Atomic Migration and Ordering of Binary Ferromagnetic Intermetallic L1₀Phases and Influences of Alloying Elements and Electric Fields

Abstract

The ordered body‐centered tetragonal intermetallic phase of FeNi is a promising candidate for high‐performance permanent magnets without rare‐earth elements. However, on earth FeNi is found naturally only in the disordered face‐centered‐cubic A1 phase. Herein, the atomic migration and ordering processes in binary intermetallic phases are investigated within the framework of density‐functional theory. The main objectives are 1) to develop a thorough understanding of the thermally activated diffusion processes at the atomic scale and 2) to make a critical assessment in how far electric field and current effects can be effective means for an enhanced hardening‐by‐ordering of disordered, soft‐ferromagnetic alloys. The scope is extended from FeNi to the hard‐ferromagnetic phases of FePt, FePd, MnAl, and MnGa as well as ternary Fe(Pt,Ni) alloys. These materials cover a wide range of thermal‐ordering time scales and related experimental feasibility.

The Atomic Atmosphere at the Antiphase Domain Boundary in Ni3Al: A Phase‐Field Study

“…For example, two regular occupation patterns similar to the L1 0 projection along the [001] and [100] directions are marked by white boxes and given in Figure 2c, which are also considered for ternary Ni-based alloys. [39] Regions filled with microscopic patterns expanded in volume and transferred their occupation patterns to L1 2 via timedependent ordering (Figure 2d). The effect of the timedependent ordering is presented by comparing the insets of Figure 2d-g.…”