Regensburg 2010 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 23: Nanostructures at surfaces: Dots, particles, clusters

O 23.8: Vortrag

Dienstag, 23. März 2010, 12:15–12:30, H33

Size-dependent alignment of Fe nanoparticles upon deposition onto W(110) — •Armin Kleibert¹, Andris Voitkans², and Karl-Heinz Meiwes-Broer³ — ¹Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland — ²Institute of Solid State Physics, University of Latvia, LV-1063 Riga, Latvia — ³Institute of Physics, University of Rostock, D-18051 Rostock, Germany

Size, shape, structure and orientation of supported nanostructures have crucial impact on their catalytic, electronic, optical and magnetic properties. Thus, gaining control over these parameters is subject of intense research. Deposition of preformed clusters has attracted much attention in the past since it enables stabilization of nanostructures far from equilibrium and virtually any material and particle size combination. While fragmentation, diffusion and sintering of deposited nanoparticles have been intensively studied in the past, still little is known about the orientation of the nanoparticles upon deposition. In this contribution we present an in situ reflection high energy electron diffraction (RHEED) study on mass-filtered Fe nanoparticles upon deposition onto W(110). We find that clusters below a critical diameter align spontaneously in an epitaxial manner on W(110). Larger particles land preferentially on their surface facets but with random azimuthal orientation with respect to the substrate lattice [1]. These results show that even a random deposition process can lead to uniformly oriented nanostructures.

[1] A. Kleibert, A. Voitkans, and K.-H. Meiwes-Broer, submitted.