The heart of crystalline materials

Thanks to their characteristic properties, x-rays form the basis for several methods used to investigate materials. We use:

• emission properties:

  under the effect of incident radiation (electrons or x-ray photons), a given material can emit characteristic rays of the elements that comprise it. Detection of these characteristic rays enables a chemical analysis of the material to be made. Two analysis techniques are based on this principle: the electron probe microanalyser, or Castaing microprobe (electron excitation) and x-ray fluorescence (x-ray excitation).

• absorption properties:

  these form the basis of radiography techniques.

• diffusion properties:

  in the case of crystals, elastically scattered photons are located in beams that propagate in clearly determined directions: these are diffracted beams. X-ray crystallography uses this property and provides much information about the crystallised materials.