Lattice dynamics and structural stability of ordered Fe3Ni, Fe3Pd and Fe3Pt alloys

Abstract

We investigate the binding surface along the Bain path and phonon dispersion relations for the cubic phase of the ferromagnetic binary alloys Fe3X (X = Ni, Pd, Pt) for L12 and DO22 ordered phases from first principles by means of density functional theory. The phonon dispersion relations exhibit a softening of the transverse acoustic mode at the M-point in the L12-phase in accordance with experiments for ordered Fe3Pt. This instability can be associated with a rotational movement of the Fe-atoms around the Ni-group element in the neighboring layers and is accompanied by an extensive reconstruction of the Fermi surface. In addition, we find an incomplete softening in [111] direction which is strongest for Fe3 Ni. We conclude that besides the valence electron density also the specific Fe-content and the masses of the alloying partners should be considered as parameters for the design of Fe-based functional magnetic materials.

Revised version, accepted for publication in Physical Review B

References in corpus (7)

• Lattice dynamics of BaTiO3, PbTiO3 and PbZrO3: a comparative first-principles study
• First-principles study of lattice instabilities in the ferromagnetic martensite Ni${}_2$MnGa
• Phase transitions in Ni2+xMn1-xGa with a high Ni excess
• Anomalous vibrational effects in non-magnetic and magnetic Heusler alloys
• A First-Principles Investigation of Phonon Softenings and Lattice Instabilities in the Shape-Memory System Ni${}_2$MnGa
• Tuning of crystal structure and magnetic properties by exceptionally large epitaxial strains
• Jahn-Teller like origin of the tetragonal distortion in disordered Fe-Pd magnetic shape memory alloys

Cited by in corpus (2)

• Dynamical properties of ordered Fe-Pt alloys
• A first-principles investigation on the effects of magnetism on the Bain transformation of $\alpha$-phase FeNi systems