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Performing elemental microanalysis with high accuracy and high precision by scanning electron microscopy/silicon drift detector energy-dispersive X-ray spectrometry (SEM/SDD-EDS).

Newbury DE, Ritchie NW - J Mater Sci (2014)

Bottom Line: SDD-EDS throughput, resolution, and stability provide practical operating conditions for measurement of high-count spectra that form the basis for peak fitting procedures that recover the characteristic peak intensities even for elemental combination where severe peak overlaps occur, such PbS, MoS2, BaTiO3, SrWO4, and WSi2.Accurate analyses are also demonstrated for interferences involving large concentration ratios: a major constituent on a minor constituent (Ba at 0.4299 mass fraction on Ti at 0.0180) and a major constituent on a trace constituent (Ba at 0.2194 on Ce at 0.00407; Si at 0.1145 on Ta at 0.0041).Measurement of trace constituents with limits of detection below 0.001 mass fraction (1000 ppm) is possible within a practical measurement time of 500 s.

View Article: PubMed Central - PubMed

Affiliation: Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 USA.

ABSTRACT

Electron-excited X-ray microanalysis performed in the scanning electron microscope with energy-dispersive X-ray spectrometry (EDS) is a core technique for characterization of the microstructure of materials. The recent advances in EDS performance with the silicon drift detector (SDD) enable accuracy and precision equivalent to that of the high spectral resolution wavelength-dispersive spectrometer employed on the electron probe microanalyzer platform. SDD-EDS throughput, resolution, and stability provide practical operating conditions for measurement of high-count spectra that form the basis for peak fitting procedures that recover the characteristic peak intensities even for elemental combination where severe peak overlaps occur, such PbS, MoS2, BaTiO3, SrWO4, and WSi2. Accurate analyses are also demonstrated for interferences involving large concentration ratios: a major constituent on a minor constituent (Ba at 0.4299 mass fraction on Ti at 0.0180) and a major constituent on a trace constituent (Ba at 0.2194 on Ce at 0.00407; Si at 0.1145 on Ta at 0.0041). Accurate analyses of low atomic number elements, C, N, O, and F, are demonstrated. Measurement of trace constituents with limits of detection below 0.001 mass fraction (1000 ppm) is possible within a practical measurement time of 500 s.

No MeSH data available.


Related in: MedlinePlus

SDD-EDS spectrum of NIST microanalysis glasses K496 (blue) and K497 (red) (Color figure online)
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Fig20: SDD-EDS spectrum of NIST microanalysis glasses K496 (blue) and K497 (red) (Color figure online)

Mentions: Even with a conservative counting strategy, SDD-EDS can provide high-count spectra, e.g., integrated spectrum counts >50 million, in practical counting times, e.g., 500 s, that reduce the minimum detectable limit well below a mass concentration of 0.001 (1000 parts per million). Figure 20 shows an example for NIST glasses K496 and K497, which have nearly identical major constituents (O, Mg, Al, and P), while K497 also contains trace levels of a variety of elements. For the purpose of demonstration, the spectrum of K496 can serve as a measure of the continuum background under the measured trace element peaks in K497. The concentration limit of detection, CDL, can be estimated from the measured peak intensity, NS, of a constituent of known or measured concentration, CS, and the intensity of the background under the peak, NB [2]:Fig. 20


Performing elemental microanalysis with high accuracy and high precision by scanning electron microscopy/silicon drift detector energy-dispersive X-ray spectrometry (SEM/SDD-EDS).

Newbury DE, Ritchie NW - J Mater Sci (2014)

SDD-EDS spectrum of NIST microanalysis glasses K496 (blue) and K497 (red) (Color figure online)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4555346&req=5

Fig20: SDD-EDS spectrum of NIST microanalysis glasses K496 (blue) and K497 (red) (Color figure online)
Mentions: Even with a conservative counting strategy, SDD-EDS can provide high-count spectra, e.g., integrated spectrum counts >50 million, in practical counting times, e.g., 500 s, that reduce the minimum detectable limit well below a mass concentration of 0.001 (1000 parts per million). Figure 20 shows an example for NIST glasses K496 and K497, which have nearly identical major constituents (O, Mg, Al, and P), while K497 also contains trace levels of a variety of elements. For the purpose of demonstration, the spectrum of K496 can serve as a measure of the continuum background under the measured trace element peaks in K497. The concentration limit of detection, CDL, can be estimated from the measured peak intensity, NS, of a constituent of known or measured concentration, CS, and the intensity of the background under the peak, NB [2]:Fig. 20

Bottom Line: SDD-EDS throughput, resolution, and stability provide practical operating conditions for measurement of high-count spectra that form the basis for peak fitting procedures that recover the characteristic peak intensities even for elemental combination where severe peak overlaps occur, such PbS, MoS2, BaTiO3, SrWO4, and WSi2.Accurate analyses are also demonstrated for interferences involving large concentration ratios: a major constituent on a minor constituent (Ba at 0.4299 mass fraction on Ti at 0.0180) and a major constituent on a trace constituent (Ba at 0.2194 on Ce at 0.00407; Si at 0.1145 on Ta at 0.0041).Measurement of trace constituents with limits of detection below 0.001 mass fraction (1000 ppm) is possible within a practical measurement time of 500 s.

View Article: PubMed Central - PubMed

Affiliation: Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 USA.

ABSTRACT

Electron-excited X-ray microanalysis performed in the scanning electron microscope with energy-dispersive X-ray spectrometry (EDS) is a core technique for characterization of the microstructure of materials. The recent advances in EDS performance with the silicon drift detector (SDD) enable accuracy and precision equivalent to that of the high spectral resolution wavelength-dispersive spectrometer employed on the electron probe microanalyzer platform. SDD-EDS throughput, resolution, and stability provide practical operating conditions for measurement of high-count spectra that form the basis for peak fitting procedures that recover the characteristic peak intensities even for elemental combination where severe peak overlaps occur, such PbS, MoS2, BaTiO3, SrWO4, and WSi2. Accurate analyses are also demonstrated for interferences involving large concentration ratios: a major constituent on a minor constituent (Ba at 0.4299 mass fraction on Ti at 0.0180) and a major constituent on a trace constituent (Ba at 0.2194 on Ce at 0.00407; Si at 0.1145 on Ta at 0.0041). Accurate analyses of low atomic number elements, C, N, O, and F, are demonstrated. Measurement of trace constituents with limits of detection below 0.001 mass fraction (1000 ppm) is possible within a practical measurement time of 500 s.

No MeSH data available.


Related in: MedlinePlus