Separation of pure elemental and oxygen influenced signal in ELNES

A “Thickness Series”: Weak Signal Extraction of ELNES in EELS Spectra From Surfaces

“…This technique can be extended to provide a comprehensive picture of the surfaces by combining the profile imaging techniques. Compared to other techniques (Stöger et al, 2002) studying comparable thick layers, the method can be applied to investigate reconstructed surfaces, absorbed monolayers, beam-sensitive interfaces, beam-damage layers, etc.…”

“…The isolation of energy-loss near-edge structures (ELNES) into individual surface and bulk signals in electron energy-loss spectrometry (EELS) is, in principle, possible since the measured ELNES is a linear superposition of every component generated by an incident electron beam, that is, surface and bulk signal components in the present case, in projections within a single scattering regime (Egerton, 2011). The approach of separating ELNES into two components in a TEM foil, in this case the bulk and the oxidized surface of a thin film, having comparable thickness, has been reported (Stöger et al, 2002) from two scaled ELNES spectra containing different component ratios. Although effective for relatively thick layers, the simple subtraction of two-scaled spectra introduces a large propagation error of ~15%, resulting from the uncertainty in estimated contributions of both layers, noise in the spectra, and uncertainty in quantification as directly stated in Schattschneider et al (2002).…”