• Applied Microscopy
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• 제46권3호
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• pp.164-166
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• 2016

Electron channeling contrast imaging (ECCI) is a powerful analyzing tool for identifying lattice defects like dislocations and twin boundaries. By using diffraction-based scanning electron microscopy technique, it enables microstructure analysis, which is comparable to that obtained by transmission electron microscopy that is mostly used in defect analysis. In this report, the optimal conditions for investigating crystal defects are suggested. We could obtain the best ECCI images when both acceleration voltage and probe current are high (30 kV and 20 nA). Also, shortening the working distance (6 mm) enhances the quality of defect imaging.

• Applied Microscopy
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• 제46권1호
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• pp.1-5
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• 2016

Recent cryo-electron microscopy (EM) studies reported the structure of various types of proteins at high resolution which is sufficient to visualize the intermolecular interaction at near atomic level. There are two main factors that cause the advances in cryo-EM; the development of image processing techniques, such as single particle analysis, and the improved electron detection devices. Although the atomic structures of small and asymmetric proteins are not yet to be determined by cryo-EM, this striking improvement implies the bright prospect of the application in biomedical studies. This study reviews the recently published studies reported high resolution structures using improved imaging analysis techniques and electron detectors. Furthermore, we will discuss about the future aspects of cryo-EM application.

• Applied Microscopy
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• 제38권2호
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• pp.135-140
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• 2008

본 연구에서 분만 중에 사망한 여성미라의 자궁 내에 있는 태아미라의 두피를 주사전자현미경과 투과전자현미경을 사용하여 관찰하였다. 주사전자현미경상에서 태아 두피의 표면은 잘 보존된 상태로 관찰되었으며, 각질층에 각화세포도 모양을 그대로 유지하고 있었다. 또한 땀샘과 모발도 원형 그대로 유지하고 있었으며 일부 두피표면에 모발이 빠져서 형성된 모공들이 다수 관찰되었다. 채취한 두피의 횡단면 두께는 약 1mm로 나타났으며 표피와 진피 및 피하조직이 뚜렷하게 존재하였다. 투과전자현미 경상에서 상피세포의 구조나 형태는 관찰되지 않았으며 또한, 세포의 형태를 그대로 유지하고 있는 어떠한 세포들도 전혀 관찰할 수 없었다. 그러나 진피의 교원섬유들은 잘 보존되어 있었고 이들 사이에 Clostridium 속으로 추정되는 부패세균들이 다수 관찰되었다.

• Applied Microscopy
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• 제46권4호
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• pp.206-216
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• 2016

This communication is to elucidate the state-of-the-art of techniques necessary to gather information on a new class of nanoelectronic devices known as memristors and related resistive switching devices, respectively. Unlike classical microelectronic devices such as transistors, the chemical and structural variations occurring upon switching of memristive devices require cutting-edge electron microscopy techniques. Depending on the switching mechanism, some memristors call for the acquisition of atomically resolved structural data, while others rely on atomistic chemical phenomena requiring the application of advanced X-ray and electron spectroscopy to correlate the real structure with properties. Additionally, understanding resistive switching phenomena also necessitates the application not only of pre- and post-operation analysis, but also during the process of switching. This highly challenging in situ characterization also requires the aforementioned techniques while simultaneously applying an electrical bias. Through this review we aim to give an overview of the possibilities and challenges as well as an outlook onto future developments in the field of nanoscopic characterization of memristive devices.

• ALGAE
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• 제30권4호
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• pp.291-301
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• 2015

The present study described with different microscopy approaches chloroplasts lobes in Laurencia sensu latu (Rhodophyta) species and found inter-specific differences among them. Chloroplasts were investigated using confocal laser scanning microscopy (LSM), transmission electron microscopy (TEM) and high resolution scanning electron microscopy (HRSEM). Using and TEM and HRSEM images we distinguished chloroplasts with lobes than chloroplasts without lobes in Yuzurua poiteaui var. gemmifera (Harvey) M. J. Wynne and Laurencia dendroidea J. Agardh cortical cells. The LSM images showed chloroplasts lobes (CLs) with different morphologies, varying from thicker and longer undulated projections in Y. poiteaui var. and L. dendroidea to very small and thin tubules as in Laurencia translucida Fujii & Cordeiro-Marino. The diameter and length of CLs from Y. poiteaui var. and L. dendroidea were significantly higher than L. translucida CLs (p < 0.01). Based on LSM observations, we suggest that lobes morphology has a taxonomic validity only to characterize L. translucida species.

• 한국전자현미경학회:학술대회논문집
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• 한국현미경학회 1997년도 제28차 창립30주년 기념 추계학술대회
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• pp.14-15
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• 1997

• 한국전자현미경학회:학술대회논문집
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• 한국현미경학회 1994년도 제25회 학술대회 연제 초록
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• pp.12-12
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• 1994

• 한국전자현미경학회:학술대회논문집
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• 한국현미경학회 1996년도 제27차 추계학술대회
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• pp.4-4
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• 1996

• Applied Microscopy
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• 제47권3호
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• pp.187-202
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• 2017

The classical electron band theory is a powerful tool to describe the electronic structures of solids. However, the band theory and corresponding density functional theory become inappropriate if a system comprises localized electrons in a scenario wherein strong electron correlations cannot be neglected. $SrRuO_3$ is one such system, and the partially localized d-band electrons exhibit some interesting behaviors such as enhanced effective mass, spectral incoherency, and oppression of ferromagnetism and itinerancy. In particular, a Metal-Insulator transition occurs when the thickness of $SrRuO_3$ approaches approximately four unit cells. In the computational studies, irrespective of the inclusion of on-site Hubbard repulsion and Hund's coupling parameters, correctly depicting the correlation effects is difficult. Because the oxygen atoms and the symmetry of octahedra are known to play important roles in the system, scrutinizing both the electronic band structure and the lattice system of $SrRuO_3$ is required to find the origin of the correlated behaviors. Transmission electron microscopy is a promising solution to this problem because of its integrated functionalities, which include atomic-resolution imaging and electron energy loss spectroscopy.

• Applied Microscopy
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• 제45권1호
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• pp.16-22
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• 2015

The reaction kinetics of the growth of Ni germanide in the Ni/Zr-interlayer/Ge system was investigated using isothermal in situ annealing at three different temperatures in a transmission electron microscope. The growth rate of Ni germanide in the Ni/Zr-interlayer/Ge system was determined to be diffusion controlled and depended on the square root of the time, with the activation energy of $1.04P{\pm}0.04eV$. For the Ni/Zr-interlayer/Ge system, no intermediate or intermixing layer between the Zr-interlayer and Ge substrate was formed, and thus the Ni germanide was formed and grew uniformly due to Ni diffusion through the diffusion path created in the amorphous Zr-interlayer during the annealing process in the absence of any intermetallic compounds. The reaction kinetics in the Ni/Zr-interlayer/Ge system was affected only by the Zr-interlayer.