- Phase equilibria in the Tl-TlCl-Te system and thermodynamic properties of the compound Tl5Te2Cl
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The Tl-Te-Cl system was studied in the Tl-TlCl-Te composition region by differential thermal analysis, X-ray powder diffraction, and emf and microhardness measurements. A series of polythermal sec- tions, an isothermal section at 400 K, and a projection of the liquidus surface of the phase diagram were con- structed. The ternary compound Tl5Te2Cl characterized by a wide homogeneity region and incongruent melting by a syntectic reaction at 708 K was shown to exist. This compound was found to crystallize in tetragonal lattice (space group I4/mcm) with the parameters a = 8.921 ?, c = 12.692 ?, and Z = 4. Wide phase separation regions were also found in the system, including a three-phase separation region in the Tl-TlCl-Tl2Te sub- system. Regions of primary crystallization of phases, and the types and coordinates of in-and monovariant equilibria in the T-x-y diagram were determined. From emf measurement data, the standard thermody- namic functions of formation and the standard entropy were calculated for the compound Tl5Te2Cl, as follows: =ΔG0 298 355.9 ± 1.1 kJ/mol, =ΔH0298 377.1 ± 5.0 kJ/mol, andΔS0298 = 474.1 ± 6.8 J/(mol K). Pleiades Publishing, Ltd., 2011.
- Babanly,Aliev,Dhafarli,Babanly
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- Phase equilibrium in the system Tl2Te-TlBr-TlI and thermodynamic properties of the solid solution Tl5Te2Br xI1-x
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The Tl2Te-TlBr-TlI system was investigated by means of the DTA and XRD analyses and microhardness and EMF measurements. Several polythermal and isothermal sections and the projection of the liquidus surface were constructed. The fields of prima
- Babanly, Dunya M.,Bagheri, Sara M.,Shevelkov, Andrei V.,Aliyev, Ziya S.
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- Phase equilibria in the Tl-TlI-Te system and thermodynamic properties of the Tl5Te3-xIx solid solution
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The Tl-TlI-Te ternary system was investigated by using the DTA and XRD analyses, microhardness and EMF measurements, leading to the construction of important polythermal and isothermal sections as well as the projection of the liquidus surface. Determined
- Babanly, Dunya M.,Babanly, Ilham M.,Imamaliyeva, Samira Z.,Gasimov, Vaqif A.,Shevelkov, Andrei V.
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- Phase studies on the quasi-binary thallium(I) telluride-gallium(III) telluride system
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The phase diagram for the quasi-binary Tl2Te-Ga 2Te3 system was constructed based on the results of phase studies by both common thermal analysis and X-ray diffraction. Numerical values of the phase transition temperatures
- Mucha, Igor,Wiglusz, Katarzyna,Sztuba, Zbigniew,Gawel, Wieslaw
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- Preparation, crystal structure, physical properties and electronic band structure of TlScQ2 (Q = S, Se and Te)
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The title compounds were prepared by reaction of Tl2Q (Q = S, Se and Te) Sc and Q in the temperature range of 200 to 500 °C. The structures of the selenide and the telluride adopt the α-NaFeO2 type, while TlScS2 crystallizes in the β-RbScO2 type structure. The space group is R3m for TlScSe2 and TlScTe 2 with a = 3.9370(4) A, c = 23.194(5) A, and a = 4.2129(4) A, c = 24.099(3) A, respectively. The sulphide crystallizes in P63/mmc with a = 3.761(3) A and c = 14.942(4) A. The crystal chemical relations between the three chalcogenides are discussed. According to the electrical measurements and the band structure calculations, the compounds are semiconductors or poor metals.
