It has been known that even though two elemental metals, X and Y, are immiscible, they can form alloys on surfaces of other metal Z. In order to understand such surface alloying of immiscible metals, we study the energetic stability of binary alloys, XZ and YZ, in several structures with various coordination numbers (CNs). By analyzing the formation energy modified to enhance the subtle energy difference between metastable structures, we find that XZ and YZ with B2-type structure (CN=8) become energetically stable when the X and Y metals form an alloy on the Z metal surface. This is consistent with the experimental results for Pb-Sn alloys on metal surfaces such as Rh(111) and Ru(0001). Some suitable metal substrates are also predicted to form Pb-Sn alloys.
@article{arxiv.2101.12343,
title = {Simple prediction of immiscible metal alloying based on metastability analysis},
author = {Shota Ono and Junji Yuhara and Jun Onoe},
journal= {arXiv preprint arXiv:2101.12343},
year = {2021}
}