenon occurs, are attracting attention as a space exploration technology because of the advantages of high accuracy and real-time analysis, and the ability to perform long-range detection. In this study, the tendency of the laser spectrum according to the change of the soil component was analyzed by laser spectroscopy and the two - dimensional chemical distribution was conducted based on the trend of laser spectrum. We have also established the environment of Mars (4-7 torr) and lunar atmosphere (<1 torr) in experimental setup, to prove that it is possible to measure by difference of soil chemical composition using LIBS and Raman spectroscopy even in artificial space environment.

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.