Near-edge structure in electron-energy-loss spectra of MgO

1986 ◽  
Vol 33 (1) ◽  
pp. 22-24 ◽  
Author(s):  
Th. Lindner ◽  
H. Sauer ◽  
W. Engel ◽  
K. Kambe
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Edge Structure ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra

scholarly journals Comparison Between the Experimentally Determined Orientation Dependence of the Near Edge Structure in Electron Energy Loss Spectra from Graphite with Present Theoretical Formulations

2006 ◽  
Vol 12 (S02) ◽  
pp. 1198-1199
Author(s):  
A Liu ◽  
N Zaluzec
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Orientation Dependence ◽  
Edge Structure ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2005

Electron Energy-Loss Near-Edge Structures as a Probe of Solids

1990 ◽  
Vol 48 (2) ◽  
pp. 70-71
Author(s):  
W. Engel ◽  
H. Sauer
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Excited Atom ◽  
Core Level ◽  
The Other ◽  
Edge Structure ◽  
Local Electronic Structure ◽  
Electron Energy Loss ◽  
Titanium Compounds ◽  
Electron Energy Loss Spectra

In general, core-level spectra show a very pronounced structure beyond the edge up to about 20 eV. This is called the near-edge structure, and in the case of electron energy-loss spectra its acronym is ELNES. ELNES is due to transitions of electrons from a particular core level to the lowest unoccupied states in the solid. This provides information about the local electronic structure of the solid at the site of the excited atom, and may depend very sensitively on the arrangement of the neighbouring atoms.This effect is demonstrated in a series of Ti 2p core-level spectra shown in Figs. 1 and 3 which have been obtained from various tetravalent titanium compounds. In all these compounds the Ti4+ ions are surrounded by 6 oxygen atoms but they form perfect octahedra only in the case of SrTi O3. In the other compounds the oxygen octahedra are more or less distorted, giving rise to a splitting or broadening of peaks.

Fourier deconvolution of electron energy-loss spectra

1985 ◽  
Vol 398 (1815) ◽  
pp. 395-404 ◽  
Keyword(s):  
Fine Structure ◽  
Energy Loss ◽  
Electron Energy ◽  
Core Loss ◽  
Single Scattering ◽  
Electron Interaction ◽  
Edge Structure ◽  
Fourier Deconvolution ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra

Electron energy-loss spectroscopy (e. e. l. s.) performed with an electron microscope can be used to obtain plasmon spectra, near-edge fine structure and extended electron energy-loss fine structure (ex. e. l. f. s.), as well as to do chemical analysis on truly microscopic samples. However, the very strength of the electron–electron interaction gives rise to significant and sometimes predominant plural scattering effects. To obtain consistent and reliable estimates of the single scattering distributions these effects must be accounted for. In this paper, two Fourier-transform deconvolution methods of removing plural scattering from electron energy-loss spectra and their implementation on a microcomputer, are discussed. Their relative advantages and limitations are considered together with examples of artefacts that may arise in both plasmon and core-loss spectra. As a result of deconvolution the sensitivity and accuracy of core-elemental analysis is enhanced but, more importantly, it is possible to obtain reproducible near-edge structure and plasmon spectra from relatively thick samples that would otherwise not be suitable for investigation by means of e. e. l. s.

Parallel Detection of Electron Energy Loss Spectra in Direct Mode

1990 ◽  
Vol 48 (2) ◽  
pp. 82-83
Author(s):  
Eckhard Quandt ◽  
Stephan laBarré ◽  
Andreas Hartmann ◽  
Heinz Niedrig
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Energy Resolution ◽  
Large Angle ◽  
Maximum Energy ◽  
Semiconductor Detectors ◽  
Parallel Detection ◽  
Photodiode Arrays ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra

