Density changes of crystals containing dislocations

Zener's theory of the volume expansion of self-strained elastic bodies is applied to screw and edge dislocations in isotropic media. The important physical parameters entering are the pressure dependence of the shear modulus, and, to a lesser extent, that of the bulk modulus. Numerical results for a number of materials are given. The volume expansion per atomic length of a dislocation line is found to be of the order of magnitude of one to two atomic volumes, thus confirming an earlier estimate by Stehle and Seeger.