2D- & 3D-micro-XRF

A 2D micro XRF instrument (XRF = x-ray fluorescence) has been developed in the working group at WSU. This could be further developed into a confocal 3D-micro-XRF instrument. For this purpose, polycapillary optics are used to focus the X-ray beam on a spot with a diameter of about 20 μm. An energy dispersive Silicon Drift Detector (SDD) enables the acquisition of a spectrum for each pixel (or in 3D: each voxel). Thus, information about the elemental distribution in the sample is obtained quasi-disturbance-free. This and the indifference of the method to atmospheric pressure is an advantage over electron microscopy. The comparatively greater penetration depth of the X-ray beam into the sample enables analysis at depth below the surface.

X-ray fluorescence analysis (XRF) is particularly suitable for the determination of elements with high atomic numbers. Due to the non-destructive nature of this method (excitation with photons/detection of photons), only a comparatively small amount of sample manipulation is required; for example, a battery electrode can be examined directly in an open battery. Liquid samples can be examined in a glass capillary.

CMXRF (confocal micro-XRF)

Confocal micro X-ray fluorescence analysis provides an exclusive view below the surface. Using synchrotron radiation at the ANKA-FLUO-beamline at KIT (Karlsruhe, Germany), we have obtained 3D elemental distributions in anodes of aged lithium ion batteries. These measurements will soon also be possible in our laboratory.