Due to the development of semiconductor detectors with high spatial resolution -- e.g. charge coupled devices (CCDs) or photodiode arrays (PDAs) -- the parallel detection of electron energy loss spectra (EELS) has become an important alternative to serial registration. Using parallel detection for recording of energy spectroscopic large angle convergent beam patterns (LACBPs) special selected scattering vectors and small detection apertures lead to very low intensities. Therefore the very sensitive direct irradiation of a cooled linear PDA instead of the common combination of scintillator, fibre optic, and semiconductor has been investigated. In order to obtain a sufficient energy resolution the spectra are optionally magnified by a quadrupole-lens system.The detector used is a Hamamatsu S2304-512Q linear PDA with 512 diodes and removed quartz-glas window. The sensor size is 13 μm ∗ 2.5 mm with an element spacing of 25 μm. Along with the dispersion of 3.5 μm/eV at 40 keV the maximum energy resolution is limited to about 7 eV, so that a magnification system should be attached for experiments requiring a better resolution.

Electron energy-loss near-edge structure in silicate minerals

1992 ◽  
Vol 50 (2) ◽  
pp. 1258-1259
Author(s):  
D W McComb ◽  
R S Payne ◽  
P L Hansen ◽  
R Brydson
Keyword(s):  
Solid State ◽  
Energy Loss ◽  
Electron Energy ◽  
State Energy ◽  
Local Environment ◽  
Edge Structure ◽  
Silicate Minerals ◽  
Two Samples ◽  
Electron Energy Loss ◽  
Careful Processing

Electron energy-loss near-edge structure (ELNES) is an effective probe of the local geometrical and electronic environment around particular atomic species in the solid state. Energy-loss spectra from several silicate minerals were mostly acquired using a VG HB501 STEM fitted with a parallel detector. Typically a collection angle of ≈8mrad was used, and an energy resolution of ≈0.5eV was achieved.Other authors have indicated that the ELNES of the Si L2,3-edge in α-quartz is dominated by the local environment of the silicon atom i.e. the SiO4 tetrahedron. On this basis, and from results on other minerals, the concept of a coordination fingerprint for certain atoms in minerals has been proposed. The concept is useful in some cases, illustrated here using results from a study of the Al2SiO5 polymorphs (Fig.l). The Al L2,3-edge of kyanite, which contains only 6-coordinate Al, is easily distinguished from andalusite (5- & 6-coordinate Al) and sillimanite (4- & 6-coordinate Al). At the Al K-edge even the latter two samples exhibit differences; with careful processing, the fingerprint for 4-, 5- and 6-coordinate aluminium may be obtained.

Combined ab-initio and N-K, Ti-L2,3, V-L2,3 electron energy-loss near edge structure studies for TiN and VN films

2007 ◽  
Vol 98 (11) ◽  
pp. 1060-1065 ◽  
Author(s):  
Boriana Rashkova ◽  
Petr Lazar ◽  
Josef Redinger ◽  
Raimund Podloucky ◽  
Gerald Kothleitner ◽  
...  
Keyword(s):  
Energy Loss ◽  
Ab Initio ◽  
Electron Energy ◽  
Edge Structure ◽  
Electron Energy Loss

The Use of ELNES for Microanalysis

1999 ◽  
Vol 5 (S2) ◽  
pp. 664-665
Author(s):  
A.J. Craven ◽  
M. MacKenzie
Keyword(s):  
Electron Microscopy ◽  
Energy Loss ◽  
Electron Energy ◽  
Analytical Electron Microscopy ◽  
Local Environment ◽  
Edge Structure ◽  
Similar Shape ◽  
Analytical Electron ◽  
Electron Energy Loss ◽  
Combining Information

The performance of many materials systems depends on our ability to control the distribution of atoms on a nanometre or sub-nanometre scale within those systems. This is as true for steels as it is for semiconductors. A key requirement for improving their performance is the ability to determine the distribution of the elements resulting from processing the material under a given set of conditions. Analytical electron microscopy (AEM) provides a range of powerful techniques with which to investigate this distribution. By combining information from different techniques, many of the ambiguities of interpretation of the data from an individual technique can be eliminated. The electron energy loss near edge structure (ELNES) present on an ionisation edge in the electron energy loss spectrum reflects the local structural and chemical environments in which the particular atomic species occurs. Thus it is a useful contribution to the information available. Since a similar local environment frequently results in a similar shape, ELNES is useful as a “fingerprint”.

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