Phase equilibria in the Tl-TlBr-S system

The polythermal sections TlBr-Tl₂S, TlBr-Tl₄S₃, TlBr-TlS, and Tl₆SBr₄-Tl; the isothermal section at 300 K of the phase diagram; and the projection of the liquidus surface of the Tl-S-Br system have been investigated in the composition region Tl-TlBr-S by DTA, X-ray powder diffraction analysis, and microhardness measurements. The primary crystallization regions, including that of the only ternary compound (Tl₆SBr₄), have been determined, and the types and coordinates of the invariant and univariant equilibria in the phase diagram are determined.     

Phase equilibria in the Cu-Tl-Ge system

The Cu-Tl-Ge system has been studied by DTA and powder X-ray diffraction. Several polythermal sections, the isothermal section at 400 K, and the liquidus surface projection have been constructed for the phase diagram of this system. Primary phase fields and the types and coordinates of invariant and monovariant equilibria have been determined. An immiscibility region of the Cu-Tl binary subsystem considerably (up to 60 at % Ge) protrudes into the triangular diagram and crosses peritectic and eutectic curves that originate from the Cu-Ge subsystem. This gives rise to a number of four-phase monotectic equilibria in the ternary system. Crystallization ends with peritectic equilibrium and eutectic equilibria, which are all degenerate in the vicinity of thallium. Intermediate ternary phases are not formed in the system. Solubilities in the initial components and in binary phases of the Cu-Ge system do not exceed 0.5 at %.     

Phase equilibria in the Co-Sm-B system

Metal-rich ternary alloys of the Co-Sm-B system up to a Co: B atomic ratio of 1:1 were studied to obtain an isothermal section at 800°C. Among the eight ternary compounds found in this composition range, two had not been reported previously: tetragonal Co₂₀Sm₃B with a = 0.8621 nm and c = 1.1692 nm and hexagonal Co-Sm₂B₃ with a = 0.511 nm and c = 1.273 nm. Other new information includes the Bravais lattice of Co₄SmB₄, which is tetragonal with a = 0.7038 nm and c = 1.1437 nm, and of as-cast Co₂SmB₂, which is tetragonal with a = 1.2804 nm and c = 1.4003 nm. Four of the ternary compounds are members of the homologous series Co_3n+5Sm_n+1B_2n formed by alternating one layer of Co₅Sm with n layers of Co₃SmB₂.     

Phase equilibria in the Ag-Bi-Te system

The Ag-Bi-Te system has been investigated over the whole concentration range using DTA, powder X-ray diffraction, microhardness measurements, and measurements of the emf of concentration cells with reference to Ag/AgCl electrodes. The vertical sections Ag₅Te₃-Bi₂Te₃, AgBiTe₂-Bi(Te) and Ag-Bi₂Te, an isothermal section at 400 K, and liquidus-surface projection have been designed. The fields of crystalline phases, including the ternary compound AgBiTe₂, have been determined.     

Phase equilibria in the thiourea-benzene system

Phase equilibria in the thiourea (host)-benzene (guest) binary system with clathrate formation were studied over the temperature range 260–460 K by physicochemical analysis methods. The stoichiometry and conditions of the existence of the 2.40(±0.02)(NH₂)₂CS · C₆H₆ compound, which incongruently decomposed at 358.7 K into rhombic thiourea and the guest component, were determined. The parameters of the Bravaisrhombohedral cell of the clathrate (space group R \(\bar 3\) c) were found to be a = 15.921(6), c = 12.417(8) Å, and V = 2725(5) ų; d _calc = 1.192 g/cm³ and d _expt = 1.195(7) g/cm³. The packing of guest molecules in the rhombohedral host framework was modeled taking into account stoichiometry and unit cell parameters to show that benzene molecule planes were tilted with respect to the c channel axis with the formation of a monomolecular closely packed chain in the guest subsystem.     

Phase equilibria in the silver-dysprosium system

The Ag-Dy system has been studied by differential thermal analysis, chemical analysis and metallographic and X-ray examination. The following congruently-melting phases were observed: Ag₅₁Dy₁₄ (m.p. 990 ± 10 °C), Ag₂Dy (m.p. 980 ± 10 °C) and AgDy (1185 ± 10 °C). The following eutectics occur: Ag-Ag₅₁Dy₁₄ (800 ± 5 °C, 12.0 ± 0.5 at.% Dy), Ag₅₁Dy₁₄- Ag₂Dy (905 ± 5 °C, 28.6 ± 0.5 at.% Dy), Ag₂Dy—AgDy (950 ± 10 °C, 37.5 ± 0.5 at.% Dy) and AgDy-Dy (900 ± 10 °C, 74.5 ± 0.5 at.% Dy).The Ag-Dy phase diagram is compared with the already known diagrams of other Ag-R.E. systems, and is briefly discussed.     

Phase equilibria in the Co-Cr-Ni system

The 800°C isothermal section of the Co-Cr-Ni system was plotted using a set of physicochemical methods. The section is characterized by an extensive field of a cobalt-and nickel-based γ solid solution. The homogeneity region of the σ phase is as large as 18 at % Ni and is directed to Ni₄₀Cr₆₀. The penetration depth of the hcp ? phase does not exceed 10 at % Ni.     

