• Korean Journal of Crystallography
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• v.8 no.1
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• pp.20-25
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• 1997

Two experimental methods have been developed for high resolution measurement of x-ray scattering. The methods used were (1) an x-ray double crystal diffraction (DCD) spectrometer set-up and (2) an x-ray triple crystal diffraction (TCD) spectrometer set-up. With the DCD arrangement of Si(511)-sample(hkl), rocking curves have been plotted for Si (333), Si(004) and GaAs(004). Also, with the TCD arrangement of Si(111)-Si(111)-Si(511)-sample(hkl) including monolithic monocro-collimator and $K_{\alpha1}$ selector, rocking curves have been plotted for Si(333), Si(004) and GaAs(004). The results of FWHM by DCD and TCD set-up have been compared each other and discussed. The reflection topographs (004) and (115) in an $In_{0.037}Ga_{0.0963}As/GaAs$ sample have been obtained by DCD set-up.

• Tribology and Lubricants
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• v.20 no.1
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• pp.7-13
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• 2004

High strength steels are widely used as tribo-materials in the field. Previous study revealed that for mild steel, the states of strain on the worn surface measured by X-ray diffraction has a good relationship with the state of wear. The objective of this study is to identify the relationship between the state of strain on the worn surface and the state of wear in high strength steels. Sliding wear tests were carried out using several hardened steels. X-ray diffraction tests were conducted to analyze the state of strain on the worn surface during wear. The experimental results indicated that the state of strain on worn surface in the hardened steel shows the same tendency as in the mild steel. It is clear that change of half value width on the worn surface as a function of sliding speeds is broadly similar in shape to wear characteristics curve and its magnitude has a good relationship with the wear rate at two different wear modes in the hardened steel.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.159-162
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• 2000

The purpose of this study is to develope an accurate procedure for measuring the glass content of fly ash produced by bituminous coal to assist in predicting their behavior in concrete. Quantitative mineralogical compositions of fly ashes were obtained by internal standard method using powder X-ray diffraction analysis. In the X-ray diffraction method, the specimen and standard fluorite were cautiously mixed and pulverized to 22$\mu$m in wet process so as to avoid the prefered orientation of the crystal and microabsorption effect of X-ray. calibration curve were fitted for several references peaks of four phases:$\alpha$-quartz. mullite, magnetite, hematite. The amount of glass was calculated by subtracting the amount of crystal phase and loss on ignition from the total amount. Glass content determined with this method ranged from 66.7 to 75.wt%.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.7
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• pp.116-123
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• 2008

In the fossil power plant, the reliability of the components which consist of the many welded parts depends on the quality of welding. The residual stress is occurred by the heat flux of high temperature during weld process. This decreases the mechanical properties as the strength of fatigue and fracture or causes the stress corrosion cracking and fatigue fracture. Especially, the accidents due to the residual stress occurred at the weld parts of high-temperature and high-pressure pipes and steam headers. Also, the residual stress of the welded part in the recently constructed power plants has been brought into relief as the cause of various accidents. The aim of this study is the measurement of the residual stress using the x-ray diffraction method. The merits of this are more accurate and applicable than other methods. The materials used for the study is P92 steel for the use of high temperature pipe on super critical condition. The variables of tests are the post-weld heat treatment, the surface roughness and the depth from the original surface. The test results were analyzed by the distributed characteristics of the full width at half maximum intensity (FWHM) in x-ray diffraction intensity curve and by the relation of hardness with FWHM.

• Electrical & Electronic Materials
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• v.9 no.10
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• pp.1013-1018
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• 1996

The annealing effects of Au/Te/Au/n-GaAs structure was investigated by using x-ray diffraction, scanning electron microscope, the specific contact resistance and I-V measurement. Increasing the annealing temperature, the intensity of Au-Ga peak by X-ray diffraction was increased. The Ga$\_$2/Te$\_$3/peak got evident for the samples annealed at 400.deg. C and GaAs peak by recrystallization appeared for the samples annealed at 500.deg. C. The variation from the schottky to low resistance contact was confirmed by I-V curve. The lowest value of the specific contact resistance of the samples annealed at 500.deg. C was 3.8*10$\^$-5/.ohm.-cm$\^$2/ but the value increased above 600.deg. C.

