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[en] The mode of decomposition and removing of zinc stearate from uranium dioxide matrix into hydrogen atmosphere, as well as zinc stearate quantity and green density influence on residual carbon removing are described. The work emphasizes the influence that inhomogeneous atmosphere from a sintering furnace may have, sometimes, on the removal kinetics of residual carbon. (author)
[en] We performed ultrasound velocity measurements in the geometrically-frustrated ferrite spinel ZnFe_2O_4. In the low-temperature paramagnetic phase, the elastic moduli exhibit softening with a characteristic minimum with decreasing temperature. This elastic anomaly suggests the coupling of lattice to molecular-spin excitations
[en] Due to an oversight, the Surname of Haya Alhummiany was incorrectly spelled in the published online version. The correct surname is “Alhummiany”, instead of “Alhumminay”. The correct spelling is also shown above.
[en] Molecular monolayers of zinc porphyrins deposited from liquid sources on graphite substrates have been characterized using atomic force microscopy. The morphology of the molecular layers shows a strong dependence on both the structure of the individual molecules and the properties of the solvent used for the deposition. By controlling the concentration of the starting solution and the amount of liquid applied to the graphite surface, single layer high molecular weight films have been successfully grown with a variety of zinc porphyrin molecules. The nucleation and growth, similar to those commonly observed in vapour deposition, have been found to depend on the strength of the intermolecular interaction as well as the level of interaction between the solvent molecules and the substrate
[en] Zinc borates activated with Mn2+ have effective luminescence when exciting in the vacuum ultraviolet radiation range. It is connected with excitation energy absorption by anions. The luminescence spectra represent themselves wide bands with λmax = 540 nm for Zn4O5(BO2)6 - Mn2+ and ZnB4O7 - Mn2+, 595 nm for Zn3(BO3)2 - Mn2+. The zink orthoborate luminescence in the yellow-range of the spectra is connected with disordered tetrahedral environment of an activator
[en] When prepared as a bulk material, ZnFe2O4 has a normal spinel structure with Zn2+ incorporated almost exclusively at the tetrahedral lattice sites and Fe3+ at the octahedral sites ((Zn)[Fe2]O4). Due to its 'rigid' structure, its composition is also closely defined at Zn2+/Fe3+ ≅ 0.5. However, when prepared as nanoparticles, a significant proportion of Zn can enter the zinc-ferrite structure at the octahedral sites, resulting in a flexibility of the composition. In this work, the non-stoichiometry of zinc-ferrite nanoparticles was studied as a function of the particle size. Nanoparticles with a narrow size distribution were synthesized using co-precipitation in water-in-oil microemulsions. The zinc-ferrite nanoparticles with a size of ∼9 nm retained the single-phase spinel structure when Zn/Fe was between 0 and ∼0.8. With a decrease in the particle size the compositional range of the zinc-ferrite spinel broadened. The process of structural rearrangement during the heating of the nanoparticles was also studied.
[en] Hydrothermal reaction of zinc(II) salts with 5-sulfoisophthalic acid monosodium salt (NaO3SC6H3-1,3-(COOH)2, NaH2- SIP) and 1,10-phenanthroline (phen) led to two new compounds, [Zn(phen)3]·2H2SIP·4H2O and [Zn(phen)2(H2O)2]· 2H2SIP·2H2O. They were characterized by element analysis, IR spectroscopy, thermal gravimetric analysis (TGA), X-ray powder diffraction (XRD), and single-crystal X-ray diffraction. Both compounds 1-2 represent the first example of Zn/phen/SIP system. The Zn (II) ion in 1 is six-coordinated by six nitrogen atoms from three phen molecules, and the H2SIP- ligands engage in the formation of hydrogen bond. The Zn(II) ion in 2 is coordinated by four nitrogen atoms from two phen molecules and two oxygen atoms from two water molecules. Moreover, both 1 and 2 are assembled into 3D supramolecular architectures by hydrogen bonds (O-H···O) and π-π interactions. Solvent water molecules occupying voids of the compounds serve as receptors or donors of the extensive O-H···O hydrogen bonds