• 한국세라믹학회지
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• 제49권6호
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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.

• KSBB Journal
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• 제11권5호
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• pp.557-564
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• 1996

Contact lens 재료물질로 사용되어지는 poly(2 h hydroxyethylmethacrylate), poly (HEMA) 는 물을 약 45퍼센트 포함하여 수화젤(hydrogel)을 만들 수 있는 고분자 물질이다. Poly(HEMA)와 단백질의 구성물질인 수용성 아미노산(alanine, argmme, glycine, lysine, methionine, proline, serine)과의 상호작용력과 작용위치에 대한 실험을 FT - IR과 R Raman 분광법을 사용하여 행한 결과 Arg과 Lys 이 가장 크게 작용하였고, 작용크기는 각 pH에 따라 존재하는 이온종과 양에 관계되며, 작용위치는 주로 poly(HEMA) 내에 존재하는 히드록시기에서 일어났다.

• 농업과학연구
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• 제50권4호
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• pp.675-696
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• 2023

Terpenoids, also referred to as terpenes, are a large family of naturally occurring chemical compounds present in the essential oils extracted from medicinal plants. In this study, a nondestructive methodology was created by combining ATR-FT-IR (attenuated total reflectance-Fourier transform infrared), and Raman spectroscopy for the terpenoids assessment in medicinal plants essential oils from ten different geographical locations. Partial least squares regression (PLSR) and support vector regression (SVR) were used as machine learning methodologies. However, a deep learning based model called as one-dimensional convolutional neural network (1D CNN) were also developed for models comparison. With a correlation coefficient (R²) of 0.999 and a lowest RMSEP (root mean squared error of prediction) of 0.006% for the prediction datasets, the SVR model created for FT-IR spectral data outperformed both the PLSR and 1 D CNN models. On the other hand, for the classification of essential oils derived from plants collected from various geographical regions, the created SVM (support vector machine) classification model for Raman spectroscopic data obtained an overall classification accuracy of 0.997% which was superior than the FT-IR (0.986%) data. Based on the results we propose that FT-IR spectroscopy, when coupled with the SVR model, has a significant potential for the non-destructive identification of terpenoids in essential oils compared with destructive chemical analysis methods.

• E2M - 전기 전자와 첨단 소재
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• 제10권3호
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• pp.284-288
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• 1997

FT-IR and FT-Raman spectra were measured for 15Li$_{2}$O.3Al$_{2}$O$_{3}$.78SiO$_{2}$. 4K$_{2}$O glass system after UV irradiations. Optimum UV irradiation time of Li$_{2}$O.SiO$_{2}$ crystalline phase was 60 seconds and crystalline phase of Li$_{2}$O.SiO$_{2}$ was leached out on 5% HF. 977 cm$^{1}$ band of FT-Raman spectra can be attributed to two-non bridging oxygen in unit cell for 1 hour and optimum crystallization was confirmed for 3 hrs, 630.deg. C.

• 한국세라믹학회지
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• 제25권1호
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• pp.27-34
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• 1988

In order to investigate the reason of changes in the physical properties of glasses near the region for which R(Ga/Na)=1, spectroscopic studies using FT-IR and Raman spectroscopy have been carried out on Na2O.2SiO2 glass with addition of Ga2O3 from 0 to 35 mole %, i.e., from R=0 to 1.61. The main purpose of this work is to investigate the coordination number of Ga3+ in glass with variation of glass composition and to determine the existence of tricluster in the Ga-rich region for which R>1.0 in Na2O-Ga2O3-SiO2 system.

• 분석과학
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• 제5권1호
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• pp.115-120
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• 1992

강유전체인 $LiTaO_3$ 소재는 SAW filters나 IR sensors의 기본재료로 사용되고 있다. Dopant로서 $Al_2O_3$를 $LiTaO_3$에 일부 치환함으로써 유전 특성을 변화시키고 특히 용융점을 낮춤으로써 단결정 제조를 용이하게 한다. X-선 회절분석에 의한 격자상수 변화와 Raman spectroscopy의 band broadening을 측정한 결과 $LiTaO_3$에 대한 $Al_2O_3$의 고용한계가 $Li_{1-X}Al_{2X}Ta{1-X}O_3$에서 X=0.25mol이었으며, 고용한계 이상에서는 2차상인 $Al_2O_3$상이 XRD로 관찰되었다. Grain size에 의한 Raman band의 broadening을 고려하기 위하여 단결정과 소결체 $LiTaO_3$를 측정 비교하였다.

