Epitaxial monolayers of the magnetic 2D semiconductor FeBR 2 grown on Au(111)

Abstract

Magnetic two-dimensional (2D) semiconductors have attracted a lot of attention because modern preparation techniques are capable of providing single-crystal films of these materials with precise control of thickness down to the single-layer limit. It opens up a way to study a rich variety of electronic and magnetic phenomena with promising routes toward potential applications. We have investigated the initial stages of epitaxial growth of the magnetic van der Waals semiconductor FeBr2 on a single-crystal Au(111) substrate by means of low-temperature scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), X-ray photoemission spectroscopy (XPS), low-energy electron emission microscopy (LEEM), and X-ray photoemission electron microscopy (XPEEM). Magnetic properties of the one- and two-layer thick films were measured via X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD). Our findings show a striking difference in the magnetic behavior of the single layer of FeBr2 and its bulk counterpart, which can be attributed to the modifications in the crystal structure due to the interaction with the substrate.