Microstructoral and Chemical Analysis Using Electron Beams: The Analytical Electron Microscope

1987 ◽  
Vol 31 ◽  
pp. 9-24
Author(s):  
A. D. Romig
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Prior Knowledge ◽  
Electron Beams ◽  
Analytical Electron Microscopy ◽  
X Ray ◽  
Basic Understanding ◽  
Analytical Electron ◽  
Analytical Electron Microscope

This plenary paper is intended to be an introduction to the capabilities and limitations of analytical electron microscopy (AEM). The description to be given assumes no prior knowledge of AEM or any other electron microscopy, scanning or transmission. However, a basic understanding of x-ray generation and detection will be assumed.

Analytical Formulae for Calculation of X-Ray Detector Solid Angles in the Scanning and Scanning/Transmission Analytical Electron Microscope

2014 ◽  
Vol 20 (4) ◽  
pp. 1318-1326 ◽  
Author(s):  
Nestor J. Zaluzec
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Solid Angle ◽  
Analytical Electron Microscopy ◽  
X Ray ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Scanning Transmission ◽  
Analytical Formulae ◽  
Detector Configurations

AbstractClosed form analytical equations used to calculate the collection solid angle of six common geometries of solid-state X-ray detectors in scanning and scanning/transmission analytical electron microscopy are presented. Using these formulae one can make realistic comparisons of the merits of the different detector geometries in modern electron column instruments. This work updates earlier formulations and adds new detector configurations.

An overview of Analytical Electron Microscopy

1983 ◽  
Vol 31 ◽  
Author(s):  
D. B. Williams
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Structure Data ◽  
Crystal Structure Data ◽  
Analytical Electron Microscopy ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Microscopy Techniques

ABSTRACTAnalytical electron microscopy techniques comprising imaging, chemical analysis and microdiffraction are described together with details of the instrumentation required. Using the analytical electron microscope (AEM), the materials scientist can gain combined chemical and crystallographic information with a spatial resolution and sensitivity not available in other imaging instruments. Examples of the application of the AEM to determine solute distribution and crystal structure data are given.

Application of analytical electron microscopy to the study of partitioning of silicon in a 2 wt% Si eutectoid steel

1978 ◽  
Vol 36 (1) ◽  
pp. 616-617
Author(s):  
N. Ridley ◽  
S.A. Al-Salman ◽  
G.W. Lorimer
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Analytical Electron Microscopy ◽  
Eutectoid Steel ◽  
Minimum Diameter ◽  
Thin Foils ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Transformation Front

The application of the technique of analytical electron microscopy to the study of partitioning of Mn (1) and Cr (2) during the austenite-pearlite transformation in eutectoid steels has been described in previous papers. In both of these investigations, ‘in-situ’ analyses of individual cementite and ferrite plates in thin foils showed that the alloying elements partitioned preferentially to cementite at the transformation front at higher reaction temperatures. At lower temperatures partitioning did not occur and it was possible to identify a ‘no-partition’ temperature for each of the steels examined.In the present work partitioning during the pearlite transformation has been studied in a eutectoid steel containing 1.95 wt% Si. Measurements of pearlite interlamellar spacings showed, however, that except at the highest reaction temperatures the spacing would be too small to make the in-situ analysis of individual cementite plates possible, without interference from adjacent ferrite lamellae. The minimum diameter of the analysis probe on the instrument used, an EMMA-4 analytical electron microscope, was approximately 100 nm.

Preliminary Observations on the Chemistry and Biology of the Lorica in a Collared Flagellate (Stephanoeca Diplocostata Ellis)

1974 ◽  
Vol 54 (2) ◽  
pp. 269-276 ◽  
Author(s):  
B. S. C. Leadbeater ◽  
I. Manton
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Hydrofluoric Acid ◽  
Light And Electron Microscopy ◽  
Amorphous Form ◽  
X Ray ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Biological Aspects ◽  
Stephanoeca Diplocostata

Evidence for the presence of silica in the costae of Stephanoeca diplocostata Ellis has been provided by a combination of light and electron microscopy. The solubility of costae in hydrofluoric acid has been demonstrated. The presence of silicon in the costae has been strongly confirmed by means of the X-ray analytical electron microscope (EMMA) but tests for a crystalline substructure by means of electron diffraction were negative; it is concluded that silicon is present in a crystallographically amorphous form. Preliminary observations on other biological aspects of the organism include the presence of a sac-like membrane between the lorica and protoplast, the presence of immature costal strips within the cytoplasm and the nature of ingested food. The phyletic position of the group is briefly discussed with special reference to mitochondrial substructure.

scholarly journals Overcoming Severe XEDS Peak Overlaps with the AEM

2006 ◽  
Vol 14 (2) ◽  
pp. 34-37
Author(s):  
Scott D. Walck
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Energy Dispersive Spectroscopy ◽  
Analytical Techniques ◽  
Maximum Energy ◽  
X Ray ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Scanning Electron

