Trigonal distortion in zigzag-antiferromagnet iron phosphorus trisulfide

The electronic structure of ${\mathrm{FePS}}_{3}$ 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 ${e}_{g}^{\ensuremath{\pi}}$ 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 ${\mathrm{FePS}}_{3}$ and will prove imperative in its potential spintronic applications.