Three-Dimensional Structure of Helical and Zigzagged Nanowires Using Electron Tomography

2008 ◽  
Vol 1144 ◽  
Author(s):  
Han Sung Kim ◽  
Yoon Myung ◽  
Chang Hyun Kim ◽  
Seung Yong Bae ◽  
Jae-Pyoung Ahn ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Tomography ◽  
Three Dimensional ◽  
Helical Structure ◽  
Axial Direction ◽  
Dimensional Structure ◽  
Gan Nanowires ◽  
Transmission Electron

ABSTRACTElectron tomography and high-resolution transmission electron microscopy were used to characterize the unique three-dimensional structures of helical or zigzagged GaN, ZnGa2O4 and Zn2SnO4 nanowires. The helical GaN nanowires adopt a helical structure that consists of six equivalent <0-111> growth directions with the axial [0001] direction. The ZnGa2O4 nanosprings have four equivalent <011> growth directions with the [001] axial direction. The zigzagged Zn2SnO4 nanowires consisted of linked rhombohedrons structure having the side edges matched to the <011> direction, and the [111] axial direction.

scholarly journals Recent Advances in Electron Tomography: TEM and HAADF-STEM Tomography for Materials Science and Semiconductor Applications

2005 ◽  
Vol 11 (5) ◽  
pp. 378-400 ◽  
Author(s):  
Christian Kübel ◽  
Andreas Voigt ◽  
Remco Schoenmakers ◽  
Max Otten ◽  
David Su ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Structural Information ◽  
Electron Tomography ◽  
Semiconductor Devices ◽  
Three Dimensional ◽  
Crystalline Materials ◽  
Transmission Electron ◽  
Stem Tomography

Electron tomography is a well-established technique for three-dimensional structure determination of (almost) amorphous specimens in life sciences applications. With the recent advances in nanotechnology and the semiconductor industry, there is also an increasing need for high-resolution three-dimensional (3D) structural information in physical sciences. In this article, we evaluate the capabilities and limitations of transmission electron microscopy (TEM) and high-angle-annular-dark-field scanning transmission electron microscopy (HAADF-STEM) tomography for the 3D structural characterization of partially crystalline to highly crystalline materials. Our analysis of catalysts, a hydrogen storage material, and different semiconductor devices shows that features with a diameter as small as 1–2 nm can be resolved in three dimensions by electron tomography. For partially crystalline materials with small single crystalline domains, bright-field TEM tomography provides reliable 3D structural information. HAADF-STEM tomography is more versatile and can also be used for high-resolution 3D imaging of highly crystalline materials such as semiconductor devices.

Chemical Nano-tomography of Self-assembled Ge-Si:Si(001) Islands from Quantitative High Resolution Transmission Electron Microscopy

2009 ◽  
Vol 1184 ◽  
Author(s):  
Luciano Andrey Montoro ◽  
Marina Leite ◽  
Daniel Biggemann ◽  
Fellipe Grillo Peternella ◽  
Kees Joost Batenburg ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Three Dimensional ◽  
Precise Knowledge ◽  
Transmission Electron ◽  
Self Consistent ◽  
Chemical Distribution

AbstractThe knowledge of composition and strain with high spatial resolution is highly important for the understanding of the chemical and electronic properties of alloyed nanostructures. Several applications require a precise knowledge of both composition and strain, which can only be extracted by self-consistent methodologies. Here, we demonstrate the use of a quantitative high resolution transmission electron microscopy (QHRTEM) technique to obtain two-dimensional (2D) projected chemical maps of epitaxially grown Ge-Si:Si(001) islands, with high spatial resolution, at different crystallographic orientations. By a combination of these data with an iterative simulation, it was possible infer the three-dimensional (3D) chemical arrangement on the strained Ge-Si:Si(001) islands, showing a four-fold chemical distribution which follows the nanocrystal shape/symmetry. This methodology can be applied for a large variety of strained crystalline systems, such as nanowires, epitaxial islands, quantum dots and wells, and partially relaxed heterostructures.

Three-Dimensional Imaging of Shear Band Produced by ECAP Process in Al-Ag Alloy

2006 ◽  
Vol 503-504 ◽  
pp. 603-608
Author(s):  
Koji Inoke ◽  
Kenji Kaneko ◽  
Z. Horita
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Tomography ◽  
Shear Bands ◽  
Three Dimensional ◽  
Angular Pressing ◽  
Ecap Process ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
The Matrix

A significant change in microstructure occurs during the application of severe plastic deformation (SPD) such as by equal-channel angular pressing (ECAP). In this study, intense plastic strain was imposed on an Al-10.8wt%Ag alloy by the ECAP process. The amount of strain was controlled by the numbers of passes. After 1 pass of ECAP, shear bands became visible within the matrix. With increasing numbers of ECAP passes, the fraction of shear bands was increased. In this study, the change in microstructures was examined by three-dimensional electron tomography (3D-ET) in transmission electron microscopy (TEM) or scanning transmission electron microscopy (STEM). With this 3D-ET method, it was possible to conduct a precise analysis of the sizes, widths and distributions of the shear bands produced by the ECAP process. It is demonstrated that the 3D-ET method is promising to understand mechanisms of microstructural refinement using the ECAP process.

