Zero-Loss Energy Filtered REM and RHEED Observations on Rutile (110) Surface

In reflection electron microscopy (REM), the surface reflection electrons undergo both elastic and inelastic scattering within a crystal. The dominant inelastic processes are phonon scattering, valence electron excitation, bulk and surface plasmon excitation and combinations of these processes. Multiple inelastic scattering processes are also probable as the mean traveling distance of surface reflection electrons is about 10 to 100 nm. In reflection high energy electron diffraction pattern (RHEED), 50% to 90% of the electrons contributing to surface reflection spots used for imaging have suffered energy loss of more than 10 eV, thus the main limitation on REM image resolution is due to the chromatic aberration effects given by the energy spread from inelastic scattering. An energy filter fitted inside a TEM microscope can remove most of the inelastic scattering contribution and so improve the contrast and resolution. Oxygen-annealed rutile (001), (100) and (110) surfaces were previously studied by REM and RHEED techniques without energy filtering.