ABSTRACT
In this paper we will give an overview of the different approaches that offer one angstrom or close-to-one angstrom resolution picking out some relevant points for each technique. Sample preparation, beam damage or contamination may all affect the quality of results. We will start however by examining the structural information which may be revealed in materials at a resolutions approaching one angstrom
2 What is there at 1 Angstrom? It would be nice to think that among the considerations of the Republican Government in France in 1793, the year they decided on the metre as the basic unit of length (Jerrard and McNeill, 1986), was that time in the future when microscopes would start resolving details of precisely one ten thousand millionth of that distance. But even if the size of the angstrom unit is arbitrary when it comes to the atomic structure of materials, that spacing has been used as a goal for several microscope projects. We should therefore consider the atomic structures of materials and which spacings approach one angstrom, all the while keeping in mind the possibility of potential HREM test specimens.
