MBE Synthesis and STM Characterization of 2D Magnets on Topological Insulator

Integrating two-dimensional(2D) magnet with topological insulator is an exciting topic. Other than the possible proximity induced magnetic ordering inside topological insulator, the 2D magnet/ topological insulator heterostructure can also lead to more efficient spin orbit torque switching, or the formation of magnetic skyrmions. The recent discovery of room temperature ferromagnetic ordering in 2D material MnSe₂ and VSe₂ further brings more potential in such heterostructure systems. In this talk, we report the synthesis and characterization of 2D magnet MnSe₂ and VSe₂ on topological insulator Bi₂Se₃. Monolayer and few layers of MnSe₂ and VSe₂ are grown on Bi₂Se₃ with molecular beam epitaxy. The material quality and magnetic property are characterized with RHEED, XRD, XPS, and SQUID. Furthermore, the 2D magnet/ topological insulator heterostructures are characterized with STM to study their atomic structure and local electronic properties. Finally, recent progress of measuring the local magnetic properties of these films with spin-polarized STM will also be discussed.