Pressure dependent metamagnetism of Fe3M (M = Al and Si) alloys

In this study we report the results of first-principles calculations to investigate the possibility of pressure dependent metamagnetic behavior in Fe3M (M = Al and Si) alloys. We used the WIEN2k package of the full-potential linearized-augmented-plane-wave method. For the case of Fe3Al (Fe3Si), the theoretical lattice constant, which is about 0.7 % (1 %) larger (smaller) than the experimental value, is obtained by minimizing the total energy. If the volume decreases by about 16 % (9 %) from equilibrium, the total magnetic moment decreases abruptly from 5.0 μB/cell (4.0 μB/cell) to 3.2 μB/cell (4.6 μB/cell). Since this change is considerably large (∼67 % for Fe3Al and ∼14 % for Fe3Si), it is possible to measure by a simple high-pressure experiment at about 80 kbar for Fe3Al and 50 kbar for Fe3Si. The Fe atoms, similar to fcc-Fe (FeI), exhibit metamagnetism.