• Bulletin of the Korean Chemical Society
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• 제19권5호
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• pp.549-553
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• 1998

The structure and layer distribution of cadmium arachidate Langmuir-Blodgett film were analyzed by the small angle X-ray reflectivity measurements using synchrotron radiation. Y-to X type transition was ocurred during the 39th passage of deposition of cadmium arachidate. Based on the measurement of the consumed area of the monolayer, it was determined that about 27.5 layer was deposited. Using the synchrotron X-ray, the reflectivity profile of cadmium arachidate LB film over the wide range of grazing angle was obtained. The X-ray reflectivity profile was analyzed using the recursion formula. By fitting the location and dispersion of the subsidiary maxima between the Bragg peaks of the measured reflectivity profile with that of the calculated reflectivity profile, the average thickness and the distribution of layer thickness were evaluated. The genetic algorithm was adopted to the fitting of reflectivity profile to evaluate the optimum value of the number distribution of layer. Based on the morphology measurement with an atomic force microscopy (AFM), the domain structure and mean roughness of LB films were obtained. The mean roughness value calculated based on the number of layer distribution obtained from the measurement by AFM is consistent with that obtained from X-ray reflectivity analysis.

• 한국광학회:학술대회논문집
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• 한국광학회 2007년도 하계학술발표회 논문집
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• pp.21-22
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• 2007

The periodic multilayer is considered as the X-ray reflection mirror. High X-ray reflectivity from the incident angle greater than the grazing critical angle can be obtained by the periodic multilayer structure. The Optical constants are investigated in order to determine the material for X-ray reflection mirror. The X-ray reflection mirror is designed for W, Si using computer simulation. The reflectivity is calculated for various incident angles and ratio of thickness.

• 대한방사선기술학회지:방사선기술과학
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• 제33권3호
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• pp.179-184
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• 2010

나노 공간분해능을 갖는 영상을 얻기 위한 경엑스선 현미경 시스템에서는 단색 엑스선이 요구된다. 엑스선관에서 발생되는 화이트 빔으로부터 8.4 keV의 텅스텐 $L_{\alpha}$ 특성방사선을 84% 이상 반사시킬 수 있는 5.65 nm의 단위막 두께를 가지는 C/W 다층박막 거울을 설계하였고, 이온빔 스파터링 장치를 이용하여 $50{\times}50\;mm$ 크기로 제작하였다. 제작된 C/W 다층박막 거울은 99.5% 이상의 균일도(Uniformity)를 가지며, TEM 사진을 이용해 그 구조를 확인하였다. 8.05 keV의 구리 특성방사선을 광원으로 하는 엑스선 반사율 측정 장치를 이용한 다층박막 거울의 반사율을 측정함으로써 C/W 다층박막 거울의 8.4 keV에서의 반사율을 예상할 수 있었다. 제작된 C/W 다층박막 거울과 엑스선관을 이용하여 8.4 keV의 특성방사선을 획득함으로써 단색 엑스선을 획득하였다. 이때의 반사율은 77.1%였고, 단색 엑스선의 반치폭은 0.21 keV이었다. 엑스선관에서 높은 효율로 단색 엑스선을 획득할 수 있어 실험실 규모의 경엑스선 현미경 장치의 광원으로써 사용될 수 있는 가능성을 확인하였고, 다층박막 거울의 단위막 두께를 수 나노미터로 제작한다면 17.5 keV의 몰리브덴 특성방사선에 해당하는 단색 엑스선을 얻어 유방촬영에도 적용할 수 있을 것이다.

• 한국전기전자재료학회논문지
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• 제17권2호
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• pp.223-227
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• 2004

We have studied the interfacial diffusion of Fe/Cr multilayers using synchrotron x-ray techniques, such as x-ray reflectivity, extended x-ray absorption fine structures (EXAFS), and high-resolution x-ray scattering. The results of x-ray reflectivity indicated that the interfacial roughness of Fe/Cr multilayers increased with the Cr-layer thickness. The Fourier transform (FT) of EXAFS data clearly showed that the Fe atoms dominantly diffused into the stable Cr layers at the Fe/Cr interface. The results of high-resolution x-ray scattering supported the interfacial diffusion of Fe atoms. Out study revealed that the dominantly interfacial diffusion of Fe atoms into the Cr layers effects the interfacial roughness of the Fe/Cr multilayers.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.181-181
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• 2013

