• Journal of the Mineralogical Society of Korea
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• v.5 no.1
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• pp.32-41
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• 1992

An XRD quantitative analytical method using calculated XRD patterns was discussed in this study, Deep-seabed sediments commonly contain smectite, illite, chlorite, and kaolinite, and XRD pattern of each clay mineral of appropriate chemical composition was simulated by using an XRD pattern calculation method. Theoretical peak intensities of specific reflections of four clay minerals (the 001 reflections of smectite and illite, the 004 reflection of chlorite, and the 002 reflection of kaolinite) were measured from calculated patterns, and MIF(mineral intensity factor)value of each phase was determined from the intensities of calculated patterns. The peak intensities obtaine from experimental XRD patterns of sediments were corrected using the MIF values so that the calibrated intensity values for the specimens are linearly proportional to the weight fraction of each phase, which is normalized to 100 wt%. The MIF method can provide accurate quantitaive results without the necessity of correcting the factors by the mass absorption coefficient of each phase. This method excludes the necessity of standard specimens having compositions that are similar to those of clay minerals in the sediment samples. Therefore, quantitaive analysis using XRD calculation method can be utilized for the specimens, for which the standard specimens are very difficult or impossible to obtain. this quantitative method can provide rapid, routine analysis results for a large number of samples which occur in similar geological environments.

• Applied Microscopy
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• v.37 no.3
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• pp.199-208
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• 2007

We have made an optical device to study the wave optics phenomena, such as image and diffraction pattern, constructive and destructive interference, by direct operation of laser beam and optical lenses. It consists of laser beam, goniometer, objective lens, intermediate lens, projection lens, CCD system, and computing system. As a result of the performance test, we were able to magnify samples up to 44 times with the resolution of about $5{\mu}m$. It is expected to help EM users understanding more easily principles of transmission electron microscopy (TEM).

• Journal of the Mineralogical Society of Korea
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• v.17 no.2
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• pp.177-187
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• 2004

Measurements of the lattice parameters of albite and oligoclase from electron diffraction patterns with the Au internal standard resulted in errors of less than 1 %. An electron diffraction map for natural oligoclase samples was constructed and 11 stations of zone-axes diffraction patterns were obtained. This process is indispensible for reliable TEM studies of triclinic feldspars. Utilizing the [001] cleavage plane of feldspar and the double-tilting TEM holder the following information is obtainable: Si-Al ordering and chemistry of alkali feldspars could be estimated from the $\alpha$＊ - ＊ plot, where ＊ is measured from the [001] orientation, while $\alpha$＊ is measured from the [100] orientation. Si-Al ordering of Na-rich plagioclase could be estimated from ＊ [001] patterns. Structure and chemistry or Na-poor plagioclase could be estimated from existence of e-reflections, their intensity variations as well as their positional changes.

• Journal of the Mineralogical Society of Korea
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• v.4 no.1
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• pp.11-21
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• 1991

XRD patterns of biedellite-nontronite and saponite-iron saponite series were investigated using one-dimensional pattern simulation method. Ethylene-glycolate smectites show stronger 002 and 003 reflections than hydrated specimens do. The intensities of the 002 and 003 reflections change systematically as a function of Fe enrichment in both types of smectites. The intensity ratio of 002/003 increases with increasing. Fe in both dioctahedral to the higher scattering factor of Fe than those of Al and Mg, and the scattering power of various smectites can be compared quantitatively by calculating the scattering factors of octahedral cations. Interlayer cations cause less effect on XRD profile than octahedral cations as Fe do. Although 001 reflections provide informations about the overall scattering power of the octahedral sheet, some ferrous dioctahedtal smectite cannot be distinguished unambiguously from trioctahedral smectites on the basis of XRD profile. Simulation showed that heterogeneous smectites exhibit 001 intensity distribution that is almost identical to that of homogeneous smectites having the average composition of heterogeneous ones. The broadening of 001 reflections may not be useful in evaluating the degree of heterogeneity of smectite unless other factors affecting the broadening are well known.