Phase equilibria in the NaF-LiF-LaF3 system

The NaF-LiF-LaF₃ system was studied by differential thermal and X-ray powder diffraction analyses. In the system, there are two ternary invariant points, a eutectic (580 ± 2°C, 44.0 mol % NaF, 42.0 mol % LiF, 14.0 mol % LaF₃), and a peritectic (595 ± 2°C, 45.0 mol % NaF, 39.0 mol % LiF, 16.0 mol % LaF₃). The ternary peritectic point results from the intersection of the crystallization fields of LiF, LaF₃, and NaLaF₄.     

Phase equilibria in the InP-InAs-InSb quasi-ternary system

G ^M−x curves were calculated in order to plot a solubility surface for the InP-InAs-InSb quasi-ternary. A two-phase field (a mixture of InAs_t−x Sb _x solid solution (ss) and InP _x As_1−x ss) decreases with increasing temperature, though occupying a considerable part of the concentration triangle even at moderate subsolidus temperatures. An experimental X-ray power diffraction study of alloys with compositions lying along the InP_0.8As_0.2-InsB polytherm verified that the InP _x AsySb_1−x−y ss at room temperature is stable when the InAs percentage in alloys exceeds 65 mol %. Liquidus surface isotherms of the InP-InAs-InSb quasi-ternary were plotted using the regular solutions model. Original Russian Text ? G.V. Semenova, T.P. Sushkova, O.N. Shumskaya, A.V. Tishin, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 3, pp. 521–525.     

Phase and extraction equilibria in the antipirin-pyrocatechol-water system

Solubility isotherms of the antipirin-pyrocatechol-water ternary system at 25 and 50°C were constructed. A field where two liquid phases are present in equilibrium which results from the protolytic interaction between the components was revealed. The various-composition chemical compounds that formed were isolated preparatively. Interphase distribution of a series of metal ions was studied. The half-extraction pHs of rare-earth metals were found to be linearly related to their ionic radii.     

Phase equilibria in the Ag4SSe-SnTe system

The phase diagram of the system Ag₄SSe-SnTe is studied by means of X-ray diffraction, differential thermal and metallographic analyses and measurements of the microhardness and the density of the material. This diagram is divided into two eutectic-type subdiagrams by the composition Ag₄SSe·2SnTe. The unit-cell parameters of the intermediate phases 3Ag₄SSe·SnTe (phase A) and -Ag₄SSe·2SnTe (phase B) are determined as follows: for phase A: a=0.7851 nm, b=0.7196 nm, c=0.6296 nm, =101.32°, =85.90°, =111.36°; for phase B: a=0.3662 nm, b=0.3303 nm, c=0.3343 nm, =90.74°, =108.94°, =91.91°. The phase Ag4SSe·2SnTe melts congruently at 615°C and a polymorphic transition of the phase takes place at T _- =110°C.This revised version was published online in November 2005 with corrections to the Cover Date.     

Phase equilibria in the Cu-Cu2S-As system

Phase equilibria in the Cu-Cu₂S-Assystem have been studied by DTA and X-ray powder diffraction. Cu_0.667S_0.333-As, Cu_0.667S_0.333-Cu_0.735As_0.265, and Cu_0.8S_0.2-As polythermal sections, an isothermal section at 300 K, and the liquidus projection have been constructed. Our data differ from reported data in the extents of primary crystallization phase fields and the coordinates of some invariant equilibrium points.     

Phase equilibria in the GeSe2-SnTe system

Journal of Thermal Analysis and Calorimetry - The phase diagram of the system GeSe2-SnTe is studied by means of X-ray diffraction, differential thermal and measurements of the microhardness and the...     

Phase equilibria in the Ag2Te-Cd system

The phase diagram of the Ag₂Te-Cd system, which is a polythermal section of the ternary system Ag-Cd-Te, was established by means of DTA and metallographic analysis. The diagram contains 32 phase regions, including the polymorphic modifications of Ag₂Te, solid solutions based on Ag₂Te and Cd, and two intermediate phases with variable compositions: Ag₂Cd_1+xTe and Ag₂Cd_5+xTe.

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Zusammenfassung Das Phasendiagramm des Systems Ag₂Te-Cd, eines polythermen Schnittes im ternären System Ag-Cd-Te, wurde aus DTA- und metallographischen Ergebnissen konstruiert. Das System besteht aus 32 Ein- und Zweistoffgebieten, darunter den polymorphen Modifikationen des Ag₂Te, festen Lösungen auf Basis Ag₂Te bzw. Cd, und ternären Phasen mit den variablen Zusammensetzungen Ag₂Cd_1+xTe und Ag₂Cd_5+xTe.

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Ag₂Te-Cd, AgCd-. , Ag₂Te, Ag₂Te Cd, Ag₂Cd_1+x Te Ag₂Cd_5+x Te.

