• Title/Summary/Keyword: Transmission Electron microscopy

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The Effects of Electron Beam Exposure Time on Transmission Electron Microscopy Imaging of Negatively Stained Biological Samples

  • Kim, Kyumin;Chung, Jeong Min;Lee, Sangmin;Jung, Hyun Suk
    • Applied Microscopy
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    • 제45권3호
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    • pp.150-154
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    • 2015
  • Negative staining electron microscopy facilitates the visualization of small bio-materials such as proteins; thus, many electron microscopists have used this conventional method to visualize the morphologies and structures of biological materials. To achieve sufficient contrast of the materials, a number of imaging parameters must be considered. Here, we examined the effects of one of the fundamental imaging parameters, electron beam exposure time, on electron densities generated using transmission electron microscopy. A single site of a negatively stained biological sample was illuminated with the electron beam for different times (1, 2, or 4 seconds) and sets of micrographs were collected. Computational image processing demonstrated that longer exposure times provide better electron densities at the molecular level. This report describes technical procedures for testing parameters that allow enhanced evaluations of the densities of electron microscopy images.

Cryo-Transmission Electron Microscopy in Korean Society of Microscopy

  • Han, Sung Sik
    • Applied Microscopy
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    • 제47권4호
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    • pp.215-217
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    • 2017
  • Dr. Jacques Dubochet, Dr. Joachim Frank, and Dr. Richard Henderson received the 2017 Nobel Prize for Chemistry for their efforts to develop effective ways to obtain high-resolution three-dimensional images of biomolecules using cryo-electron microscopy. Congratulations to the Nobel Prize in the field of electron microscopy, I will explain the scientific contributions of the three winners and introduce the role of cryo-electron microscopy (including cryo technology) in biology.

Transmission Electron Microscopy Sample Preparation of Ge2Sb2Te5 Nanowire Using Electron Beam

  • Lee, Hee-Sun;Lee, Jun-Young;Yeo, Jong-Souk
    • Applied Microscopy
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    • 제45권4호
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    • pp.199-202
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    • 2015
  • A simple and novel transmission electron microscopy (TEM) sample preparation method for phase change nanowire is investigated. A $Ge_2Sb_2Te_5$ (GST) nanowire TEM sample was meticulously prepared using nanomanipulator and gas injection system in a field emission scanning electron microscopy for efficient and accurate TEM analysis. The process can minimize the damage during the TEM sample preparation of the nanowires, thus enabling the crystallographic analysis of as-grown GST nanowires without unexpected phase transition caused by e-beam heating.

Three-Dimensional Automated Crystal Orientation and Phase Mapping Analysis of Epitaxially Grown Thin Film Interfaces by Using Transmission Electron Microscopy

  • Kim, Chang-Yeon;Lee, Ji-Hyun;Yoo, Seung Jo;Lee, Seok-Hoon;Kim, Jin-Gyu
    • Applied Microscopy
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    • 제45권3호
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    • pp.183-188
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    • 2015
  • Due to the miniaturization of semiconductor devices, their crystal structure on the nanoscale must be analyzed. However, scanning electron microscope-electron backscatter diffraction (EBSD) has a limitation of resolution in nanoscale and high-resolution electron microscopy (HREM) can be used to analyze restrictive local structural information. In this study, three-dimensional (3D) automated crystal orientation and phase mapping using transmission electron microscopy (TEM) (3D TEM-EBSD) was used to identify the crystal structure relationship between an epitaxially grown CdS interfacial layer and a $Cu(In_xGa_{x-1})Se_2$ (CIGS) solar cell layer. The 3D TEM-EBSD technique clearly defined the crystal orientation and phase of the epitaxially grown layers, making it useful for establishing the growth mechanism of functional nano-materials.

Cross-Sectional Transmission Electron Microscopy Specimen Preparation Technique by Backside Ar Ion Milling

  • Yoo, Jung Ho;Yang, Jun-Mo
    • 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 (> $1{\mu}m$).

