• Journal of the Korean Vacuum Society
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• v.13 no.2
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• pp.92-98
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• 2004

DBPAS has been used to characterize atomic size defect structures in materials. In this investigation the numerical analysis of the Doppler spectra was employed to the determination of the shape parameter, S, defined as the ratio between the amount of counts in a central portion of the spectrum and the total counts of whole spectrum. As the samples were exposed by X-ray increasing the exposed doses from 3, 6, and 9 Gy with 6 MV and 15 MV, respectively and also irradiated by X-ray as the medical applications used for in 0, 2, 4 and 6 years. The S-parameter values were increased as increasing the exposed time and the energies, that indicated the defects generate more. The S-parameters of the samples with medical treatment is varied from 0.4932 to 0.4956.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.126.2-126.2
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• 2015

대표적인 금속 칼코지나이드 2차원 물질인 이황화 몰리브덴($MoS_2$)의 대면적 합성을 위해 화학적 기상 증착 (Chemical Vapor Deposition) 방법을 이용하였다. 몰리브덴을 포함한 $Mo(CO)_6$ 전구체와 황이 포함된 $H_2S$ 가스를 적절한 비율로 반응시켰고, 증착 속도를 조절하여 한 층부터 다섯 층까지의 얇은 $MoS_2$ 박막을 제작할 수 있었다. $MoS_2$ 박막들이 층별로 균일 하게 증착 되었는지 확인하기 위해 라만 분광법을 이용 하였고, x-선 분광법을 통해 몰리브덴과 황의 정확한 정량비를 알 수 있었다. 뿐만 아니라, 우리는 두께 의존성을 갖는 이차원 물질인 $MoS_2$ 각 층마다 나타나는 전자 구조적 특성 분석을 위해 자외선 분광법, 역광전자 분광법, 전자 에너지 손실 분광법을 사용하였다. 그 결과, $MoS_2$ 박막의 두께 별 일함수, 가전자대 최대값, 전도대 최소값, 밴드갭의 변화를 관찰할 수 있었다. 이는 기존 계산 결과와 비교하여 잘 일치함을 알 수 있다.

• Journal of the Korean Chemical Society
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• v.31 no.1
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• pp.64-70
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• 1987

Rare earth elements including Y and Th in the monazite were separated and determined by X-ray fluorescence spectrometry. The matrix effects among the rare earth elements were simultaneously corrected by means of empirical coefficient method. The values of the coefficients were quite dependent on the number of the standards. However, the different set of coefficients led to the same results. The analytical results corrected by the present method agreed with those by the inductively coupled plasma spectrometry.

• Journal of the Korean Vacuum Society
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• v.2 no.2
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• pp.171-180
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• 1993

X-ray photoelectron diffraction (XPD) is used to characterize the crystallographically cleaved GaAs(110) surface. By using polar and azimuthal scans of the usual angle-resolved x-ray photoelectron spectroscopy, we get the reconstruction geometry of the clean GaAs(110) surface from the intensity ratio of Ga 3d core-level peaks. The reconstruction parameters are determined by fitting the diffraction pattern with the single scattering cluster (SSC) model, and the results show similar tendencies to those obtained by other techniques.

• The Science & Technology
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• v.27 no.10 s.305
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• pp.66-67
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• 1994

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.577-580
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• 2007

분자 크기가 너무 커 가스 하이드레이트를 형성하지 않는다고 알려진 n-펜탄과 n-헥산이 다른 구조-H 형성 화합물과 혼합되어 사용될 경우 구조-H 동공 내에 함께 포접되는 것으로 확인되었다. 구조-H 하이드레이트의 형성 및 미세구조 분석은 고체 NMR 및 X-선 회절 분광법을 이용하여 확인하였다. 이러한 혼합 화합물에서 보이는 구조-H 하이드레이트 형성은 전체적인 구조-H 형성 화합물에서 나타나는 일반적 특징인 것으로 여겨진다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.04a
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• pp.5-6
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• 2007

반투명 전도성 음극 (semi-transparent conducting cathode)인 Ba (x nm)/Au (20 nm)/ITO (100 nm)을 이용하여 전면발광 유기전계 발광 소자 (top-emitting organic light-emitting didodes, TEOLEDs)를 제작했다. Ba과 bis(8-quinolinolato)aluminum (III) ($Alq_3$) 계면의 전자구조는 엑스선 광전자 분광법 (X-ray photoelectron spectroscopy, XPS), 자외선 광전자 분광법 (ultraviolet photoelectron spectroscopy, UPS) 및 가까운 끝머리 엑스선 흡수 미세구조 (near-edge x-ray absorption fine structure, NEXAFS) 스펙트럼의 광 방출 특성을 통하여 조사되었다. $Alq_3$/Ba 계면 특성에 있어서 XPS와 NEXAFS 특성에 의하면, $Alq_3$ (10.0 nm) 위에 Ba이 연속적으로 증착됨에 따라 Ba으로부터 $Alq_3$로의 전자전달 (electron charge transfer) 특성은 꾸준희 증가된다. 그러나 Ba의 두께가 1.0 nm 이상 초과되면 Ba의 전자전달에 기인한 반응성때문에 $Alq_3$의 분자구조가 해리된다. 한편, 제작된 TEOLEDE의 전류-전압-휘도 곡선의 경우에서도 바륨의 증착 두께가 1.0 nm일 때 가장 우수한 구동특성을 나타냈다.

• Proceedings of the Korean Magnestics Society Conference
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• 1997.11a
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• pp.68-69
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• 1997

• Journal of the Korean Chemical Society
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• v.40 no.9
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• pp.607-614
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• 1996

The structural changes and dielectric properties of Pb1-x(Na1/2La1/2)x(Mg1/3Nb2/3)O3 compounds substituted by 0∼50 mol.% of Na+/La3+ mixed ions were investigated by X-ray diffraction method, IR and Raman spectroscopy, and LCR meter. The amount of perovskite phase increased with the increases of Na+/La3+ substituents and sintering temperatures. Although the superlattice lines due to 1:1 ordering were not detected by X-ray diffraction method, it was found, from the Raman spectroscopy and the increase of diffuseness coefficient, that the ordering behavior was related to the decrease of A site ion size. Dielectric properties in Pb1-x(Na1/2La1/2)x(Mg1/3Nb2/3)O3 were affected by the amount of perovskite phase, grain size, and density. The phase transitions were broadened and phase transition temperatures were lowered by the increase of Na+/La3+ ions.

• Journal of the Korean Chemical Society
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• v.28 no.5
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• pp.302-308
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• 1984

X-ray spectrometric determination of $Ta_2O_54, $Nb_2O_5$ and $ZrO_2$ in tin-slag samples using the double dilution technique was conducted. Tin-slag samples and one synthesized standard sample having similar composition to the samples were diluted with anhydrous $Li_2B_4O_7$ at the level of 1.00, 2.00 and 3.00% of the sample content, respectively. The diluted samples were fused at $1,150^{\circ}C$ for 30 minutes, and these glass beads were finely ground and pelletized. With the X-ray intensities measured, analytical results were calculated by the double dilution equation. The results agreed to the reference values obtained by the standard calibration method and the simple dilution technique within allowable error range and were reproducible.