Phase transition of cadmium fluoride under high pressure

We investigated the high pressure phases of CdF2 by a joint theoretical and experimental study. The structural and electronic properties of CdF2 were extensively explored to high pressure by ab initio calculations based on the density functional theory. A structural phase transition from the fluorite-type (Fm-3m, Z = 4 ) structure to the cotunnite-type (Pnma, Z = 4 ) structure was estimated below 8 GPa, and this phase transition was examined by the high pressure experiments up to 35 GPa at room temperature. Both high pressure angle dispersive X-ray diffraction and Raman spectroscopy experiments provided convincing evidence to verify the phase transition. Our work makes clear pressure-induced phase transitions and structural information of CdF2 under high pressure.