Recently, nanostructure and the molecular orientation of organic thin films have been largely paid attention due to its importance in organic electronics such as organic thin film transistors (OTFTs), organic light emitting diodes (OLEDs), and organic photovoltaics (OPVs). Among various methods, the diffraction and scattering techniques based on synchrotron x-rays have shown powerful results in organic thin film systems. In this work, we introduce the in-situ annealing system installed at PLS-II (Pohang Light Source II) for organic thin films by simultaneously conducting various x-ray scattering measurements of x-ray reflectivity, conventional x-ray scattering, grazing incidence wide angle x-ray scattering (GI-WAXS) and so on. Using the in-situ measurement, we could obtain real time variation of nanostructure as well as molecular orientation during thermal annealing in metal-phthalocyanine thin films. The variation of surface and interface also could be simultaneously investigated by the x-ray reflectivity measurement.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 초전도 자성체 연구회
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• pp.84-87
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• 2003

The interfacial diffusion in Fe/Cr/MgO(001) multilayers has been studied using synchrotron x-ray techniques, such as x-ray reflectivity, extended x-ray absorption fine structures (EXAFS), and anomalous x-ray scattering (AXS). The results of x-ray reflectivity indicated that the interfacial roughness of Fe/Cr multilayers with Cr-$4{\AA}$-thick was larger than that with Cr-$4{\AA}$-thick. The results of EXAFS indicated that the Fe element dominantly diffuse into the stable Cr layers at the Fe/Cr interface. The AXS was certified the existence of the interdiffused Fe element in the Cr layers. Our study revealed that the rough interface of the Fe/Cr multilayers was caused by the interfacia diffusion of Fe element into the Cr layers.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.192.2-192.2
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• 2013

Crystalline order and surface stability of 1,4,5,8,9,11-hexaazatriphenylene-hexanitrile (HATCN) thin films on organic surface were investigated using grazing incidence wide angle x-ray scattering and x-ray reflectivity measurements. In the initial growth regime (less than 20 nm), HATCN molecules were stacked to low crystalline order with substantial amorphous phase. Meanwhile, a thicker film with 50 nm thickness showed high crystalline order of hexagonal phase with three different orientational domains. The domain distribution was quantitatively obtained as a function of tilted angle. By an organic-inorganic interface formation of IZO/HATCN thin film from an indium zinc oxide (IZO) electrode deposition, the surface stability of HATCN film was investigated and the sharp interface was confirmed by the x-ray reflectivity measurement.

• 한국방사선학회논문지
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• 제12권1호
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• pp.101-106
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• 2018

다층박막거울은 높은 반사 효율로 엑스선을 단색화 하는데 많이 사용되고 있다. 반사되는 엑스선의 파장은 두께주기와 입사각도에 의해 결정되고, 반사율은 층수와 표면 거칠기에 크게 의존하게 된다. 다층박막거울은 중원소와 경원소가 번갈아 적층되어 있는 구조로 되어 있으며 각 계면에서의 거칠기를 고려해야 한다. 본 논문에서는 두께 변화 W/Si 다층박막거울에서 계면 거칠기와 상호확산을 동시에 고려하여 반사율을 조사하였다. 두께 변화 다층박막거울은 균일한 다층박막거울에 비해 반사율은 감소하나 각도 및 에너지 반치폭이 넓은 특징을 보였으며, 상호확산에 따른 반사율의 저하가 크게 증가하였다. 이론적인 설계값에 가까운 반사율을 획득하기 위해서는 다층박막거울을 제작 할 때 나타나는 상호확산의 효과를 고려하여 설계함으로써 목적에 부합하는 최적의 다층박막거울을 설계하고 제작할 수 있을 것이다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.59-64
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• 2002

One of the exciting research areas of the X-ray microscope is the observation of a living cell. In order to study a living cell with high resolution the order of the several tens nm, we need to improve the efficiency of mirrors which are components of an X-ray microscope system. In this paper we present the mirror design and manufacture to give a high resolution and reflectivity. We designed Wolter type I the condenser and objective mirror with the several tens of nm resolution. According to mirror design. we made the program using the visual basic. Using the new processing method as well as the ultra-precision diamond cutting, we directly processed the inside of an aluminum hulk in order to manufacture mirrors. From the experimental result, we think that the new processing method will improve a high reflectivity through the improved cutting tools and optimum cutting conditions.

• 한국광학회:학술대회논문집
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• 한국광학회 1999년도 제16회 광학 및 양자전자 학술발표회Proceedings of 16th Optics and Quantum Electronics Conference, 1999
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• pp.134-135
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• 1999