Phase transformations and phase diagram at equilibrium in the Cu-Ni-Sn system

The Cu-Ni-Sn ternary phase diagram in the Cu rich side has not been experimentally determined or calculated at low temperatures. Two Cu9NixSn alloys with x=2 and 6 mass% Sn were studied. The precipitation sequence during the ageing and phases responsible for the strengthening were determined.     

Thermodynamic and phase diagram investigation of Pb-BiIn section in Pb-Bi-In ternary system

The results of thermodynamic study of Pb-BiIn section of Pb-Bi-In system done experimentally by Oelsen calorimetry and calculated by general solution model, as well as measurements performed by DTA and optic microscopy in order to investigate phase diagram of the given section, are presented in this paper. Thermodynamic properties, such as integral molar enthalpies of mixing, activities, activity coefficients, partial and integral excess Gibbs energies at 600 and 650 K were determined and comparison between obtained experimental and calculated values were done. Also, based on cooling curves, DTA recordings and optic microscopy results phase diagram was constructed and compared with literature data.     

Tailoring poly(vinylidene fluoride‐co‐chlorotrifluoroethylene) microstructure and physicochemical properties by exploring its binary phase diagram with dimethylformamide

Poly(vinylidene fluoride‐co‐chlorotrifluoroethylene) (PVDF‐CTFE) membranes were prepared by solvent casting from dimethylformamide (DMF). The preparation conditions involved a systematic variation of polymer/solvent ratio and solvent evaporation temperature. The microstructural variations of the PVDF‐CTFE membranes depend on the different regions of the PVDF‐CTFE/DMF phase diagram, explained by the Flory‐Huggins theory. The effect of the polymer/solvent ratio and solvent evaporation temperature on the morphology, degree of porosity, β phase content, degree of crystallinity, mechanical, dielectric, and piezoelectric properties of the PVDF‐CTFE polymer were evaluated. In this binary system, the porous microstructure is attributed to a spinodal decomposition of the liquid‐liquid phase separation. For a given polymer/solvent ratio, 20 wt % , and higher evaporation solvent temperature, the β phase content is around 82% and the piezoelectric coefficient, d₃₃, is ? 4 pC/N © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 761–773     

The equilibrium phase diagram of the copper-indium system: a new investigation

The entire phase diagram of the Cu-In system was investigated using differential scanning calorimetry (DSC), powder X-ray diffraction (XRD), metallography and electron probe microanalysis (EPMA) studies. The results indicate the existence of a solubility region of In in Cu with the limit of the solid solution at 5.20 at.% In at 400 °C and of six intermediate phases, the three low-temperature phases δ, η and Cu₁₁In₉, and the three high-temperature phases γ, η′ and β. The boundaries of each phase were defined with respect to temperature and composition.     

Rubidium and lithium butanoates binary phase diagram

The temperature and enthalpy vs. composition diagrams of the binary system [xC₃H₇CO₂Li+(1–x)C₃H₇CO₂Rb], where x=mole fraction, were determined by differential scanning calorimetry (DSC). This binary systems displays the formation of two mixed salts with a composition 1:1 and 1:2, which melt incongruently at T _fus=590.5 K, with Δ_fus H _m=11.6 kJ mol^–1, and congruently at T _fus=614.5 K, with Δ_fus H _m=20.2 kJ mol^–1, respectively. The phase diagram also presents an ionic liquid-crystalline phase in a wide temperature range: 95 K.     

Comparative thermodynamic investigation of binary Ga-Bi system; Experimental determination of enthalpies of mixing and activity estimation for liquid Ga-Bi alloys

The results of experimental and analytical thermodynamic investigation of binary Ga-Bi system are presented in this paper. Integral molar enthalpies of mixing for liquid Ga-Bi alloys were obtained using quantitative differential thermal analysis. Activities of bismuth in the entire composition range and temperature interval 573-1073 K, were calculated by Zhang-Chous method for binary systems having two liquid or solid coexisting phases in combination with other Chous method developed for simple eutectic systems. Activities of gallium were derived from Gibbs-Duhem equation. Comparison between experimental, calculated values and existing literature data shows good agreement.     

Contribution to the phase diagram of the system PbCl2-AgCI

The side parts of the phase diagram of the binary system PbCl₂-AgCl were studied by using DTA. The only miscibility was found on the silver chloride side up to a concentration of 1.5±0.5 mole% PbCl₂. No solid solution of AgCl in PbCl₂ was observed on the lead chloride side.

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Zusammenfassung Mittels DTA wurden die Randzonen des Phasendiagrammes des binären Systemes PbCl₂-AgCl untersucht. Mischbarkeit konnte lediglich auf der Silberchloridseite bis zu einer Konzentration von 1.5±0.5 mol% mol% PbCl₂ festgestellt werden. Auf der Bleichloridseite konnten keinerlei Mischkristalle zwischen AgCl und PbCl₂ beobachtet werden.

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PbCl₂-AgCl. 1,5±0,5 %. .

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We are very grateful to our colleagues Dr E. Krová and Dr Z. Pokorná for the preparation of the single-crystals and for the chemical analysis.     

