X-ray fluorescence

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X-ray fluorescence (XRF) is the emission of characteristic secondary (or fluorescent ) X-rays from a material that has been excited with high-energy radiation . The phenomenon is used in X-ray fluorescence analysis to determine the elemental composition of metals, glasses, ceramics and other materials.

Basics

If materials are exposed to radiation from short-wave X-rays, the components are ionized by the ejection of one or more electrons. If the energy of the radiation is high enough, not only the binding electrons but also electrons are knocked out of the inner shells. This makes the electronic structure of the atom unstable and electrons from higher shells fall into the gap created, emitting radiation that is characteristic of the element.

  • Physics of X-ray fluorescence in a schematic representation

  • Electron transitions in a calcium atom.

  • Typical energy dispersive X-ray fluorescence spectrum

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