Determination of phase fields in the CsBr-Cs2ZnBr4-Cs2CdBr4-Cs2HgBr4 quaternary system

Phase equilibria in the CsBr-Cs₂ZnBr₄-Cs₂CdBr₄-Cs₂HgBr₄ quaternary system were studied by differential thermal analysis. The CsBr-Cs₂ZnBr₄-Cs₂HgBr₄ ternary system has a ternary eutectic, E ₁, at ～83 mol % Cs₂HgBr₄, 2 mol % Cs₂ZnBr₄, and 15 mol % CsBr with a melting point of ～415°C. The CsBr-Cs₂ZnBr₄-Cs₂CdBr₄ ternary system has a ternary eutectic, E ₂, at ～53.5 mol % Cs₂CdBr₄, 1.5 mol % Cs₂ZnBr₄, and 45 mol % CsBr with a melting point of ～450°C. The polythermal section Cs₃ZnBr₅-Cs₂CdBr₄-Cs₂HgBr₄ in the CsBr-Cs₂ZnBr₄-Cs₂CdBr₄-Cs₂HgBr₄ quaternary system was constructed and investigated. This section is a quasi-ternary system and is characterized by the formation of regions of solid solutions Cs₂Zn _x Cd _y Hg_{1?x ? y} Br₄ and solid solutions based on Cs₃ZnBr₅. The liquidus surface of the quaternary system consists of three fields of primary crystallization of cesium bromide, a solid solution Cs₂Zn _x Cd _y Hg_{1?x ? y} Br₄, and a solid solution based on Cs₃ZnBr₅.     

Interaction in the ternary system HgBr<Subscript>2</Subscript>-PbBr<Subscript>2</Subscript>-CsBr

Several vertical sections are investigated in the HgBr₂-PbBr₂-CsBr system by the methods of physicochemical analysis. Six compounds, namely, CsHg₂Br₅, CsHgBr₃, Cs₂HgBr₄, CsPb₂Br₅, CsPbBr₃, and Cs₄PbBr₆, are formed in the bordering binaries of the ternary system. By the results of investigation, the projection of the liquidus surface of the HgBr₂-PbBr₂-CsBr system on the composition triangle is constructed, and the fields of primary crystallization of nine phases are plotted, namely, HgBr₂, PbBr₂, CsBr, CsHg₂Br₅, CsHgBr₃, Cs₂HgBr₄, CsPb₂Br₅, CsPbBr₃, and Cs₄PbBr₆. An immiscibility region is found in the system. This region occupies a considerable part of the primary crystallization field of PbBr₂. The coordinates of invariant points are determined, and isotherms are plotted.     

Interaction of components in the Cs2HgBr4-Cs2ZnBr4-CsBr ternary system

The interaction of components in the Cs₂HgBr₄-Cs₂ZnBr₄-CsBr ternary system was studied by differential thermal and X-ray powder diffraction analyses. The liquidus surface consists of the crystallization fields of three phases: CsBr, a solid solution of Cs₂HgBr₄ with Cs₂ZnBr₄ (??), and solid solution ?? based on Cs₃ZnBr₅. The ternary eutectic near Cs₂HgBr₄ has the coordinates ??83 mol % Cs₂HgBr₄, 2 mol % Cs₂ZnBr₄, and 15 mol % CsBr and the melting point ??415°C. The triangulating section Cs₂HgBr₄-Cs₃ZnBr₅ is characterized by the eutectic interaction with the eutectic that is degenerate near Cs₂HgBr₄, contains ??3 mol % Cs₃ZnBr₅, and melts at 420°C. This section divides the Cs₂HgBr₄-Cs₂ZnBr₄-CsBr ternary system into two ternary systems Cs₂HgBr₄-CsBr-Cs₃ZnBr₅ and Cs₂HgBr₄-Cs₃ZnBr₅-Cs₂ZnBr₄.     

