X-Ray Fluorescence (XRF)
X-ray Fluorescence (XRF) is a non-destructive technique that is used to quantify the elemental compositions of materials and to measure film thickness and composition. X-rays are used to excite the sample, causing the emission of X-rays with energies characteristic of the elements present.
XRF is capable of detecting elements from B-U in concentrations from the ppm range to 100%. Additionally, Be can be measured in copper. Because X-rays are used to excite the sample, analysis depths from a few micrometers to several millimeters can be achieved depending on the material. Through the use of appropriate reference standards, or fundamental parameters (FP) when standards aren’t available, XRF can accurately quantify the elemental composition of most materials.
Two XRF systems are available, a wavelength dispersive instrument (WDXRF) and an energy dispersive instrument (EDXRF) with the main difference being the way in which the X-rays are separated and measured. WDXRF has very good energy resolution which leads to fewer spectral overlaps and improved background intensities. EDXRF has higher signal throughput which enables small area analysis or mapping.