Structural, magnetic, and electronic properties of EuSi2 thin films on the Si(111) surface.

ABSTRACT

Searching for magnetic silicide thin films has long been a hot topic in condensed matter physics and materials science based on their fundamental physics and promising device applications. Here we report a systematic study on the structural, magnetic, and electronic properties of EuSi2 thin films on the Si(111) surface by ab initio calculations. Total energy calculations show that the EuSi2 thin film in AA stacking is more favorable than that in AB or ABC stacking. The Eu2 + ions are coupled ferromagnetically within each layer and antiferromagnetically across the adjacent silicene layers with a large local spin moment of 6.96-7.00µB derived from the Eu-4f orbital electrons. Electronic band structure calculations indicate that the monolayer EuSi2 thin film is a semiconductor with an indirect surface band gap of 0.45 eV, while the multilayer EuSi2 thin films exhibit metallic behavior. These findings provide a systematic understanding of rare-earth metal silicides on the Si surface and will provide guidance for Si-based nanoelectronics and spintronics.