We report on a source for producing size-selected nanoclusters based on the combination of radio frequency magnetron plasma sputtering and gas condensation. The use of plasma sputtering to vaporize a target is applicable to a large range of materials; Ag, Au, Cu, and Si have been attempted to date. The source, combined with a time-of-flight mass filter, can produce clusters in the size range from 2 up to at least 70 000 atoms, depending on the target material, with a constant mass (M) resolution (M∕ΔM∼25) at an intensity that produces atomic monolayer coverage in as little as a few minutes. The source is also attached to an ultrahigh vacuum analysis chamber, which allows in situ surface chemical and structural analysis. Examples of cluster deposition experiments with the source are also presented.

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Indium oxide (InOx) films with a thickness of 100–500 nm were prepared by dc magnetron sputtering onto Corning 7059 glass substrates. The as-deposited films were microcrystalline as revealed by x-ray diffraction analysis. The conductivity of the as-deposited films was of the order of 10−3–10−2 Ω−1 cm−1 and increased up to the order of 101–102 Ω−1 cm−1 by exposure to ultraviolet light hν≥3.5 eV in vacuum. By subsequently exposing the same films to an oxidizing atmosphere they reverted to the insulating state. Photoreduction and oxidation have been shown to change the conductivity properties of one and the same film in a fully reversible manner. In this article, we demonstrate that the large reversible conductivity changes produced by UV photoreduction and oxidation are not limited to amorphous InOx but are equally observed in microcrystalline InOx.

This paper discusses a novel deposition route of size-selected metal clusters, specifically AgN+ (where N = 2700), on graphite. The clusters are produced via a magnetron sputtering, gas aggregation cluster beam source and are size selected via a lateral time-of-flight mass filter. These clusters are deposited on a highly oriented pyrolytic graphite (HOPG) target predecorated with surface defects via Ar+ sputtering. Scanning tunnelling spectroscopy (STM) reveals a stable, randomly dispersed array of Ag2700 clusters after deposition.