Issue |
J. Phys. IV France
Volume 112, October 2003
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Page(s) | 985 - 988 | |
DOI | https://doi.org/10.1051/jp4:20031046 |
J. Phys. IV France 112 (2003) 985
DOI: 10.1051/jp4:20031046
A first-principles investigation of tetragonal and orthorhombic deformations in the ferromagnetic Heusler alloy Ni 2MnGa
A.T. Zayak1, P. Entel1 and J. Hafner21 Theoretical Physics, Gerhard-Mercator University, Lotharstr. 1, 47048 Duisburg, Germany
2 Institut für Materialphysik, Universitât Wien, Sensengasse 8/12, 1090 Wien, Austria
Abstract
Tetragonal and orthorhombic deformations in Ni
2MnGa were studied by using the Density Functional Theory formalism with US GGA pseudopotentials implemented in the VASP code
in order to find an optimal geometry of the low-temperature structure. Structural and magnetic parameters of the initial L2
1 structure and elastic constants are in a good agreement with experimental data and previous calculations. Not all of the
low-temperature martensitic structures could be reproduced by applying the tetragonal and the orthorhombic deformations. It
was argued that the modulation arising from shuffling of atoms is important for these structures. A simple kind of shuffling
was studied. That gives experimentally predicted structural instability associated with a soft phonon mode, but does not stabilize
any new structures.
© EDP Sciences 2003