In this study a special type of silicoaluminophosphate with opal structure (Opal-SAPO) was prepared under microwave condition using tetraethylorthosilicate (TEOS), triethanolamine (TEA), aluminiumisopropoxid and phosphoric acid 85%. The product was characterized by X-ray diffraction (XRD), thermogravimetric (TGA) and Fourier Infrared Spectroscopy (FTIR).The crystalline product showed a good act...

The influence of the addition of carbon on the crystalline structure and resistivity of polycrystalline silicon layers grown by simultaneous decomposition of SiH,, C^H. a n d P H T a t '°"° c w a s studied. Carbon content, morphology, preferred orientation, crystallite size, lattice strains and resistivity were determined. It was found that carbon has a pronounced effect on the crystalline stru...

An approach for description of the photoinduced nonlinear optical effects in the superconducting MgB₂:Cr₂O₃ nanocrystalline film is proposed. It includes the molecular dynamics step-by-step optimization of the two separate crystalline phases. The principal role for the photoinduced nonlinear optical properties plays nanointerface between the two phases. The first modified layers possess a form ...

Using first principles variable cell shape molecular dynamics, we predict a new structure for silica. This structure results from annealing a-quartz at pressures near a major phonon instability. The new phase is obtained by rotations of SiO4 tetrahedra producing edge-sharing SiO6 octahedra and SiO5 cuboids. This type of mechanism was proposed to account for structural transitions in silicate me...

We report single-crystalline mesoporous molybdenum nitride nanowires (meso-Mo3N2-NWs) prepared by topotactic reaction using single-crystalline molybdenum oxide nanowires. The single-crystalline nature of meso-Mo3N2-NWs was clearly observed by field-emission transmission electron microscopy. The meso-Mo3N2-NWs exhibited mesoporous structure with 45 m/g in specific surface area and 4.6 nm in aver...

The progressive conversion of crystalline raffinose pentahydrate to its amorphous form by dehydration at 60 degrees C, well below its melting temperature, was monitored by X-ray powder diffraction over a period of 72 h. The presence of defects within the crystal structure and any amorphous structure created was determined computationally by a total diffraction method where both coherent long-ra...

2 Condensed matter and structure 4 2.1 Structure of liquids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2 Structure of water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.3 Structure of solids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Crystalline solids . . . . . . . . . . . . ....