Motion of a screw dislocation in a crystal at finite temperature

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Abstract
In a simple model of a cubic lattice with piecewise linear nearest‐neighbor interactions, a solution is obtained for the motion of a straight screw dislocation at finite temperature T, under the action of a constant applied stress. This external stress is balanced by the frictional stress due to the scattering and emission of phonons by the core of the dislocation. The results are compared with those obtained by the authors and others for the case of zero temperature. It is found that the thermal agitation greatly affects the dislocation motion for T comparable to the Debye temperature. At low T, the shape of the stress‐velocity curve is the same as at T=0, except that an additional phonon‐scattering term, proportional to the number of phonons, is present.