ISLAND ASSISTED SURFACE ALLOYING OBSERVED AFTER NI DEPOSITION ON AU(110)-(1X2)

The influence of adislands on surface alloying is studied with scannin g tunneling microscopy, ion scattering, and x-ray photoelectron spectr oscopy. 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 ro ws of the terrace. An asymmetry in their lateral distribution with res pect to adislands along [110] is found. It reveals that these Ni atoms are incorporated during island ripening, when small clusters of adato ms, in a double row configuration, merge to form 2D adislands. This me chanism, termed ''island assisted alloying,'' interrelates surface all oying and growth.