Valence band electronic structure of the van der Waals antiferromagnet FePS3

Antiferromagnetic van der Waals materials have gained a lot of interest in recent years. They can be exfoliated down to the two-dimensional (2D) limit while potentially preserving intriguing properties of antiferromagnets, such as insensitivity to external magnetic fields and ultrafast spin dynamics in the THz range. The investigation of the electronic band structure of these materials is crucial to understand their behavior and thus to identify paths for future applications. Here, we investigate the valence band structure of one of the most studied 2D antiferromagnets –iron phosphorus trisulfide (FePS₃)– using angle-resolved photoemission spectroscopy (ARPES) and compare our results with first-principles calculations based on Hubbard-corrected density functional theory (DFT+U). This allows us to identify the bands originating respectively from the Fe 3d, the S 3p, and the P 3p orbitals and to describe their dispersion throughout the whole Brillouin zone. Our results represent an important step towards an accurate theoretical description of the electronic properties of transition metal phosphorus trisulfides, which is a pre-requisite for understanding the behavior of antiferromagnetic materials at the 2D limit.