Münster 1999 – wissenschaftliches Programm
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O: Oberflächenphysik
O 30: Teilchen und Cluster (II)
O 30.2: Vortrag
Donnerstag, 25. März 1999, 14:45–15:00, S1
Co NANOPARTICLES GETTING BURIED IN Cu AND Ag FILMS: A NEW PHENOMENON IN CLUSTER DEPOSITION — •Claus G. Zimmermann1,2, Ulrich Herr1, Mark Yeadon2, Mai Ghaly2, J.Murray Gibson2, Robert S. Averback2, and Konrad Samwer1 — 1Institut f"ur Physik, Universit"at Augsburg, Universit"atsstr. 1, 86135 Augsburg — 2Materials Research Laboratory, 104 S Goodwin Ave, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
We have investigated the soft landing of Co nanoparticles on clean metal surfaces using in-situ ultra high vacuum (UHV) transmission electron microscopy (TEM) combined with ex-situ atomic force microscopy (AFM). Particles with an average size of 13 nm were generated by dc-sputtering in argon and transferred directly into the microscope along a connecting tube. The particles were deposited onto clean (001) Cu- and Ag-films with thickness between 50 and 100 nm. Particles deposited at room temperature are highly faceted and randomly oriented on the substrate. Particles deposited at 300 oC assume the orientation of the substrate and in addition they become buried below the surface. The explanation for this behavior relies on the fact that it is energetically more favorable for the system to replace the high Co surface energy with the much lower particle-substrate interface energy. To our knowledge this is the first time that such a behavior has been observed for agglomerates of many thousand Co atoms.