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Using a density-functional framework, we investigate the vibrational spectra of vitreous SiO2 to determine to what extent these spectra provide information about the medium-range structure of the oxide network. We carry out a comparative study involving th ...
During the last several years, new lead-free piezoelectric materials have been developed to replace the lead-based materials, such as PZT. Presently, the family of lead-free ceramics showing the most promising piezoelectric properties is based on potassium ...
The crystal structure and property changes of sodium bismuth titanate (Na0.5Bi0.5TiO3, NBT) piezoelectric ceramics are reported as a function of La modification (0.5-2.0 at. %) and increasing temperature using high resolution x-ray diffraction, permittivit ...
It is known that the addition of supplementary cementitious materials (SCMs) in concretes reduces or even stops expansion due to alkali silica reaction (ASR). It has been widely shown that the main mechanism controlling ASR in blends is the alkali fixation ...
We wish to report the discovery of a new and unexpected polymorph of dicesium tetracyanoplatinate. Short, linear chains of five platinum atoms (platinum “needles”) appear in a zigzag arrangement, interspersed by isolated tetracyanoplatinate ions. ...
The synthesis of bismuth vanadate (BiVO4) nanoparticles has drawn considerable attention to their application as a visible-light-driven photocatalyst. Several techniques are addressing the enlargement of surface area, but some of them can cause impurities ...
New Ba5(V2O7)2Cl2 was isolated by a high-temp. (850°) reaction employing a CsCl/RbCl flux. The structure was detd. by single crystal x-ray diffraction methods. This compd. crystallizes in an orthorhombic crystal system, space group Pmmn, with a 11.558(2), ...
Dislocations alter perfect crystalline order and produce anisotropic broadening of the X-ray diffraction profiles, which is described by the dislocation contrast factor. Owing to the lack of suitable mathematical tools to deal with dislocations in crystals ...
NOVELTY - The component partially or wholly comprises pigmented ceramic. The pigment comprises nanoparticles of metal of group IB in periodic table, alkaline metals or their alloy, coated with a layer of silica such as crystalline silica. The crystalline s ...
The invention relates to nanoparticles based on a metal, on a metal alloy or on a metal derivative coated with a silica layer, in which the silica is crystalline silica, in particular crystalline silica in the cristobalite form. They may be prepared from n ...
