Grain boundary diffusion in Yukawa crystals
Phys. Rev. E 114, 025205 – Published 17 August, 2026
DOI: https://doi.org/10.1103/ty6k-rl2w
Abstract
We present calculations of diffusion coefficients in grain boundaries (GBs) in Yukawa crystals for astrophysics. Our methods follow from our recent work calculating diffusion coefficients in perfect body-centered cubic crystals. These diffusion coefficients show only a weak dependence on the crystal orientations at the GB and are consistent with those expected for a supercooled liquid scaled down by 1–2 orders of magnitude. We argue that the local disorder at the GB produces a landscape of potential barriers similar to that of an amorphous liquid thin film, significantly reducing activation barriers to diffusive hops relative to the bulk solid. This also introduces a screening dependence, such that boundary diffusion does not exhibit the same universality as the bulk crystal. These diffusion coefficients suggest that GBs may be a dominant source of plastic dissipation in neutron star crusts.
