• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1988년도 추계학술대회 논문집
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• pp.5-7
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• 1988

Effect of isothermal aging on the crystallization of $Fe_{78}B_{13}Si_{9}$ metallic glass has been investigated by electrical resistivity, X-ray measurements, bending test, thermal analysis and transmission electron microscopy. Amorphous $Fe_{78}B_{13}Si_{9}$ alloy was annealed isothermally for 5 to 1200 mon. between 300 C and 540 C. It has been found that close relation between relative resistivity and X-ray diffraction pattern showed. The crystalline peak of $\alpha$-(Fe, Si) and Fe$_2$B are detected by X-ray experiment. The crystalline phases observed by TEM show $\alpha$-(Fe, Si) and Fe$_3$B with dendritic and cylindrical morphology, respectively. It has been also found that the embrittleness of aged samples rapidly increased with the crystallization and was shown before the crystallization.th the crystallization and was shown before the crystallization.

• 한국전기전자재료학회논문지
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• 제21권11호
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• pp.995-999
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• 2008

ZnO nanowires with tetrapod shape were formed on the surface of the sample by direct melt oxidation of Al-Zn alloy at $1000^{\circ}C$ in air. X-ray diffraction (XRD) pattern revealed that the ZnO nanowires had wurtzite structure of hexagonal phase. Any other element except Zn and O was not detected in energy dispersive X-ray spectrum. The c- and a-axis lattice constants estimated from the XRD pattern were 0.520 and 0.325 nm, respectively. These are in well accordance with those of bulk ZnO single crystal, indicating high quality crystallinity. The green light emission at a wavelength of 510 nm was observed from the nanowires at room temperature, which was ascribed to high density of oxygen vacancies in nanowires.

• 한국자기학회지
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• 제12권5호
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• pp.184-188
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• 2002

수직자기이방성을 가지는 Cu/Ni/Cu(002)/Si(100) 자성박막을 전자빔 증발법을 이용하여 초고진공에서 증착 하였다. 증착 시 RHEED로 측정 한 결과 실리콘 기판 위에 자성박막이 적층성장되었음을 확인하였다. 이러한 Cu/Ni/Cu(001)/Si(100) 자성박막에 1 MeV C 이온을 이온선량 2$\times$$10^{16}$ ions/$\textrm{cm}^2$로 조사한 후 MOKE로 자기이력곡선을 측정한 결과 이온 조사에 의해 자화용이축이 수직에서 수평방향으로 변화되었음을 확인하였다 포항 방사광가속기를 이용하여 X-선 반사도와 Grazing Incident X-ray diffraction(GE) 분석을 수행한 결과 첫 번째 Cu층과 Ni층 사이의 계면은 이온 조사 후 거칠기는 증가하였으나, Cu와 Ni의 전자밀도의 대비는 더욱 명확해졌다. 그리고, 증착 후 Cu와 Ni원자의 격자 상수 차이에 의해 Ni층이 가지고 있었던 strain은 이온 조사 후 완화되었음을 알 수 있었다. 끝으로, 이온조사 시 자성특성 변화와 직접적인 관계가 있는 strain 완화, 계면 혼합층(혹은 새로운 상)등이 생성되는 기구를 탄성충돌 및 비탄성충돌에 의한 열화학적 구동력으로 규명하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.103-103
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• 2011

The epitaxial Cu-doped ZnO and pure ZnO thin films were grown on Al2O3 (0001) substrates by RF sputtering method. The structures and crystallographic orientations were investigated using X-ray diffraction (XRD) and X-ray absorption spectroscopy. From the XRD pattern, it is observed that peak positions shift towards higher $2{\theta}$ value with Cu doping. The ${\omega}$-scan measurements at the (0002) diffraction peak for these samples reveal that the full-widths at half-maxima (FWHMs) are about $0.017-0.019^{\circ}$, which indicate a good c-axis orientation of the Zn1-xCuxO films. From phi-scan, all of the Zn1-xCuxO films were epitaxially grown. EXAFS measurements also demonstrated that Cu incorporated into a Zn-atom position substitutionally. All the results confirmed that copper ion were well incorporated into the ZnO lattices by substituting Zn sites without changing the wurtzite structure and no secondary phase existed in Cu-doped ZnO thin films.

• 약학회지
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• 제19권4호
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• pp.219-226
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• 1975

Physical and chemical properties on the aging inhibition mechanism of hydrous aluminum oxide were studied by means of dehydration velocity, activation energy, DTA, TGA, IR spectra, X-ray diffraction and TMA. During aging, changes may occur in the hydrous aluminum oxide structure which results in a loss of acid reactivity and in crystal formation to the hydrated hydrous alumina. The results obtained from the X-ray diffraction pattern and DTA, TGA thermogram studies showed that the aging product stabilized with either sorbitol or mannitol was hydrous aluminum oxide ($Al_{2}O_{3}{\cdot}xH_{2}O$) but the aging product not stabilized with either sorbitol or mannitol product not stabilized was hydrated hydrous aluminum oxide $Al_{2}O_{3}{\cdot}xH_{2}O{\cdot}yH_{2}O$. The activation energy of dehydration of the hydrous almina was about 17 Kcal. mol$^{1}$ deg$^{-1}$ which was observed a little less than that of 22 kcal.mol.$^{-1}$ deg.$^{-1}$ of or mannitol, the inhibition mechanism in the aging process from oxide is assumed to prevent the formation of the hydrated hydrous aluminum oxide and the aging process is thought of as analogous to the polymorphic transformations which occur as a system converts to its most stable state.

