ХАРАКТЕР ХИМИЧЕСКОЕ ВЗАИМОДЕЙСТВИЕ И СТЕКЛООБРАЗОВАНИЕ В СИСТЕМЕ AS2SE3-IN2TE3

Mетодами дифференциально-термического (ДТА), рентгенофазового (РФА), микроструктурного (МСА) анализа, а также измерения микротвердости и плотности, исследована система As2Se3-In2Te3 и построена Т - х фазовая диаграмма. Система As2Sе3-In2Te3 является квазибинарным сечением тройной взаимной системы As,In//Sе,Te. Cоединение In2As2Se3Te3 кристаллизуется в тетрагональной сингонии с параметрами решетки: а =9,40; с =6,36 Å, плотность ρпикн.=5,36 г/см3, ρрент.=5,85 г/см3. В системе образуется одно инконгруэнтное соединение In2As2Sе3Te3,плавящееся при 620оС. Выявлено, что в системе твердые растворы на основе In2Te3 доходят до 3 мол. %, а на основе As2Sе3 практически не обнаружены. В системе при медленном охлаждении область стеклообразования на основе As2Sе3 доходит до 7 мол. % In2Te3, а в режиме закалки в ледяной воде около 12 мол. % In2Te3. By the methods of differential thermal (DTA), X-ray phase (XRD), microstructural (MSA) analysis, as well as measurements of microhardness and density, the As2Se3-In2Te3 system was investigated and the T-x phase diagram was constructed. The As2Sе3-In2Te3 system is a quasi-binary section of the ternary reciprocal system As, In // Se, Te. One incongruent compound In2As2Sе3Te3 is formed in the system, melting at 620оС. Compound In2As2Sе3Te3 crystallizes in the tetragonal system with lattice parameters: a = 9.40; с = 6.36 Å, density ρpycn. = 5.36 g/cm3, ρX-rey. = 5.85 g/cm3. It was found that in the system, solid solutions based on In2Te3 reach 3 mol. %, and practically not found on the basis of As2Sе3. In the system, upon slow cooling, the glass formation region based on As2Se3 reaches 7 mol. % In2Te3, and in the mode of quenching in ice water about 12 mol. % In2Te3.

Investigation of BaSO4-KPO3-Na2B4O7 Low-Melting Glass System as a Basis for Synthesis of a Glass-Solder Material

The possibility of using the compositions of BaSO4-KPO3-Na2B4O7 system as a glass-solder (frit) material was shown. A glass formation region has been established in BaSO4-KPO3-Na2B4O7 system which is located in the borate-phosphate part of the concentration triangle and occupies ~41% of the triangle area. The concentration dependences of linear thermal expansion coefficient (TCLE), the softening temperature and the glass transition temperature was determined and discussed. It is established that the glass formation region, the concentration dependences of TCLE and technological temperatures values are significantly closer to those for CaSO4-KPO3-Na2B4O7 system than for MgSO4-KPO3-Na2B4O7 system. That may point out at the similar effect barium sulphate and calcium sulphate doping in the sulphate-phosphate-borate systems.

Investigation of CaSO4-KPO3-Na2B4O7 System as a Basis for Synthesis of Low-Melting Glasses Used as a Glass-Solder Material

The possibility of using the compositions of CaSO4-KPO3-Na2B4O7 system as a glass-solder material is shown. A glass formation region has been established in ternary system. The concentration dependences of linear thermal expansion coefficient, the softening temperature and the glass transition temperature are determined and discussed.

PHASE EQUILIBRIUM AND GLASS FORMATION IN THE AS2SE3-CUCR2TE4 SYSTEM

Studies of the interaction of As2Se3 with CuCr2Te4 chalcogenides are of interest both for the development of the general theoretical foundations of this type of process and for the creation of magnetic and magneto-optical materials. To clarify the nature of the physicochemical properties, the As2Se3-CuCr2Te4 system was investigated. The results of a physicochemical study of the As2Se3-CuCr2Te4 system found that the state diagram of the system is quasi-binary eutectic type. In the system near the initial components, a narrow homogeneous region was revealed. At room temperature, solid solutions based on As2Se3 extend to 2 mol %, and on a CuCr2Te4 basis, solid solutions reach 6 mol. % .The joint crystallization of As2Se3 and CuCr2Te4 ends at the double eutectic point. Upon slow cooling in the As2Se3-CuCr2Te4 system based on As2Se3, the glass formation region reaches 10 mol. % CuCr2Te4.

