Solute-atom segregation is high-angle (002) twist boundaries in dilute Au–Pt alloys

Abstract

Solute-atom segregation is studied by Monte Carlo simulations for three high-angle symmetrical (002) twist boundaries in Au-1 at. % Pt and Pt-1 at. % Au alloys at T = 850 K. It complements our previous study, that focused mainly on low-angle boundaries in the same alloys. Solute enhancement occurs on the Pt-rich side of the phase diagram, while on the Au-rich side net depletion in solute is observed. Following the trend observed for low-angle boundaries, Au as a solute prefers the structural units of the perfect crystal type, while Pt as a solute is depleted at those sites. The solutc concentration at structural units depends on the planar fraction of those units in the boundary.