Component interactions in the Cs2CdBr4-Cs2ZnBr4-CsBr ternary system

Component interactions in the Cs₂CdBr₄-Cs₂ZnBr₄-CsBr ternary system have been studied by differential thermal analysis and X-ray powder diffraction. The liquidus surface is comprised of three crystallization fields: CsBr, a solid solution of Cs₂CdBr₄ with Cs₂ZnBr₄ (??), and a Cs₃ZnBr₅-based solid solution (??). The ternary eutectic coordinates are as follows: ??53.5 mol % Cs₂CdBr₄, 1.5 mol % Cs₂ZnBr₄, 45 mol % CsBr, and ??450°C. A Cs₂CdBr₄-Cs₃ZnBr₅ triangulating section, which is characterized by peritectic interaction with peritectic (p) coordinates of 20 mol % Cs₃ZnBr₅ and 480°C, divides the Cs₂CdBr₄-Cs₂ZnBr₄-CsBr ternary system into two ternary systems: Cs₂CdBr₄-CsBr-Cs₃ZnBr₅ and Cs₂CdBr₄-Cs₃ZnBr₅-Cs₂ZnBr₄.     

Glass formation in the HgBr2-PbBr2-CsBr ternary

Results of investigation of glass formation in the HgBr₂-PbBr₂-CsBr system are presented. The glass formation region has been outlined. Characteristic temperatures have been determined by differential thermal analysis, and the ratio T _g /T _m and factor H_R have been calculated for vitreous samples of the HgBr₂-PbBr₂-CsBr ternary. Original Russian Text ? I.Ya. Zaitseva, I.S. Kovaleva, V.A. Fedorov, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 2, pp. 338–343.     

HgBr2-CsPbBr3 and CsHgBr3-PbBr2 joins of the HgBr2-PbBr2-CsBr system

The HgBr₂-CsPbBr₃ (1) and CsHgBr₃-PbBr₂ (2) joins of the HgBr₂-PbBr₂-CsBr system are studied using differential thermal analysis (DTA) and X-ray powder diffraction. Both joins are non-quasi-binary. The primary phase fields, joint crystallization fields, and invariant temperatures are determined along these joins. X-ray powder diffraction results validate the diagrams mapped for these joins.     

Glass formation along the CsHgBr3-CsPbBr3, Cs2HgBr4-CsPbBr3, and CsHg2Br5-CsPbBr3 sections of the HgBr2-PbBr2-CsBr ternary system

Glass formation is studied along the CsHgBr₃-CsPbBr₃, Cs₂HgBr₄-CsPbBr₃, and CsHg₂Br₅-CsPbBr₃ sections of the HgBr₂-PbBr₂-CsBr ternary system. The glass formation region is demarcated. Characteristic temperatures are determined by differential thermal analysis; the ratio T _g/T _m and the Hruby factor H _R for glassy samples are determined. The data are analyzed, and the most promising glass compositions along the specified sections are determined.     

CsBr—Cs<Subscript>2</Subscript>ZnBr<Subscript>4</Subscript>—Cs<Subscript>2</Subscript>CdBr<Subscript>4</Subscript>—Cs<Subscript>2</Subscript>HgBr<Subscript>4</Subscript> Four-component system

Component interactions in the CsBr—Cs₂ZnBr₄—Cs₂CdBr₄—Cs₂HgBr₄ system were studied using differential thermal analysis (DTA) and powder X-ra y diffraction. The system is characterized by a continuous solid solution series. New compounds have not been found.     

Glass formation in systems of mercury,cesium, and lead bromides

The results of studies of glass formation in the binary subsystems of the ternary system HgBr₂-PbBr₂-CsBr and in several samples whose compositions lie near ternary eutectic points of the indicated ternary systems are reported. The conditions for glass formation have been determined. The characteristic temperatures have been determined by DTA, and T _g /T _m ratios and H _R factors for glassy samples calculated.     

Interaction in the TlSe-Pr2Se3 system

The interaction of components in the TlSe-Pr₂Se₃ system was studied by differential thermal, X-ray powder diffraction, and microstructural analyses and also by microhardness and density measurements. The state diagram of this system was constructed. It was found that the section TlSe-Pr₂Se₃ is a quasi-binary section of the Tl-Pr-Se ternary system. In the TlSe-Pr₂Se₃ system at the component ratio 1: 1, a new chemical compound, TlPr₂Se₄, forms, which melts congruently at 1295°C. In the system based on TlSe, solid solutions form until 3.5 mol % Pr₂Se₃, and in the system based on Pr₂Se₃, solid solutions occur until 2.5 mol % TlSe.     

