Comparative study on structural, electronic, optical and mechanical properties of normal and high pressure phases titanium dioxide using DFT

Abstract

In this paper, a Self-consistent Orthogonalized linear combination of atomic orbitals (OLCAO) technique with a generalized gradient approximation such as Perdew-Burke-Ernzerhof Solid (GGA-PBE SOL) has been used to scrutinize the structural, optical, electronic and mechanical properties of normal pressure phase (Anatase and Rutile) and high pressure phase i.e., cubic (Fluorite and Pyrite) TiO 2 . Electronic and optical properties of normal pressure phases of TiO 2 are also investigated using (Meta) MGGA-Tran and Blaha (TB09) and obtained results are a close approximation of experimental data. It is seen that the virtually synthesized structural parameter for cubic and tetragonal phases of TiO 2 are consistent with experimental and theoretical data. From the effective mass of charge carriers (m * ), it can be observed that pyrite TiO 2 is having lower effective mass than the fluorite and hence shows higher photocatalytic activity than fluorite. Furthermore, it is seen that fluorite is more dense than anatase, rutile and pyrite TiO 2 . From the theoretical calculations on the optical properties, it can be concluded that optical absorption occursin the near UV region for high and normal pressue phases of TiO 2 . Again from the reflectivity characteristics R(ω), it can be concluded that TiO 2 can be used as a coating material. Elastic constants, elastic compliance constants, mechanical properties are obtained for anatase, rutile, fluorite and pyrite TiO 2 . A comparison of the results with previously reported theoretical and experimental data shows that the calculated properties are in better agreement with the previously reported experimental and theoretical results.

Polymorphs of Titanium Dioxide: An Assessment of the Variants of Projector Augmented Wave Potential of Titanium on Their Geometric and Dielectric Properties

“…The trend in the cell properties for a given correlated method with respect to the three PAW potentials is consistent with that observed for R-, A-, and B-TiO 2 (see above). We have observed that F- and P-TiO 2 lattices are relatively denser than that of the brookite, anatase, and rutile lattices of TiO 2 , in agreement with the computational data of Dharmale et al…”

“…In this study, we have theoretically investigated the lattice properties, zone-center phonon vibrations, and the low- and high-frequency-dependent (ionic and electronic contributions, respectively) dielectric permittivity of rutile (R-)­TiO 2 using DFT at PBEsol and PBE , levels, with and without incorporating the Hubbard term U. , Density functional perturbation theory (DFPT) was employed for the evaluation of phonon vibrations and dielectric properties. − The same properties were also investigated for the anatase and brookite phases, as well as for the two high-pressure structures of TiO 2 (called pyrite − and fluorite − ) for comparison.…”

High-pressure phase behaviors of titanium dioxide revealed by a $Δ$-learning potential

“…It is thought that this discrepancy may be due to unphysical delocalisation of titanium's 3d electrons 21 , but it is not well-understood. Nevertheless, DFT, in particular using the PBEsol function, remains a useful tool for studying the high-pressure behavior [22][23][24] . It is also possible to overcome the incorrect ordering of phases using semi-empirical methods, such as DFT+U 25 and DFT+D 26 .…”

Pressure-Induced Phase Transition Study on Brookite to Rutile TiO2 Transformation

“…Experimentally, 15,16 and 17 reported high-pressure behavior of rutile. Theoretically, many researchers [18][19][20][21][22][23][24][25] did first-principle calculations on brookite and rutile TiO 2 without considering the pressure effect. Phase stability studies on various phases of TiO 2 are also published in the literature.…”