Raising the Standard of Specimen Preparation for Aberration-Corrected TEM and STEM

Abstract

With the recent advances made in monochromation of electron sources and Cs-correction, the point resolution of the transmission electron microscope (TEM) has been extended into the sub-Angstrom regime. This development has led to an important consequence—that specimen preparation has become a more critical issue for the materials scientist. Nanoscale artifacts that could be tolerated a few years ago when imaging in the 0.1–0.15 nm range can no longer be allowed. An example is hydrocarbon contamination, which although only a few monolayers thick, obscures the area of interest. Other examples include residual deformation and oxidation following traditional mechanical methods. Ion-based methods may induce amorphization and implantation defects, depending on the type of ion, its energy, and the particular protocol that is used.