• 한국표면공학회:학술대회논문집
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• 한국표면공학회 1998년도 춘계학술발표회 초록집
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• pp.3-3
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• 1998

The atmospheric corrosIOn properties of Zinc (Zn) under wet/dry transition of $H_20$ film were investigated in this study. The atmospheric corrosion of metal is usually occurred as a result of repetitious thickness transition (so called wet/dry transition) of liquid phase which is covering the metal surface. Corrosion potential and the polarization behaviour of Zn during liquid film thickness transition were measured by Kelvin probe method which IS using vibrating reference electrode without touching the liquid film. The oxidized states of Zn as a result of successive wet/dry transition were also investigated by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results show that the corrosion potential and the corrosIOn rate of Zn both are increasing during drying. However, the corrOSIon rate is decreasing again when the Zn surface is completely dried while the corrosion potential still remains high. This behaviour can be explained by the polarization behaviour change of Zn according to the $H_20$ film thickness change. The completely dried surface is consisted mostly with Zn and ZnO phases. After a number of cycles of wet/dry transition, however, the oxidized Zn phase of ${\varepsilon}-Zn(OH)_2$, which has rather voluminous and defected structure, were found.

• Corrosion Science and Technology
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• 제18권2호
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• pp.39-48
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• 2019

The feasibility of using benzotriazole (BTAH) to inhibit pitting corrosion in the sprinkler copper tubes was investigated by filling the tubes with BTAH-water solution in 829 households at an eight-year-old apartment complex. The water leakage rate was reduced by approximately 90% following BTAH treatment during 161 days from the previous year. The leakage of one of the two sprinkler copper tubes was investigated with optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction analysis to determine the formation of Cu-BTA film inside the corrosion pits. All the inner components of the corrosion pits were coated with Cu-BTA films suggesting that BTAH molecules penetrated the corrosion products. The Cu-BTA film was about 2 nm in thickness at the bottom of a corrosion pit. A layer of CuCl and $Cu_2O$ phases lies under the Cu-BTA film. This complex structure effectively prevented the propagation of corrosion pits in the sprinkler copper tubes and reduced the water leakage.

• Electronic Materials Letters
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• 제14권6호
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• pp.733-738
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• 2018

Undoped and Mn-doped $In_2O_3$ films were prepared by radiofrequency magnetron sputtering technique. The effects of Mn doping on the structural and optical properties of as-prepared films were investigated using X-ray diffraction, X-ray photoelectron spectroscopy and ultraviolet-visible spectroscopy. Mn doping can enhance the intensity of (222) peak in Mn-doped $In_2O_3$ thin film, indicating Mn dopant promotes preferred orientation of crystal growth along (222) plane. XPS analyses revealed that the doped Mn ions exist at + 2 oxidation states, substituting for the $In^{3+}$ sites in the $In_2O_3$ lattice. UV-Vis measurements show that the optical band gap $E_g$ decreases from 3.33 to 2.87 eV with Mn doping in $In_2O_3$, implying an increasing sp-d exchange interaction in the film. Our work demonstrates a practical means to manipulate the band gap energy of $In_2O_3$ thin film via Mn impurity doping, and significantly improves the photoelectrochemical activity.

• 한국표면공학회지
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• 제57권2호
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• pp.86-91
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• 2024

In this study, we investigated the effect of Na₂SiO₃ concentration on the Plasma Electrolytic Oxidation(PEO) film formation of Al6061 alloy. The morphology of the PEO films were examined by Optical Microscope(OM) and Scanning Electron Microscope(SEM). PEO film thickness increases as the Na₂SiO₃ concentration increases. The elemental analysis of PEO films was conducted using Dispersive X-ray Spectrometer(EDS). The cross-sectional elemental analysis result shows that the Si concentration tends to increase as the concentration of Na₂SiO₃ increases. X-Ray Diffraction(XRD) analysis was performed to confirm the degree of phase change according to Na₂SiO₃ concentration. In addition, Vickers hardness was measured to confirm the mechanical strength of the PEO film. As the concentration of Na₂SiO₃ increases, the hardness value also tends to increase.

