• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.97-101
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• 2017

X-ray diffractometers are used to characterize material properties, such as the phase, texture, lattice constant and residual stress, based on the diffracted beams obtained from specimens. Quantitative analyses using X-rays are typically conducted by measuring the peak positions of the diffracted beams. However, the long-term use of the diffractomer, like any other machine, results in errors associated with the mechanical parts, which can deteriorate the accuracy of the quantitative analyses. In this study, the process of correcting systematic errors in the $2{\theta}$ range of $30{\sim}90^{\circ}$ is discussed, for which strain-free Si powders from NIST were used as the standard specimens. For the evaluation of the impact of such error correction, we conducted a quantitative analysis of the true lattice constant for tungsten thin films.

• 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.20 no.4
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• pp.351-356
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• 2007

The crystal structure of $Li(ND_4)SO_4$ was analyzed by X-ray and neutron diffraction methods. The crystal is a deuterated $Li(NH_4)SO_4$ and one of the ferroelectric materials with hydrogen atoms. The crystal is orthorhombic at room temperature, $P2_1nb$, with lattice parameters of $a=5.2773(5)\;{\AA},\;b=9.1244(23)\;{\AA},\;c=8.7719(11)\;{\AA}$ and Z=4. Neutron intensity data were collected on the Four-Circle diffractometer (FCD) at HANARO in Korea Atomic Energy Research Institute and X-ray date were given by Prof. Y. Noda of Tohoku University Japan. The structure was refined by full-matrix least-square to final R value of 0.070 for 1450 observed reflections by X-ray diffraction and to final R=0.049 for 745 observed reflections by neutron diffraction. With X-ray data we obtained only one hydrogen atomic position. However, not only all atomic positions of four hydrogen atoms at $NH_4$ but also the occupation factors of D and H were refined with neutron data. From this results we obtained the average chemical structure of this sample, $LiND_{3.05}H_{0.95}SO_4$.

• Journal of the Mineralogical Society of Korea
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• v.16 no.1
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• pp.65-73
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• 2003

In this study we have derived the two correction methods of hydrogen bonding distance. In case of the intermediate or long hydrogen bond(＞2.5 $\AA$), hydrogen bonding distances can be corrected by using the function d(O-H)=exp((2.173-d(O…O))/0.138)+0.958 obtained by least- squares fit to the data from the neutron diffraction at low temperatures. The valence-least-squares method is effective for the distance correction of very short hydrogen bond(<2.5 $\AA$). The distance correction is necessary for the long intermolecular hydrogen bond obtained from X-ray diffraction analysis.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.4
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• pp.431-445
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• 2022

A quantitative phase analysis method of X-ray powder diffraction was studied to determine the mineral content of clay-rich rocks practically as well as effectively. For quantitative X-ray powder diffraction analysis of the clay-rich rocks, it is necessary to prepare whole-rock powder samples with a random orientation by side mounting method. In addition, for the identification of the clay minerals in the rock, it is required to prepare an oriented mount specimen with a clay particle size of 2 ㎛ or less, ethylene glycol treatment, and heat treatment. RIR (reference intensity ratio) and Rietveld method were used for the quantitative analysis of the clay-rich rocks. It was possible to obtain the total clay and the non-clay minerals contents from the whole-rock X-ray diffraction profiles using the RIR values. In addition, it was possible to calculate the relative content of each clay mineral from the oriented X-ray diffraction profiles of the clay particle size and assign it to the total clay. In the Rietveld method of whole-rock X-ray diffraction, effective quantitative values were obtained from the Rietveld diffraction patterns excluded the region of less than 10 degrees (2θ). Similar quantitative values were shown in not only the RIR but the Rietveld methods. Therefore, the analysis results indicate a possibility of a routine quantitative analysis of clay-rich rocks in the laboratory. However, quantitative analysis of clay minerals is still a challenge because there are numerous varieties of clay minerals with different chemical and structural characteristics.

• Journal of the Korean Ceramic Society
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• v.34 no.2
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• pp.175-180
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• 1997

새로운 복합페로브스카이트계 고용체 (1-x)Ba(Mg1/3Ta2/3)O3-xLa(Mg2/3Ta1/3)O3(x=0.0-1.0)를 설계하고 조성에 따른 고용체의 결정구조의 변화 및 MPB(Morphotropic Phase Boundary)를 분말 XRD를 이용하여 분석하였다. 초격자회절선의 변화로부터 MBT에 10mol%의 LMT를 치환함에 따라 1:2에서 1:1로의 규칙화타입의 전이가 일어남을 알 수 있었다. 면심입방정구조 영역(0.10.8조성의 경우, 주회절선의 피이크분리 및 새로운 회절선들로부터 격자비틀림의 형태가 단사정임을 알 수 있었다.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.371-371
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• 2013

사파이어 단결정 웨이퍼는 제조과정에서 결정 성장 조건 및 기계적 연마에 의하여 내부적인 결함이 발생할 수 있다. 사파이어 단결정은 일반적으로 LED용 기판 재료로 사용되며, 내부결함이 발생 시 기판 위의 GaN 등 layer의 결함도 함께 증가하므로 기판의 결함을 줄이는 과정이 중요한 이슈이다. 이 과정에 X-선 토포그래피는 단결정의 내부 결함을 모니터링 하는데 있어서 매우 유용한 방법이다. 이에 본 연구에서는 사파이어 단결정 웨이퍼에 내재하는 결함 형태를 X-선 Lang 토포그래피 방법(X-ray Lang Topography)으로 이미징하여 관찰, 분석하였다. Lang 토포그래피 방법은 X-선 투과법으로 넓은 부분을 우수한 강도와 분해능으로 내부 결함을 관찰할 수 있는 장점을 지니고 있다. X-선 source는 Mo $k{\alpha}$ 1을 사용하였으며, 시료는 c-plane 사파이어 웨이퍼를 사용하였다. 사파이어 웨이퍼의 (110), (102) 회절면의 X-선 토포그래피 이미지를 통해 전위 결함의 유형에 따른 이미지 패턴의 형성 메커니즘에 대해 연구하였고, 측정 회절면과 두께, 표면 데미지에 따른 전위 결함 이미지의 변화를 확인하였다. X-선 토포그래피 이미지를 통해 단결정 c-plane 사파이어 웨이퍼의 전위 결함의 형성 메카니즘 연구와 유형별 이미지와 회절면, 두께, 표면 데미지에 따른 이미지 변화 등을 확인하였다.

• 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.

• Journal of the Korean Society of Radiology
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• v.6 no.6
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• pp.477-481
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• 2012

An X-ray diffractometer which has various X-ray optics can give qualitative and quantitative information for a sample using a nondestructive analysis method. A parallel beam optic passes the parallel beam and removes divergent beam generated from an X-ray tube. The parallel beam optic used in the X-ray diffractometer was fabricated by wire cut and grading of stainless steel plates and was evaluated its performance using an X-ray imaging system. The measured parallelization of 6.6 mrad for the fabricated the parallel beam optic was a very close to the expected value of 6 mrad. An X-ray imaging technique for evaluating the parallel beam optics can estimate parallelization for each plate and can be used to other X-ray optics.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.6 no.3
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• pp.377-385
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• 1996

ZnS/ZnSe superlattices were prepared on GaAs (100) substrates by hot wall epitaxy, an the structures were analyzed using x-ray diffraction. It is shown that the x-ray diffraction of the strained superlattice gives very useful information about the thickness of each layer, strain, interdiffusion, and the fluctuation of the superlattice period. Interdiffusion length of the S and Se is estimated to be less than $2\;{\AA}$.