• 한국세라믹학회지
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• 제51권4호
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• pp.350-356
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• 2014

Recently, Chemical Vapor Deposition (CVD) synthetic diamonds have been introduced to the jewelry gem market, as CVD technology has been making considerable advances. Unfortunately, CVD diamonds are not distinguishable from natural diamonds when using the conventional gemological characterization method. Therefore, we need to develop a new identification method that is non-destructive, fast, and inexpensive. In our study, we employed optical microscopy and spectroscopy techniques, including Fourier transform infra-red (FT-IR), UV-VIS-NIR, photoluminescence (PL), micro Raman, and cathodoluminescent (CL) spectroscopy, to determine the differences between a natural diamond (0.30 cts) and a CVD diamond (0.43 cts). The identification of a CVD diamond was difficult when using standard gemological techniques, UV-VIS-NIR, or micro-Raman spectroscopy. However, a CVD diamond could be identified using a FT-IR by the Type II peaks. In addition, we identified a CVD diamond conclusively with the uneven UV fluorescent local bands, additional satellite PL peaks, longer phosphorescence life time, and uneven streaks in the CL images. Our results suggest that using FT-IR combined with UV fluorescent images, PL, and CL analysis might be an appropriate method for identifying CVD diamonds.

• 한국전기전자재료학회논문지
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• 제19권10호
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• pp.930-934
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• 2006

This paper reports a change of carbon nanotubes(CNTs) properties by post-treatment process after growth of CNTs. CNTs were treated by thermal method and solution method, and then investigated in detail using field emission scanning electron microscopy(FE-SEM), high resolution transmission scanning electron microscopy(HR-TEM), RAMAN spectroscopy, and Fourier Transform Infrared Spectrometer (FT-IR). FT-IR spectra showed that the amount of hydroxyl generated on surface of CNTs were changed with post-treatment condition. FE-SEM and TEM images were shown CNTs diameter and density variations were dependent with their treatment conditions. RAMAN spectroscopy was shown that carbon nanotubes structure vary with treatment conditions.

• 한국진공학회지
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• 제7권3호
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• pp.248-254
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• 1998

PECVD(Plasma Enhanced Chemical Vapor Deposition) 방법을 이용하여 비정질 고 상 탄소 박막의 하나인 유사 다이아몬드(Diamond-Like-Carbon; DLC) 박막을 증착하였다. FT-IR Spectroscopy와 Raman Scattering 등을 통해 박막의 구조적 특징을 조사하였는데, 박막은 microcrystalline diamond domain과 graphitelike carbon domain들이 수소화된 $sp^3$사 면체 구조의 비정질 탄소에 의해 그물 구조로 연결되어진 것으로 보인다. 이러한 추정은 I-V 특성 조사의 결과와도 좋은 일치를 보이는데, 특히 I-V조사에서는 전류의 갑작스러운 증가가 관측되어졌으며 이것은 graphitelike carbon domin들간의 전자 tunneling 현상으로 이해되어진다. 그리고 대단히 얇은 탄소 박막에 대한 Raman산란 조사에서는 증착 초기 상 태에 $\beta$-SiC층이 형성되어지는 것을 확인할 수 있었다.

• Journal of Electrochemical Science and Technology
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• 제11권2호
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• pp.165-171
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• 2020

The electrochemical preparation and spectroscopic characterisation of iridium-antimony (Ir-Sb) species is important owing to their potential applications as nanostructure materials. Nanostructures, i.e. nanoflower and nanodisk, of Ir-Sb were electrodeposited on conductive substrates using a practical electrochemical method based on the simultaneous underpotential deposition (UPD) of Ir and Sb from the IrCl₃ and Sb₂O₃ at a constant potential. Electrochemical UPD mechanism of Ir-Sb was studied using cyclic voltammetry and potential-controlled electrochemical deposition techniques. Herein, X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron and Raman spectroscopy were used to determine the morphological and structural properties of the electrochemically-synthesised Ir-Sb nanostructures.