Epitaxial Growth and Electronic Properties of Single- and Few-Layer FeBr₂ on Bi(111)

Abstract

Magnetic van der Waals (vdW) materials have attracted considerable attention in recent years because of their future spintronics applications. 3d Transition metal dihalides are a promising class of materials to realize two-dimensional vdW magnets with intriguing magnetic and electronic properties. We report the epitaxial growth of (0001)-oriented FeBr2 films from the monolayer by molecular beam epitaxy on the Bi(111) surface. The atomic structure was confirmed to be identical to that of the bulk FeBr₂ crystal by dynamical low-energy electron diffraction analysis. Angle-resolved photoelectron spectroscopy revealed that the topmost valence band composed of Fe 3d orbitals is located at 2.2 eV below the Fermi level, showing that the FeBr₂ films are insulating down to the monolayer.