Quantitative Electron Energy Loss Mapping

Elemental Concentration ◽

Core Loss ◽

Elemental Distribution ◽

The intensity of a characteristic electron energy loss spectroscopy (EELS) image does not, in general, directly reflect the elemental concentration. In fact, the raw core loss image can give a misleading impression of the elemental distribution. This is because the measured core edge signal depends on the amount of plural scattering which can vary significantly from region to region in a sample. Here, we show how the method for quantifying spectra due to Egerton et al. can be extended to maps.

Some problems and solutions in electron energy loss spectroscopy of cryosections

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100148666 ◽

1993 ◽

Vol 51 ◽

pp. 566-567

Author(s):

Zhifeng Shao ◽

Ruoya Ho ◽

Andrew P. Somlyo

Keyword(s):

High Resolution ◽

Energy Loss ◽

Electron Energy ◽

Biological Research ◽

Specimen Thickness ◽

Elemental Distribution ◽

Electron Dose ◽

Simple Assumption ◽

Electron energy loss spectroscopy (EELS) has been a powerful tool for high resolution studies of elemental distribution, as well as electronic structure, in thin samples. Its foundation for biological research has been laid out nearly two decades ago, and in the subsequent years it has been subjected to rigorous, but by no means extensive research. In particular, some problems unique to EELS of biological samples, have not been fully resolved. In this article we present a brief summary of recent methodological developments, related to biological applications of EELS, in our laboratory. The main purpose of this work was to maximize the signal to noise ratio (S/N) for trace elemental analysis at a minimum dose, in order to reduce the electron dose and/or time required for the acquisition of high resolution elemental maps of radiation sensitive biological materials.Based on the simple assumption of Poisson distribution of independently scattered electrons, it had been generally assumed that the optimum specimen thickness, at which the S/N is a maximum, must be the total inelastic mean free path of the beam electron in the sample.

Image Formation Based on Atomic Resolution Core-loss Electron Energy Loss Spectroscopy

10.1017/s1431927606062416 ◽

2006 ◽

Vol 12 (S02) ◽

pp. 1138-1139

Author(s):

MP Oxley ◽

K van Benthem ◽

M Varela ◽

SD Findlay ◽

LJ Allen ◽

...

Keyword(s):

Energy Loss ◽

Electron Energy ◽

Core Loss ◽

Image Formation ◽

Atomic Resolution ◽

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

Empirical Identification of Uranium Oxides and Fluorides Using Electron Energy-loss Spectroscopy in the Transmission Electron Microscope

10.1017/s1431927699990505 ◽

1999 ◽

Vol 5 (6) ◽

pp. 437-444 ◽

Cited By ~ 4

Author(s):

Stephen B. Rice ◽

Hazel H. Bales ◽

John R. Roth ◽

Allen L. Whiteside

Keyword(s):

Energy Loss ◽

Electron Energy ◽

Contaminated Soils ◽

Core Loss ◽

Uranium Oxides ◽

Low Loss ◽

Electron Dose ◽

Core Losses ◽

Abstract: A set of uranium compound particles relevant to contaminated soils and other environmental concerns surrounding uranium bioavailability were studied by electron energy-loss spectroscopy (EELS). Core-loss EELS results suggest that uranium 4+ compounds have an energy loss resolvable from 6+ compounds. Shoulders on the uranium O4,5 edge further distinguish UO2 from UF4. Low-loss characteristics distinguish carbon-free uranium oxide specimens on holey substrates. In the presence of carbon, correction techniques must be applied. Uranium oxides, fluorides, and minerals show a tendency toward reduction of uranium toward 4+ under the beam. The electron dose required to achieve the transformation from 6+ to 4+ is more severe than that usually required to obtain satisfactory spectra, but the possibility for reduction should be considered. The conditions for low-loss analysis need not be as vigorous as those for core losses, and can be done without altering the valence of most oxides.

