A tilting procedure to enhance compositional contrast and reduce residual diffraction contrast in energy-filtered TEM imaging of planar interfaces

This paper systematically demonstrates that energy-filtered transmission el ectron microscope (EFTEM) images of a planar interface between two single c rystals have increased compositional contrast and decreased residual diffra ction contrast when the sample is oriented so that the electron beam is par allel to the interface, but not directly on a zone axis. This off-axis orie ntation reduces diffraction contrast in the unfiltered (and zero-loss) imag e, which in turn, reduces residual diffraction contrast in single energy-fi ltered TEM (EFTEM) images, thickness maps, jump-ratio images, and elemental maps. Most importantly, this procedure produces EFTEM images that are more directly interpretable and, in most cases, possess superior spatial resolu tion compared to EFTEM images acquired directly on a zone axis. (C) 2001 El sevier Science Ltd. All rights reserved.