Three-Dimensional Chemistry of Multiphase Nanomaterials by Energy-Filtered Transmission Electron Microscopy Tomography

2012 ◽  
Vol 18 (5) ◽  
pp. 1118-1128 ◽  
Author(s):  
Lucian Roiban ◽  
Loïc Sorbier ◽  
Christophe Pichon ◽  
Pascale Bayle-Guillemaud ◽  
Jacques Werckmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Tomography ◽  
Three Dimensional ◽  
Point Of View ◽  
Analysis Tool ◽  
Shell Nanoparticles ◽  
3D Nanostructures ◽  
Transmission Electron ◽  
Silica Alumina

AbstractA three-dimensional (3D) study of multiphase nanostructures by chemically selective electron tomography combining tomographic approach and energy-filtered imaging is reported. The implementation of this technique at the nanometer scale requires careful procedures for data acquisition, computing, and analysis. Based on the performances of modern transmission electron microscopy equipment and on developments in data processing, electron tomography in the energy-filtered imaging mode is shown to be a very appropriate analysis tool to provide 3D chemical maps at the nanoscale. Two examples highlight the usefulness of analytical electron tomography to investigate inhomogeneous 3D nanostructures, such as multiphase specimens or core-shell nanoparticles. The capability of discerning in a silica-alumina porous particle the two different components is illustrated. A quantitative analysis in the whole specimen and toward the pore surface is reported. This tool is shown to open new perspectives in catalysis by providing a way to characterize precisely 3D nanostructures from a chemical point of view.

Morphometric, quantitative, and three-dimensional analysis of the heart muscle fibers of old rats: Transmission electron microscopy and high-resolution scanning electron microscopy methods

2012 ◽  
Vol 76 (2) ◽  
pp. 184-195 ◽  
Author(s):  
Diego Pulzatto Cury ◽  
Fernando José Dias ◽  
Marcia Consentino Kronka Sosthenes ◽  
Carlos Alexandre Dos Santos Haemmerle ◽  
Koichi Ogawa ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Dimensional Analysis ◽  
Heart Muscle ◽  
Three Dimensional ◽  
Transmission Electron ◽  
Old Rats ◽  
Scanning Electron

TEM and STEM Electron Tomography Analysis of Amorphous Alloys CoP-CoNiP System

2012 ◽  
Vol 590 ◽  
pp. 9-12 ◽  
Author(s):  
Tamara Mekhantseva ◽  
Oleg Voitenko ◽  
Ilya Smirnov ◽  
Evgeny Pustovalov ◽  
Vladimir Plotnikov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Amorphous Alloys ◽  
Electron Tomography ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
High Resolution Images ◽  
Electron Energy Loss ◽  
Tomography Analysis

This paper covers the analysis of amorphous alloys CoP-CoNiP system by means of high-resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy and electron tomography. The last years have seen a sufficient progress in the analysis of nanomaterials structure with the help of high resolution tomography. This progress was motivated by the development of microscopes equipped with aberration correctors and specialized sample holders which allow reaching the tilts angles up to ±80°. The opportunities delivered by the method of electron tomography sufficiently grow when producing high resolution images and using chemical analysis, such as X-Ray energy-dispersive microanalysis and electron energy loss spectroscopy (EELS).

scholarly journals Three-dimensional reconstruction of an actin bundle.

1988 ◽  
Vol 107 (2) ◽  
pp. 597-611 ◽  
Author(s):  
E S Bullitt ◽  
D J DeRosier ◽  
L M Coluccio ◽  
L G Tilney
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Three Dimensional ◽  
Oblate Spheroid ◽  
Potassium Thiocyanate ◽  
Dimensional Structure ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Dimensional Reconstruction ◽  
Molecular Masses

We present the three-dimensional structure of an actin filament bundle from the sperm of Limulus. The bundle is a motile structure which by changing its twist, converts from a coiled to an extended form. The bundle is composed of actin plus two auxiliary proteins of molecular masses 50 and 60 kD. Fraying the bundle with potassium thiocyanate created three classes of filaments: actin, actin plus the 60-kD protein, and actin plus both the auxiliary proteins. We examined these filaments by transmission electron microscopy and scanning transmission electron microscopy (STEM). Three-dimensional reconstructions from electron micrographs allowed us to visualize the actin subunit and the 60- and 50-kD subunits bound to it. The actin subunit appears to be bilobed with dimensions 70 X 40 X 35 A. The inner lobe of the actin subunit, located at 20 A radius, is a prolate ellipsoid, 50 X 25 A; the outer actin lobe, at 30 A radius, is a 35-A-diam spheroid. Attached to the inner lobe of actin is the 60-kD protein, an oblate spheroid, 55 X 40 A, at 50 A radius. The armlike 50-kD protein, at 55 A radius, links the 60-kD protein on one of actin's twin strands to the outer lobe of the actin subunit on the opposite strand. We speculate that the 60-kD protein may be a bundling protein and that the 50-kD protein may be responsible for the change in twist of the filaments which causes extension of the bundle.

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