• 한국분말재료학회지
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• 제21권3호
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• pp.207-214
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• 2014

In this study, nano-scale copper powders were reduction treated in a hydrogen atmosphere at the relatively high temperature of $350^{\circ}C$ in order to eliminate surface oxide layers, which are the main obstacles for fabricating a nano/ultrafine grained bulk parts from the nano-scale powders. The changes in composition and microstructure before and after the hydrogen reduction treatment were evaluated by analyzing X-ray diffraction (XRD) line profile patterns using the convolutional multiple whole profile (CMWP) procedure. In order to confirm the result from the XRD line profile analysis, transmitted electron microscope observations were performed on the specimen of the hydrogen reduction treated powders fabricated using a focused ion beam process. A quasi-statically compacted specimen from the nano-scale powders was produced and Vickers micro-hardness was measured to verify the potential of the powders as the basis for a bulk nano/ultrafine grained material. Although the bonding between particles and the growth in size of the particles occurred, crystallites retained their nano-scale size evaluated using the XRD results. The hardness results demonstrate the usefulness of the powders for a nano/ultrafine grained material, once a good consolidation of powders is achieved.

• 한국자기학회지
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• 제18권6호
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• pp.217-220
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• 2008

Rare-earth iron oxide $ErFe_2O_4$의 다결정체 시료의 자기적 특성을 연구하였다. 단일상의 다결정체 $ErFe_2O_4$ 시료를 CO/$CO_2$ gas 분위기에서 고체상태반응법으로 합성하였다. X-ray diffraction 측정을 통해 $ErFe_2O_4$ 시료는 space group R3m Rhombohedral 구조를 가지며, 온도에 의존하는 magnetization 측정을 통해 250 K에서는 자기적 전이가, 220 K에서는 구조적 전이가 일어나는 2단계 상전이 현상을 확인하였다.

• 한국식생활문화학회지
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• 제36권5호
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• pp.484-491
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• 2021

This study investigated the effect of dry heat treatment (DHT) on the physicochemical properties of hard type (HR) and floury type (FR) rice to improve the processing aptitude of rice flour. The rice flour was heated at 130℃ for 0, 2 and 4 hours, and the color value, water absorption index (WAI), water soluble index (WSI), swelling power, solubility, pasting properties, particle shape and the X-ray diffraction were measured. After DHT, the L value of rice flour decreased, and the b value increased. The WAI, WSI, swelling power and solubility of HR and FR increased with the increase of treatment time. The cold viscosity and setback increased, while breakdown decreased. Cracks and lumps formed with fine particles were observed. The X-ray diffraction pattern was A-type, while the diffraction intensity decreased. According to the results of the two-way analysis of variance (ANOVA) test, the hydration and pasting properties were significantly different between HR and FR and were affected by DHT time. The results suggest that the properties of modified rice flour by DHT can be used in the food industry.

• 한국식품영양과학회지
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• 제29권5호
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• pp.766-769
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• 2000

수침과정을 달리하여 제조한 도토리 앙금의 입자 특성을 조사하였다. 도토리 앙금의 X-선 회절도는 회절각도 $(2{\theta})14.5^{\circ},\;17.2^{\circ},\;19.7^{\circ},\;22.2^{\circ},\;24.5^{\circ}$에서 피크를 보이는 B형의 결정형을 보였으며, 열매의 수침과 앙금의 수침에는 영향을 받지 않았다. 또한 도토리 앙금 중 전분 입자는 대부분 타원형이며 일부는 모서리가 둥근 삼각형 모양이 존재하였고 중앙에는 hilum이 있었으며, 크기는 대부분 $10~20\;\mu\textrm{m}$ 범위였다. 열매의 앙금의 수침 과정 중 전분 입자에 붙어 있었던 비전분 성분은 대부분 제거되었다. 이상의 결과로 보아 도토리 열매와 앙금을 수침하는 기간이 입자의 성상이나 결정도에 큰 영향을 주지 않는 것으로 판단된다.

• 한국재료학회지
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• 제4권3호
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• pp.268-279
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• 1994

단일상을 갖는 $Bi_2S_2CaCu_2O_{8+x}$ (2212)의 x-ray 분말 pattern을 a=5.408, c=30.83 $\AA$의 격자상수 및 역격자 벡터 $q^*=0.211b^*-c^*$을 갖는 pseudo tetragonal subcell을 이용하여 모두 index하였다. 임계온도 110K를 갖는 $Bi_2S_2CaCu_2O_{10+x}$ 상은 incommensurate supercell에 속하는 매우 많은 x-ray분말선들을 가지고 있다. Indixing guide로 전자회절사진(electron diffraction photographs)을 이용 x-ray분말 pattern에 대한 지수결정방법을 얻었다.$Bi_2S_2CaCu_2O_{10+x}$(2223)의 단위세표(unit cell)는 기하학적으로 격자상수 a=5.411, b=5.420, c=37.29(2) A을 갖는 orthorhombic subcell이다. Supercell반사 지수들은 subcell의 파 벡터 $\pm q^*=0.211b^*-0.78c^*$을 갖는 k,1지수로부터 영향을 받은 것이다. b 방향으로의 inconnensurate성분 $\delta$는 두 상에 대해 다 같으나, 2212에서 2223 상으로의 변환에 따라 c 방향으로의 초격자성분(superlattic component)은 connensurate($\varepsilon$=1)로부터 incommensurate($\varepsilon$=0.78)로 변한다.