Fe valence determination and Li elemental distribution in lithiated FeO0.7F1.3/C nanocomposite battery materials by electron energy loss spectroscopy (EELS)

Micron ◽

10.1016/j.micron.2011.05.009 ◽

2012 ◽

Vol 43 (1) ◽

pp. 22-29 ◽

Cited By ~ 55

Author(s):

F. Cosandey ◽

D. Su ◽

M. Sina ◽

N. Pereira ◽

G.G. Amatucci

Keyword(s):

Energy Loss ◽

Electron Energy ◽

Elemental Distribution ◽

Battery Materials ◽

Rapid Simulation of Elemental Maps in Core-Loss Electron Energy Loss Spectroscopy

10.1017/s143192761900360x ◽

2019 ◽

Vol 25 (S2) ◽

pp. 574-575

Author(s):

H. G. Brown ◽

S. D. Findlay ◽

L. J. Allen ◽

J. Ciston ◽

C. Ophus

Keyword(s):

Energy Loss ◽

Electron Energy ◽

Core Loss ◽

Elemental Maps ◽

Theory of Electron Energy Loss Spectroscopy and its Application to Threading Edge Dislocations in GaN

MRS Proceedings ◽

10.1557/proc-693-i10.1.1 ◽

2001 ◽

Vol 693 ◽

Author(s):

C. J. Fall ◽

R. Jones ◽

P. R. Briddon ◽

A. T. Blumenau ◽

T. Frauenheim ◽

...

Keyword(s):

Electronic Structure ◽

Energy Loss ◽

Electron Energy ◽

Core Loss ◽

Extended Defects ◽

Low Loss ◽

Defect Accumulation ◽

Edge Dislocations ◽

AbstractThe electronic structure of dislocations in GaN is controversial. Several experimental techniques such as carrier mobility studies and cathodoluminescence experiments have indicated that dislocations are charged while theoretical studies point to intrinsic states and/or point defect accumulation along the core as a source of electrical activity. Electron Energy Loss Spectroscopy (EELS) studies have the ability to probe the electronic structure of extended defects. Here we report rst principles calculations of the EELS spectrum applied to edge dislocations in GaN. It is found that the electrostatic potential at N atoms in the vicinity of the dislocation varies by the order of a volt and casts doubt on any simple interpretation of core loss spectroscopy. On the other hand, low loss spectroscopy leads directly to detailed information about any gap states. The low loss spectrum obtained by the theory is in good agreement with recent experimental work and indicates that threading dislocations in p-type GaN possess acceptor levels in the upper half of the gap.

Probing the Chemical Structure in Diamond-Based Materials Using Combined Low-Loss and Core-Loss Electron Energy-Loss spectroscopy

10.1017/s1431927614000579 ◽

2014 ◽

Vol 20 (3) ◽

pp. 779-783 ◽

Cited By ~ 5

Author(s):

Paolo Longo ◽

Ray D. Twesten ◽

Jaco Olivier

Keyword(s):

Energy Loss ◽

Electron Energy ◽

Core Loss ◽

Amorphous Region ◽

Low Loss ◽

Plasmon Energy ◽

Carbon Structure ◽

Experimental Conditions ◽

AbstractWe report the analysis of the changes in local carbon structure and chemistry caused by the self-implantation of carbon into diamond via electron energy-loss spectroscopy (EELS) plasmon energy shifts and core-edge fine structure fingerprinting. These two very different EELS energy and intensity ranges of the spectrum can be acquired under identical experimental conditions and nearly simultaneously using specially designed deflectors and energy offset devices known as “DualEELS.” In this way, it is possible to take full advantage of the unique and complementary information that is present in the low- and core-loss regions of the EELS spectrum. We find that self-implanted carbon under the implantation conditions used for the material investigated in this paper creates an amorphous region with significant sp2 content that varies across the interface.

Characterization of Some 3d Transition Metal Oxides through Core Loss Electron Energy Loss Spectroscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600000490 ◽

1980 ◽

Vol 38 ◽

pp. 122-123

Author(s):

L. A. Grunes

Keyword(s):

Energy Loss ◽

Electron Energy ◽

Transition Metal Oxides ◽

Core Loss ◽

The Core ◽

Medium Resolution ◽

Core Losses ◽

Electron Energy Loss Spectroscopy (EELS) is a useful technique for chemical microanalysis in the electron microscope. In particular, medium resolution (˜leV) measurements of core losses involving ionization of the tightly bound inner shell electrons reveal fine structure which identify both the core atom and the neighboring chemical environment. The transition metals of the third period possess narrow partly filled d-bands which give rise to striking magnetic and electronic properties of technological importance.