• Applied Microscopy
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• 제25권1호
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• pp.130-138
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• 1995

TEM specimen preparation methods have been examined to characterize Cu oxide particles in the polyimide film. Polyimide films were prepared by coating polyamic acid onto Cu films which had been deposited on TEM-mask and glass substrates and Cu foil, followed by thermal curing. In case of TEM-mask, direct observation was possible without further preparation. In other cases, TEM specimen were made by separating polyimide film from the substrate. Polyimide films were removed from glass and Cu foil by dissolving glass in HF solution and Cu foil in $H_{2}SO_{4}$ solution. TEM-mask observation confirms that fine $Cu_{2}O$ particles precipitate in the polyimide as a result of reaction of polyamic acid with Cu. However $Cu_{2}O$ particle reacts with HF and $H_{2}SO_{4}$ solution during dissolving the substrate and interpretation could be misled. It is concluded characterization of $Cu_{2}O$ particle in polyimide using TEM-mask is better than other methods.

• 한국생산제조학회지
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• 제6권3호
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• pp.52-57
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• 1997

Electronic Speckle Pattern Interferometry(ESPI) using the Model 95 Ar. laser, a video system and an image processor was applied to the in-plane displacement measurements. Unlike traditional strain gauges or Moire method, ESPI method requires no special surface preparation or attachments and can be measured in-plane displacement with no special surface preparation or attachments and can be measured in-plane displacement with no contact and real time. In this experiment specimen was loaded in parallel with a loadcell. The specimen was the cold rolled steel sheet of 2mm thickness, which was attached strain gauges. The study provides an example of how ESPI have been used to measure strain displacement in this specimen. The results measured by ESPI compare with the data which was measured by strain gauge method in tensile testing.

• Applied Microscopy
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• 제48권4호
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• pp.122-125
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• 2018

The focused ion beam (FIB) method is widely used to prepare specimens for observation by transmission electron microscopy (TEM), which offers a wide variety of imaging and analytical techniques. TEM has played a significant role in material investigation. However, the FIB method induces amorphization due to bombardment with the high-energy gallium ($Ga^+$) ion beam. To solve this problem, electron beam induced deposition (EBID) is used to form a protective layer to prevent damage to the specimen surface. In this study, we introduce an optimized TEM specimen preparation procedure by comparing the EBID of carbon and tungsten as protective layers in FIB. The selection of appropriate EBID conditions for preparing specimens for TEM analysis is described in detail.

• Applied Microscopy
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• 제45권4호
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• pp.189-194
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• 2015

Backside Ar ion milling technique for the preparation of cross-sectional transmission electron microscopy (TEM) specimens, and backside-ion milling combined with focused ion beam (FIB) operation for electron holography were introduced in this paper. The backside Ar ion milling technique offers advantages in preparing cross-sectional specimens having thin, smooth and uniform surfaces with low surface damages. The back-side ion milling combined with the FIB technique could be used to observe the two-dimensional p-n junction profiles in semiconductors with the sample quality sufficient for an electron holography study. These techniques have useful applications for accurate TEM analysis of the microstructure of materials or electronic devices such as arrayed hole patterns, three-dimensional integrated circuits, and also relatively thick layers (> $1{\mu}m$).

• Applied Microscopy
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• 제51권
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• pp.19.1-19.7
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• 2021

The main purpose of this paper is the preparation of transmission electron microscopy (TEM) samples from the microsized powders of lithium-ion secondary batteries. To avoid artefacts during TEM sample preparation, the use of ion slicer milling for thinning and maintaining the intrinsic structure is described. Argon-ion milling techniques have been widely examined to make optimal specimens, thereby making TEM analysis more reliable. In the past few years, the correction of spherical aberration (Cs) in scanning transmission electron microscopy (STEM) has been developing rapidly, which results in direct observation at an atomic level resolution not only at a high acceleration voltage but also at a deaccelerated voltage. In particular, low-kV application has markedly increased, which requires a sufficiently transparent specimen without structural distortion during the sample preparation process. In this study, sample preparation for high-resolution STEM observation is accomplished, and investigations on the crystal integrity are carried out by Cs-corrected STEM.

