AN ELECTRON ENERGY LOSS SPECTRAL LIBRARY AND ITS APPLICATION TO MATERIALS SCIENCE

1984 ◽  
Vol 45 (C2) ◽  
pp. C2-429-C2-432 ◽  
Author(s):  
N. J. Zaluzec
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Materials Science ◽  
Spectral Library ◽  
Electron Energy Loss

Trends in Electron Energy Loss Spectroscopy

1977 ◽  
Vol 35 ◽  
pp. 228-229
Author(s):  
C. Colliex ◽  
P. Trebbia
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Materials Science ◽  
Analytical Technique ◽  
Recent Developments ◽  
Quantitative Results ◽  
Electron Microscopes ◽  
Electron Energy Loss ◽  
Primary Electrons

The physical foundations for the use of electron energy loss spectroscopy towards analytical purposes, seem now rather well established and have been extensively discussed through recent publications. In this brief review we intend only to mention most recent developments in this field, which became available to our knowledge. We derive also some lines of discussion to define more clearly the limits of this analytical technique in materials science problems.The spectral information carried in both low ( 0<ΔE<100eV ) and high ( >100eV ) energy regions of the loss spectrum, is capable to provide quantitative results. Spectrometers have therefore been designed to work with all kinds of electron microscopes and to cover large energy ranges for the detection of inelastically scattered electrons (for instance the L-edge of molybdenum at 2500eV has been measured by van Zuylen with primary electrons of 80 kV). It is rather easy to fix a post-specimen magnetic optics on a STEM, but Crewe has recently underlined that great care should be devoted to optimize the collecting power and the energy resolution of the whole system.

Stopping-power determination for compound by EELS

1994 ◽  
Vol 52 ◽  
pp. 948-949 ◽  
Author(s):  
David C. Joy ◽  
Suichu Luo ◽  
John R. Dunlap ◽  
Dick Williams ◽  
Siqi Cao
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Materials Science ◽  
Average Energy ◽  
Stopping Power ◽  
Accurate Information ◽  
Power Calculation ◽  
Coulomb Collisions ◽  
Electron Energy Loss

In Physics, Chemistry, Materials Science, Biology and Medicine, it is very important to have accurate information about the stopping power of various media for electrons, that is the average energy loss per unit pathlength due to inelastic Coulomb collisions with atomic electrons of the specimen along their trajectories. Techniques such as photoemission spectroscopy, Auger electron spectroscopy, and electron energy loss spectroscopy have been used in the measurements of electron-solid interaction. In this paper we present a comprehensive technique which combines experimental and theoretical work to determine the electron stopping power for various materials by electron energy loss spectroscopy (EELS ). As an example, we measured stopping power for Si, C, and their compound SiC. The method, results and discussion are described briefly as below.The stopping power calculation is based on the modified Bethe formula at low energy:where Neff and Ieff are the effective values of the mean ionization potential, and the number of electrons participating in the process respectively. Neff and Ieff can be obtained from the sum rule relations as we discussed before3 using the energy loss function Im(−1/ε).

The Influence of Specimen Thickness in Quantitative Electron Energy Loss Spectroscopy

1980 ◽  
Vol 38 ◽  
pp. 112-113
Author(s):  
Nestor J. Zaluzec
Keyword(s):  
Quantitative Analysis ◽  
Adverse Effects ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Materials Science ◽  
Light Element ◽  
Specimen Thickness ◽  
Element Analysis ◽  
Electron Energy Loss

The application of electron energy loss spectroscopy (EELS) to light element analysis is rapidly becoming an important aspect of the microcharacterization of solids in materials science, however relatively stringent requirements exist on the specimen thickness under which one can obtain EELS data due to the adverse effects of multiple inelastic scattering.1,2 This study was initiated to determine the limitations on quantitative analysis of EELS data due to specimen thickness.

