Short-Range Order In Vi3

We present a detailed investigation of the crystal structure of VI3, a two-dimensional van der Waals material of interest for studies of low-dimensional magnetism. As opposed to the average crystal structure that features R (3) over bar symmetry of the unit cell, our Raman scattering and X-ray atomic pair distribution function analysis supported by density functional theory calculations point to the coexistence of short-range ordered P (3) over bar 1c and long-range ordered R (3) over bar phases. The highest-intensity peak, A(1g)(3), exhibits a moderate asymmetry that might be traced back to the spin-phonon interactions, as in the case of CrI3.