Three-component systems LiBr-LiVO<Subscript>3</Subscript>-Li<Subscript>2</Subscript>MoO<Subscript>4</Subscript> and LiBr-Li<Subscript>2</Subscript>SO<Subscript>4</Subscript>-Li<Subscript>2</Subscript>MoO<Subscript>4</Subscript>

Phase equilibria in the three-component systems LiBr-LiVO₃-Li₂MoO₄ and LiBr-Li₂SO₄-Li₂MoO₄ have been studied using differential thermal analysis (DTA). Eutectic compositions have been determined (mol %): in the system LiBr-LiVO₃-Li₂MoO₄, 56.0 LiBr, 22.0 LiVO₃, and 22.0 Li₂MoO₄ with a melting temperature of 413°C; and in the system LiBr-Li₂SO₄-Li₂MoO₄, 65.0 LiBr, 14.0 Li₂SO₄, and 21.0 Li₂MoO₄ with a melting temperature of 421°C. Phase fields have been demarcated.     

Phase equilibria in the Ce<Subscript>2</Subscript>O<Subscript>3</Subscript>-K<Subscript>2</Subscript>O-P<Subscript>2</Subscript>O<Subscript>5</Subscript> system

Ce₂O₃-K₂O-P₂O₅ ternary system has been investigated by thermoanalytical methods (DTA, DSC), powder X-ray diffraction, XPS and IR spectroscopy. The existence of three double potassium-cerium(III) phosphates has been confirmed and a new binary phosphate K₄Ce₂P₄O₁₅ has been found. Phase diagram and isothermal section at room temperature of the system Ce₂O₃-K₂O-P₂O₅ have been presented.     

Thermal synthesis of the CeO<Subscript>2</Subscript>-PrO<Subscript>2</Subscript>-Nd<Subscript>2</Subscript>O<Subscript>3</Subscript>pigments

Summary The synthesis of new compounds based on the CeO₂-PrO₂-Nd₂O₃system, which can be used as pigments for colouring of ceramic glazes, is investigated in our laboratory. The optimum conditions for the syntheses of these compounds have been estimated. The methods of thermal analysis provided first information about the temperature region of the formation of the pigments investigated. The synthesis of these compounds was followed by thermal analysis using STA 449/C Jupiter (Netzsch, Germany).     

Phase relations in the MgO-Bi<Subscript>2</Subscript>O<Subscript>3</Subscript>-Bi<Subscript>2</Subscript>O<Subscript>3</Subscript> system

Phase relations in the MgO-Bi₂O₃-B₂O₃ system have been investigated by X-ray powder diffraction analysis and DTA. No ternary compounds have been found in the system. Quasi-binary sections have been the 600°C determined and isothermal section of the system has been constructed.     

LiF-LiCl-LiVO<Subscript>3</Subscript>-Li<Subscript>2</Subscript>SO<Subscript>4</Subscript>-Li<Subscript>2</Subscript>MoO<Subscript>4</Subscript> system

Phase equilibria in the LiF-LiCl-LiVO₃-Li₂SO₄-Li₂MoO₄ system have been studied by differential thermal analysis. The eutectic composition has been determined as follows (mol %): LiF, 17.4; LiCl, 42.0; LiVO₃, 17.4; Li₂SO₄, 11.6; and Li₂MoO₄, 11.6, with the melting temperature equal to 363°C and the enthalpy of melting equal to (284 ± 7) kJ/kg.     

Projection of the liquidus surface of the Sb<Subscript>2</Subscript>Te<Subscript>3</Subscript>-Gd<Subscript>2</Subscript>Te<Subscript>3</Subscript>-Bi<Subscript>2</Subscript>Te<Subscript>3</Subscript> system

Phase equilibria in the Sb₂Te₃-Gd₂Te₃-Bi₂Te₃ ternary system have been studied using differential thermal analysis, namely, X-ray powder diffraction, microstructure examination, thermodynamic analysis, and microhardness and alloy density measurements. Phase diagrams of some polythermal joins and liquidus surface have been constructed. The regions of primary crystallization of phases and the coordinates of all invariant and univariant equilibria in the system under investigation have been established.     

