[en] Investigation results of lithium, sodium and potassium interaction with tellurium dioxide at 1073-1223 K are presented. Decrease of the value of polyphosphate average molecular mass and melt viscosity by the growth of tellurium dioxide content in initial impurities, temperature and interaction time is stated. Polyanion destruction is confirmed by tetra-, piro-, orthophosphate availability in hardened interaction products. Tellurium dioxide interaction with polyphosphate was followed by formation of tellurium (6) compounds

[en] By the method of DTA in soldered platinum ampoule the melting temperature of InF₃, being 1320±10 deg C, was determined. It is detected that when kept in the air InF₃ reacts with atmosphere. Using the methods of DTA and X-ray phase analysis, phase equilibria in systems LiF-InF₃ and YbF₃-InF₃ are studied. In the first system compounds Li₃InF₆(two modifications) and LiInF₄ are found, in the second one-solid solutions on the basis of the components

[en] Polythermal outs in two cross sections, that is, Y₂BaCuO₅-Y₂Cu₂O₅ and BaCuO₂-Y₂O₃ of Y₂O₃-BaO-CuO(Cu₂O3 ternary system within 850-1450 deg C range are plotted using annealing and quenching techniques, as well as, differential thermal, X-ray phase and crystal optical analyses. Equilibrium phase ratios in these cuts are of complicated character with transition from eutectic to peritectic one. Nonequilibrium phase ratios in BaCuO₂-Y₂O₃ system are determined in both low-temperature part of the system (caused by kinetic factors) and above solidus line linked, apparently, with peculiarities of liquid phase chemical composition

[en] By means of X-ray phase, differential thermal analyses it is determined that europium (2) sulfide interacts with phosphorus (5) sulfide at 540-600 deg C with formation of compounds of Eu₅P₂S₁₀, Eu₃(PS₄)₂, Eu₂P₂S₇ composition. During heating at the air europium (2) thiophosphates are stable up to 250 deg C, are unstable to the action of diluted and concentrated mineral acids, and are slowly hydrolyzed by water

[en] Solubility and composition of solid phases in (HCOO)₃Y-(HCOO)₂M-H₂O systems, where M=Cu²⁺, Co²⁺, Ni²⁺, Cd²⁺, Ca²⁺, are studied at 25 deg C. The investigated systems belong to eutonic ones. Despite the fact that isotherm branch trend differs essentially in them, the formation of new compounds at 25 deg C does not occur. Effect of transition and rare earth metal ions on character of isotherm branches, in particular, at erbium ion substitution for yttrium is analysed. Mutual increase in solubility of the initial components (HCOO)₃Y- (HCOO)₂Cu - H₂O system is determined that turns to be essential at synthesis of initial compounds from aqueous solutions for preparation of high-temperature superconducting materials

[en] Ba₃V₄O₁₃(1) and new vanadate Ba₄V₂O₉(2) are synthesized from BaO and Ba₃V₂O₈ at 700 deg C during 80 hs. Compound 1 is crystallized in monoclinic syngony, elementary cell parameters are as follows: a=15.073±0.015, b=8.94±0.009, c=10.16±0.01 A; β=103.495±0.014 deg. Vanadate 2 is crystallized in tetragonal syngony with the following cell parameters: a=18.75±0.01; c=18.09±0.01 A. At 800-1000 deg C vanadate 2 reacts with the air carbon dioxide with formation of carbonate and orthovanadate. IR spectra and roentgenographic properties of the prepared compounds are studied

[en] Short note

[en] Short note

[en] Aqueous systems which contain yttrium, barium and copper formates are investigated. Solubility and composition of solid phases crystallizing (HCOO)₂Ba-(HCOO)₂Cu-H₂O and (HCOO)₂Ba-(HCOO)₃Y-H₂O systems at 25 deg C are studied. Formation of new congruently soluble compound of BaY(HCOO)₅x2H₂O composition is determined. Existence concentration interval for Ba₂Cu(HCOO)₆x4H₂O compound is found. BaY(HCOO)₅x2H₂O and Ba₂Cu(HCOO)₆x4H₂O phases are identified using X-ray phase, thermal and crystal optic analyses. Synthesis technique for YBa₂Cu₃O_7±δ; La_1.8Sr_0.2CuO_4-y; Y_1.8Sr_0.2CuO_4-y; Y_1.8Sr_0.2CuO_4-y ultradispersion phases representing the base for preparation of high-temperature superconducting materials is suggested

[en] Dissociation of vinylidenediphosphonic acid (H₄V) was studied by the method of pH-metric titration in KCl aqueous solution at different ionic force of solutions. Thermodynamic protonation constants were calculated. Complexing of three-valent rare earth ions with H₄V was studied in the region of ⁴I_9/2 → ²P_1/2 electron transition for Nd³⁺-Ln³⁺-H₄V (Ln=La, Nd, Eu, Gd, Tb, Yb, Ln, Y) systems, using the method of high resolution spectrography of Nd³⁺ aqua-ion spectra. Concentration stability constants of LnH₂V⁺ complexes were calculated. The dependence of stability constant logarithm on atomic number is of nonmonotonous character and passes through the maximum in the middle of rare earth series