Circular Fast Fourier Transform Application: A Useful Script for Fast Fourier Transform Data Analysis of High-resolution Transmission Electron Microscopy Image

  • Kim, Jin-Gyu;Yoo, Seung Jo;Kim, Chang-Yeon;Jou, Hyeong-Tae
    • Applied Microscopy
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    • 제44권4호
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    • pp.138-143
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    • 2014
  • Transmission electron microscope (TEM) is an excellent tool for studying the structure and properties of nanostructured materials. As the development of $C_s$-corrected TEM, the direct analysis of atomic structures of nanostructured materials can be performed in the high-resolution transmission electron microscopy (HRTEM). Especially, fast Fourier transform (FFT) technique in image processing is very useful way to determine the crystal structure of HRTEM images in reciprocal space. To apply FFT technique in HRTEM analysis in more reasonable and friendly manner, we made a new circular region of interest (C-ROI) FFT script and tested it for several HRTEM analysis. Consequentially, it was proved that the new FFT application shows more quantitative and clearer results than conventional FFT script by removing the streaky artifacts in FFT pattern images. Finally, it is expected that the new FFT script gives great advantages for quantitative interpretation of HRTEM images of many nanostructured materials.

Principles and Analysis of Electron Diffraction Patterns in Transmission Electron Microscopy : Utilization of Microcomputers (전자회절도형의 원리와 분석 : Microcomputer의 이용)

  • Sung, Chang-Mo
    • Applied Microscopy
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    • 제21권1호
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    • pp.108-120
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    • 1991
  • Principles of electron diffraction patterns in transmission electron microscope are described for beginners in terms of reciprocal lattices and Ewald sphere. Analysis of both ring patterns and spot patterns are illustrated with practical examples as well as basic calibrations of TEM. Especially convergent beam electron diffraction method is emphasized for the determination of lattice parameters, microstrains, and thickness of thin foil followed by a review of microcomputer programs for the electron diffraction analyses explained in this paper.

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Dynamical Instability of Interfaces

  • Saka, H.;Tsukimoto, S.;Sasaki, K.
    • Applied Microscopy
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    • 제36권spc1호
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    • pp.9-17
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    • 2006
  • An interface and a grain boundary in the solid state can be quite unstable and vibrate violently under special circumstances. Two examples of such a vibration, as observed by in-situ transmission electron microscopy, were presented.

Development of High-Temperature Solders: Contribution of Transmission Electron Microscopy

  • Bae, Jee-Hwan;Shin, Keesam;Lee, Joon-Hwan;Kim, Mi-Yang;Yang, Cheol-Woong
    • Applied Microscopy
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    • 제45권2호
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    • pp.89-94
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    • 2015
  • This article briefly reviews the results of recently reported research on high-temperature Pb-free solder alloys and the research trend for characterization of the interfacial reaction layer. To improve the product reliability of high-temperature Pb-free solder alloys, thorough research is necessary not only to enhance the alloy properties but also to characterize and understand the interfacial reaction occurring during and after the bonding process. Transmission electron microscopy analysis is expected to play an important role in the development of high-temperature solders by providing accurate and reliable data with a high spatial resolution and facilitating understanding of the interfacial reaction at the solder joint.

Electron Microscopy for the Morphological Characterization of Nanocellulose Materials (전자현미경을 이용한 나노셀룰로오스 물질의 형태학적 특성 분석 연구)

  • Kwon, Ohkyung;Shin, Soo-Jeong
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • 제48권1호
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    • pp.5-18
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    • 2016
  • Electron microscopy is an important investigation and analytical method for the morphological characterization of various cellulosic materials, such as micro-crystalline cellulose (MCC), microfibrillated cellulose (MFC), nanofibrillated cellulose (NFC), and cellulose nanocrystals (CNC). However, more accurate morphological analysis requires high-quality micrographs acquired from the proper use of an electron microscope and associated sample preparation methods. Understanding the interaction of electron and matter as well as the importance of sample preparation methods, including drying and staining methods, enables the production of high quality images with adequate information on the nanocellulosic materials. This paper provides a brief overview of the micro and nano structural analysis of cellulose, as investigated using transmission and scanning electron microscopy.