Four-component system LiF-K<Subscript>2</Subscript>WO<Subscript>4</Subscript>-CaF<Subscript>2</Subscript>-BaWO<Subscript>4</Subscript>

The four-component system LiF-K₂WO₄-CaF₂-BaWO₄ has been studied for the first time using physicochemical methods. The a priori prediction of the phase complex revealed the phase tree and crystallization path of the system. The prediction was verified experimentally, by construction of a topologic model of the phase diagram, and the solution of the equations of the general law of liquidus-surface formation. The density has been measured, and the heat-storage properties of eutectic mixtures have been estimated.     

Glass formation in the Li<Subscript>2</Subscript>O-Ta<Subscript>2</Subscript>O<Subscript>5</Subscript>-TeO<Subscript>2</Subscript> system

In the Li₂O-Ta₂O₅-TeO₂ system, the boundaries of the glass region have been determined. The electrical and spectral properties of glasses and crystalline materials have been investigated.     

Quasi-ternary system Tl<Subscript>2</Subscript>Se-AgTlSe-TlBiSe<Subscript>2</Subscript>

The quasi-ternary system Tl₂Se-AgTlSe-TlBiSe (A) has been investigated by DTA, X-ray powder diffraction, microstructural analysis, and microhardness measurements. Polythermal sections AgTlSe-TlBiSe₂, AgTlSe-Tl₉BiSe₆, [Ag_0.5Tl_1.5Se]-TlBiSe₂, Tl₂Se-AgBiSe₂ (0–50 mol % AgBiSe₂), an isothermal section at 500 K, and the projection of the liquidus surface of system A have been constructed. It has been shown that the quasi-binary join AgTlSe-Tl₉BiSe₆ divides system A into two subordinate triangles, namely, Tl₂Se-Tl₉BiSe₆-AgTlSe (B) and AgTlSe-Tl₉BiSe₆-TlBiSe₂ (C). The phase diagram of subsystem B involves a univariant eutectic equilibrium while subsystem C involves an invariant eutectic equilibrium. The ternary eutectic has the coordinates 650 K, 10 mol % TlBiSe₂, and 61 mol % AgTlSe. A continuous series of solid solutions (0–12 mol % AgTlSe) has been found along the Tl₂Se-Tl₉BiSe₆ bordering system. The homogeneity region of TlBiSe₂ extends to 5 mol %.     

Glasses in the CuNbOF<Subscript>5</Subscript>-BaF<Subscript>2</Subscript> and CuNbOF<Subscript>5</Subscript>-PbF<Subscript>2</Subscript> systems

Nonhygroscopic, colored glasses have been synthesized in the CuNbOF₅-BaF₂ and CuNbOF₅-PbF₂ systems proceeding from crystals of the complex compound CuNbOF₅ · 4H₂O. The glasses have been studied structurally and thermally. The crystallization resistance of the glasses has been studied as a function of glass composition. Lead difluoride glasses are more stable than barium difluoride glasses of the same composition. These glasses have lower glass-transition temperatures than the binary glasses formed in the NbO₂F-BaF₂ system. The glass structure is built of Nb(O,F)₆ polyhedra, which are linked in glass networks through oxygen bridges. Modifier cations influence both the structure of glass networks and the linkage of polyhedra.     

