Low energy electrons (LEED, STM and HREELS) in the microanalytical characterization of complex surface structures

The use of surface analytical techniques has created a broad knowledge of the geometric structures of even complex single-crystal surfaces and surf ace-adsorbate systems; which is essential to the understanding of their physical and chemical properties. Four techniques that use low-energy electrons as a probe are reviewed in this paper. These are low-energy electron diffraction (LEED), low-energy electron microscopy (LEEM), scanning tunneling microscopy (STM) and high-resolution electron energy loss spectroscopy (HREELS). Their experimental principles, theoretical backgrounds and specific capabilities in surface science studies are discussed. Recent examples of these techniques for structure determination of complex clean surfaces and complex adsorbate molecular systems are presented, with an emphasis on organic adsorbate molecules.