Sub-THz Phonon drag on dislocations by coarse-grained atomistic simulations

• Dislocation–phonon interactions are simulated by a concurrent atomistic-continuum (CAC) method.
• Dislocation migration and phonon transport in fcc crystals are simulated.
• The phonon induced oscillations of the distance between the leading and trailing partials are explicitly reproduced.
• Phonon drag coefficients on dislocation motions in fcc crystals are predicted by CAC.
• The effects of phonon wave magnitudes and incident angles on the drag coefficients are investigated.

In this paper, dislocation–phonon interactions in fcc crystals are simulated using the concurrent atomistic-continuum (CAC) method. With significantly less computational cost than that by full molecular dynamics (MD) simulations, dislocation migration, phonon transport, and their interactions are explicitly modeled. Sub-THz Phonon drag coefficients on moving dislocations are predicted using CAC and compared with MD and experimental results. During the interactions between phonons and dislocations, the local temperature is found to rise due to energy dissipation, and dislocations are observed to exhibit “breathing modes” in which the separation between leading and trailing partials varies in time in a quasi-periodic fashion. Simulation results show that the phonon drag coefficient on dislocation migration increases with phonon wave packet magnitudes or sizes but is insensitive to the incident angles.