First-principles study of static displacements in Fe-Pd magnetic shape-memory alloys

In: Magnetic Shape Memory Alloys (Mater. Res. Soc. Symp. Proc. Volume 1200E) / Quandt, E.; Wuttig, M.; Kakeshita, T.; Fähler, S. (Hrsg.)
Warrendale, PA: Materials Research Society (2010), S. 1200-G04-04 (6 pp.)
Buchaufsatz / Kapitel / Fach: Physik
This contribution reports static ionic displacements in ferromagnetic disordered Fe70Pd30 alloys obtained by relaxation of the ionic positions of a 108-atom supercell within the framework of density functional theory. Comparison with a simple statistical model based on Lennard-Jones pair interactions reveals that these displacements are significantly larger than can be explained by the different sizes of the elemental constituents. The discrepancies are presumably related to collective displacements of the Fe atoms. Corresponding distortions are experimentally observed for ordered Fe3Pt and predicted by first-principles calculations for all ordered Fe-rich L12 alloys with Ni group elements and originate from details of the electronic structure at the Fermi level.