Line Energies of 30°- and 90°-Partial Dislocations in Silicon and Germanium

For the 30°- and 90°-partial dislocations in Si and Ge line energy calculations are considered. Basic requirements are discussed on empirical interaction potentials to make them suited for estimating the line energies. In case of the considered ‘reconstructed’ dislocation core geometries the potentials have to describe properly the elastic constants and the full phonon dispersion curves including the TA phonon branch flattening. For Weber's bond charge model, which fulfils the requirements, dislocation line energies are presented and compared with data from Keating, Tersoff, and Stillinger-Weber model calculations.