SURFACE STUDIES BY CORE-EXCITATION REFLECTION ELECTRON-ENERGY-LOSS SPECTROSCOPY

Inelastic electron scattering in a reflection geometry is a useful alt ernative to synchrotron radiation X-ray absorption spectroscopy for in ner-shell excitation studies of surfaces. This article reviews the cur rent capabilities of reflection electron energy loss spectroscopy for core-excitation studies of the electronic and geometric structure of s urfaces. Issues discussed include: momentum transfer dependence, compa rison to X-ray techniques, orientational sensitivity, spatial and ener gy resolution, and technological applications. Examples of application s to clean surfaces, atomic and molecular adsorbates, and thin films a re given.