• 치과방사선
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• 제25권1호
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• pp.51-70
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• 1995

The purpose of this investigation was to compare the direct digital radiographic system with film-based digital imaging system using Ektaspeed and Ektaspeed Plus film with respect to image characteristics and detectability and evaluate the sensor noise with the use of subtraction method. Direct digital radiographic system which used was Sens-A-Ray system(Regam Medical Systems, Sundsvall, Sweden) and film-based digital imaging system was composed of Macintosh II ci computer, high resolution Sony XC-77 CCD camera and intraoral x-ray film(Kodak Ektaspeed film, Kodak Ektaspeed Plus film). Images were taken by using CCD sensor of Sens-A-Ray system, Ektaspeed film and Ektaspeed Plus film with variable exposure time(0.06s, 0.1s, 0.16s, 0.2s, 0.3s, 0.4s, 0.5s, 0.6s, O.8s, LOs), 5 times at each exposure time. And then ektaspeed films and ektaspeed plus films were digitized using CCD camera. Image groups were divided into 3 groups; Sens-A-Ray group(direct digital radiographic system), Ektaspeed group and Ektaspeed Plus group (film-based digital imaging system) They were assessed by the following three aspects; image density, image contrast and detectability and sensor noise of Sens-A-Ray system was also evaluated. The results were as follow : 1. S group showed higher density than E , EP group except at the low exposure time(p<0.01). 2. S group showed higher contrast than E,EP group except at the high exposure time(p<0.01). 3. All groups showed good detectability at the each proper exposure time. Lowest exposure time which shows maximum detectability in S,EP group(0.5s) was lower than that in E group(0.6s). 4. Sensor noise of Sens-A-Ray system generally increased according to exposure time. On the basis of the above results, it was considered that Sens-A-Ray system could show higher speed, higher contrast than Ektaspeed, Ektaspeed Plus film except at too high and low exposure time and the same detectability as the conventional intraoral film.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.202-202
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• 2003

• 한국표면공학회지
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• 제33권1호
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• pp.34-37
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• 2000

We prepared ZnO thin film with Facing Targets Sputtering system that can deposit thin film in plasma-free situation and change the deposition condition in wide range. And prepared thin film's c-axis orientation and grain size were analyzed by XRD (x-ray diffractometer). In the results, we suggest that FTS system is very suitable to preparing high quality ZnO thin film with good c-axis orientation.

• Current Photovoltaic Research
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• 제4권1호
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• pp.21-24
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• 2016

Chalcopyrite based (CIGS) thin films have considered to be a promising candidates for industrial applications. The growth of quality CIGS thin films without secondary phases is very important for further efficiency improvements. But, the identification of complex secondary phases present in the entire film is crucial issue due to the lack of powerful characterization tools. Even though X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and normal Raman spectroscopy provide the information about the secondary phases, they provide insufficient information because of their resolution problem and complexity in analyzation. Among the above tools, a normal Raman spectroscopy is better for analysis of secondary phases. However, Raman signal provide the information in 300 nm depth of film even the thickness of film is > $1{\mu}m$. For this reason, the information from Raman spectroscopy can't represent the properties of whole film. In this regard, the authors introduce a new way for identification of secondary phases in CIGS film using depth Raman analysis. The CIGS thin films were prepared using DC-sputtering followed by selenization process in 10 min time under $1{\times}10^{-3}torr$ pressure. As-prepared films were polished using a dimple grinder which expanded the $2{\mu}m$ thick films into about 1mm that is more than enough to resolve the depth distribution. Raman analysis indicated that the CIGS film showed different secondary phases such as, $CuIn_3Se_5$, $CuInSe_2$, InSe and CuSe, presented in different depths of the film whereas XPS gave complex information about the phases. Therefore, the present work emphasized that the Raman depth profile tool is more efficient for identification of secondary phases in CIGS thin film.

• 한국자기학회지
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• 제6권3호
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• pp.170-173
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• 1996

3-gun 마그네트론 스퍼터 장치로 Co-Zr 다층 박막을 제작하여 저온 비정질화를 시도하였다. 박막 x-ray와 단면 투과 전자현미경 분석에 의해 지르코늄 층이 코발트의 확산에 의해 비정질화 됨과 그의 위쪽 계면의 지르코늄 비정질화 속도가 아래쪽 계면의 그것보다 두 내지 세배 빠른 것을 발견하였다. 이 현상은 스퍼터링 중의 분자 섞임으로 설명되었다.

• 대한방사선기술학회지:방사선기술과학
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• 제6권1호
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• pp.35-41
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• 1983

Boot-Strap method is used to measure the sensitivity of X-ray film, but it is too complicated to design the plot and this method is generally a falling-off in the accuracy and the reproducibility. Authors made an attempt a new method to obtain the stable H-D curve, that is to say; Boot-Strap method used in combination with distance-change method, and the accuracy and the reproducibility.