Application of electron energy loss spectroscopy to microanalysis of irradiated stainless steels

1991 ◽  
Vol 49 ◽  
pp. 732-733
Author(s):  
E. A. Kenik ◽  
J. Bentley ◽  
N. D. Evans
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Stainless Steels ◽  
Electron Energy Loss Spectroscopy ◽  
Analytical Electron Microscopy ◽  
Radioactive Decay ◽  
Acquisition Time ◽  
Detector Performance ◽  
Radiation Induced ◽  
Electron Energy Loss

Energy dispersive X-ray spectroscopy (EDXS) has limited application to microanalysis of radioactive materials because of degraded detector performance and the “intrinsic” spectrum associated with the radioactive decay. Electron energy loss spectroscopy (EELS) is not affected by specimen radioactivity and also offers the possibility of improved spatial resolution. Measurements of radiation-induced segregation (RIS) in irradiated stainless steels have been made by both techniques. Analytical electron microscopy was performed at 100 kV in a Philips EM400T/FEG, equipped with an EDAX 9100/70 EDXS system and a Gatan 666 parallel detection EELS (PEELS). Microanalysis was performed in the STEM mode (<2-nm-diam probe with >0.5 nA) with the same acquisition time (50 s) used for both techniques.Initial measurements were performed on an ion-irradiated modified type 316 stainless steel (designated LS1A), which had moderate-width (∼20 nm) RIS profiles at grain boundaries. Profiles measured by EDXS and PEELS match well and show chromium depletion and nickel enrichment (Fig. 1).

Low atomic number imaging of cells by electron energy loss spectroscopy

1983 ◽  
Vol 41 ◽  
pp. 590-591
Author(s):  
R.D. Leapman ◽  
R.L. Ornberg
Keyword(s):  
Electron Microscopy ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Analytical Electron Microscopy ◽  
Image Point ◽  
Cell Physiology ◽  
Significant Information ◽  
Adrenal Chromaffin ◽  
Electron Energy Loss

Recent advances in electron microscopy and analytical electron microscopy now make it possible to obtain elemental images of biological samples. In particular, electron energy loss spectroscopy is sensitive to the low Z elements, carbon, nitrogen, and oxygen which constitute most of the mass of a cell. Since the relative numbers of these atoms vary from one cellular compartment to another, significant information should be contained in C, N, and O images. The resolution in such images will clearly depend on the susceptibility of biological compounds to radiation damage. In order to learn how low Z imaging can be applied to cell physiology, we have obtained and describe here some preliminary carbon and nitrogen maps of the well characterized bovine adrenal chromaffin cells.Dissociated 3-day old bovine chromaffin cell cultures were quick frozen, freeze substituted in tetrahydrofuran, and embedded in Lowicryl HM20 resin as previously described. Energy loss images were obtained with recently developed instrumentation consisting of a Hitachi H700H TEM-5TEM and a magnetic sector electron spectrometer interfaced to a Digital Equipment Corporation PDP 11/60 and LSI 11/23 computer system. During image aquisition the computer steps the probe (∽10 nm dia.) across the sample and acquires several spectrum channels around selected core edges at each image point (pixel).

scholarly journals Analytical electron microscopy at the atomic level with parallel electron energy loss spectroscopy

1990 ◽  
Vol 1 (5-6) ◽  
pp. 443-454 ◽  
Author(s):  
Danièle Bouchet ◽  
Christian Colliex ◽  
Parmjit Flora ◽  
Ondrej Krivanek ◽  
Claudie Mory ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Analytical Electron Microscopy ◽  
Atomic Level ◽  
Analytical Electron ◽  
Electron Energy Loss

Microanalysis and electron energy loss spectroscopy of polymers

1987 ◽  
Vol 45 ◽  
pp. 430-433
Author(s):  
R. M. Briber
Keyword(s):  
Energy Loss ◽  
Radiation Damage ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Analytical Electron Microscopy ◽  
Incident Beam ◽  
Quantitative Information ◽  
Chemical Information ◽  
X Ray ◽  
Electron Energy Loss

Analytical electron microscopy has progressed in recent years such that quantitative chemical information can be obtained from very small volumes of sample. In principle, the composition of regions on the order of a few namometers in both diameter and thickness can be determined using energy dispersive x-ray analysis (EDS) and electron energy loss spectroscopy (EELS) [1,2], In the case of organic polymers the limitations to quantitative microanalysis are generally due to the sample and not to the instrument. Radiation damage induced mass loss often proves to be the constraining factor in obtaining quantitative information from small volumes of sample [3], The principles and processes of radiation damage in organic materials and polymers can be found in various review articles [4,5].The principles underlying both analytical x-ray spectroscopy and electron energy loss spectroscopy are closely related. When an electron in the incident beam loses energy (i.e. inelastically scattered) by "knocking" out an inner shell electron from an atom present in the sample there are two aspects that are of value for compositional analysis.

Structure Studies of Thin Amorphous Films by Synchrotron X-Ray Absorption and Analytical Electron Microscopy.

1986 ◽  
Vol 77 ◽  
Author(s):  
S. M. Heald ◽  
J. Tafto
Keyword(s):  
Electron Microscopy ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Amorphous Materials ◽  
Analytical Electron Microscopy ◽  
Low Energy ◽  
X Rays ◽  
Amorphous Films ◽  
Electron Energy Loss

ABSTRACTWe combine the techniques of EXAFS and XANES using synchrotron x-rays, and the corresponding techniques using electron energy loss spectroscopy (EXELFS and ELNES) to characterize and study the local atomic arrangement in thin amorphous films. These probes are complementary in that x-rays are best suited for absorption edges above 3 keV and electron energy loss spectroscopy for low energy edges, and thus this combination is very useful for amorphous materials containing both low and high Z elements. We use in addition transmission electron microscopy, electron diffraction, and electron energy loss spectroscopy in the low energy loss region. Results from amorphous T1O2 and amorphous SnO2 made by reactive sputtering are presented.

Capabilities and Limitations of Biological Electron Energy-Loss Spectroscopy

1997 ◽  
Vol 3 (S2) ◽  
pp. 871-872
Author(s):  
R.D. Leapman ◽  
S.B. Andrews
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Collection Efficiency ◽  
Analytical Electron Microscopy ◽  
Scanning Transmission Electron Microscope ◽  
Atomic Fraction ◽  
Macromolecular Assemblies ◽  
Scanning Transmission ◽  
Electron Energy Loss

Perhaps the ultimate aim of analytical electron microscopy in biology is to detect single atoms or ions bound to isolated macromolecular assemblies and small cellular organelles rapidly frozen in their native state. Although the meaningful spatial resolution in such analyses is limited to ∽10 nm or more by radiation damage, the high intrinsic sensitivity of electron energy-loss spectroscopy (EELS) coupled with recent developments seems to make this rather ambitious goal—originally proposed some twenty years ago—within reach. Here we describe examples where EELS has been able to detect surprisingly small numbers of atoms in biological specimens and discuss some fundamental limits that are encountered as well as some possible strategies for circumventing these difficulties.In our laboratory we have used a scanning transmission electron microscope (STEM) equipped with a field-emission source and parallel-detection EELS because the probe size and collection efficiency of this instrument are optimized to give the lowest detectable number of atoms and lowest detectable atomic fraction.

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