Regensburg 2002 – wissenschaftliches Programm
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MA: Magnetismus
MA 10: Poster : Dünne Schichten(1-21),Spinabh.Transp.(22-39),Exch.Bias(40-51),Spindyn.(52-55),Mikromag.(56-66),Partikel(67-74),Abb.Verf.(75-77),Oberfl.+Spinelektr.+Elektr.Theo+Mikromag(75-87),PÜ+Aniso+Werkst/Leg.(88-103),Mol.Mag.+N-dim+Messm.+Postdead(104-111
MA 10.103: Poster
Dienstag, 12. März 2002, 15:00–19:00, Bereich A
Ab-initio calculations of Ni2MnGa properties — •Alexei Zaiak and Peter Entel — Theoretische Tieftemperaturphysik, Gerhard-Mercator University, 47048 Duisburg, Germany
Ni2MnGa is a ferromagnetic Heusler alloy and a promising candidate for a functional shape-memory material. We discuss its properties on the basis of ab-initio calculations. In particular, we focus on the charge and spin density for ratios of lattice constants c/a, for which the lattice undergoes tetragonal deformations with respect to the initial L21 structure. Two different orthorhombic deformations leading to body centered and face centered orthorhombic structures are investigated. The results for magnetic and elastic properties of the parent cubic L21 structure agree well with the experimental data for Ni2MnGa. However, the deformations of the lattice lead to some disagreement with experiments like the state of lowest energy is found to occur for c/a > 1, and not for c/a < 1 as experimentally observed. Nevertheless, the calculations provide a certain insight into the associated with Heusler structure physics. The spin density shows interesting features connected with the Ni - Mn magnetic coupling.