Quantitative Energy-Filtering Transmission Electron Microscopy (EFTEM) In Materials Science

1998 ◽  
Vol 4 (S2) ◽  
pp. 128-129
Author(s):  
F. Hofer ◽  
W. Grogger ◽  
P. Warbichler
Keyword(s):  
Materials Science ◽  
Important Application ◽  
Elemental Mapping ◽  
Secondary Phases ◽  
Edge Image ◽  
Energy Filtering ◽  
Window Method ◽  
Transmission Electron ◽  
Elemental Maps

Equipping a transmission electron microscope with an energy-filter offers extraordinary advantages for the characterization of both materials science and biological samples. Besides improvements for TEM imaging and electron diffraction like better contrast and resolution, elemental mapping using inner-shell ionizations has become the main application of EFTEM. Elemental maps with resolution down to 1 nm and elemental sensitivities down to a single monolayer have been reported. Using a Philips CM20 equipped with a Gatan Imaging Filter (GIF) for our experimental work, we acquired elemental maps with the three window method (A.E-1r background extrapolation from two pre-edge windows) and jump ratio images (division of post-edge image by a pre-edge image). One important application of EFTEM is the detection of secondary phases in materials e.g. precipitates and grain boundary phases. For example, fig.la shows the TEM-image of a 10%Cr steel with the secondary phases mostly invisible.

Quantitative Energy-filtering Transmission Electron Microscopy in Materials Science

2000 ◽  
Vol 6 (2) ◽  
pp. 161-172 ◽  
Author(s):  
Werner Grogger ◽  
Ferdinand Hofer ◽  
Peter Warbichler ◽  
Gerald Kothleitner
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Materials Science ◽  
Steel Specimen ◽  
Elemental Distribution ◽  
Secondary Phases ◽  
Energy Filtering ◽  
Transmission Electron ◽  
The Matrix ◽  
Titanate Ceramics

Energy-filtered transmission electron microscopy (EFTEM) can be used to acquire elemental distribution images at high lateral resolution within short acquisition times. In this article, we present an overview of typical problems from materials science which can be preferentially solved by means of EFTEM. In the first example, we show how secondary phases in a steel specimen can be easily detected by recording jump ratio images of the matrix element under rocking beam illumination. Secondly, we describe how elemental maps can be converted into concentration maps. A Ba-Nd-titanate ceramics serves as a typical materials science example exhibiting three different compounds with varying composition.

Compositional Mapping with Energy Filtering TEM: The Present Status

2001 ◽  
Vol 7 (S2) ◽  
pp. 1136-1137
Author(s):  
Ferdinand Hofer ◽  
Gerald Kothleitner ◽  
Peter Warbichler
Keyword(s):  
High Performance ◽  
Materials Science ◽  
Detection Efficiency ◽  
Signal To Noise Ratio ◽  
Energy Filtering ◽  
Transmission Electron ◽  
Experimental Parameters ◽  
Elemental Maps ◽  
High Performance Level

Energy filtering transmission electron microscopy (EFTEM) has matured into an important nanoanalytical technique in both materials and life sciences. One of the technique′s main advantages stems from the possibility to quickly form images that contain two-dimensional elemental information for most elements (Li to Pu) from relatively large specimen areas with nanometer resolution. Over the last years numerous and wide-ranging applications have demonstrated its almost unrivalled power for assessing typical materials science questions.Both in-column or post-column filter microscopes have reached a high performance level, but future improvements are still desirable, in particular with respect to increased transmissivity, improved isochromaticity and higher detection efficiency. Current instruments allow to acquire elemental maps with 1-5 nm spatial resolution limited mainly by the aberrations of the microscope and by the quality of the specimen. As recently shown 0.4 nm resolution is feasible.One major practical problem of EFTEM compositional mapping is the poor signal-to-noise ratio, which means that experimental parameters have to be chosen very carefully in order to optimize this ratio.

