Resolution in conventional transmission electron microscopy

Abstract

In conventional transmission electron microscopy (CTEM) imaging, diffraction contrast is most often used to form image features, but this increases the image width and reduces the distinguishable separation between closely spaced features within the structure, such as dislocations and interfaces. High-resolution CTEM techniques, however, are used to decrease the image width and thus increase the resolution. In this paper, we describe CTEM techniques and list the contrast mechanisms, based on kinematical theory used to enhance image details. In aperture-selected-area electron diffraction technique both the size of the area selected for diffraction and the smallest measurable change in lattice parameter constitute the resolution. This paper includes illustrative examples from current research of some of the experimental conditions that enhance image contrast and improve resolution both in CTEM imaging and aperture-selected diffraction.