Free Access
Issue
Microsc. Microanal. Microstruct.
Volume 4, Number 6, December 1993
Page(s) 539 - 560
DOI https://doi.org/10.1051/mmm:0199300406053900
Microsc. Microanal. Microstruct. 4, 539-560 (1993)
DOI: 10.1051/mmm:0199300406053900

Quantitative microanalysis using electron energy-loss spectrometry. I. Li and Be in oxides

Ferdinand Hofer et Gerald Kothleitner

Forschungsinstitut für Elektronenmikroskopie, Graz University of Technology, Graz, A-8010, Austria


Abstract
Electron energy-loss spectrometry enables the detection of Li and Be via the K ionization edges. However, the detection and quantification of these low energy edges present several problems, like low edge-to-background ratios, problems with background extrapolations, overlapping of edges and multiple scattering in case of thicker specimens. All these problems can be overcome by careful application of well known procedures: Spectra have to be recorded from very thin specimen regions (t/λ < 0.5) and subsequently deconvoluted by the Fourier-log-method. This procedure improves the background in front of the edges, so that the conventional A . E-r model can be used for background fitting without problems. The Li and Be K edges overlap with other edges e.g. the L23 edges of elements Mg to P and the M23 edges of the elements Ca to Cu. In such a situation quantitative analysis is only possible by a multiple-least-square fit with reference spectra and if experimentally determined partial cross-sections are used. The successful application of these methods is demonstrated for inorganic materials like phenacite, beryl, spodumene, Be-phosphate and Li-Cr-oxide. The quantification and detection limits for Li and Be in typical material science specimens are discussed.

PACS
8280P - Electron spectroscopy (x-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.).
0781 - Electron and ion spectrometers.

Key words
Microanalysis -- Quantitative chemical analysis -- Electron energy loss spectra -- Data analysis -- Deconvolution -- Lithium compounds -- Beryllium compounds -- Oxides -- Silicates -- Concentration measurement -- Chemical composition


© EDP Sciences 1993