We take another look at two compounds which have been discussed as possible realizations of “spin ice”, namely holmium titanate and dysprosium titanate. As we have earlier observed, holmium titanate does not display icelike behaviour at low temperatures because the long ranged dipolar interactions between spins are strong compared to the nearest neighbour interactions. We show, analytically, th...

Density functional theory calculation was conducted to determine the optoelectronic properties of bismuth titanate sillenite (Bi12TiO20) and perovskite-like (Bi4Ti3O12) structures. The lattice parameters were experimentally obtained from Rietveld analysis. The density functional perturbation theory approach was used with the standard Perdew-Burke-Ernzerhof functional and screened Coulomb hybrid...

Ž . Ultrafine lead titanate PbTiO powders in tetragonal form have been successfully prepared via two processing routes, 3 Ž . Ž . namely, conventional coprecipitation CPC and microemulsion-refined coprecipitation MCP . The formation process of lead titanate from the resulting precursors was monitored using techniques such as thermal analyses, FTIR spectroscopy, Raman scattering spectroscopy and...

We take another look at two compounds which have been discussed as possible realizations of ‘‘spin ice,’’ namely holmium titanate and dysprosium titanate. As we have earlier observed, holmium titanate does not display icelike behavior at low temperatures because the long-ranged dipolar interactions between spins are strong compared to the nearest-neighbor interactions. We show, exactly, that th...

The response of titanate pyrochlores (A2Ti2O7, A = Y, Gd and Sm) to electronic excitation is investigated utilizing an ab initio molecular dynamics method. All the titanate pyrochlores are found to undergo a crystalline-to-amorphous structural transition under a low concentration of electronic excitations. The transition temperature at which structural amorphization starts to occur depends on t...

Sodium titanate nanobelt was synthesized by treating titanium dioxide hydrothermally in concentrated sodium hydroxide solution. The product was characterized by SEM analysis and zeta potential measurements. It served as a microparticle to constitute a microparticle retention system with cationic polyacrylamide (CPAM), while the microparticle system was employed to induce the flocculation of kao...

The sequence of steps of a chemical treatment having as its goal the induce of nucleation and the growth of hydroxyl carbonated apatite (HCA) at the surface of titanium implants was studied by scanning and transmission electron microscopy in cross-section. In the first step, an acid etching forms a rough titanium hydride layer, which remains unchanged after subsequent treatments. In the second ...

The full matrix of electro-elastic constants of sillenite-type crystals Bi12TiO20 (BTO) and Bi12SiO20 (BSO) were determined by the resonance method, with d14 and k14 being on the order of 40–48 pC/N and 31%–36%, respectively. In addition, double-rotated orientation dependence of d33 was investigated, with the maximum values of 25–28 pC/N being achieved in ZXtl45°/54°-cut samples. The electrical...