Ferromagnetic Fe₃GeTe₂/semiconducting SiSb van der Waals spin-interface

Two-dimensional van der Waals heterostructures have garnered significant interest owing to their intriguing characteristics in comparison to individual constituent materials. Here, we design a heterostructure of Fe₃GeTe₂/SiSb, integrating metallic van der Waals magnet Fe₃GeTe₂ with semiconducting SiSb, and perform a systematic investigation on the feasibility of exploiting such a van-der-Waals-based metal-semiconductor interface in spintronics. By means of density functional theory, we reveal that the heterostructure effectively preserves the hard magnetism, high Curie temperature (T_C) and strong perpendicular magnetic anisotropy of single-layer Fe₃GeTe₂, with a p-type Schottky contact formed at the interface. External flexible strains are applied to tailor the properties of the heterostructure, and interestingly, they prove effective in modulating its magnetic properties. Prominent representatives lie in the application of a biaxial strain which boosts the T_C to even above room temperature. In addition, we explore the application of an external electric field, which is rather effective in modifying the Schottky barrier height. Our findings, especially in the strain- and electric field-tunable properties of the Fe₃GeTe₂/SiSb heterostructure, provide a promising and effective way to embedding the ferromagnetic/semiconducting van der Waals interface into two-dimensional spintronic devices.