Low-energy electron diffraction
（重定向自Low energy electron diffraction）
![Figure 1: LEED pattern of a Si(100) reconstructed surface. The underlying lattice is a square lattice while the surface reconstruction has a 2x1 periodicity. As discussed in the text, the pattern shows that reconstruction exists in symmetrically equivalent domains which are oriented along different crystallographic axes. The diffraction spots are generated by acceleration of elastically scattered electrons onto a hemispherical fluorescent screen. Also seen is the electron gun which generates the primary electron beam. It covers up parts of the screen.](/Images/godic/202501/25/Si100Reconstructed2914.png")
![Figure 2 Diagram of a LEED optics apparatus.](/Images/godic/202501/25/LEED_Experimental_Diagram2914.jpg")
![Image 1: LEED pattern of a clean platinum-rhodium (100) (Miller-index) single crystal. Taken in high vacuum using an electron gun with an energy of 85 eV.](/Images/godic/202501/25/LEED_pattern_of_clean_Platinum-Rhodium_single_crystal2914.jpg")
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Low-energy electron diffraction (LEED) is a technique for the determination of the surface structure of single-crystalline materials by bombardment with a collimated beam of low energy electrons (20–200 eV) and observation of diffracted electrons as spots on a fluorescent screen.