Energy and Atomic Configurations of Complete and Dissociated Dislocations. II. Screw Dislocation in an fcc Metal

摘要: The arrangement of atoms around a screw dislocation in copper has been calculated by variational method. pairwise interaction between discrete was represented Morse potential function. displacements parallel to the line agree well with those given linear elastic theory except for within distance about 5.3 \AA{} center dislocation. Because this, there is disparity atomistic and energies inside core radius complete $〈110〉$ ($\mathrm{Burgers}\mathrm{vector}=(\frac{{a}_{0}}{2})〈110〉$), where ${a}_{0}$ lattice parameter. corresponding energy 1.0 eV per nearest-neighbor distance. In calculation dislocation, were not permitted relax direction perpendicular line. This prevented dissociation. When this constraint removed, dissociation into two partial dislocations occurs spontaneously. If replaced hole ${r}_{\mathrm{eh}}$ (the equivalent radius), which hollow outside linear-elastic holds at all points, 1.1 \AA{}. varies as $\mathrm{ln}r$ large radii, agreement elastic-continuum theory. By comparing asymptotic behavior curve edge values shear modulus Poisson's ratio obtained.