Initial growth of Au on Ni(110): Surface alloying of immiscible metals

Abstract

Atomic resolution scanning tunneling microscopy of Au deposited on Ni (110) shows that even though Au is completely insoluble in bulk Ni, it replaces Ni in the first surface layer forming a surface Au-Ni alloy and the squeezed out Ni atoms agglomerate in Ni islands on the surface. This picture is supported by total energy calculations within the effective-medium theory, which also provide a detailed understanding of this surprising phenomenon.