Role of sulfur in BaVS3 probed by S K-edge absorption spectroscopy

We show that the quasi-1D behavior of BaVS3 can be understood analyzing the X-ray absorption near edge spectra at the sulfur K edge. Linear dichroïsm experiments, analyzed with the help of ab initio calculations, reveal two strong and polarization dependent pre-edge features, induced by the band character of the 3d   vanadium levels. They are related to crystal field split t2gt2g and eg states. When the temperature is lowered, the t2gt2g feature shifts progressively to higher energy, and its intensity increases for the polarization along the c-axis, stacking direction of the V–S face sharing octahedra. This behavior points to the depletion of sulfur states and thus the lack of S 3p–V 3d hybridization in the direction of V–S chains.