Point-defect-driven flattened polar phonon bands in fluorite ferroelectrics

Abstract The scale-free ferroelectric polarization of fluorite M O 2 ( = Hf, Zr) due to flat polar phonon bands are promising for nonvolatile memories. Defects also widely introduced improve the emergent ferroelectricity. However, their roles still not fully understood at atomic-level. Here, we report a significant effect point-defect-driven flattening with more modes and contribution in doped . La-doped can be significantly flattened, compared pure ones. lower energy barrier larger V -only cases suggest that local lattice distortion should balanced high-performance work is believed bridge relation between point defects generally enhanced induced ferroelectricity ferroelectrics atomic-level inspire further property optimization via defect-engineering.