Elastic, electronic and optical properties of baddeleyite TiO2 by first-principles

Abstract

Baddeleyite TiO2 is one of the most important phases of titanium dioxide, from technological and industrial point of view. We have carried out theoretical investigation by using plane wave ultrasoft pseudopotential methods based on density functional theory. The Electronic band structure, elastic constants and optical properties as well as, the lattice parameters of baddeleyite TiO2 are calculated by using the optimized crystal structure. The bulk modulus, shear modulus, Young׳s modulus and Poisson ratios for baddeleyite TiO2 are also explored. The Debye temperature of baddeleyite TiO2 is investigated by using calculated mean sound velocity. The anisotropy ratios are computed from elastic constants. Our investigated elastic properties are in contrast with the previous reported results of Ma et al. (2009, Phys. Status Solidi B, 246 (9) 2132) by means of the same DFT method. Electronic properties are presented by considering the computed band structure and densities of states (DOS). Furthermore, the results of electronic properties are consistent with the available reported theoretical results. To explore the optical properties of baddeleyite TiO2, the dielectric functions, refractive index, absorption and energy loss spectrums are presented and analyzed by means of the electronic properties. Also, the considered DFT methods in this work are self-consistent.