The study of thin films and surfaces has received increasing attention over the last 10 years. Furthermore, there has been an increasing number of techniques devoted to these studies.1The majority of the techniques achieve their surface sensitivity as a result of the strong coupling between the charged particle and the material that the particle traverses before it is detected. For example, with electron detection techniques (e.g., photoemission [XPS, UPS] and Auger electron spectroscopy [AES]), this strong coupling leads to an electron mean free path that ranges from 5 to 30 Å for most materials in the electron energy range of 10 to 1000 eV.2