2-DIMENSIONAL REGULAR ARRAYS OF NANOSCALE METAL PARTICLES BY ORDERED NUCLEATION ON RECONSTRUCTED SURFACES

The capabilities of a route to cluster-assembled nanophase materials b y ordered nucleation on reconstructed {111} surfaces of AgBr are prese nted. Under ultrahigh vacuum conditions vapour deposition of a small q uantity of gold on AgBr thin films topped off with {111} faces results in nearly equisized particles (about 5 nm) that are highly ordered al ong three directions. The regular arrays are coherent in domains of se veral hundred up to a few thousand nm in size. Depending on the growth conditions of AgBr different spacings and directions are obtained ran ging from 5.6 nm along <110> to 8.3 nm along <321>. They are explained by a fractal model based on a procedure of covering the lattice sites of AgBr(111). The surface configurations obtained may act as preferre d sites of metal accommodation during vapour deposition because of loc ally uncompensated charges. Possible applications of the regularity of this nucleation mechanism are considered.