Constructing topological insulator-ferromagnet heterojunctions of Bi2Se3/Fe3GeTe2 and Bi2Te3/Fe3GaTe2

Heterostructures composed of topological insulators and ferromagnets are predicted to exhibit the quantum anomalous Hall effect (QAHE). The morphology and interfacial structure have a significant impact on physical properties and transport performances of such heterostructures. Here, we report the epitaxial growth of topological insulators Bi₂Se₃and Bi₂Te₃thin films on ferromagnetic substrates of Fe₃GeTe₂and Fe₃GaTe₂, respectively. The morphology and composition of the Bi₂Se₃and Bi₂Te₃thin films were characterized using atomic force microscopy, x-ray photoelectron spectroscopy and Raman spectroscopy. After optimizing growth parameters, we successfully generated large-area films with high crystallinity, presenting new types of topological insulator-ferromagnet heterojunctions for the pursuit of QAHE.