- Teske, Christoph L.,Bensch, Wolfgang,Mankovsky, Sergey,Ebert, Hubert
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- Tl2Te and its relationship with Tl5Te3
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The crystal structure of dithallium telluride was determined using the single crystal X ray diffraction. The structural relationship of dithallium telluride with the related Tl5Te3 phase was discussed. The crystal structure of dithal
- Cerny, Radovan,Joubert, Jean-Marc,Filinchuk, Yaroslav,Feutelais, Yves
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- Phase Equilibria in the Tl2S-Tl2Te-Tl 9BiTe6-TlBiS2 system
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The phase equilibria in the Tl2S-Tl2Te-Tl 9BiTe6-TlBiS2 system have been studied by differential thermal analysis and x-ray diffraction. The results have been used to construct the T-x phase diagram a
- Jafarov,Rzaeva,Babanly
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- Phase equilibria in the Tl-TlBr-Te system and thermodynamic properties of the compound Tl5Te2Br
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The Tl-TlBr-Te composition region of the Tl-Te-Br phase diagram has been explored by DTA, X-ray diffraction, microhardness measurements, and electromotive force (emf) measurements relative to a thallium electrode in concentrations cells. The phase diagrams along a number of joins, the isothermal section at 400 K of the phase diagram, and a projection of the liquidus surface have been constructed. Extensive phase-separation areas, including a three-liquid-phase field in the Tl-TlBr-Tl2Te subsystem, have been revealed. The homogeneity ranges and primary crystallization fields of phases have been mapped, and the coordinates of nonvariant and univariant equilibria in the T-x-y diagram have been determined. The standard thermodynamic functions of formation of the Tl5Te2Br compound and its standard entropy have been derived from emf data.
- Babanly,Babanly
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- HEAT CAPACITY AND THERMODYNAMIC PROPERTIES OF Tl2Te AT LOW TEMPERATURES.
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Among a number of Tl//2X(X equals S, Se, Te)-type thallium chalcogenides the heat capacities of Tl//2Se and Tl//2S compounds have been studied and their thermodynamic parameters calculated. However, for Tl//2Te such data are lacking. The aim of the present investigation is to study the heat capacity of Tl//2Te and to calculate its thermodynamic parameters, as well as to interpret the resultant data on the low-temperature heat capacity in the light of heat-capacity theories of solids.
- Guseinov,Yangirov,Mamedov,Mamedova,Mekhtiev,Gumbatov
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- New thallium neodymium tellurides
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The phase equilibria in the composition region Tl2Te-Tl 2Te3-Nd2Te3-NdTe of the Tl-Nd-Te system have been studied by differential thermal analysis and x-ray diffraction, and the 500-K section of its phase diagram has been mapped out. The ternary compounds identified are Tl9NdTe6, Tl4NdTe 3, Tl6Nd4Te9, Tl4Nd 6Te11, Tl2NdTe3, TlNdTe3, and TlNd3Te6. X-ray powder diffraction data indicate that the compounds Tl9NdTe6 and Tl4NdTe3 are structural analogs of Tl5Te3 and have tetragonal cell parameters a = 8.855 A, c = 13.010 A and a = 8.858 A, c = 12.998 A, respectively (sp. gr. I4/mcm, Z = 4). Tl9NdTe 6 and Tl4NdTe3 are phases of variable composition (δ-phase), and their fields cover most of the Tl 2Te-Tl5Te3-Tl4NdTe3 composition triangle. The structure of Tl5Te3 and its ternary analogs is discussed, and the conclusion is drawn that, in spite of the broad field of the δ-phase, Tl9NdTe6 and Tl 4NdTe3 are daltonides, i.e., distinct chemical compounds.
- Imamalieva,Sadygov,Babanly
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- Phase equilibria in the system Tl2Te-SnTe-TlBiTe2
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The phase equilibria in the system Tl2Te-SnTe-TiBiTe2 (A) have been studied using differential thermal analysis, x-ray diffraction, and microhardness measurements. We have constructed the T-x phase diagrams along the SnTe-TlBiTe2, SnTe-Tl9BiTe6, and Tl 4SnTe3-TlBiTe2 joins, the 600-and 800-K sections of the phase diagram of system A, and its liquidus diagram. The results demonstrate that the system contains broad ranges of Tl5Te 3-structured and SnTe-based solid solutions (δ and γ1 phases, respectively). There are also relatively small fields of the Tl2Te-based phase (α) and low-and high-temperature TlBiTe2-based solid solutions (γ2 and γ′2). The liquidus surface of system A comprises the primary crystallization fields of the δ, γ1, and γ′2 phases. The liquidus of the α phase is degenerate. The ternary eutectic between the δ, γ1, and γ′2 phases melts at 755 K.
