Mass selected cluster deposition in strongly or weakly interacting media

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.…”

“…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.…”

“…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. As discussed above, this is also known from theoretical predictions [26,27].…”

“…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.…”

Determining the size-dependent structure of ligand-free gold-cluster ions

“…Furthermore, these monodispersed clusters must then be characterized under conditions ensuring minimal (or at least uniform) environmental perturbation of the inherent electronic and geometric structure. This is done either: (i) directly in the gas phase (typically within the molecular beam itself or after electrostatic extraction and trapping of cluster ions from the beam), (ii) within a cryogenic inert gas matrix after cluster co-deposition (Harbich & Felix 2002), or (iii) on a clean, single-crystal surface also after fragment-free cluster deposition from a low kinetic energy ion beam (Dicenzo et al 1988). In particular, the first approach has been extensively pursued and has yielded results for a wide range of monodispersed gold-cluster sizes.…”