scholarly journals Synthesis and Characterization of a Bioconjugate Based on Oleic Acid and L-Cysteine

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1791
Author(s):  
Marco Vizcarra-Pacheco ◽  
María Ley-Flores ◽  
Ana Mizrahim Matrecitos-Burruel ◽  
Ricardo López-Esparza ◽  
Daniel Fernández-Quiroz ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Materials Science ◽  
Critical Micellar Concentration ◽  
Synthesis And Characterization ◽  
New Materials ◽  
Visible Spectroscopy ◽  
Amide Bonds ◽  
Transmission Electron ◽  
Self Assembled

One of the main challenges facing materials science today is the synthesis of new biodegradable and biocompatible materials capable of improving existing ones. This work focused on the synthesis of new biomaterials from the bioconjugation of oleic acid with L-cysteine using carbodiimide. The resulting reaction leads to amide bonds between the carboxylic acid of oleic acid and the primary amine of L-cysteine. The formation of the bioconjugate was corroborated by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and nuclear magnetic resonance (NMR). In these techniques, the development of new materials with marked differences with the precursors was confirmed. Furthermore, NMR has elucidated a surfactant structure, with a hydrophilic part and a hydrophobic section. Ultraviolet-visible spectroscopy (UV-Vis) was used to determine the critical micellar concentration (CMC) of the bioconjugate. Subsequently, light diffraction (DLS) was used to analyze the size of the resulting self-assembled structures. Finally, transmission electron microscopy (TEM) was obtained, where the shape and size of the self-assembled structures were appreciated.

Elemental Mapping of Materials Using Omega Filter and Imaging Plate

2000 ◽  
Vol 6 (S2) ◽  
pp. 216-217
Author(s):  
Y. Ikematsu ◽  
D. Shindo ◽  
T. Oikawa ◽  
M. Kersker
Keyword(s):  
Electron Microscope ◽  
Ccd Camera ◽  
Mapping Technique ◽  
Imaging Plate ◽  
Elemental Distribution ◽  
Elemental Mapping ◽  
Window Method ◽  
Transmission Electron ◽  
Window Technique ◽  
Imaging Plates

Elemental microanalysis has been important in materials characterization, since the elemental distribution strongly affects the property of various materials. A recently developed post-column energy filter coupled with a slow scan CCD camera makes it possible to carry out elemental mapping with a transmission electron microscope. Here, we develop the elemental mapping technique utilizing the omega filter and imaging plates (3760x3000 pixels). Since the data obtained from the imaging plates consist of a large number of pixels, fine and detailed elemental analysis will be expected.Energy-filtered images were obtained by a JEM-2010 electron microscope installed with an omega-type energy filter, and they were recorded on imaging plates (FDL-UR-V:25 μm/pixel). The width of an energy-selecting slit was set to be 20 eV. Elemental maps were obtained from the energy-filtered images using the three window technique. Special care was taken to reduce the image shifts among the three filtered images used in the three-window method.

scholarly journals Characterization of Pd Impurities and Finite-Sized Defects in Detector Grade CdZnTe

2011 ◽  
Vol 1341 ◽  
Author(s):  
M.C. Duff ◽  
J.P. Bradley ◽  
Z.R. Dai ◽  
N. Teslich ◽  
A. Burger ◽  
...  
Keyword(s):  
Room Temperature ◽  
Cubic Phase ◽  
Secondary Phases ◽  
Detector Performance ◽  
X Ray ◽  
Metal Impurities ◽  
Transmission Electron ◽  
Large Numbers ◽  
Topographic Imaging

