For electrical spin injection and detection of spin-polarized electrons in silicon, we explore highly epitaxial growth of ferromagnetic full-Heusler-alloy Co2FeSi on silicon substrates using low-temperature molecular beam epitaxy (LT-MBE). Although in-situ reflection high energy electron diffraction images clearly show two-dimensional epitaxial growth for growth temperatures (TG) of 60, 130, and 200 °C, cross-sectional transmission electron microscopy experiments reveal that there are single-crystal phases other than Heusler alloys near the interface between Co2FeSi and Si for TG = 130 and 200 °C. On the other hand, almost perfect heterointerfaces are achieved for TG = 60 °C. These results and magnetic measurements indicate that highly epitaxial growth of Co2FeSi thin films on Si is demonstrated only for TG = 60 °C.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry