Which type of electrons are ejected in X-ray absorbance spectroscopy?

In X-ray absorbance spectroscopy, core electrons are ejected when a material is exposed to X-ray radiation. This technique primarily targets electrons that are tightly bound to the nuclei of atoms, specifically those found in inner electron shells. The energy of the incoming X-rays is sufficient to overcome the binding energy of these core electrons, resulting in their ejection from the atom.

Core electrons play a crucial role in determining the elemental composition and electronic structure of materials. The specific binding energies of core electrons vary depending on the element and its electronic environment, allowing for precise identification of elements present in a sample through their characteristic X-ray absorption edges. The transition of core electrons to higher energy states or their ejection is not only essential for absorbing X-rays but is also linked to the subsequent emission of fluorescence or Auger electrons, which can provide additional information about the sample.

The other types of electrons listed, such as valence electrons, conductive electrons, and surface electrons, do not typically participate in the absorption processes at the energies involved in X-ray spectroscopy. Instead, they may be involved in other types of spectroscopy, such as ultraviolet-visible (UV-Vis) spectroscopy or photoelectron spectroscopy, but are not the focus of X-ray absorbance spectroscopy.