• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.5
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• pp.230-234
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• 2003

CuPt-type ordering has been observed in Zn-rich $Cd_xZn_{1-x}$Te epilayers grown on (001)GaAs and ZnTe/GaAs(001) substrates. X-ray diffraction, electron beam diffraction, high-resolution transmission electron microscopy and low-temperature photoluminescence have been used to characterize the CuPt-type ordering in Zn-rich $Cd_xZn_{1-x}$Te epilayers.

• Journal of the Mineralogical Society of Korea
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• v.13 no.1
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• pp.1-14
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• 2000

알루나이트는 포항지역의 제3기 연일층군의 이암 층내의 탄산염 결핵체 주변에서 할로이사이트와 함께 극미립 변질물 (1-2 $\mu\textrm{m}$)로서 산출된다. 알루나이트는 정육면체와 유사한 능면체 결정형을 이루고 침상 내지 단주상의 할로이사이트와 밀접한 공생관계를 이룬다. X-선회절 분석에 의해서 이 알루나이트는 a=6.9897(1) $\AA$, c=17.2327(4)$\AA$, V=728.75(3) $\AA$3의 격자상수값을 갖는 것으로 밝혀졌다. X-선형광된 이 알루나이트의 화학식은 (K0.94N0.06)(Al2.55Fe3+0.45)(SO4)2(OH)6 으로서, 나트로알루나이트 단성분을 6-7 mole%정도 함유하는 것으로 분석되었다. 또한 시차열분석 (TG-DTG-DTA)을 통해서 알루나이트의 승화성 성분들 (H2O와 SO3)의 존재와 함유 정도를 조사하였고, 고온X-선회절분석을 병행하여 이 광물의 OH기의 이탈 반응 (52$0^{\circ}C$)과 고온상으로의 전이 반응 ($600^{\circ}C$ 및 $700^{\circ}C$)을 감정 하였다. K/Ar 법으로 측정된 알루나이트의 생성 연대 ($0.342\pm$0.008 Ma)와 안정동위원소들의 분석 결과 ($\delta$18Oso4=-1.7, $\delta$DSMOW=-31, $\delta$34S=-10.8)는 이 알루미늄 황산염 광물이 연일충군의 융기 이후에 야기된 민물의 유입에 의한 표성기원의 변질작용의 결과로 생성되었음을 지시한다. 알루나이트+할로이사이트 공생군의 침전은 이암 내에서 조성된 강산성 (pH=2-3)의 알루미늄 황산염 용액이 탄산염 결핵체를 만나 반응하여 pH가 국지적으로 증가되어 (pH=4) 과포화되는 과정에 의해서 야기되었다. 컴퓨터를 이용한 Al3+의 포화지수에 관한 화학적 평형 모델링 실험 결과, 알루미늄 황산염 용액으로부터의 알루나이트와 할로이사이트의 침전은 pH=4 및 \ulcornerSO42-=10-4M 조건에서 K+과 Si(OH)4의 농도가 10-4M 이상 유지되어야 가능한 것으로 밝혀졌다.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.8
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• pp.248-261
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• 1999

The fatigue life of mechanical components and structures has been influenced by mechanical, material and environmental conditions. It is important to search out the load type and size for accurate cause of fracture at the damaged surface of material. The fractographic method by x-ray diffraction can utilize residual stress $\sigma$_r and half-value breadth B and find out the types and the mechanical conditions of fracture. This study showed the relationship between fracture mechanical parameters $\Delta$K, $K_{max}$ and X-ray residual stress $\sigma$_r for normalized SS41 steel with homogeneous crystal structure and M.E.F. dual phase steel(martensite encapsulated islands of ferrite). The fatigue crack propagation tests were carried out under stress ratios 0.1 and 0.5. The x-ray diffraction technique according to crack propatation direction was applied to fatigue fractured surface. Residual stress $\sigma$_r was independent on stress ratios by arrangement of $\Delta$K. The equation of $\sigma$_r$\Delta$K was established by the experimental data. Therefore, fracture mechanical parameters can be estimated can be estimated by the measurement of X-ray parameters.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.5
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• pp.673-680
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• 2003

This study verified the relationship between fracture mechanics parameters(ΔK, ΔK$\sub$eff/, K$\sub$max/) and X-ray parameters (${\alpha}$$\sub$r/, B) for SG365 steel at elevated temperature up to 300$^{\circ}C$. The fatigue crack propagation test were carried out and X-ray diffraction technique according to crack length direction was applied to fatigue fractured surface. The residual stress on the fracture surface was found to increase low ΔK region, reach to a maximum value at a certain value of K$\sub$max/ or ΔK and then decrease. Residual stress were independent on stress ratio by arrangement of ΔK and half value breadth were independent by the arrangement of K$\sub$max/. The equation of ${\alpha}$$\sub$r/ - ΔK was established by the experimental data. Therefore, tincture mechanics parameters could be estimated by the measurement of X-ray parameters.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.317-323
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• 2001

