• Applied Microscopy
• /
• 제47권3호
• /
• pp.203-207
• /
• 2017

A homogeneous $KNbO_3$ (KN) phase was formed by sintering at $1,040^{\circ}C$ for 1 hour, without formation of the $K_2O$-deficient secondary phase even though suffering the minor loss of $K_2O$. KN liquid phase was formed during sintering and abnormal grain growth occurred in this specimen. The detailed microstructural observations on KN during sintering were carried out using high resolution transmission electron microscopy. The ledged structures were found at the KN grain boundary and the abnormal grain growth was performed by the lateral migration of these ledges in the presence of the liquid phase. The liquid pockets were found in the KN grains. They have various external shapes mainly due to the kinetic factors. They have atomically flat interfaces with some ledges with one atomic height. The slight deficient $K_2O$ by evaporation might somewhat reduce the melting point of KN from the reported at $1,058^{\circ}C$. The liquid pockets play an important role in supplying the liquid phase during the abnormal grain growth in the sintering process of KN ceramics.

• 대한전자공학회논문지SD
• /
• 제41권1호
• /
• pp.15-20
• /
• 2004

산화막위에 증착된 금속박막과 산화막과의 계면효과를 조사하였다. 산화막으로는 현재 반도체소자제조공정에 많이 사용되고 있는 BPSG 산화막과 PETEOS 산화막을 사용하였다. 이 두 종류의 산화막위에 적층구조의 금속박막을 형성한 후, 금속박막의 열처리에 의한 계면의 영향을 SEM (scanning electron microscopy), TEM (transmission electron microscopy), AES (auger electron spectroscopy)를 사용하여 조사하였다. BPSG 산화막위에 증착된 금속박막을 $650^{\circ}C$ 이상에서 RTP anneal을 한 경우, BPSG 산화막과 금속박막의 계면결합상태가 좋지 않았고, BPSG 산화막과 금속박막의 계면에 phosphorus가 축적된 영역을 확인하였다. 반면에 PETEOS 산화막위에 증착된 금속박막의 경우, RTP anneal 온도에 관계없이 계면결합상태는 좋았다. 본 연구에서 BPSG 산화막위에 금속박막을 증착할 경우 RTP anneal 온도는 $650^{\circ}C$ 보다 작게 하여야 함을 알 수 있었다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
• /
• pp.63-66
• /
• 2004

Transparent MgO thin films were deposited on glass substrates by electron beam evaporation of MgO (99.99%) under $O_2$ atmosphere at 150-250 $^{\circ}C$. These films were characterized for their useful properties such as thickness, transmission, and refractive index using ultraviolet / visible (UV/VIS) spectrophotometer, scanning electron microscopy (SEM), and Spectroscopic Ellipsometry. The thickness of MgO films were measured by alpha step instrument and found to be 600 nm to 1000 nm and are meeting the stoichiometry. The transmission spectrum of these films shows transmittance values ${\sim}$92%..

• Journal of Microbiology and Biotechnology
• /
• 제16권8호
• /
• pp.1316-1319
• /
• 2006

An antibody displayed phage collection (SBAE-2R), screened from a human synthetic phage antibody library (Fab 21ox), was used for the determination of dextran. The dextran-binding affinity was determined by serologically specific transmission electron microscopy (TEM) and a paper dipstick assay. The phage collection was distributed over the dextrancoated grids with 39$\pm$25 phages/$\mu$m$^2$ on the grids. Phages were not seen on dextran-coated grids exposed to the Fab 2lox phage library. The phage collection (SBAE-2R) produced 54$\pm$3 color normalized intensity (N.I.) from 125 ppm to 1,000 ppm of dextran and 5$\pm$1 (N.I.) for 63 ppm of dextran in a paper dipstick assay. This research extends the analytical options for dextran analysis by antibody displayed phage with a minimum of equipment usage.

