Atomistic modeling of Pd site preference in NiTi

An analysis of the site substitution behavior of Pd in NiTi was performed using the BFS method for alloys. Through a combination of Monte Carlo simulations and detailed atom-by-atom energetic analyses of various computational cells, representing compositions of NiTi with up to 10 at.% Pd, a detailed understanding of the site occupancy of Pd in NiTi was revealed. Pd substituted at the expense of Ni in an NiTi alloy will prefer the Ni-sites. Pd substituted at the expense of Ti shows a very weak preference for Ti-sites that diminishes as the amount of Pd in the alloy increases and as the temperature increases.