Itinerant-electron metamagnetic phase transition in FeGe thin films

Metamagnetism, or metamagnetic transition (MT), is the sudden jump in magnetization of a material as it changes its magnetic phase in an external magnetic field. A careful manipulation of its magnetic phase facilitates better harnessing of its properties in many applications. Using first-principles collinear fixed-spin-moment calculations, we give the first report on metamagnetism in itinerant magnetic FeGe films, and predict that it mainly originates from its film surface. In contrast, bulk FeGe is not metamagnetic. Binding surface and field contour plots show that the magnetic polarization energy, magnetization, and critical fields of bulk FeGe and FeGe film remain fairly constant at small deviations to its lattice sizes, suggesting that the magnetic phases of FeGe are robust against small amounts of strain. Moreover, FeGe film becomes more bulk-like magnetically beyond approximately 11.0 μB.