Phase relations in the ternary Cu-Ga-In system

The phase relations of the Cu-Ga-In system were investigated in a composition range which is relevant for the production of Cu(In,Ga)Se₂ based thin film solar cells. The alloys Cu₁₆(In_{1 − y}Ga_y)₉, Cu₉(Ga,In)₄ and elemental In could be identified as the equilibrium phases of a ternary subsystem in the Cu-Ga-In phase diagram. The coexisting phases are well developed until 220 °C. In the case of Cu₉Ga₄ it is remarkable that the solubility of In in Cu₉Ga₄ highly increases with increasing temperature. Consequences for the selenization of metallic Cu-In-Ga precursors are discussed.     

Phase relations in the oxygen rich region of the CrWO ternary system

The phases occurring in the ternary CrWO system at 1370 K have been determined using x-ray diffraction and electron and optical microscopy. It was found that at this temperature no Cr enters WO₃ or the other tungsten oxides and no ternary CS phases appear to form. Instead, the Cr reacts to form one or two ternary rutile phases and equilibrium lies between them and the appropriate binary tungsten oxide. The compositions of these ternary oxides are Cr₂WO₆ and a previously unreported phase CrWO₄. No extended homogeneity ranges have been detected for these oxides. A phase diagram summarises the results which are also considered in the light of the formation of crystallographic shear phases in tungsten oxides.     

Phase relations and ordering in the dysprosia-zirconia system

The phase diagram in the subsolidus for the system Dy₂O₃-ZrO₂ has been established. The areas of existence of the high temperature solid solutions based on ZrO₂ and Dy₂O₃ were determined using the precision lattice parameter method. At low temperature, long-range ordering occured in the Dy₂O₃-rich region (>50 mol% Dy₂O₃) and two hexagonal compounds of an M₇O_11.5- and M₇O₁₁-type were found. The first of these compounds is formed at about 55 mol% Dy₂O₃ and possesses a very narrow homogeneity range. At approximately 1750° C this compound undergoes a transformation into cubic solid solutions of fluorite and C-type. The second is formed within the Dy₂O₃ concentration range between ~65 and 90 mol% Dy₂O₃. Above 1700° C the hexagonal compound Dy₆ZrO₁₁ undergoes a transformation into a cubic solid solution of C-type.     

Phase relations in the MoO3-MgMoO4 system

Journal of Materials Science Letters -     

Phase relations in the BiI3-ZnI2 system

The liquidus diagram of the BiI₃-ZnI₂ system has been studied for the first time by differential thermal analysis, x-ray diffraction, and optical microscopy. The crystallization temperatures and melt compositions corresponding to eutectic and transition points have been determined, and a compound of composition ZnBiI₅, melting congruently at 400°C, has been identified. Some of its physicochemical properties have been studied.     

Phase relationship in the Gd-Ti-Al ternary system at 500°C

The phase relationship in the Gd-Ti-Al ternary system at 500°C was investigated by powder X-ray diffraction (XRD), differential thermal analysis (DTA), optical microscopy and electron probe microanalysis (EPMA) techniques. The 500°C isothermal section of this ternary system consists of 14 single-phase regions, 27 two-phase regions and 14 three-phase regions. At 500°C, the maximum solid solubilities of Ti in Gd₂Al, Gd₃Al₂ and GdAl₂ is 2.0 at.%, 3.5 at.%, 16.3 at.%, respectively and that of Gd in Ti, Ti₃Al, TiAl is less than 1 at.%.     

Phase relationship in the Fe-Pt-Pr ternary system at 500°C

The phase relationship in the Fe-Pt-Pr ternary system at 500°C was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) energy dispersion spectroscopy techniques. The 500°C isothermal section consists of 13 single-phase regions, 23 two-phase regions and 11 three-phase regions. At 500°C, the maximum solid solubility of Pt in α-Fe is about 10 at.% and Fe in Pt is about 18 at.%; the maximum solubilities of Pr in α-(Fe,Pt), Fe₃Pt, FePt, FePt₃ and (Pt,Fe) (the solid solution of Fe in Pt) are about 6 at.% 1.5 at.% 2 at.%, 2.5 at.% and 1.5 at.%, respectively. No Pr₃Pt₄ binary compound and new ternary compounds were found.     

Phase relations in the CuFeSe system at 300°C

Phase equilibria in the CuFeSe system and the stability field of the intermediate solid solution (“Se-iss”) in the system have been investigated at 300°C by means of silica tube techniques in combination with microscopic, X-ray, electron microprobe and differential thermal analysis methods. In the Se-rich region of the system, the (Cu,Fe)Se_2?X solid solution coexists stably with Cu_2?XSe, CuSe, CuSe₂, FeSe₂ and Se-iss while, in the central portion, this last phase coexists with (Cu,Fe)Se_2?X, FeSe₂, γ-Fe_1?XSe, δ-Fe_1?XSe and Cu_2?XSe. The stability fields of Se-iss at 300°C and 500°C have been divided into quenching zones based on the presence of one or the other of two optically and compositionally different types of Se-iss. It was also determined that β-FeSe dissolves, at 300°C, up to 11.5 at .% of Cu. The stability of the Cu_2?XSe Fe tie-line in the metal-rich region of the system was confirmed.     

