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Improving the Analytical Accuracy in the Analysis of Particles by Employing Low Voltage Analysis



John A. Small, J T. Armstrong


The energy of the electron beam, in conventional electron probe microanalysis, is generally in the range of 15-25 keV which provides the necessary overvoltage to excite efficiently the K and L x-ray lines for elements with atomic numbers in the range of about 5-83. One of the primary microanalytical methods for obtaining compositional information on particles is x-ray analysis in the electron probe and these same voltage criteria have been applied to the procedures developed for this purpose. The main difference in analytical procedures for bulk samples and particles is that corrections have to be applied to the particle k-ratios or calculated compositions to compensate for: 1) the penetration or scattering of electrons out of the particle volume and 2) variations in the absorption due to particle geometry of x-rays less than about 3 keV. In general, particle corrections improve the accuracy and reduce the relative uncertainty estimates from several tens of percent for uncorrected data to about 10% for corrected data. (1) Although a significant improvement, a relative uncertainty of 10% is often not sufficient to distinguish between many materials with similar compositions.
Microscopy and Microanalysis


electron beam, electron probe microanalysis, overvoltage


Small, J. and Armstrong, J. (2000), Improving the Analytical Accuracy in the Analysis of Particles by Employing Low Voltage Analysis, Microscopy and Microanalysis (Accessed July 18, 2024)


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Created August 1, 2000, Updated February 17, 2017