ABSTRACT
Elemental analysis by quadrupole mass spectrometry with direct current powered glow discharge ion source has been improved for flat Cu samples. The line ratio of analyte to Ar-related interferents can be enhanced for several orders of magnitude when ion source geometry, ion extraction system and operating parameters are optimised quasi-simultaneously. Such an extreme improvement may partially be explained by different ion energy distributions depending on their origin: matrix and analytes, working gas, residual gases. Probably it is due to a synergistic effect of several processes needing further investigation.
ABSTRACT
Principal component analysis and cluster analysis have been used in AES investigations of fibre-matrix interactions in alumina fibre reinforced MgLi-alloys prepared by high-pressure infiltration. The samples have been fractured in ultra high vacuum to expose surfaces and interfaces without contamination. All main components exhibit Auger valence band transitions which change their shape with the chemical state. Chemometric methods have been utilized to identify characteristic peak shapes and to classify the investigated areas by composition. Fibre fracture surfaces are characterized by Al, magnesia and Li oxide formed by a redox reaction of alumina with Mg and Li penetrating along grain boundaries. For samples with high silica content a thin interfacial oxide layer on matrix grain boundaries and matrix-fibre interfaces has been found.