On the Damping of Screw Dislocation Motion in FCC Crystals by Phonon Viscosity

TL;DRAbstract

The phonon viscosity mechanism, as it applies to screw dislocations
\nmoving on the {111} planes of face-centered-cubic crystals,
\nis examined. Formulas are derived for changes in the elastic stiffnesses
\nof cubic crystals with the impression of an arbitrary elastic
\nstrain. The result is specialized to the case of the strain field of a
\nscrew dislocation in a face-centered-cubic crystal. Lattice energy
\nabsorption from a moving screw dislocation is then considered
\nthrough the relaxation of the elastic stiffnesses. Using the formula
\nfor energy absorption, a dislocation damping coefficient, B, is
\nfound. B is independent of temperature above the Debye temperature,
\nand at lower temperatures has different forms for anisotropic and
\nisotropic crystals. The damping coefficient for an edge dislocation
\nis qualitatively similar to that of the screw dislocation.
\nThe results are consistent with recent measurements
\nof the

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