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Accurate composition determination of Be‐Ti alloys by electron energy loss spectroscopy
Author(s) -
Liu D. R.,
Williams D. B.
Publication year - 1989
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1111/j.1365-2818.1989.tb02919.x
Subject(s) - calibration , extrapolation , spectroscopy , weighting , energy dispersive x ray spectroscopy , electron energy loss spectroscopy , analytical chemistry (journal) , materials science , ionization , computational physics , chemistry , optics , scanning electron microscope , physics , mathematics , transmission electron microscopy , statistics , nanotechnology , ion , organic chemistry , chromatography , quantum mechanics , acoustics
SUMMARY Accurate quantification of the Be content in Be‐Ti alloys on a submicrometre scale can be accomplished with electron energy loss spectroscopy in an analytical electron microscope. The three major steps required to ensure the accuracy of the numerical results are analysed. The first step is the choice of the specimen thickness which should be such that the influence of the specimen surface effects can be ignored yet thin enough so that deconvolution of the spectra is unnecessary. The second step is the background extrapolation under the ionization edge of interest. In this study, a direct least‐squares fit with a progressive weighting is used to avoid the drawbacks of the conventional linear least‐squares fit. The third step is the calibration of the partial ionization cross‐section ratio with the use of a standard specimen. Without this calibration step, the error in the final microanalysis result could be excessive, as demonstrated. With all these precautions taken into consideration, we are able to show that the intermetallic phase TiBe 12 exhibits a great deviation from its nominal stoichiometry.