Characterizing lattice oscillations of bulk chromium based mixed halides

Chromium based mixed halides are a promising class of semiconductors. A recent resonant inelastic x-ray scattering (RIXS) experiment on bulk Chromium Sulfur Bromide (CrSBr), which is a material belonging to this family of mixed halides, has shown the presence of a potential phonon excitation peak in the L- edge RIXS spectrum. To understand the possible origins of this peak, as a first step, we perform an ab-initio density functional theory (DFT) characterization of bulk CrSBr. Utilizing Quantum Espresso, we compute various properties such as the electronic band structure, phonon dispersion, phonon density of states, and the effects of electron-phonon interaction. The results of our supercell calculation, both on monolayer and bulk CrSBr, hint at the possibility of phonon modes co-existing with other excitations in an energy range typically thought of as belonging to lattice oscillations. Additionally, to compare our findings with other materials belonging to this family, we perform a similar phonon analysis on CrSCl and CrSI.