Phase relations and properties of alloys in the SnSe-DySe system

Phase relations in the SnSe-DySe system have been studied using differential thermal analysis, X-ray diffraction, microstructural analysis, microhardness tests, and density measurements, and its T-x phase diagram has been mapped out. The SnSe-DySe system contains a new ternary compound with the composition DySnSe₂, which crystallizes in orthorhombic symmetry with unit-cell parameters a = 5.74 ± 0.02 Å, b = 10.49 ± 0.03 Å, and c = 11.66 ± 0.05 Å (Z = 7, V = 702 ų, measured density ρ_meas = 7.02 g/cm³, X-ray density ρ_x = 7.26 g/cm³). In addition, the system contains SnSe-based solid solutions, Sn_{1 ? x} Dy _x Se (up to 4 mol % DySe). Their electrical conductivity and thermoelectric power have been measured as functions of temperature.     

Phase relations in the CaMnO system

The use of solid solution precursors is introduced as an effective low temperature synthesis technique which facilitates solid state reaction in selected mixed metal oxide systems. This synthesis technique has been used to study phase relations in the manganese-rich portion of the CaMnO system at temperatures below 1000°C, and has resulted in the assemblage of a new isobaric (P_O2 = 1.0 atm), subsolidus phase diagram. This diagram contains several low temperature phases having the following compositions: Ca₂Mn₃O₈, CaMn₃O₆, CaMn₄O₈ and CaMn₇O₁₂. The experimental results of this study along with literature data are used to present a proposed isobaric (P_O2 = 0.2 atm) phase diagram for the entire CaMnO system.     

Phase formation in the Al-B-C ternary system at high pressures and temperatures

The formation of composites in the Al-B-C system at high p, T parameters using aluminum borides, diamonds, boron and aluminum carbides as the initial components has been studied. It has been shown by transmission and scanning electron microscopies that chemical interaction of diamond with aluminum borides in the C_diam-AlB₂ and C_diam-AlB₁₂ systems takes place starting at 1500°C and at T ≥1700°C becomes more pronounced. The composite produced at 1900–2100°C has been characterized only by intragranular fracture of diamond, which is indicative of the high-strength of phase boundaries. The Al-B₄C system is characterized by the formation of high-strength composites that consist of substitutional solid solutions based on the boron carbide lattice.     

Phase relations and crystallization of glass in the system PbO-GeO2

Thermal properties and chemical compositions of glasses suitable for crystallization of ferro-electric Pb₅Ge₃O₁₁ are described. The crystallization of lead germanate glass was investigated by DTA and X-ray diffraction. In the range from 62 to 62.5 of PbO in mole per cent, Pb₅Ge₃O₁₁ was obtained as a single phase after a heat treatment. In the chemical composition around 5PbO·3GeO₂ in the binary system of PbO-GeO₂, Pb₅Ge₃O₁₁ and two new phases of Pb₃Ge₂O₇ and Pb₃GeO₅ were found to exist. The crystal structure of Pb₃Ge₂O₇ had a hexagonal symmetry witha=10.16 Å andc=19.37 Å, and Pb₃GeO₅ was classified into orthorhombic system witha=4.85 Å,b=15.52 Å and c=11.77 Å.     

Phase relations in the PbF2-BaF2-ZrF4 system

We have investigated phase equilibria between PbZrF₆ and the barium fluorozirconates Ba₂ZrF₈, Ba₃Zr₂F₁₄, BaZrF₆, and BaZr₂F₁₀. The PbZrF₆-Ba₂ZrF₈ join has been shown to be pseudobinary, with simple eutectic phase relations. It defines the PbZrF₆-ZrF₄-Ba₂ZrF₈ compatibility triangle in the PbF₂-BaF₂-ZrF₄ system. Semicrystalline samples have been obtained at ZrF₄ contents in the range 40–70 mol %.     

Phase relations and activities in the Co-Ni-O system at 1373 K

The tie-lines delineating equilibria between CoO-NiO and Co-Ni solid solutions in the ternary Co-Ni-O system at 1373 K have been determined by electron microprobe andedax point count analysis of the oxide phase equilibrated with the alloy. The oxygen potentials corresponding to the tie-line compositions have been measured using a solid oxide galvanic cell with calcia-stabilized zirconia electrolyte and Ni + NiO reference electrode. Activities in the metallic and oxide solid solution have been derived using a new Gibbs-Duhem integration technique. Both phases exhibit small positive deviations from ideality; the values ofG ^E/X ₁ X ₂ are 2640 J mol⁻¹ for the metallic phase and 2870 J mol⁻¹ for the oxide solid solution.     

Phase relations in the system CaO-B2O3-SiO2

Phase relations in the lime-rich portion of the system CaO-B₂O₃-SiO₂ have been studied by microscopy, infrared spectroscopy and X-ray powder diffraction of heated mixtures and quenched charges. Extensive solid solution of B₂O₃ in Ca₂SiO₄ occurs along the Ca₂SiO₄-Ca₃B₂O₆ boundary, which has been studied in detail. It contains a ternary compound, Ca₁₁B₂Si₄O₂₂, which is stable to liquidus temperatures, melting incongruently to Ca₂SiO₄ and liquid at 1420 °C. Ca₁₁B₂Si₄O₂₂forms a eutectic with Ca₃B₂O₆ at 1400 °C and, in the ternary system, with CaO and Ca₃B₂O₆ at 1390 °C.     

Phase relations in the HgCr2Se4-CdCl2 system

The phase relations in the HgCr₂Se₄-CdCl₂ system have been investigated using differential thermal analysis and x-ray diffraction, and the primary crystallization field of the spinel phase in this system has been located: 560–750°C, 84–97 mol % CdCl₂. By optimizing growth conditions and using CdCl₂ as a flux, single crystals of Hg_1?x Cd_xCr₂Se₄ solid solutions containing up to 5 wt % Cd have been grown.