Dresden 2006 – wissenschaftliches Programm

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MA: Magnetismus

MA 20: Poster: Films(1-36) Transp(37-56) Ex.Bias(57-67) Spindyn(68-80) Micromag(81-95) Particle(96-109) Imag.+Surface(110-113) Spinelectr(114-122) Theory+Micromag(123-131) Spinstr+Aniso(132-142) MagMat(143-156) Meas(157,158) MolMag+Kondo(159-162) Postdead(163-)

MA 20.103: Poster

Dienstag, 28. März 2006, 15:15–19:15, P1

Ab initio investigation of structural and magnetic properties of nanosized Fe-clusters — •Markus E. Gruner, Georg Rollmann, Alfred Hucht, and Peter Entel — Theoretische Physik, Universität Duisburg-Essen, 47048 Duisburg

We report on the structural and magnetic properties of iron clusters of icosahedral, cuboctahedral and Bain-transformed cuboctahedral shape with up to 309 atoms. The results are obtained within the framework of density functional theory using the Vienna ab Initio Simulation Package (VASP) including full structural relaxation. We find that from 147 atoms on the bcc-like structures have the lowest energy while there is an second minimum for a closed packed structure which is only slightly higher in energy. This structure appears to be shell-wise transformed along the Mackay path with the inner shells being closer to the cuboctahedral structure and the outer shells being more icosahedral. For the bcc structures the moments agree well with experimental data, while in the other case the magnetic moment is reduced due to antiferromagnetic ordering.

Parts of the calculations have been carried out on the IBM BlueGene/L supercomputer at the Forschungszentrum Jülich.