Magnetotransport in ferromagnetic Fe$_2$Ge semimetallic thin films

Abstract

Thin films of the ferromagnet Fe 2 Ge were grown via molecular beam epitaxy, and their electrical and magneto-transport properties measured for the first time. X-ray diffraction and vibrating sample magnetometry measurements confirmed the crystalline ferromagnetic Fe 2 Ge phase. The observed high temperature maximum in the longitudinal resistivity, as well as the observed suppression of electron-magnon scattering at low temperatures, point to the presence of strong spin polarization in this material. Measurements of the Hall resistivity, ρ xy , show contributions from both the ordinary Hall effect and anomalous Hall effect, ρ AH xy , from which we determined the charge carrier concentration and mobility. Measurements also show a small negative magnetoresistance in both the longitudinal and transverse geometries. Fe 2 Ge holds promise as a useful spintronic material, especially for its semiconductor compatibility.