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MA: Magnetismus
MA 6: Magnetische Partikel / Cluster
MA 6.11: Vortrag
Montag, 8. März 2004, 17:45–18:00, H10
Magnetic hyperfine fields of Fe in Cd host — •Mohammad Ghafari1, Elisa Baggio-Saitovitch2, and K. E. Munayco2 — 1TU Darmstadt, Material- und Geowissesnchaften, Petersenstr. 23, 64287 Darmstadt — 2CBPF/ Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro Brazil
Isolated impurity Fe atoms in a Cd matrix are expected to develop a local magnetic moment. The local density of the state, N(E), at the Fermi level at impurity site and the Stoner parameter, I, play a decisive role for the onset of a magnetic moment. Theoretical calculations show that the Stoner criteria, N(E) · I > 1 for the development of Fe moments are fulfilled in the Cd host. The magnetic properties of Fe impurities in Cd are of particular interest as theoretical calculations predict a large magnetic moment for Fe atoms in the Cd host on the other hand there is no experimental information available about the magnetic moment of Fe in Cd. The aim of the present work is to clarify the magnetic properties of nanoscale Fe atoms in a Cd. Diluted Fe in Cd can be prepared by co-evaporation of Fe and Cd under ultra high vacuum (UHV) conditions. Of special interest is the determination of the internal magnetic hyperfine field which is correlated to the magnetic moment of Fe. In the CdFe system magnetic clusters have an average size of about 5 atoms; this means that the Fe atoms are surrounded by Cd atoms and can therefore be treated effectively as surface atoms. Such ferromagnetic clusters with surface properties offer a new kind of material for which detailed theoretical and experimental investigations are desirable.