Quantitative electron energy-loss spectroscopy (EELS) is used to characterize the chemical composition of Fe-Co alloy nanoparticles. A 300-keV analytical microscope equipped with an imaging energy filter is used to acquire parallel EELS spectra from metal nanoparticles produced using two different synthesis routes. Nanoscale materials (including the particles used in this work) present unique challenges to the analyst because of the small length scales in the system. The small absolute signal generated by individual nanoparticles results in poor counting statistics; this limits the precision of the analysis and lowers the ultimate analytical sensitivity of the technique. Fortunately, the very small transmission lengths and thin samples characteristic of nanomaterials can also be used to advantage if the measurement techniques are optimized for ultrathin specimens. EELS benefits from reduced plural scattering and continuum background levels, while lowered absorption and secondary fluorescence improve the accuracy of conventional, x-ray-based techniques such as energy dispersive spectroscopy (EDS). Quantitative microanalytical results derived from EELS spectra and a variety of theoretical inelastic scattering cross sections are compared with traditional EDS results obtained from individual nanoparticles. While some data collection modes can produce errors as large as 50% in the elemental ratios, it is found that judicious choices for theoretical cross sections and correction procedures yield results that differ from EDS data by no more than a few percent.
Quantitative EELS of Alloy Nanoparticles
AEM, EELS, electron energy-los spectroscopy, Fe-Co alloy, nanoparticles, quantitative microanalysis
and Newbury, D.
Quantitative EELS of Alloy Nanoparticles, Quantitative EELS of Alloy Nanoparticles
(Accessed March 27, 2023)