Electronic structures and optical properties of ilmenite-type hexagonal ZnTiO3

Abstract

The electronic structures of ilmenite (IL)-type hexagonal ZnTiO3 were investigated using the generalized gradient approximation (GGA) and local density approximation (LDA) based on density functional theory (DFT). The optical properties of ZnTiO3 were also calculated by the LDA method. The calculated results were compared with experimental data. Results show that the structural parameters obtained by the LDA calculation are rather close to the experimental values. IL-type hexagonal ZnTiO3 is a kind of direct bandgap (Eg=3.11 eV) semiconductor material at the Z point in the Brillouin zone. An analysis of the density of states (DOS) and the Mulliken charge population clearly reveal that the Zn-O bond is a typical ionic bond whereas the Ti-O bond, which is similar to the Ti-O bond in perovskites ATiO3 (A=Sr, Pb, Ba), is covalent in character. Furthermore, the dielectric function, absorption spectrum, and refractive index were obtained and analyzed on the basis of electronic band structures and the DOS for radiation up to 50 eV. ©Editorial office of Acta Physico-Chimica Sinica.