2011/04/30 by J. Hughto, A. Schneider, A. S. Schneider +3 · 1 citation
Earth and Planetary Sciences · Engineering · Physics and Astronomy · #Condensed matter physics #Coulomb #Diffusion #Dust and Plasma Wave Phenomena #Electron #High-pressure geophysics and materials #Materials science #Physics #Quantum mechanics #Statistical physics #Thermodynamic and Structural Properties of Metals and Alloys #astro-ph.SR #cond-mat.other #nucl-th
paper · pdf · doi:10.1103/physreve.84.016401
published as Phys. Rev. E 84, 016401 (2011) · 11 pages, 10 figures, added discussion of laboratory experiments with complex plasmas to introduction and added several references, Phys. Rev. E in press
arxiv created 2011/06/07 · openalex publication_date 2011/07/07 · arxiv updated 2015/03/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Diffusion in Coulomb crystals can be important for the structure of neutron star crusts. We determine diffusion constants D from molecular dynamics simulations. We find that D for Coulomb crystals with relatively soft-core 1/r interactions may be larger than D for Lennard-Jones or other solids with harder-core interactions. Diffusion, for simulations of nearly perfect body-centered-cubic lattices, involves the exchange of ions in ringlike configurations. Here ions "hop" in unison without the formation of long lived vacancies. Diffusion, for imperfect crystals, involves the motion of defects. Finally, we find that diffusion, for an amorphous system rapidly quenched from Coulomb parameter Γ=175 to Coulomb parameters up to Γ=1750, is fast enough that the system starts to crystalize during long simulation runs. These results strongly suggest that Coulomb solids in cold white dwarf stars, and the crust of neutron stars, will be crystalline and not amorphous.