• Journal of the Mineralogical Society of Korea
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• v.18 no.3 s.45
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• pp.155-164
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• 2005

Volcanic rocks from the Mt. Mudeung area which are composed of Hwasun andesite, Mudeungsan dacite and Togok rhyolite contain plagioclase phenocrysts in common. Majority of the repeated twins observed in optical microscopy are albite twin and some are pericline twin. EPMA studies of plagioclases from Hwansun andesite, Mudeungsan dacite and Togok rhyolte indicate calcic andesine, andesine-oligoclase, nearly pure albite, respectively Albite twin and pericline twin can be easily distinguished through TEM diffraction patterns, which is quite difficult by optical microscopy. Plagioclases in volcanic rocks from the Mt. Mudeung area do not show e-reflection in (100) electron diffraction patterns, probably because of their high cooling rate, which inhibited phase separations during cooling.

• Journal of the Korean Magnetics Society
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• v.7 no.1
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• pp.7-12
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• 1997

Amorphous $Fe_{50}Zr_{50}$ alloy has been manufactured by mechanical alloying from pure elemental powders of Fe and Zr in conventional ball mill under an Ar atmosphere. Structure and magnetic properties of the amorphous phase were studied by transmission electron microscopy and SQUID magnetometry. Selected area diffraction patterns taken from the mechanically alloyed powders showed two halo rings, indicating coexistence of Fe rich and Zr rich amorphous phases in mechanically alloyed powder. Curie temperature of the Fe rich amorphous phase, measured by Arrot plot, was 195 K. Fe content in the ferromagnetic amorphous phase, estimated from the Curie temperature, was about 65 at%. Spin wave stiffness constant of $Fe_{50} Zr_{50}$ alloys processed for 100 and 200 hrs were 52.2 and 63.8 meV, respectively. The higher spin wave stiffness constant in 200 hrs milled powders may arise from the precipitation of $\alpha$-Fe by partial crystallization of amorphous phase.

• 한국전자현미경학회:학술대회논문집
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• 2004.05a
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• pp.74-77
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• 2004

• Korean Journal of Crystallography
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• v.9 no.1
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• pp.39-43
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• 1998

The well-known geometries showing the relation between the angular coordinates of a plane normal and a Laue diffraction spot have been improved. The Bernalte's algebraic equations for the lines in the Greninger and Leonhardt charts have been alternatively derived in more intuitive and perspicuous ways than his original derivation.

• Journal of Ocean Engineering and Technology
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• v.7 no.2
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• pp.103-113
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• 1993

X-ray diffraction analysis technique was used for the fatigue damage analysis and fatigue life prediction in Al 7075-T651 alloy. The tensile test, fatigue strength and fatigue crack propagation test with change of stress ratio were carried out. As a result, half-value breadth was increased with the plastic deformation in the specimen increasint at all test conditions. In particular, half-value breadth at the surface of the specimens fractured by fatigue was increased as stress intensity factor range and effective stress intensity factor range were increased. In addition, the good relationship between half-value breadty and diffraction pattern was shown.

• Journal of Biomedical Engineering Research
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• v.21 no.6
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• pp.537-542
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• 2000

Ga이 함유된 Pd-Ga계 합금은 우수한 기계적 성질, 심미성 및 생체적합성등으로 차세대 치과 도재용 합금으로 주목 받고 있다. 본 연구에서는 상용 77.3%Pd-6.0%Ga계 합금을 원심주조법으로 주조하고, 탈개스, 세라믹소성처리한 후 미세조직을 광학현미경, X-선 회절기, 투과전자현미경으로 관찰하였다. X-선 회절분석 및 투과전자현미경 관찰 결과, Pd고용체와 미세한 석출물에 의해 나타나는 줄무늬를 확인하였다. 공정점 86$0^{\circ}C$에서 5시간 유지시킨 상평형 열처리조건에서는 Pd고용체와 금속간화합물 Pd(sub)2Ga에 해당하는 보다 명확한 제한시야회절도형을 얻었다. 이러한 결과로 77.3%Pd-6.0%Ga계 합금은 Pd고용체와 미세한 구형의 금속간화합물 Pd(sub2)Ga으로 구성되었음을 알 수 있었다.