Hydrogen generation from H<Subscript>2</Subscript>O/H<Subscript>2</Subscript>O<Subscript>2</Subscript>/MnWO<Subscript>4</Subscript> system

Hydrogen gas as a clear energy resource was found to be largely bubbled from a H₂O/H₂O₂/MnWO₄ system. MnWO₄ powder was fabricated by an aqueous reaction method. The powder was characterized with X-ray diffraction (XRD), transmission electron microscope (TEM), and X-ray photoelectron spectrometry (XPS). The efficiency of the hydrogen generation increases with an increase in initial pH in the appropriate range, H₂O₂ proportion, MnWO₄ proportion, and intensity of light resource. Calcining at 400 °C for 1 h can make the MnWO₄ powder synthesized by an aqueous reaction more effective for H₂ generation and more stable in higher initial pH. The MnWO₄ catalyst shows a long-term stability for photocatalytic H₂ generation. A mechanism was suggested for the hydrogen generation from the H₂O/H₂O₂/MnWO₄ system together with XPS analysis.     

NaBO<Subscript>2</Subscript>-Na<Subscript>2</Subscript>CO<Subscript>3</Subscript>-Na<Subscript>2</Subscript>MoO<Subscript>4</Subscript>-Na<Subscript>2</Subscript>WO<Subscript>4</Subscript> quaternary system

This is the first study of the NaBO₂-Na₂CO₃-Na₂MoO₄-Na₂WO₄ quaternary system by differential thermal analysis. Na₂[MoO_4(x)WO_{4(1 − x)}] solid solutions in the quaternary system are found to not decompose.     

Phase formation in the V<Subscript>2</Subscript>O<Subscript>5</Subscript>-Nb<Subscript>2</Subscript>O<Subscript>5</Subscript>-MoO<Subscript>3</Subscript> system

The solid-phase interaction in the V₂O₅-Nb₂O₅-MoO₃ system has been investigated, and the formation of a solid solution bounded by the compositions MoNb₂V₄O_{18 ? δ}, Mo₂NbV₅O_{21 ? δ}, Mo₂Nb₃V₃O_{21 ? δ}, and Mo₄Nb₉V₉O_{57 ? δ} has been found (δ is nonstoichiometry). In the V₂O₅?Nb₂O₅ system, the formation of three compounds is verified, namely, VNbO₅ (tetragonal structure), VNb₉O₂₅, and V₂Nb₂₃O_62.5. The first two compounds are isostructural and form a continuous solid solution with tetragonal symmetry. A new compound of the composition Mo₃NbVO_{14 ? δ} has been synthesized. This compound is isostructural to the Mo₃Nb₂O₁₄ compound described in the literature and forms a tetragonal solid solution with it. The phase equilibria in the V₂O₅-Nb₂O₅-MoO₃ system in the subsolidus region have been determined.     

Phase equilibria in the La<Subscript>2</Subscript>S<Subscript>3</Subscript>-Bi<Subscript>2</Subscript>S<Subscript>3</Subscript>-La<Subscript>2</Subscript>O<Subscript>3</Subscript> ternary system

Phase equilibria in the La₂S₃-Bi₂S₃-La₂O₃ ternary system were studied by differential thermal, X-ray powder diffraction, and microstructure analyses. Phase diagrams of five vertical sections and a liquidus surface projection were plotted for the La₂S₃-Bi₂S₃-La₂O₃ system. The regions of primary crystallization of phases and coordinates of non- and monovariant equilibria were determined for the system.     

The 3Ga<Subscript>2</Subscript>S<Subscript>3</Subscript>-EuLaGa<Subscript>3</Subscript>S<Subscript>7</Subscript> system

The La₂S₃-Ga₂S₃-EuS system has been investigated along the 3Ga₂S₃-EuLaGa₃S₇ join by physicochemical methods (DTA, X-ray powder diffraction, microstructural analysis). is a quasi-binary eutectic-type section of the ternary system. Solubility on the base of both components has been revealed in the system. Solubility at room temperature is 3 mol % EuLaGa₃S₇ on the Ga₂S₃ side 1.5 mol % Ga₂S₃ and on the base of the EuLaGa₃S₇ compound. The coordinates of the eutectic point are 80 mol% EuLaGa₃S₇ and 1020 K.     

