Calculation update! New properties have been added to the website for dislocation monopole core structures, dynamic relaxes of both crystal and liquid phases, and melting temperatures! Currently, the results for these properties predominately focus on EAM-style potentials, but the results will be updated for other potentials as the associated calculations finish. Feel free to give us feedback on the new properties so we can improve their representations as needed.
Warning! Note that elemental potentials taken from alloy descriptions may not work well for the pure species. This is particularly true if the elements were fit for compounds instead of being optimized separately. As with all interatomic potentials, please check to make sure that the performance is adequate for your problem.
Citation: Z. Fan, É. Maras, M. Cottura, M.-C. Marinica, and E. Clouet (2024), "Structure and coherency of bcc Nb precipitates in hcp Zr matrix from atomistic simulations", Physical Review Materials8(11), 113601. DOI: 10.1103/physrevmaterials.8.113601.
Abstract: We use atomistic simulations to study the structure and shape of niobium precipitates with a body-centered cubic crystallographic structure in a zirconium matrix with a hexagonal close-packed structure. We consider a Pitsch-Schrader orientation relationship, which is observed experimentally for Nb precipitates appearing under irradiation in zirconium alloys. In this regard, we have developed a Zr-Nb empirical potential using the embedded atom method. This parametrization offers a good description of the interfaces between Nb precipitates and the Zr matrix. The potential includes all the necessary physical ingredients to account for the coherency strain between both phases. The atomistic simulations reveal a significant decrease in the precipitate formation energy when they become semicoherent, with enough misfit dislocations at the interface to eliminate the lattice misfit between the Nb precipitates and the Zr matrix. The "idealized" equilibrium shape that minimizes the formation energy of these semicoherent precipitates matches the experimental shape: platelets lying in the Zr basal planes with a reduced dimension along the [0001] axis. Our simulations suggest that the platelet shape observed in zirconium for irradiation-induced Nb-enriched precipitates simply results from a minimization of their energy cost.
Notes: This potential is intended to model bcc Nb precipitates in hcp Zr.