Effects of Zr and Ti doping on the dielectric response of CeO_2: A comparative first-principles study

摘要

Zr doping in ceria (CeO_2) results in enhanced static dielectric response compared to pure ceria. On the other hand, Ti doping in ceria keeps its dielectric constant unchanged. We use first-principles density functional theory calculations based on pseudopotentials and a plane wave basis to determine electronic properties and dielectric response of Zr/Ti-doped and oxygen-vacancy-introduced ceria. Softening of phonon modes is responsible for the enhancement in dielectric response of Zr-doped ceria compared to that of pure ceria. The ceriazirconia mixed oxides should have potential use as high-k materials in the semiconductor industry.