Berlin 2005 – wissenschaftliches Programm
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MA: Magnetismus
MA 12: Elektronentheorie
MA 12.4: Vortrag
Samstag, 5. März 2005, 09:45–10:00, TU EMH225
Ferromagnetic ordering and halfmetallic state in a shandite: Co3Sn2S2 — •Helge Rosner1, Richard Weihrich2, Walter Schnelle1, M. Zabel3, and Claudia Stueckl3 — 1MPI for Chemical Physics of Solids, Dresden — 2Institut für Anorganische Festkörperchemie, Universität Regensburg — 3Institut für Anorganische Chemie, Universität Göttingen
The recent rapid development in spintronics challenges the search for new magnetic half metals with high Curie temperatures as well as an improved understanding of the underlying microscopic properties. Here, we present a joint experimental and theoretical study of the recently reinvestigated shandite Co3Sn2S2 [1]. From magnetic susceptibility, specific heat and resistivity measurements on powder samples we find a phase transition to a ferromagnetic metallic state at 177 K with a saturation moment of 0.87 µB/f.u. Full potential electronic structure calculations within the local spin density approximation result in a halfmetallic ferromagnetic groundstate with a moment of 1 µB/f.u. and a tiny gap in the minority spin channel. The calculated structure optimization and structure variations show that the size of the gap is rather sensitive to the lattice geometry. Possibilities to stabilize the halfmetallic ferromagnetic behaviour by various substitutions have been studied theoretically and will be discussed in detail.
[1] R. Weihrich et. al. Z. Anorg. Allg. Chem. 630, 1767, (2004)