- Babanly,Dashdieva,Guseinov
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- Phase equilibria in the Tl2Te-SnTe-Bi2Te3 system
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phase equilibria in the Tl2Te-SnTe-Bi2Te3 system were studied by differential thermal analysis (DTA), X-ray powder diffraction, and microhardness measurements. Some polythermal sections and isothermal (at 600 and 800 K) se
- Babanly,Zlomanov,Guseinov,Dashdyeva
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- Experimental investigation of the 3Tl2Se + Sb2Te 3 ? 3Tl2Te + Sb2Se3 phase diagram
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Phase equilibriums were established in the 3Tl2Se + Sb 2Te3 ? 3Tl2Te + Sb2Se 3 mutual system mainly by the X-ray powder diffraction and differential thermal analyses, with the aid of microhardness and EMF measurements applied to equilibrated alloys. According to the obtained experimental results the phase diagrams in form of the polythermal section and isothermal section at 300 K as well as the projection of the liquids surface have been constructed. It was found experimentally that the system is mutually reversible and is characterized by a wide solid solubility fields along the TlSbSe2-TlSbTe2 subsystem and within the Tl 2Se-Tl9SbSe6-Tl9SbTe 6-Tl2Te subsystem. The homogeneity and primary crystallization fields as well as the types and coordinates of non- and monovariant equilibriums were determined. The dependencies of crystallographic parameters, microhardness and EMF values upon the composition are discussed. From the EMF measurements, the partial molar functions of thallium (ΔG?,ΔH?,ΔS?) were calculated for the revealed nonstoichiometric quaternary phases.
- Jafarov, Yasin I.,Babanly, Mahammad B.,Shevelkov, Andrei V.,Aliev, Ziya S.
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- Phase equilibria study in systems Tl-Pb(Nd)-Bi-Te new phases of variable composition on the base of Tl9BiTe6
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By DTA, X-ray diffraction, EMF methods and microhardness measurements, the phase equilibria on the concentration sections Tl5Te3-Tl4PbTe3-Tl 9BiTe6 (I), Tl2Te-Tl4PbTe3-Tl9BiTe6 (II), Tl5Te3-Tl9NdTe6-Tl 9BiTe6 (III) and Tl2Te-Tl9NdTe6-Tl9BiTe6 (IV) of the multinary systems Tl-Pb(Nd)-Bi-Te were investigated. A number of isopleth sections, projections of liquidus and solidus surfaces of the systems (I)-(IV) were constructed. The concentration dependences of crystal lattice parameters, microhardness and of partial thermodynamic functions of thallium (Δ over(G, ?), Δ over(H, ?), Δ over(S, ?)) in alloys were determined. The investigated systems are characterized by formation of continuous (I, III) or wide (II, IV) areas of solid solutions based on Tl5Te3 compound.
- Babanly,Tedenac,Imamalieva,Guseynov,Dashdieva
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- Phase studies on the quasi-binary thallium(I) telluride-bismuth(III) selenide system
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The phase diagram for the quasi-binary Tl2Te-Bi 2Se3 system was delineated from the results of phase studies by both common thermal analysis and X-ray diffraction. Numerical values of the phase transition temperatures at different alloy compositions within the whole concentration range, were obtained. They have been listed in a table that can be used by other authors in any computational treatment of the system. The diagram was compared with that published earlier by other authors employing differential thermal analysis as a main experimental method. As a result of the present study, three new chemical compounds have been found.
- Mucha
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- Homogeneity ranges of Tl5Te2Cl and Tl 5Te2Br
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This paper systematizes phase-diagram data for the Tl-TlCl(Br)-Te systems and presents their 500-K subsolidus phase diagrams. Tl5Te 2Cl and Tl5Te2Br (Tl5Te3 structure) are shown to be nonstoichiometric compounds with wide homogeneity ranges, which have been accurately determined using emf measurements, x-ray diffraction, and microhardness tests. Using emf data for reversible concentration cells with a thallium electrode, we have evaluated the partial thermodynamic functions of the thallium in the alloys studied, the standard thermodynamic functions of formation of Tl5Te2Cl and Tl5Te2Br, and their standard entropies. The crystal chemistry of these phases of variable composition is discussed in relation to the Tl5Te3 structure.
- Babanly,Chiragov,Yusibov
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