• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.180.1-180.1
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• 2014

이중층 그래핀(graphene)의 한쪽 표면에 전하를 주입하면 반전 대칭(inversion symmetry)이 깨지며 라만-비활성 진동모드가 활성화되면서 라만 G-봉우리 부근에 새로운 봉우리가 나타난다고 알려져 있다. 삼중층 그래핀은 그래핀이 적층되는 방식에 따라 ABA (Bernal), ABC (rhombohedral) 그래핀으로 나뉘며, ABC 그래핀은 ABA와는 달리 반전 대칭성을 가지고 있다. 본 연구에서는 화학적인 방법을 이용하여 ABC 그래핀의 반전 대칭을 제어하고 그에 따른 라만 스펙트럼의 변화를 탐구하였다. ABA 그래핀과는 달리 이중층 그래핀과 ABC 그래핀에서는 저진공 열처리 또는 요오드 흡착반응을 한 후에 G-봉우리 부근에서 새로운 봉우리가 나타나는 것을 관찰하였고, 전하밀도 정도가 증가 할수록 G-봉우리와 새로운 봉우리의 위치 차이는 증가하는 것을 관찰하였다. 물과 메탄올에 의한 세척 반응으로부터 열처리는 복층 그래핀과 기판 계면에 그리고 요오드 흡착은 그래핀의 상단표면에 잉여 전하를 유발하여 반전 대칭을 깨트린다는 사실을 확인하였다. 또한 G-봉우리와 새로운 봉우리의 진동수 차이가 반전 대칭을 유발한 전하밀도의 그래디언트에 대한 척도가 될 가능성을 제시하였다.

• Journal of the Korean Chemical Society
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• v.51 no.3
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• pp.287-290
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• 2007

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.110-111
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• 2001

대기과학분야에서 대기의 온도는 풍향-풍속과 더불어 매우 중요한 기상파라메타로 사용되고 있다. 수직고도에 따른 온도의 변화는 대기의 안정도를 결정하기도하며 구름의 생성과 소멸에 직접적인 변수가 되기도 한다. 원격으로 온도를 측정하는 기술 중에서 가장 보편적으로 사용되는 방법은 산소나 질소의 회전 라만 신호를 이용하는 기술이다 이 방법은 Cooney에 의하여 최초로 시도되었는데, 온도에 따라 민감하게 변하는 두 개의 회전천이 스펙트럼을 측정함으로써 이루어진다. (중략)

• Journal of the Korean Chemical Society
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• v.36 no.1
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• pp.24-27
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• 1992

Silver sols are aggregated by a Cu or Zn rod. This is maybe due to the reduction of $Ag^+$ ion on the surfaces of silver sols to Ag metal by oxidation-reduction reaction with Cu or Zn metal. Raman spectra of silver sols aggregated by a Cu rod have been studied. The evidence of borate and nitrate ions adsorbed on silver colloid surfaces is found. It is also found that these ions adsorbed on silver colloid surfaces are easily replaced by adsorbated added.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.461-462
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• 2006

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.5280-5287
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• 2014

This paper proposes a method in which classes are grouped as a hierarchical tree structure for the effective classification of the Raman spectra. As experimental data, the Raman spectra of 28 chemical compounds were obtained, and pre-treated with noise removal and normalization. The spectra that induced a classification error were grouped into the same class and the hierarchical structure class was composed. Each high and low class was classified using a PCA-MAP method. According to the experimental results, the classification of 100% was achieved with 2.7 features on average when the proposed method was applied. Considering that the same classification rates were achieved with 6 features using the conventional method, the proposed method was found to be much better than the conventional one in terms of the total computational complexity and practical application.

• Analytical Science and Technology
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• v.17 no.3
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• pp.225-229
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• 2004

The effect of the silicon acrylate as a reactive additive on the UV-curing photopolymerization reaction was studied by micro raman technique. For the study, acrylate systems and Darocur 1173 were used as oligomer and monomers, and a photo initiator, respectively. The content of silicon acrylate was within the range of 0-3 wt%. The extent of photo-polymerization reaction as a function of depth from the air interface was obtained from the conversion ratio of acrylate double bond calculated from the intensities of measured bands at $1410cm^{-1}$ and at $1635cm^{-1}$. Micro raman spectroscopic technique can be an useful tool for the investigation of the factors, which can affect the reaction progress, such as oxygen inhibition, composition of the formulations, depth, etc.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.3
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• pp.448-453
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• 1998

An inverted, stagnation point flow OMVPE reactor was studied by laser Raman spectroscopy. Pure rotational Raman scattering by the carrier gas $(N_2; or; H_2)$ was used to determine the axial centerline temperature profile in the reactor as a function of the inlet flow velocity and the rector aspect ratio. A larger temperature gradient normal to the susceptor surface was obtained with higher gas glow velocity, larger aspect ratio, and the use of a $N_2$ carrier gas.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.5
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• pp.223-228
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• 2002

We have studied the characteristics of Raman scattering spectroscopy from $_ZnS{1-x}Te_x$ alloys in the whole range of Te composition x. The Raman spectra showed two-mode behaviors for those alloys. The Raman line shape showed the changes of an asymmetry and broadening of that with Te composition x. The asymmetric broadening of the line shape could be explained with a spatial correlation model.

• Analytical Science and Technology
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• v.8 no.3
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• pp.313-319
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• 1995

Surface-enhanced Raman scattering(SERS) spectroscopy was employed to analyze the genotoxic nucleobase adducts of benzo[a]pyrene(BP) formed through one-electron oxidation pathway. SERS spectroscopy provided sufficient resolution to distinguish if BP intermediate was bound to different nucleobases(e. g. adenine or guanine). Furthermore, SERS specroscopy was also able to detect the difference in the binding position of the adduct to the various sites of the nucleobase. The linearity of the calibration curve for N7Ade-BP ranged from 20 picogram to 800 nanogram per microliter and the detection limit under the current conditions was determined 20 picogram per microliter in a solution volume of 20 microliter.