title: Multicomponent phase-field model for extremely large partition coefficients.
abstract: We develop a multicomponent phase-field model specially formulated to robustly simulate concentration variations from molar to atomic magnitudes across an interface, i.e., partition coefficients in excess of 10±23 such as may be the case with species which are predominant in one phase and insoluble in the other. Substitutional interdiffusion on a normal lattice and concurrent interstitial diffusion are included. The composition in the interface follows the approach of Kim, Kim, and Suzuki [Phys. Rev. E 60, 7186 (1999)] and is compared to that of Wheeler, Boettinger, and McFadden [Phys. Rev. A 45, 7424 (1992)] in the context of large partitioning. The model successfully reproduces analytical solutions for binary diffusion couples and solute trapping for the demonstrated cases of extremely large partitioning.
authors.affiliation: Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Welland
authors.affiliation: Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Dieter
authors.initials: D
authors.lastname: Wolf
authors.affiliation: Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
authors.forename: Jonathan E
authors.initials: JE
authors.lastname: Guyer