Of all the analytical techniques in electron microscopy, X-ray energy dispersive spectroscopy (XEDS) is perhaps the most useful. It provides a quick identification of the elements and even with semiquantitative methods; a reasonable composition can be obtained. However, in the scanning electron microscopy (SEM), there are materials systems in which severe peak overlaps of heavier elements L and M lines cannot be easily deconvolved with lighter elements' K lines. In addition, without a sufficient overvoltage in the SEM, even identification of the heavier elements can be difficult. In the analytical electron microscope (AEM), there is always sufficient overvoltage to excite all of the elements' K-lines. However, all of the K-lines might not be able to be detected with commercially available instruments. This is illustrated in Fig.l where the maximum energy of the detector system might be set to 10, 20, or 40 keV.

Analytical Electron Microscopy (AEM) of Meningeal Cells Exposed to Particulate Cobalt During Studies of Experimental Epilepsy

1982 ◽  
Vol 40 ◽  
pp. 186-187
Author(s):  
R.G. Frederickson ◽  
R.G. Ulrich ◽  
J.L. Culberson
Keyword(s):  
Electron Microscopy ◽  
Analytical Electron Microscopy ◽  
Experimental Epilepsy ◽  
Metallic Cobalt ◽  
Experimental Animals ◽  
X Ray ◽  
Brain Surface ◽  
Meningeal Cells ◽  
Analytical Electron ◽  
The Brain

Metallic cobalt acts as an epileptogenic agent when placed on the brain surface of some experimental animals. The mechanism by which this substance produces abnormal neuronal discharge is unknown. One potentially useful approach to this problem is to study the cellular and extracellular distribution of elemental cobalt in the meninges and adjacent cerebral cortex. Since it is possible to demonstrate the morphological localization and distribution of heavy metals, such as cobalt, by correlative x-ray analysis and electron microscopy (i.e., by AEM), we are using AEM to locate and identify elemental cobalt in phagocytic meningeal cells of young 80-day postnatal opossums following a subdural injection of cobalt particles.

The effect of small additions of Cu on precipitation in Al-Mg-Si alloys

1990 ◽  
Vol 48 (2) ◽  
pp. 442-443
Author(s):  
M. Tamizifar ◽  
G. Cliff ◽  
R.W. Devenish ◽  
G.W. Lorimer
Keyword(s):  
Electron Microscopy ◽  
Analytical Electron Microscopy ◽  
Scanning Transmission Electron Microscope ◽  
Argon Atmosphere ◽  
Age Hardening ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated ◽  
Analytical Electron ◽  
Scanning Transmission

Small additions of copper, <1 wt%, have a pronounced effect on the ageing response of Al-Mg-Si alloys. The object of the present investigation was to study the effect of additions of copper up to 0.5 wt% on the ageing response of a series of Al-Mg-Si alloys and to use high resolution analytical electron microscopy to determine the composition of the age hardening precipitates.The composition of the alloys investigated is given in Table 1. The alloys were heat treated in an argon atmosphere for 30m, water quenched and immediately aged either at 180°C for 15 h or given a duplex treatment of 180°C for 15 h followed by 350°C for 2 h2. The double-ageing treatment was similar to that carried out by Dumolt et al. Analyses of the precipitation were carried out with a HB 501 Scanning Transmission Electron Microscope. X-ray peak integrals were converted into weight fractions using the ratio technique of Cliff and Lorimer.

point-Analysis Using the Extrapolation Method in the Analytical Electron microscope

1990 ◽  
Vol 48 (2) ◽  
pp. 430-431
Author(s):  
Zenji Horita ◽  
Ryuzo Nishimachi ◽  
Takeshi Sano ◽  
Minoru Nemoto
Keyword(s):  
Electron Microscope ◽  
Extrapolation Method ◽  
X Ray ◽  
Absorption Correction ◽  
Point Analysis ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Data Points ◽  
Identical Composition ◽  
X Ray Absorption

Absorption correction is often required in quantitative x-ray microanalysis of thin specimens using the analytical electron microscope. For such correction, it is convenient to use the extrapolation method[l] because the thickness, density and mass absorption coefficient are not necessary in the method. The characteristic x-ray intensities measured for the analysis are only requirement for the absorption correction. However, to achieve extrapolation, it is imperative to obtain data points more than two at different thicknesses in the identical composition. Thus, the method encounters difficulty in analyzing a region equivalent to beam size or the specimen with uniform thickness. The purpose of this study is to modify the method so that extrapolation becomes feasible in such limited conditions. Applicability of the new form is examined by using a standard sample and then it is applied to quantification of phases in a Ni-Al-W ternary alloy.The earlier equation for the extrapolation method was formulated based on the facts that the magnitude of x-ray absorption increases with increasing thickness and that the intensity of a characteristic x-ray exhibiting negligible absorption in the specimen is used as a measure of thickness.

Sign in / Sign up

Export Citation Format

Share Document