Integrated mapping using a range of laboratory based instruments

Full text: Characterising minerals, processed minerals and materials to understand their chemical or structure makeup often requires a number of microanalytical techniques. The Microbeam Laboratory has access to a range of microanalytical tools including scanning electron microscopes, electron microprobes, proton microprobe and mapping X-ray diffraction instruments. For example the characterisation of metal electrodes for the aluminium industry requires knowledge about both the crystal structures and chemical compositions of the surface species and the their distribution across the electrode cryolite bath interface. Sample are sectioned and polished to reveal representative surfaces. The electrodes have structures existing on a range of sizes so often several millimetres must be examined at micron to sub-micron resolution. Crystalline structures are determined using a fine beam XRD equipped with a mapping stage. The same areas are then mapped using an electron microprobe to determine the chemistry and in some cases the structures present X-rays, backscattered electrons and cathodoluminescence (CL) signals are all collected and examined for spatially related information. Elemental scatter plots can be used to locate clusters however with the large number of potential correlations minor ones can easily be missed and a better approach is to cluster automatically using computers. The cluster centroids can then displayed and key features located. A similar clustering technique can also be applied to the x-ray diffraction data then spectra within clusters can be added together to provide better structural determinations. Access to a range of analytical instruments can done through the desktop PC. A number of packages exist usually either web or PC based. We have developed a Java based graphical user interface that enables secure and controlled access to a range of microscopes. Instrument control is available combined with streaming images from both the instrument a controllable room camera In addition x-ray, CL, gamma and optical spectra generated by the various instruments are available for the remote user. This enables remote users to collaborate with the specialist operator and bring their knowledge about the sample into the laboratory. Copyright (2002) Australian Society for Electron Microscopy Inc