     

Phase equilibria in the CuBr−TlBr system

The phase diagram for the CuBr?TlBr system was investigated using the differential thermal analysis completed by the X-ray powder diffraction data. Three intermediate phases were found: Tl₂CuBr₃ (stable from room temperature up to 234°C where decomposes in the solid state), Tl₃Cu₂Br₅ (stable between 168°C and its incongruent melting point 262°C) and a nonstochiometric δ phase (centered about 75 mol% CuBr and stable above about 240°C).     

Phase equilibria in the binary system PbO-PbCl2

The present paper forms part of a series of studies on the ternary system PbO-P₂O₅ -PbCl₂. The side binary system PbO-PbCl₂ has been investigated over the entire composition range and its phase diagram has been established. The components form three oxychlorides: Pb₅Cl₂O₄, Pb₃Cl₂O₂ and Pb₂Cl₂O. The examinations were carried out by means of thermal, microscopic, dilatometric, X-ray and IR absorption analyses. X-ray identification data for Pb₅Cl₂O₄ are presented.

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Zusammenfassung Vorliegende Arbeit ist Teil einer Untersuchungsreihe des ternÄren Systemes PbO-P₂O₅-PbCl₂. Dabei wurde das binÄre Untersystem PbO-PbCl₂ im gesamten Konzentrationsbereich untersucht und ein Phasendiagramm erstellt. Die Komponenten bilden die drei Oxidchloride Pb₅Cl₂O₄, Pb₃Cl₂O₂ und Pb₂Cl₂O. Die Untersuchungen wurden mittels mikroskopischer, dilatometrischer, röntgenographischer, IR- und Thermoanalyse durchgeführt. Die röntgenographischen Angaben für Pb₅Cl₂O₄ werden gegeben.

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The author is most grateful to Or. Janusz Matuszewski for bis help in the X-ray investigations.     

Phase equilibria in the iodine-potassium iodide-water-propanol-2 four-component system

Isothermal-isobaric sections of the phase diagram of the iodine-potassium iodide-water-propanol-2 (2-C₃H₇OH) four-component system were studied at 25°C and atmospheric pressure. In all sections, threephase eutonic equilibria were observed with potassium iodide and crystalline iodine as solid phases. Potassium iodide was a iodine salting in agent in sections containing 15 and 25 wt % propanol-2 and a salting out agent in the section with 50 wt % alcohol. H₂O-2-C₃H₇OH (85: 15 and 75: 25 wt %) mixed solvent compositions showed a higher ability to dissolve iodine than mixture components.     

Phase equilibria and oxidation mechanisms in the LA-S-O system

The phase diagram of the La-S-O system at 1073 K was established with the vacuum seal technique. Six phases exist at this temperature: La₂O₃ (B-type), LaS₂, La₂S₃, La₂O₂SO₄, La₂O₂S and La₂O₂S₂. The thermodynamic functions for the reaction La₂O₂SO₄=La₂O₃+SO₂+1/2 O₂ were determined by using the emf method at temperatures from 1123 to 1373 K. The mechanisms of the oxidation reactions in the La-S-O system under different partial pressures of oxygen (–4.4 < log <–0.7) were also investigated by means of DTA, TG and powder X-ray diffractometry.

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Zusammenfassung Das Phasendiagramm des La-S-O-Systems bei 1073 K wurde bestimmt. Bei dieser Temperatur liegen 6 Phasen vor, und zwar La₂O₃ (B-Typ), LaS₂, La₂S₃, La₂O₂SO₄, La₂O₂S und La₂O₂S₂. Für die Reaktion La₂O₂SO₄=La₂O₃+SO₂+1/2 O₂ wurden die thermodynamischen Funktionen im Temperaturbereich von 1123–1373 K nach der EMF-Methode bestimmt. DTA, TG und Pulver-Röntgendiffraktometrie wurden zur Untersuchung der Mechanismen der im La-S-O-System verlaufenden Oxydationsreaktionen herangezogen, wobei der Sauerstoffpartialdruck in den Grenzen von – 4.4 < log < <-0.7 variiert wurde.

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La-S-O 1073 . : La₂O₃ (-), LaS₂, La₂S₃, La₂O₂SO₄, La₂O₂S La₂O₂S₂. . . ., La₂O₂SO₄=La₂O₃+ SO₂+1/2 ₂ 1123–1373. , La-S-O –4.4 < log < –0.7.

     

Phase equilibria in the InS-Sb2Te3 system

The interaction character of the InS-Sb₂Te₃ system was studied by differential thermal analysis, X-ray powder diffraction, microstructure examinations, microhardness measurements, and density determinations, and its phase diagram was constructed. The InS-Sb₂Te₃ phase diagram is a partially non-quasi-binary section of the In,Sb∥S,Te ternary reciprocal system. Two compounds are formed in the InS-Sb₂Te₃ system, namely: In₃Sb₂S₃Te₃ and InSb₂Te₃S. Sb₂Te₃-based solid solutions at room temperature have an extent of up to 6 mol % InS, while InS-based solid solutions are virtually nonexistent.