LAUSR

The novel ability to detect vibrational excitations with monochromated electron energy-loss spectroscopy (EELS) has great potential in high spatial resolution characterization of materials [1]. Such instrumentation capabilities can be leveraged to investigate delocalized behavior of the bulk as well as localized behavior of surfaces and interfaces. For a comprehensive understanding of this technique, experiments need to be performed on simple model systems and the results need to be compared with theory. In this paper, we explore the experimental spatial variation in the vibrational stretch signals from the bulk, surfaces and interfaces when an electron beam is scanned across a SiO2/Si interface. The resultant profiles are interpreted in terms of non-relativistic and relativistic dielectric theories [2,3].