Berlin 2015 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 38: Magnetic Nanoparticles
MA 38.12: Vortrag
Donnerstag, 19. März 2015, 12:30–12:45, H 0110
Magnetism of free Rh clusters via ab-initio calculations: which intuitive concepts can or cannot be used — •Ondřej Šipr1, Hubert Ebert2, Sergey Mankovsky2, and Ján Minár2, 3 — 1Institute of Physics ASCR, Praha, Czech Republic — 2Universität München, München, Germany — 3University of West Bohemia, Plzeň, Czech Republic
A fully relativistic ab-initio study on free Rh clusters of 13-135 atoms is performed to identify general trends concerning their magnetism and to check whether concepts which proved to be useful in interpreting magnetism of 3d metals are applicable to magnetism of 4d systems. Some important intuitive concepts which proved to be useful in interpreting magnetism of 3d metals are not applicable to magnetism of 4d systems (such as Rh clusters). In particular, there is no systematic relation between local magnetic moments and coordination numbers. On the other hand, the Stoner model appears to be well-suited as a criterion for the onset of magnetism of Rh clusters and, on the top of that, it can serve as a guide for the dependence of local magnetic moments on the local density of states at the Fermi level.
Fully-relativistic calculations indicate that in some cases there can be large orbital magnetic moments antiparallel to the spin magnetic moments. The intra-atomic magnetic dipole Tz term can be quite large at certain sites, however, as a whole it is unlikely to affect the interpretation of x-ray magnetic circular dichroism (XMCD) experiments based on the sum rules.