Electron Microprobes have been widely used for over 40 years for non-destructive, quantitative, elemental microanalysis of solid materials. They are the instrument of choice for quantitative elemental analyses of solid particles including major, minor and trace elements.
The electron beam, produced by an incandescent LaB6 or W filament hit the specimen in the desired point of interest, selected on optical, backscatter or secondary electron images. Interacting with the sample, the primary electron beam produces characteristic secondary X-ray spectra for each element species present in the analysed point. These characteristic X-rays are then filtered with high sensitivity diffracting crystals and sent to a detector where they are counted and then compared to a standard. The result will be a quantitative analysis of the elements present in a small volume of material and with high spatial resolution of analysed points. In addition, microprobes can produce quantitative element maps of larger areas showing variations in elements distributions on the investigated surface.
All elements from F to U can be routinely analysed. Elements presents in major and minor quantities can be determined using standard diffracting crystals. Trace element and light element (B-O) analysis requires special high-sensitivity or light element spectrometer crystals, which also are part of the system.
The electron microprobe is equipped with four wavelength dispersive spectrometers (WDS) for simultaneous determination of four different major, minor or trace elements. In addition, a cathode-luminescence (CL) detector allows the investigation of zircon textures for the selection of crystals for U-Pb isotope age dating.
Chemistry, Environmental Sciences, Geosciences, Life Sciences, Material Sciences