Atomic or point defects are disturbances of the periodicity of the crystal lattice extending over only a few atomic distances. Many physical and mechanical properties of solids are sensitive to their presence. Furthermore other defects which are crucial to material behaviour are influenced by their interaction with atomic defects. A detailed knowledge of production mechanisms and properties of point defects is therefore essential for assessing and for understanding the atomistic as well as the macroscopic behaviour of materials. As a result of the use of new research methods in recent years,...