A series of Fe 2 YSi (Y = Cr, Mn, Fe, Co, Ni) alloys were synthesized and their electronic and magnetic properties were studied both theoretically and experimentally. In particular, a novel Heusler alloy Fe 2 CrSi single phase was synthesized by means of the melt-spinning method. First principles FLAPW calculations were performed on Fe 2 YSi alloys. Based on the results, Fe 2 CrSi is predicted to be a half-metallic ferromagnet with a spin moment of 2μ B /f.u. and a gap of 0.42 eV. Fe 2 MnSi is also half-metallic in the ferromagnetic state. The saturation magnetic moments at 5 K for this series of alloys fit the theoretical calculations well. Specifically, the saturation magnetic moment of Fe 2 CrSi is 2.05μ B /cell, which agrees with the ideal value of 2μ B derived from the Slater-Pauling rule. The Curie temperatures of Fe 2 YSi alloys are all higher than 500 K except for Fe 2 MnSi, which has a T C below room temperature. Finally, the effect of lattice distortion on the electronic and magnetic properties of Fe 2 CrSi and Fe 2 CoSi was studied. It is found that Fe 2 CrSi is half-metallic from -3% to +1% uniform lattice distortion, and this character is preferred in systems containing large strain, such as melt-spun ribbons or thin films.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Acoustics and Ultrasonics
- Surfaces, Coatings and Films