Regensburg 2002 – wissenschaftliches Programm
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MA: Magnetismus
MA 11: Molekularer Magnetismus
MA 11.5: Vortrag
Mittwoch, 13. März 2002, 15:30–15:45, H22
First-principles DFT studies of the molecular nanomagnet Fe8 and the spin complex V15 — •Jens Kortus1, C. Stephen Hellberg2, and Mark R. Pederson2 — 1MPI für Festkörperforschung Stuttgart — 2Center for Computational Materials Science, Washington DC, USA
Molecular magnets such as Mn12-Ac and Fe8 are a class of materials that have raised significant scientific interest due to the observation of quantum tunneling of magnetization and hysteresis of a purely molecular origin.
We have performed ab-initio density-functional based calculations on the nature of electronic states and the magnetic coupling of these clusters using the massively parallel cluster code NRLMOL. We report first-principles DFT calculations on the electronic and magnetic properties of the high-spin (S=10) Fe8 cluster. For the case of the V15 spin system we have determined a Heisenberg Hamiltonian with one ferromagnetic and five antiferromagnetic exchange couplings. The Heisenberg Hamiltonian allowed us to find the DFT ground state of the 215=32768 total magnetic arrangements with only about 10 DFT calculations [1].
[1] J. Kortus, C. S. Hellberg, and M. R. Pederson, Phys. Rev. Lett 86 3400 (2001)