Why are electron diffraction methods especially useful for studying crystal surfaces?

In materials science, electron diffraction methods—particularly low-energy electron diffraction (LEED)—are uniquely valuable for studying crystal surfaces because of how electrons interact with matter.

Unlike X-rays, which penetrate deeply into a material, electrons are scattered very strongly by atoms. When a beam of low-energy electrons is directed at a crystal, these electrons scatter multiple times within the first few atomic layers before reflecting backward. Because they interact so intensely with the surface atoms, the resulting diffraction patterns provide information exclusively about the atomic arrangement of those outermost layers, rather than the bulk of the material.1

This surface sensitivity makes electron diffraction an essential tool for characterizing the crystalline structure of surfaces, as it allows researchers to isolate and analyze the specific atomic configurations present at the interface of a solid.1