Atomic resolution with the electron microscope

In principle the structure of matter at the atomic level can be revealed by utilizing the sbort wavelength of the high-energy beam of an electron microscope. In practice, a number of difficulties, mainly technical in nature, have previously prevented such atomic resolution bom being attained. Here we describe how atomic resolution has been realised in the electron microscope and review the potential impact of this achievement on our understanding of materials. We emphasize the role of the microscope in clarifying the nature of local irregularities in the structure, since it is these which point to an explanation of macroscopic behaviour. Specific examples are presented of the succes of this approach, drawn from a variety of disciplines. The prospects for further development of atomic resolution and its applications are also considered.