Bimetallic Particle Formation in Pt–Re/Al2O3Reforming Catalysts Revealed by Energy-Dispersive X-Ray Spectrometry in the Analytical Electron Microscope

1998 ◽  
Vol 176 (1) ◽  
pp. 246-252 ◽  
Author(s):  
Rune Prestvik ◽  
Bård Tøtdal ◽  
Charles E. Lyman ◽  
Anders Holmen
Keyword(s):  
Electron Microscope ◽  
Particle Formation ◽  
Energy Dispersive ◽  
X Ray ◽  
Bimetallic Particle ◽  
Analytical Electron ◽  
Analytical Electron Microscope

Energy-dispersive x-ray spectroscopy: A tutorial

1984 ◽  
Vol 42 ◽  
pp. 336-339
Author(s):  
Ernest L. Hall
Keyword(s):  
Electron Microscope ◽  
Materials Science ◽  
Biological Materials ◽  
Energy Dispersive ◽  
Current Status ◽  
Future Directions ◽  
X Ray ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
The Subject

The purpose of this paper is to present a tutorial review of the principles and practice of energy dispersive X-ray spectroscopy (EDXS) in the analytical electron microscope (AEM). Since this topic can only be treated here in the most cursory fashion, references which constitute a short bibliography on the subject are provided at the end of the paper. Excellent detailed summaries of the current status and future directions of EDXS in the AEM have been provided by Goldstein, Zaluzec, Williams, and Goldstein and Williams. In this paper, some of the important considerations for obtaining meaningful results from X-ray spectra will be described. Although all of the specific examples will be taken from materials science, this description applies equally to biological materials.

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.

Peak-to-background measurements on a 300-kV TEM/STEM

1992 ◽  
Vol 50 (2) ◽  
pp. 1236-1237 ◽  
Author(s):  
S. M. Zemyan ◽  
D. B. Williams
Keyword(s):  
Electron Microscope ◽  
X Ray ◽  
Background Ratio ◽  
Window Method ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Cr Film

As has been reported elsewhere, a thin evaporated Cr film can be used to monitor the x-ray peak to background ratio (P/B) in an analytical electron microscope. Presented here are the results of P/B measurements for the Cr Ka line on a Philips EM430 TEM/STEM, with Link Si(Li) and intrinsic Ge (IG) x-ray detectors. The goal of the study was to determine the best conditions for x-ray microanalysis.We used the Fiori P/B definition, in which P/B is the ratio of the total peak integral to the average background in a 10 eV channel beneath the peak. Peak and background integrals were determined by the window method, using a peak window from 5.0 to 5.7 keV about Cr Kα, and background windows from 4.1 to 4.8 keV and 6.3 to 7.0 keV.

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