• 자원리싸이클링
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• 제14권4호
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• pp.3-9
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• 2005

석란광산에서 발생되는 선탄폐석을 효율적으로 이용하기 위하여 세라믹스 원료 소재로의 활용 가능성을 고찰하였다. 석탄폐석의 첨가량이 증가함에 따라 소성 시험편의 소성수축률이 저하되고, 압축강도는 약간 감소하는 등의 효과와 선탄페석에 함유되어 없는 탄소분의 연소에 의한 기공의 증가로 제품의 경량화도 가능한 것으로 판단되었다. 선탄폐석의 첨가량을 변화시켜 $1,150^{\circ}C$ 이상에서 소성한 경우 흡수율은 $10\;wt\%$ 이하를 나타내었고, 압축강도는 모두 21MPa이상으로 KS L 4201에서 규정한 1종 점토벽돌의 기준에 모두 적합함을 확인할 수 있었다.

• 대한의생명과학회지
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• 제13권4호
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• pp.361-368
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• 2007

Biological samples can be fixed either by chemical method by using chemical solution or physical methods by using heat treatment. The problem in traditional heat fixation is unsatisfactory quality due to uneven heat conduction in specimen and loss of inner cell contents. Chemical fixation method also bears several intrinsic problems like the limit in specimen size, time consumption in fixative impregnation, and loss of low molecular weight cell components. These factors deteriorate the quality of fixed specimen, thus limit the magnification and contrast of tissue pictures. Microwave heat has been reported to be a good alternative to current chemical methods to overcome these problem. In this study, we tried to introduce the microwave energy method to routine fixation work in hospital. We replaced chemical fixative with saline to provide moderate reaction condition, and used frozen section to reduce time for sample preparation. Temperature was measured at each experiment. The fixation of rat kidney tissue with 2.45 GHz electromagnetic wave and saline showed similar result to the control group fixed with traditional chemical method. Human tumor tissue fixed with 2.45 GHz electromagnetic in frozen section was improved in terms of histochemistry of PAS and immunohistochemistry of tumor marker like cytokeratin. Total turnaround time was reduced from $24\sim38$ h to to $2\sim4$ h. In conclusion, the quality of samples prepared by microwave heating method was at least as good as that of traditional method. If the condition for the fixation of different specimens is standardized, this new method could be applied to routine work in hospital, and could save working time as well.

• Geomechanics and Engineering
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• 제14권2호
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• pp.131-139
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• 2018

The preparation of repeatable and uniformly reconstituted soil specimens up to the specified conditions is an essential requirement for the laboratory tests. In this study for large samples replication, the simultaneous usage of the traveling pluviation and curtain raining technique is used to develop a new method, called the curtain travelling pluviator (CTP). This simple and cost effective system is based on the air pluviation approach, whilst reducing the sample production time, can reproduce uniform samples with relative densities ranging from 25% to 96%. In order to investigate the resulting suitability and uniformity from the proposed method, a series of tests is performed. The effect of curtain traveling velocity, curtain width, drop height, and flow rate on the parameters of the sample is thoroughly investigated. Increase in the curtain velocity and drop height leads to the increase in relative density for the sand specimen. Increase in curtain width typically resulted in the reduction of relative density. Test results reveal that the terminal drop height for the sand specimen in this study is more than 500 mm. Relative density contour lines are presented that can be utilized in optimizing the drop height and curtain width parameters. Sample uniformity in the vertical and horizontal orientation is investigated through the sampling containers. Increasing relative density tends to result in the higher sample repeatability and uniformity.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1994년도 추계학술대회 논문집
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• pp.65-66
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• 1994

This paper describes study on the preparation of ferrite powder for bonded mallets. The specimen which has the basic composition of SrO$.$nF$_2$O$_3$ with n=5.9 is in nonstoichiomatric region. Calcination is performed under N$_2$ atmosphere 1175$^{\circ}C$, 1200$^{\circ}C$, 1225$^{\circ}C$, 1250$^{\circ}C$ and 1275$^{\circ}C$ respectively. Then, Cooling is carried out in the furnace. In order to increase coecivity and obtain uniform grain size, we add to the specimen 0.7wt%CaCO$_3$, 0.3wt % SiO$_2$, 0.5wt%Na$_2$SiO$_3$ and 0.5wr% Al$_2$O$_3$. Also, in order to increase milling effect, carbon coating on sample particles is tried. As the result, single magnetic domain partic1e with Size of 1$\mu\textrm{m}$ in obtained and magnetic properties are improved.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.224-224
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• 2003