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MA: Magnetismus

MA 13: Poster:Schichten(1-23),Spinabh.Trsp(24-41),Exch.Bias(42-56),Spindyn.(57-67),Mikromag.(68-76),Partikel(77-90),Spinelektr.(91-97),Elektr.Theo.(98-99),Mikromag+PhasÜ+Aniso.(100-105),Magn.Mat.(106-118),Messmethod.(119-121),Obflm.+Abbverf.(122-123)

MA 13.109: Poster

Dienstag, 9. März 2004, 15:00–19:00, Bereich A

Electronic Structure of Transition-Metal Dicyanamides Me[N(CN)₂]₂ (Me = Mn, Fe, Co, Ni, Cu) — •Takács Albert¹, Chiuzbăian Sorin¹, Crainic Traian Ionica¹, Demchenko D. O.², Filkenstein L.D.³, Galakhov V.R.³, Kmety Carmen R.⁴, Kurmaev E. Z.³, Liu Amy Y.², Moevs A.⁵, Neumann Manfred¹, and Stevensson Knneth L.⁶ — ¹Universität Osnabrück — ²Department of Physics, Georgetown University, Washington — ³Institute of Metal Physics, Yekaterinburg — ⁴Argonne National Laboratory, USA — ⁵University of Saskatchewan, Canada — ⁶Purdue University Indiana , USA

The electronic structure of Me[N(CN)₂]₂ (Me=Mn, Fe, Co, Ni, Cu) molecular magnets has been investigated using x-ray emission spectroscopy (XES) and x-ray photoelectron spectroscopy (XPS) as well as theoretical density-functional-based methods. Both theory and experiments show that the top of the valence band is dominated by Me 3d bands, while a strong hybridization between C 2p and N 2p states determines the valence band electronic structure away from the top. The 2p contributions from non-equivalent nitrogen sites have been identified using resonant inelastic x-ray scattering spectroscopy with the excitation energy tuned near the N 1s threshold. The binding energy of the Me 3d bands and the hybridization between N 2p and Me 3d states both increase in going across the row from Me = Mn to Me = Cu. Calculations indicate that the ground-state magnetic ordering is largely dependent on the occupation of the metal 3d shell and that structural differences in the superexchange pathways for different compounds play a secondary role.