Electron Energy Loss Spectroscopy in the Electron Microscope: Present State of Affairs

1978 ◽  
Vol 36 (3) ◽  
pp. 268-279
Author(s):  
C. Colliex ◽  
P. Trebbia
Keyword(s):  
Electron Microscope ◽  
Chemical Properties ◽  
Primary Electron ◽  
Formation Mechanisms ◽  
Transmitted Beam ◽  
Spatially Resolved ◽  
Energy Filtering ◽  
Transmission Electron ◽  
Microanalytical Technique ◽  
State Of Affairs

In the transmission electron microscope, among the various signals resulting from the interaction between the primary electron beam of well defined energy E0 and the specimen, the energy spectral distribution in the transmitted beam contains useful additional informations concerning the physical or chemical properties of the sample. As a consequence the insertion of a proper energy filtering device on any existing microscope column opens new fields of investigation from the fundamental understanding of the image formation mechanisms or the determination of the excitations spectrum in a solid to the development of a localized microanalytical technique at the spatially resolved scale of the electron microscope.

Analysis of Diffraction Contrast as A Function of Energy Loss in Energy Filtering Transmission Electron Microscope (EFTEM) Imaging and Possible Implications on High-Resolution Compositional Mapping

1999 ◽  
Vol 5 (S2) ◽  
pp. 620-621
Author(s):  
K.T. Moore ◽  
J.M. Howe
Keyword(s):  
Electron Microscope ◽  
Energy Loss ◽  
Electron Energy ◽  
Transmission Electron Microscope ◽  
Diffraction Contrast ◽  
Energy Filtering ◽  
Background Removal ◽  
Transmission Electron ◽  
Important Relationship ◽  
Electron Energy Loss

The dependence of diffraction contrast on electron energy loss is an important relationship that needs to be understood because of its potential effect on energy-filtering transmission electron microscope (EFTEM) images. Often when either a two-window jump-ratio image or a three-window elemental map is produced diffraction contrast is not totally eliminated and contributes to the intensity of the final EFTEM image. Background removal procedures often are unable to completely account for intensity changes due to dynamical effects (i.e., elastic scattering) that occur between images acquired at different energy losses, leaving artifacts in the final EFTEM image.In this study, the relationship between diffraction contrast and electron energy loss was investigated by obtaining EFTEM images of a bend contour in aluminum in 100 eV increments from 0 to 1000 eV (Fig. 1). EFTEM images were acquired a JOEL 2010F FEG TEM with a Gatan imaging filter (GIF) at a microscope magnification of 8 kX using a 1 eV/pixel dispersion, 2X binning (512 x 512) and exposure times ranging from 0.25 s for 0 eV energy loss up to 132 sec for 1000 eV energy loss.

Quantitative Analysis Of Bological Specimens by Spectrum-Imaging in the Energy Filtering Transmission Electron Microscope

2000 ◽  
Vol 6 (S2) ◽  
pp. 160-161
Author(s):  
R.D. Leapman ◽  
C.M. Brooks ◽  
N.W. Rizzo ◽  
T.L. Talbot
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Beam Current ◽  
Scanning Transmission Electron Microscope ◽  
Accurate Analysis ◽  
Energy Filtering ◽  
Inverse Power Law ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Spectrum Imaging

Electron energy loss spectrum-imaging (EELSI) in the energy filtering transmission electron microscope (EFTEM) can provide more accurate analysis of elemental distributions than that obtainable by the standard two-window or three-window background subtraction techniques. Spectra containing many channels can be extracted from regions of interest and analyzed using established methods for quantitation. For example, the pre-edge background can be fitted by an inverse power law and subtracted from the post-edge spectrum. EELSI in the EFTEM is often superior to spectrum-imaging in the scanning transmission electron microscope for mapping specimen regions of size greater than 1 μm. This is due the much larger total beam current that is available at the specimen in a fixed-beam microscope relative to a scanned-beam microscope. Our aim here is demonstrate the advantages of such EELSI measurements for analysis of biological specimens. However, we also indicate some potential pitfalls in acquiring elemental maps in the EFTEM, which can be attributed to specimen instabilities during the acquisition.

