Island assisted surface alloying observed after Ni deposition on Au(110)-(1x2)

The influence of adislands on surface alloying is studied with scanning tunneling microscopy, ion scattering, and x-ray photoelectron spectroscopy. After deposition of Ni on the Au(110)-(1 x 2) surface at 300 K, substitutional Ni atoms are found between adislands in the top Au rows of the terrace. An asymmetry in their lateral distribution with respect to adislands along [110] is found. It reveals that these Ni atoms are incorporated during island ripening, when small clusters of adatoms, in a double row configuration, merge to form 2D adislands. This mechanism, termed ''island assisted alloying,'' interrelates surface alloying and growth.