ABSTRACTSynthetic CdZnTe or “CZT” crystals are highly suitable for γ-spectrometers operating at the room temperature. Secondary phases (SP) in CZT are known to inhibit detector performance, particularly when they are present in large numbers or dimensions. These SP may exist as voids or composites of non-cubic phase metallic Te layers with bodies of polycrystalline and amorphous CZT material and voids. Defects associated with crystal twining may also influence detector performance in CZT. Using transmission electron microscopy, we identify two types of defects that are on the nano scale. The first defect consists of 40 nm diameter metallic Pd/Te bodies on the grain boundaries of Te-rich composites. Although the nano-Pd/Te bodies around these composites may be unique to the growth source of this CZT material, noble metal impurities like these may contribute to SP formation in CZT. The second defect type consists of atom-scale grain boundary dislocations. Specifically, these involve inclined “finite-sized” planar defects or interfaces between layers of atoms that are associated with twins. Finite-sized twins may be responsible for the subtle but observable striations that can be seen with optical birefringence imaging and synchrotron X-ray topographic imaging.

scholarly journals Energy-filtering transmission electron microscopy in materials science

1992 ◽  
Vol 3 (2-3) ◽  
pp. 141-157 ◽  
Author(s):  
Ludwig Reimer ◽  
Inge Fromm ◽  
Christoph Hülk ◽  
Reinhold Rennekamp
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Materials Science ◽  
Energy Filtering ◽  
Transmission Electron

An Integrated Energy-Filtering TEM for The Life Sciences

1996 ◽  
Vol 54 ◽  
pp. 466-467
Author(s):  
A.F. de Jong ◽  
H. Coppoolse ◽  
U. Lücken ◽  
M.K. Kundmann ◽  
A.J. Gubbens ◽  
...  
Keyword(s):  
Low Dose ◽  
Life Sciences ◽  
Ccd Camera ◽  
Cold Trap ◽  
Objective Lens ◽  
Elemental Mapping ◽  
Energy Filtering ◽  
Transmission Electron ◽  
Computer Controlled ◽  
High Degree

Energy-filtered transmission electron microscopy (EFTEM) has many uses in life sciences1. These include improved contrast for imaging unstained, cryo or thick samples; improved diffraction for electron crystallography, and elemental mapping and analysis. We have developed a new system for biological EFTEM that combines advanced electron-optical performance with a high degree of automation. The system is based on the Philips CM series of microscopes and the Gatan post-column imaging filter (GIF). One combination particulary suited for the life sciences is that of the CM 120-BioTWIN and the GIF100: the CM120-BioFilter. The CM 120-BioTWIN is equipped with a high-contrast objective lens for biological samples. Its specially designed cold-trap, together with low-dose software, supports full cryo-microscopy. The GIF 100 is corrected for second-order aberrations in both images and spectra. It produces images that are isochromatic to within 1.5 eV at 120 keV and distorted by less than 2% over lk x lk pixels. All the elements of the filter are computer controlled. Images and spectra are detected by a TV camera or a multi-scan CCD camera, both of which are incorporated in the filter. All filter and camera functions are controlled from Digital Micrograph running on an Apple Power Macintosh.

scholarly journals Energy-Filtering Transmission Electron Microscopy for the Characterization of Polymer Blend Morphologies

1997 ◽  
Vol 29 (4) ◽  
pp. 380-383 ◽  
Author(s):  
Shin Horiuchi ◽  
Kiyoshi Yase ◽  
Takeshi Kitano ◽  
Noboru Higashida ◽  
Toshiaki Ougizawa
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Polymer Blend ◽  
Energy Filtering ◽  
Transmission Electron

Elemental Mapping by Energy-Filtered Electron Microscopy

1994 ◽  
Vol 332 ◽  
Author(s):  
Ondrej L. Krivanek ◽  
Michael K. Kundmann ◽  
Xavier Bourrat
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Materials Science ◽  
Elemental Mapping ◽  
Quantitative Technique ◽  
Transmission Electron ◽  
Distribution Of Elements

ABSTRACTEnergy-filtered imaging in a transmission electron microscope provides a fast and quantitative technique for mapping the distribution of elements in solids at nm-level resolution. The technique and its instrumental requirements are reviewed, and illustrated in the context of materials science.

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