Identification of site-specific isotopic labels by vibrational spectroscopy in the electron microscope

Science ◽  
2019 ◽  
Vol 363 (6426) ◽  
pp. 525-528 ◽  
Author(s):  
Jordan A. Hachtel ◽  
Jingsong Huang ◽  
Ilja Popovs ◽  
Santa Jansone-Popova ◽  
Jong K. Keum ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Spatial Resolution ◽  
Theoretical Calculations ◽  
Scanning Transmission Electron Microscope ◽  
Real Space ◽  
Site Specific ◽  
Spatially Resolved ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Isotopic Labels

The identification of isotopic labels by conventional macroscopic techniques lacks spatial resolution and requires relatively large quantities of material for measurements. We recorded the vibrational spectra of an α amino acid, l-alanine, with damage-free “aloof” electron energy-loss spectroscopy in a scanning transmission electron microscope to directly resolve carbon-site–specific isotopic labels in real space with nanoscale spatial resolution. An isotopic red shift of 4.8 ± 0.4 milli–electron volts in C–O asymmetric stretching modes was observed for 13C-labeled l-alanine at the carboxylate carbon site, which was confirmed by macroscopic infrared spectroscopy and theoretical calculations. The accurate measurement of this shift opens the door to nondestructive, site-specific, spatially resolved identification of isotopically labeled molecules with the electron microscope.

Doping of Al-catalyzed Vapor-liquid-solid Grown Si Nnanowires

2007 ◽  
Vol 1018 ◽  
Author(s):  
Sung Jin Whang ◽  
Sung Joo Lee ◽  
Wei Feng Yang ◽  
Hai Chen Zhu ◽  
Han Lu Gu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Photoelectron Spectroscopy ◽  
Chemical Properties ◽  
Si Nanowires ◽  
Vapor Liquid Solid ◽  
Transmission Electron ◽  
Plasma Doping ◽  
Physical And Chemical ◽  
Vapor Liquid

AbstractWe successfully synthesized high quality single crystal Si nanowires using Al catalyst via vapor-liquid-solid (VLS) mechanism, having diameters ranging from 10 to 200 nm with 10∽20 §­ of length. Characterization of physical and chemical properties of Al-catalyzed Si nanowires using transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) analysis showed that single crystal Si nanowires can be grown with Al-catalyst at 540 ¡C and selective etching of Al existing at the tip of nanowire can provide metal-free Si nanowires that are compatible with conventional Si-based IC process. By using plasma doping method, it was confirmed that the doping level can be controlled and the boron was successfully introduced on Si substrate with 3×1022/cm3 of peak doping concentration.

Preparation of Pd/γ-Al2O3 Nanocatalyst and Characterization by X-Ray Diffraction and Transmission Electron Microscope

2013 ◽  
Vol 685 ◽  
pp. 312-315
Author(s):  
Karim. H. Hassan
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Selective Hydrogenation ◽  
Chemical Properties ◽  
Impregnation Method ◽  
Activated Alumina ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Physical And Chemical

In petrochemical industry, and mainly in ethylene production plants, acetylene presents in trace amount in ethylene gas and causes a serous problems owing to it is higher activity and being explosive at certain concentration limits with air, so it has to be converted to ethylene in selective hydrogenation. Three selective hydrogenation nanocatalysts Pd/γ-Al2O3 that contain 0.03 %, 0.05% and 0.07 wt % of palladium loaded on activated alumina were prepared by impregnation method. They were characterized for physical and chemical properties and structurally by X-ray diffraction, metal dispersion, and transmission electron microscope.

Nonorthogonal Twining in Epitaxial SrRuO3 Thin Films Grown on (001) LaAlO3

2001 ◽  
Vol 7 (S2) ◽  
pp. 332-333
Author(s):  
W. Tian ◽  
J. C. Jiang ◽  
X. Q. Pan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Rf Sputtering ◽  
Perovskite Oxides ◽  
The Other ◽  
Formation Mechanisms ◽  
Spatially Resolved ◽  
Transmission Electron ◽  
Electron Energy Loss

Nonorthogonal twinings have commonly been observed in perovskite oxides such as SrTi03 and BaTi03. Among them, the ﹛111﹜ Σ3 type twining exists with a relative large amount of population and has been extensively studied. By combining quantitative high resolution transmission electron microscopy (HRTEM) and spatially resolved electron energy loss spectroscopy (EELS), one was able to determine the atomic structure of the ﹛111﹜Σ3 twin boundary in these oxides.[l] On the other hand, nonorthogonal twinings in SrRuO3 have been much less studied. SrRu03, a ternary ruthenium metal oxide, has a perovskite-compatible structure and exhibits low electrical resistivity (10-4 Ω•cm), showing an unparallel technique importance in microelectronic applications. Since the properties of material strongly depend on the microstructure and defect configurations, it is important to study the twining structures and their formation mechanisms in SrRuO3 thin films.Transmission electron microscopy (TEM) was used to study the SrRuO3 thin films grown on (001) LaAlO3 by 90° off-axis rf sputtering.

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