Ternary reciprocal systems Na,K||BO<Subscript>2</Subscript>,CO<Subscript>3</Subscript> and Na,K||BO<Subscript>2</Subscript>,Cl

The phase diagrams of the ternary reciprocal systems Na,K||BO₂,CO₃ and Na,K||BO₂,Cl were studied for the first time by a calculation-experimental method and by differential thermal analysis. Analytical models of phase equilibrium states were derived, and the coordinates of eutectics were found to be (680°C, 32 mol % NaBO₂, 68 mol % KCl) and (648°C, 9 mol % NaBO₂, 45.5 mol % NaCl, 45.5 mol % KCl). Binary solid solutions based on metaborates and carbonates of sodium and potassium were shown to be stable. The possibility of synthesizing tungsten oxide bronzes in a eutectic melt in the ternary system NaBO₂–NaCl–КCl was revealed.     

Physicochemical study of SmTe-In2Te3 and SmTe-InTe systems

SmTe-In₂Te₃ and SmTe-InTe quasi-binary joins were studied using physicochemical methods. The SmTe-In₂Te₃ system forms two compounds, SmIn₂Te₄ and SmIn₄Te₇, which melt incongruently at 1075 and 960 K, respectively. An In₂Te₃-base solid solution at 400 K extends to 3 mol % SmTe. The SmTe-InTe system at the component ratio 3: 2 (mol/mol) forms the ternary compound Sm₃In₂Te₅, which melts with decomposition at 970 K. The InTe-based solubility range is 10 mol % SmTe.     

Phase equilibrium in the As2S3-TlSe system

The interaction between the components of the As₂S₃-TlSe system has been studied using diffeential thermal analysis, powder X-ray diffraction, microstructure examination, and microhardness and density measurements. Two new quaternary compounds, TlAs₂S₃Se and Tl₃As₂S₃Se₃, are formed in the system. Both compounds may be prepared in a glassy state. They melt congruently at 350 and 280°C, respectively. The section As₂S₃-TlSe is a stable diagonal of the ternary reciprocal system As,Tl ‖ S, Se. The As₂S₃-base solid solution extends to 1.5 mol % TlSe. The extent of the TlSe-base solution is 5.2 mol % As₂S₃. Under slow cooling, the glass field in the system extends to 85 mol % TlSe; when the system is quenched to liquid nitrogen, the extent of the glass field is 100 mol % TlSe.     

Phase equilibrium in the Pb2SnSb2S6-SnS system

The Pb₂SnSb₂S₆-SnS system was studied over a wide range of concentrations using a set of physicochemical methods (powder X-ray diffraction, DTA, microstructure examination, and microhardness measurement). A phase diagram for the title quasi-binary join was constructed for the first time. The phase diagram is of the eutectic type; the eutectic coordinates are 25 mol % SnS and 775 K. The extents of solid solutions based on the terminal components were determined to be 10 mol % SnS and 5 mol % Pb₂SnSb₂S₆. Alloys having compositions in the SnS-based solid solution region are semiconductors.     

Li, K‖Br, VO3 ternary mutual system

Phase equilibria in the Li, K‖Br, VO₃ ternary mutual system were studied by differential thermal analysis. The composition square of the ternary mutual system is divided into two phase triangles, LiVO₃-KBr-KVO₃ and LiBr-LiVO₃-KBr. The ternary eutectics E ₁ at 331°C and E ₂ at 330°C have the compositions 40.0 mol % LiVO₃, 6.0 mol % KBr, 54.0 mol % KVO₃ and 58.0 mol % LiBr, 3.2 mol % LiVO₃, 38.8 mol % KBr, respectively. The fields of phases crystallizing in the system were delimited.     

MnS-Pr<Subscript>2</Subscript>S<Subscript>3</Subscript> phase diagram

The MnS-Pr₂S₃ phase diagram is of the eutectic type with incomplete solubility based on the starting sulfides (MnS and Pr₂S₃). The extent of the MnS-based solid solution at 1470 K is 1 mol % Pr₂S₃. γ-Pr₂S₃ at 1470 K dissolves 23 mol % MnS, α-Pr₂S₃ at 1170 K dissolves 6 mol % MnS. The eutectic composition (30 mol % Pr₂S₃ at 1550 K) coincides with the value calculated from the Schroeder equation for the liquidus branch descending from MnS. A value of 64 kJ/mol was calculated for the heat of melting of Pr₂S₃ using the Schroeder equation.     

