Experimental realization and magnetotransport properties of half-metallic Fe2Si

Thin films of the high Curie temperature intermetallic ferromagnet β-Fe2Si were synthesized via molecular beam epitaxy. Investigation using X-ray diffraction and atomic force microscopy shows a hexagonal crystal structure and a smooth topography. Theoretically, Fe2Si has been predicted to exhibit uniquely desirable magnetotransport properties. We report on these properties experimentally, including the ordinary Hall coefficient R0 and anomalous Hall resistivity ρxyAH. The compound is found to be a soft Heisenberg ferromagnet with temperature dependent magnetization based on the thermal excitation of spin waves. We present a detailed look into the contributions to its longitudinal resistivity, which due to the presence of a spin-flip gap ΔkB, indicating a half-metallic band structure. The correct scaling relations between these components of the resistivity tensor (ρxx and ρxy) are also discussed.