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.

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 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.

Extending Energy-Filtered Transmission Electron Microscopy (EFTEM) into Three Dimensions Using Electron Tomography

2003 ◽  
Vol 9 (6) ◽  
pp. 542-555 ◽  
Author(s):  
Matthew Weyland ◽  
Paul A. Midgley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Energy Loss ◽  
Electron Tomography ◽  
Three Dimensional ◽  
High Energy ◽  
Three Dimensions ◽  
Series Data ◽  
Elemental Distribution ◽  
Transmission Electron

The length scales on which materials microstructures are being formed, grown, and even designed are becoming increasingly small and increasingly three-dimensional. For such complex structures two-dimensional transmission electron microscopy (TEM) analysis is often inadequate and occasionally misleading. One approach to this problem is the modification of electron tomography techniques, developed for structural biology, for use in materials science. Energy-Filtered (EF) TEM elemental distribution images approximate to true projections of structure, and, as such, can be used to reconstruct the three-dimensional distribution of chemical species. A sample holder has been modified to allow the high tilt (±60°) required for tomography and a semiautomatic acquisition script designed to manage energy-loss acquisition. Tilt series data sets have been acquired from two widely different experimental systems, Cr carbides in 316 stainless steel and magnetite nanocrystals in magnetotactic bacteria, demonstrating single- and multiple-element tomography. It is shown that both elemental maps and jump-ratio images are suitable for reconstruction, despite the effects of diffraction contrast in the former and thickness changes in the latter. It is concluded that the image contrast, signal, and signal-to-noise ratio (SNR) are key to the achievable reconstruction quality and, as such, the technique may be of limited value for high energy loss/small inelastic cross section edges.

Three Dimensional Energy Filtered Transmission Electron Microscopy (3D-EFTEM)

2001 ◽  
Vol 7 (S2) ◽  
pp. 1162-1163
Author(s):  
M Weyland ◽  
P.A. Midgley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Tomography ◽  
3D Structure ◽  
Three Dimensional ◽  
Biological Macromolecules ◽  
Physical Sciences ◽  
Flexible Tool ◽  
Spatially Resolved ◽  
Transmission Electron

Energy filtered transmission electron microscopy (EFTEM) has been developed in recent years to be a highly flexible tool for spatially resolved microanalysis. The basic technique has been extended to allow fully quantitative mapping of single elements, or a large range of elements using an image-spectroscopy approach . All these techniques are still limited by the nature of the TEM as a structure projector; any elemental map is only a 2D projection of what is in reality a 3D structure. A fully 3D approach to EFTEM analysis would offer additional insights into many materials problems and make possible meaningful analysis of certain systems for the first time. Three-dimensional electron microscopy (electron tomography) offers one path for the reconstruction of 3D structures from 2D projections. Although this has been well developed for solving the structure of biological macromolecules and viruses its use in the physical sciences is quite new.

Characterization of Precipitates by Three-Dimensional Electron Tomography

2007 ◽  
Vol 561-565 ◽  
pp. 2009-2012 ◽  
Author(s):  
Kenji Kaneko ◽  
Keisuke Sato ◽  
Z. Horita ◽  
Koji Inoke
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Tomography ◽  
Three Dimensional ◽  
Dimensional Electron ◽  
Transmission Electron

Structures and morphologies of Ge precipitates in an Al-Ge alloy were characterized by a combination of transmission electron microscopy and three-dimensional electron tomography. Faceting of the precipitates was clearly seen using transmission electron microscopy and varieties of precipitate morphologies were identified by three-dimensional electron tomography.

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