First-principles study on lanthanide dopants in BaTiO3

Using first-principles calculation based on density-functional theory and density-functional perturbation theory, the microscopic structure and dielectric properties of Lanthanide (Ln) doped BaTiO3 3 are investigated. The doped Ln atoms exhibit significant displacement from Ba sites for charge compensation, forming off-centered configurations. This displacement is more pronounced for elements with smaller ionic radii. The change in ionic dielectric constant is strongly correlated with Ln displacement and Ln ion radius. As Ln displacement (ionic radius) increases (decreases), Ln-doped BaTiO3 3 has a higher ionic dielectric constant. However, regardless of the Ln species, the added Ln reduces the ionic dielectric constant compared to pristine BaTiO3. 3 .