Phase equilibriums,ion association,and mechanisms of solvation in the LiN(CF<Subscript>3</Subscript>SO<Subscript>2</Subscript>)<Subscript>2</Subscript>-(CH<Subscript>3</Subscript>)<Subscript>2</Subscript>SO<Subscript>2</Subscript> system

The phase diagrams, isotherms of the electrical conductivity, Raman spectra, and time correlation functions of vibrational dephasing are studied for the LiN(CF₃SO₂)₂-(CH₃)₂SO₂ system, which is promising for use as an electrolyte in medium-temperature lithium-ion batteries. The phase diagram of this system contains a broad supercooled region. It is shown that the concentration dependences of the electrical conductivity are typical for solutions of strong electrolytes. The Raman spectra and the time correlation functions of vibrational dephasing for the anion and the solvent indicate that in the supercooling range, cations are weakly solvated by solvent molecules and form ion pairs.     

LiF-LiBr-LiVO<Subscript>3</Subscript> and LiBr-Li<Subscript>2</Subscript>SO<Subscript>4</Subscript>-LiVO<Subscript>3</Subscript> ternary systems

Phase equilibria in the LiF-LiBr-LiVO₃ and LiBr-Li₂SO₄-LiVO₃ systems have been investigated by differential thermal analysis. Eutectic compositions have been revealed (mol %). In the LiF-LiBr-LiVO₃ system, 16.8% LiF, 52.0% LiBr, 31.2% LiVO₃ with a melting point of 428°C; in the LiBr-Li₂SO₄-LiVO₃ system, 52.0% LiBr, 38.0% LiVO₃, 10.0% Li₂SO₄ with a melting point of 444°C. Crystallization fields of the phases have been demarcated.     

Phase diagrams of the KF-K<Subscript>2</Subscript>TaF<Subscript>7</Subscript> and KF-Ta<Subscript>2</Subscript>O<Subscript>5</Subscript> systems

The phase diagrams of the systems KF-K₂TaF₇ and KF-Ta₂O₅ were determined using the thermal analysis method. The phase diagrams were described by suitable thermodynamic model. In the system KF-K₂TaF₇ eutectic points at x _KF=0.716 and t=725.4°C and at x _KF=0.214 and t=712.2°C has been calculated. It was suggested that K₂TaF₇ melts incongruently at around 743°C forming two immiscible liquids. The system KF-Ta₂O₅ have been measured up to 8 mol% of Ta₂O₅. The eutectic point was estimated to be at x _KF∼0.9 and t∼816°C. The formation of KTaO₃ and K₃TaO₂F₄ compounds has been observed in the solidified samples.     

Subsolidus phase relations in the Al<Subscript>2</Subscript>O<Subscript>3</Subscript>-Li<Subscript>2</Subscript>O-Ta<Subscript>2</Subscript>O<Subscript>5</Subscript> (Nb<Subscript>2</Subscript>O<Subscript>5</Subscript>) systems

The phase composition has been studied and an equilibrium phase diagram has been designed for the Al₂O₃-Li₂O-R₂O₅ (R = Ta or Nb) systems in the subsolidus region up to 1000°C and 85 mol % Li₂O. New phases with the composition Li_1+x Al_1?x O_2?x , where x = 0–0.67, have been found.     

Phase equilibria in the system Li<Subscript>2</Subscript>O-MgO-B<Subscript>2</Subscript>O<Subscript>3</Subscript>

The subsolidus region of the Li₂O-MgO-B₂O₃ system has been studied by X-ray powder diffraction and differential thermal analysis. Isothermal sections at 500–550 and 650–700°C have been designed. The following complex borates have been found to form: at 500–550°C, Li₂MgB₂O₅ and LiMgBO₃ are formed; at 650–700°C, a new phase Li₄MgB₂O₅ is formed along with LiMgBO₃; and at 5500–600°, Li₂MgB₂O₅ is formed.