Trigonal distortion in zigzag-antiferromagnet iron phosphorus trisulfide

The electronic structure of FePS3 was resolved using x-ray absorption spectroscopy with linear dichroism of x ray between in-plane and out-of-plane geometries. By integrating the measurements with semiempirical calculations, the observed nonvanishing feature in the dichroism spectra demands a site symmetry lower than cubic to be taken into account. These effects cause an energy splitting between a(1g) and e(g)(pi)orbitals of around 0.350 eV, contrary to previous reports purporting a smaller and insignificant energy splitting. Furthermore, reduction in the Slater integral was needed to establish agreement with experiment and theory suggesting metal-ligand covalency in the system. These findings shed light on how the local crystalline environment affects the electronic structure and the anisotropy in FePS3 and will prove imperative in its potential spintronic applications.