I. D. Zakir’yanova

Raman Spectra of Crystalline and Molten GdCl 3

The Raman spectra of crystalline (over a wide temperature range) and molten GdCl3 are mea- sured. The hexagonal structure C26h (UClC26h3 type) of crystalline GdCl3 is found to change weakly over the entire temperature range under study. The temperature dependences of the characteristic frequencies change in the premelting range.

Specific features of the interaction of α- and γ-modifications of Al2O3 with carbonate and carbonate-chloride melts

Data on reactivities of α- and γ-Al2O3 finely dispersed powders in a melted carbonate eutectic (Li2CO3–Na2CO3–K2CO3)eut and carbonate-chloride mixture 0.72(Li2CO3–Na2CO3–K2CO3)eut–0.28NaCl were obtained. The methods of synchronous thermal and X-ray phase analyses and Raman spectroscopy confirmed that, in contrast to γ-Al2O3, α-Al2O3 does not chemically interact with the melted carbonate eutectic and carbonate-chloride mixture (Li2CO3–Na2CO3–K2CO3)eut–NaCl can be recommended as a thickening agent for a carbonate fuel cell.

Phonon spectrum of lead oxychloride Pb3O2Cl2: Ab initio calculation and experiment

IR and Raman spectra of Pb3O2Cl2 in the range of 50–600 cm–1 have been detected for the first time. Ab initio calculations of the crystal structure and the phonon spectrum of Pb3O2Cl2 in the framework of LCAO approach have been performed by the Hartree–Fock method and in the framework of the density functional theory with the use of hybrid functionals. The results of calculations have made it possible to interpret the experimental vibration spectra and reveal silent modes, which do not manifest themselves in these spectra but influence the optical properties of the crystal.

Raman spectroscopy study of the phase transitions in rare-earth metal trichlorides

The structures of crystalline (over a wide temperature range) and molten rare-earth metal-LnCl3 (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy) trichlorides are comprehensively studied by Raman spectroscopy.

Raman spectra and conductivity of PbO–PbCl 2 –CsCl melts

The structure and the conductivity of homogeneous CsCl–PbCl2–PbO melts with different compositions are studied. The Raman spectra (RS) of the chloride and oxide–chloride melts containing lead oxide have been measured. It is found that the CsCl (71.3 mol %)–PbCl2 (28.7 mol %) system with the addition of 12 mol % PbO and the CsCl (18.3 mol %)–PbCl2 (81.7 mol %) system with the addition of 18 mol % PbO contain Pb3O2Cl+ oxide–chloride groups. The temperature dependences of the electrical conductivity are measured in the PbCl2–CsCl chloride melts containing 28.7 and 81.7 mol % lead chloride and in homogeneous molten mixtures CsCl (71.3 mol %)–PbCl2 (28.7 mol %) with the addition of 12 mol % PbO and the CsCl (18.3 mol %)–PbCl2 (81.7 mol %) with the addition of 18 mol % PbO. Significant degradation of the ion conductive properties of the PbO–PbCl2–CsCl oxide–chloride melts as compared to those of the PbCl2–CsCl chloride electrolytes has been revealed. It is shown that the decrease in the electrical conductivity of the PbCl2–CsCl oxide–chloride melts as lead oxide is added is due to the presence of Pb3O2Cl+ oxide–chloride groups.

Electrical Conductivity and Raman Spectra of Disperse Systems α-Al 2 O 3 –Li 2 CO 3 –Na 2 CO 3 –K 2 CO 3 –NaCl Melt

The conductivities of the disperse system α-Al2O3–molten carbonate chloride mixture Li2CO3–Na2CO3–K2CO3–NaCl are dtermined in the temperature range 455–550°C. As follows from Raman spectroscopy data, α-Al2O3 does not interact chemically with the carbonate–chloride melt in this temperature range. The force and energy characteristics of the CO32- anion in the systems are revealed.

Synthesis of lithium cobaltate in halide melts

A new method for the synthesis of lithium cobaltate LiCoo2 in salt melts is proposed and tested. The method is based on the oxidation of halide ions with molecular oxygen in LiX-CoCl2 mixtures (X = Cl, Br, I). The chemical and phase compositions of the prepared powders and the crystal structure of the synthesized compound are studied by Fourier transform infrared spectroscopy and X-ray diffraction analysis. The average size of LiCoO2 crystallites is estimated from the X-ray diffraction data.