Function of the Non-Crystalline X-Ray Amorphous Phase of Highly Dispersed Powder of CaO in Adsorption of CO2 and H2O

Russian Journal of General Chemistry - Highly dispersed CaO has been synthesized by heating an aqueous solution of calcium nitrate and D-glucose up to 800°C. Calcium oxide is formed with an...     

On-line spectrophotometric method for monitoring weak residual absorption of CaMoO4 single crystals near the intrinsic luminescence peak

The optical and spectral characteristics of isotopically enriched Czochralski-grown ⁴⁰Ca¹⁰⁰MoO₄ single crystals have been investigated. This material is promising for detecting double neutrinoless β decay. The possibility and the technique of spectrophotometric monitoring of weak residual absorption near the intrinsic luminescence peak of this scintillation material, which is designed for developing new-generation detectors of elementary particles, are considered.     

[Co(solv)<Subscript>6</Subscript>][B<Subscript>10</Subscript>H<Subscript>10</Subscript>] (solv = DMF and DMSO) for low-temperature synthesis of borides

The synthesis and structure of complexes [Co(solv)₆][B₁₀H₁₀] (solv = DMF and DMSO) have been reported. Both complexes have been prepared in a high yield by the reaction between cobalt(II) salts and closo-decaborates Cat₂[B₁₀H₁₀] in the corresponding solvent. The complexes have been characterized by elemental analysis, IR and UV spectroscopy, X-ray powder diffraction, and X-ray crystallography. The thermal properties of the compounds have been studied in the temperature range 20–600°C under argon. The conditions to form cobalt borides have been determined based on the results of thermal analysis, subsequent annealing of the complexes in various conditions, and analysis of IR spectra of the resulting thermolysis products.     

Luminescence Properties of Undoped Langasite Crystals

Physics of the Solid State - The optical and luminescence properties of La3Ga5SiO14 lanthanum–gallium silicate crystals grown in atmospheres of argon and argon with the addition of oxygen are...     

Low-temperature heat capacity and thermal behavior of Zn<Subscript>0.98</Subscript>Co<Subscript>0.02</Subscript>O in the high-temperature region

The low-temperature heat capacity of Zn _0.98Co_0.02O oxide was measured by adiabatic calorimetry. The formation of a solid solution was shown to be accompanied by a change in the entropy by 0.4 J/(K mol). No anomalies in the heat capacity or the thermal behavior confirming the phase transformations found earlier by other methods were observed. A heat capacity anomaly was revealed below 15 K and tentatively attributed to a change in the magnetic properties of the substance.     

Yuriĭ Andreevich Osip’yan (February 15, 1931–September 10, 2008)

Crystallography Reports -     

Advanced piezoelectric crystal Ca3TaGa3Si2O14: growth,crystal structure perfection,and acoustic properties

A five-component crystal of the lanthanum–gallium silicate family Ca₃TaGa₃Si₂O₁₄ (CTGS) was grown by the Czochralski method. The CTGS crystal, like the langasite crystal (La₃Ga₅SiO₁₄, LGS), possesses unique temperature properties and the fewer number of the Ga atoms in the unit cell makes the density much lower and, consequently, increases the velocity of acoustic wave propagation. The unit-cell parameters were determined by the powder diffraction technique. The defects in the CTGS crystal structure were studied by X-ray topography, which enables the visualization of growth banding characteristics of crystals grown by the Czochralski method. Surface acoustic wave (SAW) propagation in the CTGS crystal was investigated by the high-resolution X-ray diffraction method on the BESSY II synchrotron radiation source. The velocities of propagation and power flow angles of SAWs in the Y- and X-cuts of the CTGS crystal were determined from the X-ray diffraction spectra.     

Complex [Ag(PPh3)4][2-B10H9NH3 · 2DMF]: Synthesis and Structure

Russian Journal of Coordination Chemistry - The formation of complex salt [Ag(PPh3)4][2-B10H9NH3 ? 2DMF] (I) by the reaction of the salts of the [2-B10H9NH3]– anion with [Ag(PPh3)4]NO3...     

Nuclear magnetic resonance study of langatate

A langatate crystal was studied using the nuclear magnetic resonance method. The temperature dependence of the spin-lattice relaxation rate of ⁷¹Ga nuclei was measured in a single-crystal sample in the range 294–500 K. It was shown that the relaxation rate depends linearly on the square of the temperature. The shape of the powder spectrum obtained under static conditions was found to correspond to large values of the quadrupole coupling constant of gallium nuclei. The measurements of the powder spectra obtained upon magic-angle spinning made it possible to estimate the quadrupole coupling constant for gallium in the tetrahedral and octahedral oxygen coordinations.