Connections between the electron-energy-loss spectra, the local electronic structure, and the physical properties of a material: A study of nickel aluminum alloys

1998 ◽  
Vol 57 (14) ◽  
pp. 8181-8202 ◽  
Author(s):  
David A. Muller ◽  
David J. Singh ◽  
John Silcox
Keyword(s):  
Electronic Structure ◽  
Aluminum Alloys ◽  
Energy Loss ◽  
Physical Properties ◽  
Electron Energy ◽  
Nickel Aluminum ◽  
Local Electronic Structure ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra

Local Electronic Structure Of Defects In Gan From Spatially Resolved Electron Energy-Loss Spectroscopy

1997 ◽  
Vol 482 ◽  
Author(s):  
M. K. H. Natusch ◽  
G. A. Botton ◽  
R. F. Broom ◽  
P. D. Brown ◽  
D. M. Tricker ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Crystal Defects ◽  
Vacuum Field ◽  
Spatially Resolved ◽  
Local Electronic Structure ◽  
Electron Energy Loss

AbstractThe optical properties and their modification by crystal defects of wurtzite GaN are investigated using spatially resolved electron energy-loss spectroscopy (EELS) in a dedicated ultra-high vacuum field emission gun scanning transmission electron microscope. The calculated density of states of the bulk crystal reproduces well the features of the measured spectra. The profound effect of a prismatic stacking fault on the local electronic structure is shown by the spatial variation of the optical properties derived from low-loss spectra. It is found that a defect state at the fault appears to bind 1.5 electrons per atom.

scholarly journals Electronic structure and electron energy-loss spectra of Sr0.35CoO2

2005 ◽  
Vol 135 (11-12) ◽  
pp. 687-691 ◽  
Author(s):  
R.J. Xiao ◽  
H.X. Yang ◽  
L.F. Xu ◽  
H.R. Zhang ◽  
Y.G. Shi ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra

Investigations of Bonding in Skutterudites by Electron Energy-Loss Spectroscopy

2007 ◽  
Vol 1044 ◽  
Author(s):  
Oystein Prytz ◽  
Ragnhild Saterli ◽  
Randi Holmestad ◽  
Johan Tafto
Keyword(s):  
Electronic Structure ◽  
Energy Loss ◽  
Fermi Level ◽  
Ab Initio ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Filled Skutterudite ◽  
Local Electronic Structure ◽  
Electron Energy Loss

AbstractThe local electronic structure of phosphorus in the binary skutterudites CoP3 and NiP3, and in the filled skutterudite LaFe4P12 are studied using a combination of electron energy-loss spectroscopy and ab initio calculations. Relative to CoP3 we observe a filling of phosphorus s and d states in NiP3, while for LaFe4P12 increased EELS intensity indicates more empty s and d states close to the Fermi-level.

Improved Measurement and Analysis of Series of Valence Electron Energy Loss Spectra and The Local Electronic Structure

1997 ◽  
Vol 3 (S2) ◽  
pp. 943-944
Author(s):  
H. Müllejans ◽  
R. H. French ◽  
G. Duscher ◽  
M. Rühle
Keyword(s):  
Electronic Structure ◽  
Energy Loss ◽  
Electron Energy ◽  
Valence Electron ◽  
Primary Electron ◽  
Full Data ◽  
Data Set ◽  
Automatic Data ◽  
Local Electronic Structure ◽  
Electron Energy Loss

The local electronic structure of ceramic materials can be determined from valence electron energy loss (Veel) spectra via the dielectric function. The quality of the data is comparable to vacuum ultraviolet spectroscopy with the added benefit of high spatial resolution. We have built and implemented a system for spectrum imaging which not only allows automatic data acquisition but also analysis of the full data set. The system consists of a Gatan PEELS and a Gatan Digiscan fitted to a VG HB501 UX STEM and home-built hardware additions. The hardware extensions allow to acquire 1, 2, 3, 4 or 8 spectra for each pixel and in the case of 2 spectra/pixel to vary the exposure time of the specimen to the primary electron beam by controlling the beam blanker (Fig. 1). The first spectrum (2 to 20 ms) contains an unsaturated zero loss peak and the second spectrum (0.05 to 100 s) at the same position the plasmon peak near to but below saturation (Fig. 2).

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.

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.

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