Method of creating a Pd-covered single-atom sharp W pyramidal tip: Mechanism and energetics of its formation

Stabilities in field electron emissions from noble‐metal covered W nano‐tips: apex structure dependence

“…According to Fu, the potential barrier of the topmost single atom for diffusion was higher than 2.8 eV, which is much higher than those on the other sites. 14 The occupation of the top site with the noble metal largely reduced the total surface energy of the nano-tip, Temporal changes were also observed in the total energy curves of the FE beams. Figure 6 shows the FE energy spectra (FE spectra) of a third-layer tip; one of them (a) was measured just after confirming the structure by means of FIM; the other (b) was measured after a 30-min lapse.…”

Oxidation of CO Catalyzed by a Cu Cluster: Influence of an Electric Field

“…[48] This agrees with the experimental result that a single-atomended nanopyramid is a thermodynamically stable structure during the heating process. [64][65] For comparison purposes, the four-layer Cu(111) and twelve-layer Cu(211) surface systems are constructed with a vacuum width of 12 in the vertical direction, as seen in plots (b) and (c) of Figure 1. A· (22) and (2 1) unit cell is set for the flat Cu(111) and stepped Cu(211) surface, respectively, with a 5 5 1 k-point sampling.…”

Diffusion and desorption of submonolayer platinum deposited on the multi-faceted surface of a tungsten micro-crystal

“…Instead, this region was getting darker with increasing platinum coverage. Considerable decrease of the local tip curvature near the {1 1 1} pole, caused by faceting, is known for the tungsten emitter surface adsorbed with oxygen [27,28] or palladium [29,30]. In these systems the (1 1 2) facets were growing upon annealing the adsorbed tip to form small and relatively sharp pyramid on the emitter tip apex.…”

“…Spreading, alloying and desorption are the subjects important from the point of view of possible application of platinum as the model catalyst [26] and the faceting factor for ultrasharp tips fabrication. W(1 1 1) oriented tips additionally etched in faceting processes are still a subject of special interest as possible sources of electron or ion beams as well as STM tips [27][28][29][30].…”