The optical properties of titanium dioxide (TiO2) in rutile, anatase and brookite phases were investigated via density functional theory (DFT) framework. The Hubbard U term in Ti 3d electrons of the TiO2 phases was introduced to observe the optical behavior with the effect of U parameter. The calculated structural parameters from the optimized TiO2 are in good agreement with the previous experimental and theoretical data. The values of static dielectric constant and refractive index from exchange-correlation functional in standard DFT are slightly higher than the DFT+U method. The energy peaks of reflectivity and loss function spectra show the good match with each other. The TiO2 with rutile, anatase and brookite phases have optical absorption in the ultraviolet (UV) light region. Thus, the inclusion of U parameters turn out to shift the wavelength photon towards the low region. Furthermore, this work provides a good theoretical understanding of the optical properties of TiO2 which helpful in a technological application such as photocatalysis and photovoltaics

The electronic, structural, elastic, and optical properties of zinc oxide (ZnO) with wurtzite-type structure were investigated using first-principles calculation based on density functional theory (DFT) with local density approximation (LDA) plus Hubbard U (DFT–LDA+U)method. Hubbard U improved the calculated results, allowing it to exhibit good agreement with experimental data. The DFT–LDA+U method successfully predicted the electronic properties of ZnO with better described the localization of transition metal Zn 3d electron. The calculated optical dielectric function of ZnO and its relation with electronic properties were further discussed.

The ceramic body strength enhancement in sanitary ware becomes a crucial situation in order to achieve new design development. This design development is directly related to the investigation of present manufacturing process that involved forms, materials and techniques. The material use in this work is typical ceramic body namely porcelain. Porcelain is composed from china clay, feldspar and quartz. In sanitary ware, the challenge is to design forms within the limitations of the porcelain body which are the strength after casting and firing. In this work we modified the present porcelain body using a waste marble that obtained from the marble quarry. The obtained marble waste was grinded into dust and mixed into porcelain body slips. Standard slip casting characteristic was determined. Later the drying and firing characteristics were also determined, specifically the strength. The strength enhancement was observed as well as other properties enhancement. Thus the intricate design can be developed.

The properties of cubic (Pm3m, 221 space group) perovskite prototypes PbTiO₃ (PTO), SnTiO₃ (STO), and SnZrO₃ (SZO) were investigated via first-principles calculation using the density functional theory as implemented in CASTEP computer code. The lattice parameters of PbTiO₃ (as the reference compound) were calculated. The accuracy values of the calculation functional (GGA-PBEsol) were acceptable relative to the experimental values with typical error of approximately 0.6% underestimate. The independent elastic constants (C₁₁, C₁₂, and C₄₄) and bulk modulus, B, were obtained and analyzed. The density of state studies indicated hybridizations among anion O 2p, cation Pb 6s/Sn 5s and the Ti 3d/Zr 4d states of PTO, STO, and SZO. An indirect band gap was respectively obtained for both PTO and STO at the X-G point. A direct band gap was attained for SZO at the X-X point along the high-symmetry direction in the Brillouin zone. The born effective charge values of PTO, STO, and SZO were attributed to the responses of the bond charges to the displacement caused by the strong covalency between the cation orbital and O 2p (strong covalency A-O and B-O bonding). Results also reveal that anion O 2p, cation Pb 6s/Sn 5s, and Ti 3d/ Zr 4d states have played an important role in the instability of perovskite oxide. Comparative results from the PTO, STO, and SZO prototypes showed the calculated theoretical and experimental values were in good agreement.