QUANTITATIVE MICROANALYSIS USING ELECTRON-ENERGY-LOSS SPECTROMETRY .1. LI AND BE IN OXIDES

Electron energy-loss spectrometry enables the detection of Li and Be v ia the K ionization edges. However, the detection and quantification o f these low energy edges present several problems, like low edge-to-ba ckground ratios, problems with background extrapolations, overlapping of edges and multiple scattering in case of thicker specimens. All the se problems can be overcome by careful application of well known proce dures: Spectra have to be recorded from very thin specimen regions (t/ lambda < 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 w ithout problems. The Li and Be K edges overlap with other edges e.g. t he 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 experimentall y determined partial cross-sections are used. The successful applicati on of these methods is demonstrated for inorganic materials like phena cite, beryl, spodumene, Be-phosphate and Li-Cr-oxide. The quantificati on and detection limits for Li and Be in typical material science spec imens are discussed.