Scanning tunneling microscopy study of van der Waals metallic magnet Fe₃GeTe₂

Van der Waals crystals with robust long-range magnetic order down to the monolayer limit are widely sought for the development of electronic and spintronic quantum devices. Fe₃GeTe₂ is a promising candidate, however the presence of both localized magnetic moments and itinerant electrons in Fe₃GeTe₂ complicates the theoretical picture of its magnetism. Native defects such as Fe vacancies impact its magnetic ground states and strongly alter its magnetic critical temperature, adding difficulties in interpreting experimental results. Here we use scanning tunneling microscopy (STM) to reveal the electronic structure of Fe₃GeTe₂ in both real and momentum space, and to correlate local electronic variations with specific atomic defects. Our work provides insight into magnetism in strongly correlated d-electron systems.