GLASS FORMATION IN TERNARY SYSTEM La2O3–As2S3–Pr6O11

Boundaries of glass formation in ternary system La2O3-As2S3-Pr6O11 were studied using methods of physical-chemical analysis (DTA, DTG, X-ray analysis, MSA). It was established that in glass formation region the range of concentration covers from As2S3-La2O3 15 mol%, but from As2S3-Pr6O11 it is 13 mol%. To our opinion the decrease in glass formation region of Pr6O11 comparing to La2O3 is related to crystalline structure of oxide, i.e. to the change in coordination number of lanthanides. Because properties of compounds of lanthanide are more sensitive to the change in coordination numbers relative to radii of ion. In the system the region of transparent glass formation is limited with the region of non-transparent one. The reason of non-transparency of a glass is the formation of primary centers of crystallization, which was confirmed by the results of X-ray analysis and SEM. Raman spectra of transparent glass containing(La2O3)0.07(As2S3)0.90(Pr6O11)0.03 were studied. Intensity of bands which characterize the bonds of As–S, La–O, Pr–O in Raman spectrum and shift of energy of waves in the big party are related to the strengthening of bonds and probably, appearance of new bonds in glasses. When heating glasses of the composition (La2O3)0.07(As2S3)0.90(Pr6O11)0.03 in inert atmosphere (He) at 224,61 °С it softens which is followed by endoeffects. Observed exoeffect at 315,80 °С satisfies crystallization of glass, but at 380,80 °С thermal decomposition begins. Samples in the region of glass formation are stable at 300 K to air, water and organic solvents. When heated, glasses are dissolved in chromic mixture. They decompose in mineral acids and alkalies.Forcitation:Bakhtiyarly I.B., Fatullayeva G.M., Kerimli O.Sh. Glass formation in ternary system La2O3–As2S3–Pr6O11. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 4-5. P. 43-48

Defining Borders of Vitrification Region in the Li2O⋅B2O3-B2O3-Yb2O3⋅B2O3 System

ABSTRACTPhase relations along the Li2O⋅2B2O3-Yb2O3⋅B2O3 polythermal section of the Li2O –B2O3–Yb2O3 system were investigated by differential thermal analysis, x-ray diffraction, and microstructural analysis. The state phase diagram of the Li2O⋅2B2O3-Yb2O3⋅B2O3 section is an eutectic system with invariant eutectic point corresponding to ∼0.2 mole fraction of Yb2O3⋅B2O3 and 800 °C. According to physico-chemical analysis, the Li2O⋅2B2O3-Yb2O3⋅B2O3 polythermal section is quasi-binary, allowing us to partially triangulate the Li2O-B2O3-Yb2O3 system. The borders of the glass formation region were defined in the Li2O⋅2B2O3-B2O3-Yb2O3⋅B2O3 concentration triangle. The vitreous samples showed a semiconducting nature.

Glass Transition Behavior of the Quaternary Ammonium-Type Ionic Liquid: N,N-Diethyl-N-methyl-N-(2-methoxyethyl)ammonium Bromide-H2O Mixtures

By a simple differential thermal analysis (DTA) system, the concentration dependence of the glass transition temperatures (Tgs) for the quaternary ammonium-type ionic liquid, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bromide [DEME][Br] and H2O mixtures, after quick precooling was measured as a function of water concentration x (mol% H2O). We compared the results with the previous results of [DEME][I]-H2O and [DEME][BF4]-H2O mixtures in which a double-glass transition behavior was observed. Remarkably, the [DEME][Br]-H2O mixtures basically show one-Tg behavior and the Tg decreases monotonically with increasing H2O content up to around x=91.5. But it suddenly jumps to higher Tg value at a specific x=~92. At this very limited point, two Tgs (Tg1,Tg2) which we might consider as a transition state from the structure belonging to the Tg1 group to another one due to the Tg2 group were observed. These results clearly reflect the difference in the anionic effects among Br−, I−, and BF4-. The end of the glass-formation region of [DEME][Br]-H2O mixtures is around x=98.9 and moves to more water-rich region as compared to those of [DEME][BF4]-H2O (x=96.0) and [DEME][I]-H2O (x=95.0) mixtures.

Tm3+/Yb3+ Codoped YAG Glass-Ceramic Formed in Silicate Glass System

Based on the analysis of glass formation region of Y2O3-Al2O3-SiO2 glass system, the glass composition 5Li2O-18Y2O3-29Al2O3-48SiO2 (LYAS) in mol% central in the glass formation region of Y-Al-Si glass system was chosen for present work. The Tm3+ and Yb3+ were introduced as activators in LYAS glass. The glass samples were prepared by the high-temperature solid-state melting and then the derived YAG glass-ceramic was obtained by heat-treating the precursor glass. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis results indicate that the lattice constant of the obtained glass-ceramic is consistent with the pure YAG phase. The primary crystallite size is calculated to be 46nm and the crystal grains grow with excellent orientation (444) in the internal network. The secondary particle size is estimated to be ~8μm and the large grain size is owing to the particles aggregation. The crystal grains distributed uniformly in the glass matrix, and consistent well with the XRD analysis results.