• Transactions on Electrical and Electronic Materials
• /
• 제4권4호
• /
• pp.1-6
• /
• 2003

Aluminum oxide ($Al_2O_3$) nanotubes and nanorods were fabricated by coating and filling of multiwalled carbon nanotubes (MWNTs) with atomic-layer deposition (ALD). $Al_2O_3$ material was deposited on the MWNTs at a substrate temperature of $300^{\circ}C$ using trimethylaluminum and distilled water. Transmission electron microscopy, high resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, and selected area electron diffraction of the deposited MWNTs revealed that amorphous $Al_2O_3$ material coats the MWNTs conformally and that this material fills the inside of the MWNTs. These illustrate that ALD has an excellent capability to coat and fill any three-dimensional shapes of MWNTs conformally without producing any crystallites.

• 한국공작기계학회논문집
• /
• 제14권1호
• /
• pp.44-51
• /
• 2005

Material degradation is a multibillion-dollar problem which affects all the industries amongst others. The last decades have seen the development of newer and more effective techniques such as Focused-ion beam(FIB), Transmission electron microscopy(TEM), Secondary-ion mass spectroscopy(SIMS), auger electron spectroscopy(AES), X-ray Photoelectron spectroscopy(XPS) , Electrochemical impedance spectroscopy(EIS), Photo- stimulated luminescence spectroscopy(PSLS), etc. to study various forms of material degradation. These techniques are now used routinely to obtain information on the chemical state, depth profiling, composition, stress state, etc. to understand the degradation behavior. This paper describes the use of these techniques specifically applied to materials degradation and failure analysis.

• Applied Microscopy
• /
• 제42권4호
• /
• pp.218-222
• /
• 2012

Modern aberration-corrected transmission electron microscope (TEM) with appropriate electron beam energy is able to achieve atomic resolution imaging of single and bilayer graphene sheets. Especially, atomic configuration of bilayer graphene with a rotation angle can be identified from the direct imaging and phase reconstructed imaging since atomic resolution Moir$\acute{e}$ pattern can be obtained successfully at atomic scale using an aberration-corrected TEM. This study boosts a reliable stacking order analysis, which is required for synthesized or artificially prepared multilayer graphene, and lets graphene researchers utilize the information of atomic configuration of stacked graphene layers readily.

• Bulletin of the Korean Chemical Society
• /
• 제33권12호
• /
• pp.3977-3980
• /
• 2012

Nanostructured thermoelectric bismuth telluride ($Bi_2Te_3$) powders with various morphologies, such as nanoplates, nanorods, and nanotubes, were prepared by a hydrothermal method based on the reaction between $BiCl_3$, Te, and sodium ethylenediaminetetraacetate ($Na_2$-EDTA) at 150, 180, and $210^{\circ}C$. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED). The effect of reaction temperature on the morphology of the $Bi_2Te_3$ particles was investigated, and the possible mechanism of morphology control was proposed.

• International Journal of Korean Welding Society
• /
• 제3권2호
• /
• pp.29-39
• /
• 2003

The durability and reliability of thermal barrier coatings (TBCs) play an important role in the service reliability, availability and maintainability (RAM) of hot­section components in advanced turbine engines for aero and utility applications. Photostimulated luminescence spectroscopy (PSLS) and electrochemical impedance spectroscopy (EIS) are being concurrently developed as complimentary non­destructive evaluation (NDE) techniques for quality control and life­remain assessment of TBCs. This paper overviews the governing principles and applications of the luminescence and the impedance examined in the light of residual stress, phase constituents and resistance (or capacitance) in TBC constituents including the thermally grown oxide (TGO) scale. Results from NDE by PSLS and EIS are discussed and related to the microstructural development during high temperature thermal cycling, examined by using a variety of microscopic techniques including focused ion beam (FIB) in­situ lift­out (INLO), transmission and scanning transmission electron microscopy (TEM and STEM).

• Applied Microscopy
• /
• 제51권
• /
• pp.10.1-10.9
• /
• 2021

We investigate the sensitivity of symmetry quantification algorithms based on the profile R-factor (R_p) and the normalized cross-correlation (NCC) coefficient (γ). A DM (Digital Micrograph^©) script embedded in the Gatan digital microscopy software is used to develop the symmetry quantification program. Using the Bloch method, a variety of CBED patterns are simulated and used to investigate the sensitivity of symmetry quantification algorithms. The quantification results show that two symmetry quantification coefficients are significantly sensitive to structural changes even for small strain values of < 1%.