This study verified the relationship between fracture mechanics parameters$({\Delta}K,\;{\Delta}K_{eff},\;K_{max})$ and X-ray parameters $(\sigma_r,\;B)$ for SG365 steel at elevated temperature up to $300^{\circ}C$. The fatigue crack propagation test were carried out and X-ray diffraction technique according to crack length direction was applied to fatigue fractured surface. The residual stress on the fracture surface was found to increase low ${\Delta}K$ region, reach to a maximum value at a certain value of $K_{max}\;or\;{\Delta}K$ and then decrease. Residual stress were independent on stress ratio by arrangement of ${\Delta}K$ and half value breadth were independent by the arrangement of $K_{max}$. The equation of $\sigma_r-{\Delta}K$ was established by the experimental data. Therefore, fracture mechanics parameters could be estimated by the measurement of X-ray parameters.

• Journal of the Korean Vacuum Society
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• v.10 no.1
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• pp.57-60
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• 2001

We prepared uniform CdS nanowire arrays ways with lengths up to 5 $\mu\textrm{m}$ and diameters as small as 20 nm by electrochemically depositing the semiconductor directly into the pores of anodic alumina films from an electrolyte containing $CdCl_2$ and S in dimethyl sulfoxide. The nanowire arrays were characterized by scanning electron microscopy and X-ray diffraction. The deposited materials are composed mainly of hexagonal CdS with (100) preferential orientation.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.11 no.1
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• pp.33-37
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• 2001

Kaolinite was synthesized through th acid treatment of mixture which consisted of psudoboehmite and colloidal silica in hydrothermal reaction at $213^{\circ}C$ under autogeneous vapor pressure. Crystallization process was characterized by X-ray powder diffraction pattern, IR spectra and Hinckley index was calculated. The synthesis in acidic solution promotes the dissolution of the starting materials and leads to crystallization of kaolinite. The rate of crystallization to kaolinite and stacking defect were found to e affected by kind of anion, acidity and starting materials.

• Journal of the Mineralogical Society of Korea
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• v.27 no.4
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• pp.283-291
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• 2014

Talc ($Mg_3Si_4O_{10}(OH)_2$), one of sheet silicates, is soft and has been widely used in industry. Powdered talc specimen was synthesized at the pressure of 200 MPa and temperature of $600^{\circ}C$ using external heated hydrothermal high pressure apparatus. High pressure angular dispersive X-ray diffraction (ADXRD) mode experiments were performed at the Pohang Light Source (PLS) using the symmetrical diamond anvil cell (SDAC). Compression pressure was loaded up to 11.06 GPa at room temperature. This synthetic talc shows no phase transition(s) within the present pressure limit. Based on ADXRD data, bulk modulus of talc was calculated to be 72.4 GPa using Birch-Muranghan equation of state (EOS). This value is lower than that of natural talc determined previously.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.3
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• pp.94-98
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• 2014

$LiCoO_2$ thin film has received diverse attention as cathodes material of thin-film micro-batteries. In this study, $LiCoO_2$ thin films were synthesized on Au substrates by sol-gel spin coating method and an annealing process. Their structures were studied using X-ray diffraction and Raman Spectroscopy. The particle morphologies of these thin films were observed by Scaning electron microscope. From the results of X-ray diffractometry and Raman Spectroscopy analyses, it was found that as-grown films had the structure of spinel (LT-$LiCoO_2$) and layered-Rock-salt (HT-$LiCoO_2$) at $550^{\circ}C$ and $750^{\circ}C$ respectively. The annealed films at $650^{\circ}C$ were presumed to be the mixed state of these two types. Throlugh the scanning electron microscope, It was estimated that the particle size in as-grown films at $750^{\circ}C$, were larger crystilline particle than in those at the other lower temperature and well distributed in the film.

• Journal of the Mineralogical Society of Korea
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• v.20 no.3
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• pp.213-222
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• 2007

Changes of turbidity and suspended solid concentration of inflow tend to be very similar in Andong and Imha dam, and show significant effect on the amount of rainfall. Concentrations of suspended solid and turbidity in Imha are higher than these of Andogn dam, and Banbyon have higher values than that of Yongjeon stream in Imha dam. There is no difference in size distribution and mineral composition of the suspended particles in Andong and Imha dam. The turbidity-causing materials are composed of vermiculite. illite, kaolinite, quartz and albite. X-ray diffraction analysis shows that turbidity-causing materials are have similar mineralogy between Andong and Imha Dam, but they have different abundance.