The Micro-XRF is a non-destructive method for semi-quantitative elemental analysis with high sensitivity, especially for heavier elements. The instrument M4 TORNADO (Bruker) is dedicated to fast chemical analysis in points, line profiles or raster maps. Analytical range is Na – U. Samples of solids, powders or even liquids do not require any treatment, however a smooth planar surface is a prerequisite for line profiling or element distribution mapping.
Principle of method: After ionization of K-shell by incident X-rays the electrons from higher level fall into vacant lover orbital, whereby emitting a secondary X-ray photon of a wavelength/energy characteristic for a given element. Intensities of secondary x-ray peaks are used in calculation of elemental concentrations.
- focussing of incident beam by polycapillary optics to 25 micron spot, interaction depth ca. 10-1000 µm.
- wide-angle camera and two coaxial digital microscopes 10x and 100x for easy navigation on sample surface. Mosaic imaging may be used for large samples.
- X-ray tube with rhodium target, excitation max. 50 kV at 600 µA, five filters.
- an SDD detector with spectral resolution 145 eV and active area 30 mm2
- motorized X-Y-Z sample stage with max. load 5 kg, stage drive 200x150x120mm
- analysis at atmospheric pressure or in vacuum for better sensitivity
- standardless quantification using fundamental parameter method.
Mgr. Stanislava Milovská, PhD.
Banská Bystrica, Ďumbierska 1, Geological Division