The CaO?MgO?P2O5 System at 1000°C for P2O5 ⩽ 33.3 mole %

The quasi ternary phase diagram CaO-MgO-P₂O₅ at 1000°C for P₂O₅ ? 33.3 mole-% is determined by heating some 140 compositions prepared from the appropriate ones of 4 starting chemicals (reagent grade CaHPO₄, CaCO₃, MgO, and MgHPO₄ · 3 aq.). Products were investigated with X-ray diffraction and heating was continued until no more changes in phase composition and peak positions in the X-ray diffraction pattern were observed, leading occasionally to heating times of over 1000 hours. There are three major regions of solid solution: for the whitlockite phase, and for the ternary compounds on the pyro- and the ortho-phosphate join. The extent of solid solution of the ternary pyrophosphate compound was determined by the change in peak position in the X-ray diffraction pattern with composition and was found to be 15.9–27.5 mole-% MgO. Two and three phase areas were determined using the change in peak position data for the whitlockite and ternary pyrophosphate compound. The experiments were carried out in air. However additional experiments in a CO₂ atmosphere revealed no changes in the X-ray diffraction patterns, apart from those in which apatite was involved. The apatite phase did not incorporate detectable amounts of Mg, not on heating in air nor on heating in a carbondioxide atmosphere.     

Interactions in the Sn<Subscript>2</Subscript>Sb<Subscript>6</Subscript>S<Subscript>11</Subscript>–PbSnSb<Subscript>4</Subscript>S<Subscript>8</Subscript> system

The Sn₂Sb₆S₁₁–PbSnSb₄S₈ system was studied by physicochemical analysis methods (differential thermal, X-ray powder diffraction, and microstructural analyses and microhardness and density measurements). It was found that this system is a quasi-binary section of the SnS–PbS–Sb₂S₃ ternary system of the eutectic type. The coordinates of the eutectic are 42 mol % PbSnSb₄S₈ and 600 K. In the studied system, regions of solid solutions were detected, which extend for solid solutions based on Sn₂Sb₆S₁₁ to 4 mol % PbSnSb₄S₈ (α) and for solid solutions based on PbSnSb₄S₈ to 6 mol % Sn₂Sb₆S₁₁ (β).     

Phase diagram of the Pb5Sb4S11-Pb2SnSb2S6 system

The Pb₅Sb₄S₁₁-Pb₂SnSb₂S₆ system was studied by a number of physicochemical methods, and its phase diagram was constructed. It was found that the system under investigation is a quasi-binary eutectic type section of the SnS-PbS-Sb₂S₃ ternary system. The coordinates of the eutectic are found to be 33 mol % Pb₅Sb₄S₁₁ and 750 K. Regions of solid solutions based on Pb₅Sb₄S₁₁ (6 mol % Pb₂SnSb₂S₆) and Pb₂SnSb₂S₆ (4 mol % Pb₅Sb₄S₁₁) were determined.     

The phase diagrams of the CdCl2-NaCl-H2O system at 298 K

Solid-liquid equilibrium of ternary system Cd²⁺, Na⁺//Cl^?-H₂O at 298 K were studied by an isothermal solution saturation method. Experimental results indicate that there are three univariant curves AE, EF, and FB, two invariant points E, F, and three crystallization fields in the ternary system. The ternary system has one double salt Na₂CdCl₄ · 3H₂O. The crystallization zones of equilibrium solid phases are CdCl₂ · H₂O (AEG field), Na₂CdCl₄ · 3H₂O (EFM field), and NaCl (FBN field), respectively. The composition of the invariant point E is CdCl₂ · H₂O and Na₂CdCl₄ · 3H₂O of which content was 52.70 and 4.11%, respectively. The composition of the invariant point F is Na₂CdCl₄ · 3H₂O and NaCl of which content was 27.92 and 14.95%, respectively. The density of solution in the ternary system show regular changes along with the increased cadmium concentration. The results indicated that CdCl₂ · H₂O possessed the highest solubility among those three salts, which means a strong transfer of Cd ion and a high pollution risk of soil environment. And the solubility of NaCl would be restrained as the three salts existing together.