• Analytical Science and Technology
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• v.25 no.1
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• pp.33-38
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• 2012

Despite the importance of chloride binding, it is very difficult to measure the binding capacity, in particular, for the concrete body in an existing structure: in fact, the measurement procedure for chloride binding is much influenced by the environmental condition such as temperature, fineness of sample and pore water extraction techniques. The present study concerns the quantification of the binding capacity of chloride ions in concrete using the X-ray diffraction (XRD) technique. Once the binding isotherm of chlorides was determined by the Langmuir isotherm, as a function of the W/C, curing age and binder type, the generation of bound chlorides (i.e. Friedel's salt) was simultaneously ensured by the XRD technique. The amount of bound chloride was then determined by analyzing the peak intensity for the bound chlorides in the XRD curve. It was found that an increase in the curing age and a decrease in the W/C resulted in an increase in the binding capacity.

• The Korean Journal of Ceramics
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• v.4 no.4
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• pp.394-398
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• 1998

$Pb_{1-x}Sr_x(Mg-{1}2}W_{1}2})O_3$$ ceramics for application in the microwave frequency range were investigated by dielectric constant and X-ray diffraction measurements. The dielectric constant curves showed two concentration dependent characteristics in the $$Pb(Mg-{1}2}W_{1}2})O_3$-rich$ region. As the Sr constant further increases to x=0.3 the dielectric curve levels off. In the concentration range between x=0.4 and x=1 in which dielectric constant dependence on temperature is negligible, it decreases and Qf value increases in the microwave frequency with increasing Sr. The temperature coefficient (${\tau}_{\varepsilon} $) of the dielectric constant changes from the negative to positive value between x=0.9 and x=1. The dielectric constant, Qf and $\tau\varepsilon$ are correlated with tolerance factor(t). From the X-ray diffraction results for $0.1{\le}x{\le}1$ the cell parameter is found to decrease as x increases and B-site ordering is observed in all the composition ranges.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.2
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• pp.58-61
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• 2016

Bulk GaN crystals were grown by the basic ammonothermal method. The c-plane GaN templates grown by hydride vapor phase epitaxy were used as seed crystals and sodium metal, amide, and azide were added as a mineralizer. The growth conditions are at temperatures from $500{\sim}600^{\circ}C$ and pressures from 2~3 kbar. The growth rate for the c-axis was increased with increasing the operating pressure. Average dislocation density was measured $1{\times}10^5/cm^2$ by the cathodoluminescence measurement. The full-width at half-maximum of the X-ray diffraction rocking curve for (002) reflection was approximately 270 arcsec for Ga face and 80 arcsec for N face.

• Proceedings of the Korean Magnestics Society Conference
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• 2009.12a
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• pp.204-205
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• 2009

The magnetic properties and structure of FeRh thin film pitaxially grown onto MgO(001) substrate were studied by MPMS(Magnetic Properties Measure System) and in-situ temperature synchrotron XRD(X-ray Diffraction). The transition temperature of FeRh thin films was around 380K. Both M-T curve and d-spacing changes correspond to each other very closely.

• Archives of Pharmacal Research
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• v.9 no.1
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• pp.55-61
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• 1986

To increase the dissolution rate of piroxicam, chitin and chitosan which are widely occurring biodegradable natural materials were used as drug carriers. The ground mixtures of piroxicam with chitin or chitosan were prepared by grinding in a ball mill. The dissolution rates of piroxicam from the ground mixtures were enhanced markedly than that from the physical mixtures or from intact piroxicam. The X-ray diffraction peaks disappeared in the ground mixture indicating the production of the amorphous form. The comparison of infrared spectra of the physical mixture and the ground minture showed an interaction such as association between the functional groups of piroxicam and chitin or chitosan in the molecular level. The weight losses in TGA curves shoed all the same patterns. However, in the ground mixture by DTA curve, the undothermic peak due to the fusion of piroxicam was disappeared indicating the different thermal property.