DecoratedAg19on Pt(111) or the “Rare Gas Necklace”

Abstract

Ag19 cluster ions are mass selected and deposited on a Pt(111) surface covered by five monolayers of Kr. Almost monodispersed hexagonal shaped Ag islands are observed after Kr evaporation at 125 K. The identification of the island shape and the exact number of atoms has been successful by decorating the clusters with Kr atoms which can be counted by high resolution scanning tunneling microscopy.

Soft landing of size-selected clusters in rare gas matrices

“…As has been shown in thorough experimental investigations [19][20][21][22]24], the fragmentation rate of small metal clusters can be reduced to about 10 % by using proper soft landing conditions. From optical absorption and excitation experiments [20,21,24] on clusters soft landed in rare gas matrices it is known that the efficiency of the soft landing process and the fragmentation rate of the clusters depends on the nature of the rare gas matrix.…”

“…STM studies [22] on soft landed clusters also have shown the power of the soft landing technique. Furthermore, they reveal that most of the soft landed clusters form highly symmetric equilibrium structures on the substrate surface.…”

“…By depositing a decelerated cluster beam with kinetic energies typically of some few eV per cluster atom into rare gas multilayers, the surplus kinetic energy will be dissipated by energy transfer into the matrix and ultimately by rare gas desorption. This process has been studied experimentally [19][20][21][22][23][24][25] and theoretically [26][27][28][29][30][31][32] in detail. Molecular dynamics (MD) simulations [26,27] of the energy dissipation processes provide insight into the different stages of slowing down the impinging clusters and redistributing their initial kinetic energy.…”

“…Furthermore, they reveal that most of the soft landed clusters form highly symmetric equilibrium structures on the substrate surface. Small clusters tend to form two-dimensional structures on a surface [22,37].…”

“…Therefore, cluster deposition conditions have to be chosen under which no fragmentation, implantation, or agglomeration of the clusters occurs. For this purpose, the soft landing technique has been developed by several groups, both experimentally [19][20][21][22][23][24][25] and theoretically [26][27][28][29][30][31][32]. As a result, this technique is now well established.…”