Structural and magnetic properties of epitaxial Fe3Si/GaAs(001) hybrid structures

The structural, electrical, and magnetic properties of ${\mathrm{Fe}}_3\mathrm{Si/GaAs}\text{(001)}$ hybrid structures with high crystalline and interfacial perfection are studied. The ${\mathrm{Fe}}_3\mathrm{Si/GaAs}\text{(001)}$ hybrid structures are fabricated by molecular beam epitaxy at 200 °C. The composition of the films, which can be regarded as a Heusler alloy, is tuned over a wide range of Si content. The high crystalline and interfacial perfection is correlated with the stable ${\mathrm{Fe}}_3\mathrm{Si}$ phase. The resistivity of the films shows a strong minimum at almost exact stoichiometry which can be explained by the perfection of the ordering of the Si atoms within the ${\mathrm{Fe}}_3\mathrm{Si}$ phase. The layers are ferromagnetic at room temperature with saturation magnetization values close to bulk ${\mathrm{Fe}}_3\mathrm{Si}.$ The layers show very small coercive fields which again is correlated with high crystalline and interfacial perfection of the layers within the ${\mathrm{Fe}}_3\mathrm{Si}$ phase.