Applications of Electron Energy Loss Spectroscopy in Materials Science

1980 ◽  
Vol 38 ◽  
pp. 86-89
Author(s):  
Ondrej L. Krivanek
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Energy Resolution ◽  
Materials Science ◽  
Magnetic Shielding ◽  
Dark Count ◽  
Object Plane ◽  
Electron Energy Loss Spectrometer ◽  
Electron Energy Loss ◽  
Loss Range

The electron energy loss spectrometer developed at Berkeley differs from most other ones in four ways: 1) it uses the projector lens crossover as the spectrometer entrance object plane, 2) its magnet is asymmetric so that the entrance object is de-magnified about 5x, 3) it counts electrons admitted through the energy-selecting slit singly at rates up to 20MHz while adding zero dark count, and 4) it fits neatly at the back of the available leg space of the electron microscope, and requires no substantial alterations to the microscope. The energy resolution attainable routinely at any primary voltage is 3eV over an energy loss range 0 to 1keV, as illustrated by resolving the π* transition on the K-edge of amorphous carbon (Fig. 1). The 3 eV limit comes mainly from 120Hz stray magnetic fields (the 60Hz component has been compensated out). Fast scanning of the spectrum improves the resolution to 1eV (Fig. 2). This indicates that with proper magnetic shielding of the electron flight path, especially in the microscope viewing chamber which is made out of brass, the energy resolution attainable with the spectrometer will be limited only by the energy spread of the primary beam.

Synthesis of Electron Energy Loss Spectra for the Quantification of Detection Limits

2002 ◽  
Vol 8 (3) ◽  
pp. 203-215 ◽  
Author(s):  
Nanda K. Menon ◽  
Ondrej L. Krivanek
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Materials Science ◽  
Detection Limits ◽  
Single Atom ◽  
Experimental Conditions ◽  
Empirical Observation ◽  
Thin Carbon ◽  
Atom Detection ◽  
Electron Energy Loss

We describe a method for predicting detection limits of minority elements in electron energy loss spectroscopy (EELS), and its implementation as a software package that gives quantitative predictions for user-specified materials and experimental conditions. The method is based on modeling entire energy loss spectra, including shot noise as well as instrumental noise, and taking into account all the relevant experimental parameters. We describe the steps involved in modeling the entire spectrum, from the zero loss up to inner shell edges, and pay particular attention to the contributions to the pre-edge background. The predicted spectra are used to evaluate the signal-to-noise ratios (SNRs) for inner shell edges from user-specified minority elements. The software also predicts the minimum detectable mass (MDM) and minimum mass fraction (MMF). It can be used to ascertain whether an element present at a particular concentration should be detectable for given experimental conditions, and also to quickly and quantitatively explore ways of optimizing the experimental conditions for a particular EELS analytical task. We demonstrate the usefulness of the software by confirming the recent empirical observation of single atom detection using EELS of phosphorus in thin carbon films, and show the effect on the SNR of varying the acquisition parameters. The case of delta-doped semiconductors is also considered as an important example from materials science where low detection limits and high spatial resolution are essential, and the feasibility of such characterization using EELS is assessed.

Characterization Of SiOx Smoke Particles by Electron Energy Loss Spectroscopy and Energy-Filtering Imaging

1999 ◽  
Vol 5 (S2) ◽  
pp. 638-639
Author(s):  
D.C. Dufner ◽  
S. Danczyk ◽  
M. Wooldridge
Keyword(s):  
Energy Loss ◽  
Combustion Synthesis ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Materials Science ◽  
Particle Morphology ◽  
Burner Surface ◽  
Particle Composition ◽  
Energy Filtering ◽  
Electron Energy Loss

Combustion synthesis has led to many advances in materials science, in part via the synthesis of powders consisting of particles of nanometer dimensions. Particle morphology is a key concern regarding the powders produced, but also of comparable importance is particle composition. Electron energy loss spectroscopy (EELS) and energy-filtering imaging (EFI) can be used to interrogate the gas-phase combustion synthesis environment for elemental particle composition information. Once established, this diagnostic approach can be used to address control of particle composition and other issues associated with particle formation and growth in flames. The evolution of the particle morphology in a laboratory scale combustion synthesis facility can be examined by passing TEM grids directly through the combustion synthesis flame at various heights above the burner surface, as shown in Fig. la. For the current work, SiOx particle samples are obtained from a SilL/^/FL/Ar flame using a rapid probe insertion technique.

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