Nanostructurally stabilized zirconium oxide (NSZ) hard transparent fi lms were produced without chemical stabilizers by the ion beam assisted deposition technique (IBAD). A transmission electron microscopy study of the samples produced below 150 °C revealed that these fi lms are composed of zirconium oxide (ZrO2) nanocrystallites of diameters 7.5 ± 2.3 nm. X-ray and selected-area electron diffr...

Ab initio molecular dynamics simulations were performed to investigate the elasticity of cubic CaSiO3 perovskite at high pressure and temperature. All three independent elastic constants for cubic CaSiO3 perovskite, C11, C12, and C44, were calculated from the computation of stress generated by small strains. The elastic constants were used to estimate the moduli and seismic wave velocities at t...

Assembly of mesostructured silica using Pluronic P123 triblock copolymer (EO(20)-PO(70)-EO(20)) and n-butanol mixture is a facile synthesis route to the MCM-48-like ordered large mesoporous silicas with the cubic Iad mesostructure. The cubic phase domain is remarkably extended by controlling the amounts of butanol and silica source correspondingly. The extended phase domain allows synthesis of ...

Monocrystalline cubic and/or monoclinic Y2O3:Eu nanoparticles (10-50 nm) were synthesized continuously without post-processing by single-step flame spray pyrolysis (FSP). These particles were characterized by Xray diffraction (XRD), nitrogen adsorption (BET) and transmission electron microscopy (TEM). Photoluminescence (PL) emission was measured as well as the time-resolved PL-intensity decay. ...

Low-energy electron diffraction patterns, produced from quasicrystal surfaces by ion sputtering and annealing to temperatures below ∼700 K, can be assigned to various terminations of the cubic CsCl structure. The assignments are based upon ratios of spot spacings, estimates of surface lattice constants, bulk phase diagrams vs surface compositions, and comparisons with previous work. The CsCl ov...

Calculations using first principles methods and strong coupling theory are carried out to understand the electronic structure and superconductivity in cubic and tetragonal TiH2. A large electronic density of states at the Fermi level in the cubic phase arises from Ti-t2g states and leads to a structural instability towards tetragonal distortion at low temperatures. However, constraining the in-...

We investigated structural changes, phase diagram, and vibrational properties of hydrogen hydrate in filled-ice phase C(2) by using first principles molecular dynamics simulation. It was found that the experimentally reported "cubic" structure is unstable at low temperature and/or high pressure: The "cubic" structure reflects the symmetry at high (room) temperature where the hydrogen bond netwo...