Subsolidus phase diagram of binary system in the perovskite type layer compounds (<Emphasis Type="Italic">n</Emphasis>-C<Subscript>n</Subscript>H<Subscript>2n+1</Subscript>NH<Subscript>3</Subscript>)<Subscript>2</Subscript>MnCl<Subscript>4</Subscript>

The thermotropic phase transitions in the perovskite type layer compound (n-C₁₀H₂₁NH₃)₂MnCl₄ and (n-C₁₄H₂₉NH₃)₂MnCl₄ were synthesized and, at the same time, a series of their mixtures C₁₀Mn-C₁₄Mn were prepared. The experimental binary phase diagram of C₁₀Mn-C₁₄Mn was established by differential thermal analysis (DTA), IR and X-ray diffraction. In the phase diagram new material (n-C₁₀H₂₁NH₃)(n-C₁₄H₂₉NH₃)MnCl₄ and two eutectoid invariants were observed, two eutectic points temperatures are about 29.8 and 27.9°C. Contrasting other similar system, there are three noticeable solid solution ranges (α, β, γ) at the left and right boundary and middle of the phase diagram.     

On the Sociobiology of Hawks and Doves. A phase diagram for integration and segregation

Competing groups in a population will be integrated or segregated depending on their contest strategies. In this work a population of a fixed proportion of hawks and doves is supposed to be able to employ two different contest strategies, one more competitive than the other one. Energies are derived for populations employing these strategies and these energies depend on the availability of the resource for which hawks and doves compete. The energy for the less competitive strategy is lower than the other one when the resource is abundant. In that case hawks and doves can be in cohabitation in all proportions. If, however, the resource is scarce, the energy of the more competitive strategy is lower than the other one. In that case complete segregation of hawks and doves into colonies will result. The situation is akin to the phase pressure diagram of a binary solution with eutectic point, miscibility gap in the liquid phase and complete miscibility in the vapour phase. This revised version was published online in August 2006 with corrections to the Cover Date.     

Viscoelastic phase diagram of fluorinated and grafted polymer films and proton‐exchange membranes for fuel cell applications

The influence of temperature and moisture activity on the viscoelastic behavior of fluorinated membranes for fuel cell applications was investigated. Uncrosslinked and crosslinked ethylene tetrafluoroethylene (ETFE)‐based proton‐conducting membranes were prepared by radiation grafting and subsequent sulfonation and their behavior was compared with ETFE base film and commercial Nafion^® NR212 membrane. Uniaxial tensile tests and stress relaxation tests at controlled temperature and relative humidity (RH) were carried out at 30 and 50 °C for 10% < RH < 90%. Grafted films were stiffer and exhibited stronger strain hardening when compared with ETFE. Similarly, both uncrosslinked and crosslinked membranes were stiffer and stronger than Nafion^®. Yield stress was found to decrease and moisture sensitivity to increase on sulfonation. The viscoelastic relaxation of the grafted films was found to obey a power‐law behavior with exponent equal to ?0.04 ± 0.01, a factor of almost 2 lower than ETFE, weakly influenced by moisture and temperature. Moreover, the grafted films presented a higher hygrothermal stability when compared with their membranes counterparts. In the case of membranes, a power‐law behavior at RH < 60% was also observed. However, a markedly different behavior was evident at RH > 60%, with an almost single relaxation time exponential. An exponential decrease of relaxation time with RH from 60 s to 10 s was obtained at RH ≥ 70% and 30 °C. The general behavior of grafted films observed at 30 °C was also obtained at 50 °C. However, an anomalous result was noticed for the membranes, with a higher modulus at 50 °C when compared with 30 °C. This behavior was explained by solvation of the sulfonic acid groups by water absorption creating hydrogen bonding within the clusters. A viscoelastic phase diagram was elaborated to map critical conditions (temperature and RH) for transitions in time‐dependent behavior, from power‐law scaling to exponential scaling. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1139–1148     

The phase diagram of a single polymer chain: New insights from a new simulation method

We present simulation results for the phase behavior of a single chain for a flexible lattice polymer model using the Wang-Landau sampling idea. Applying this new algorithm to the problem of the homopolymer collapse allows us to investigate not only the high temperature coil–globule transition but also an ensuing crystallization at lower temperature. Performing a finite size scaling analysis on the two transitions, we show that they coincide for our model in the thermodynamic limit corresponding to a direct collapse of the random coil into the crystal without intermediate coil–globule transition. As a consequence, also the many chain phase diagram of this model can be predicted to consist only of gas and crystal phase in the limit of infinite chain length. This behavior is in agreement with findings on the phase behavior of hard-sphere systems with a relatively short-ranged attractive square well. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2542–2555, 2006     

Isotactic polystyrene/cis-decaline mixtures: phase diagram and molecular structures

Organized structures grown from iPS/cis-decalin solutions (ranging from 5% to 50% w/w) have been studied by several techniques. From DSC experiments the thermal behavior has been investigated as a function of the annealing temperature. The temperature-concentration phase diagram has been established. From neutron diffraction experiments the short range molecular order has been determined. We show that between the gel state formed at high undercooling and the crystalline state obtained at low undercooling there exist two intermediate phases: thes-phase, already described by Klein et al., and thep-phase. Except for the crystalline state all the other phases contain intercalated solvent molecules. Thegel state displays nematic-like order, whereas thes-phase is reminiscent of smectic arrangements. Thep-phase is less solvated and can be described as a peritectic system. Preliminary neutron scattering experiments show that chain-folding reappears in thes-phase, whereas it was shown to be absent in thegel phase.Formerly Laboratoire de Spectrométrie et d'imagerie Ultrasonores     

Solid-liquid phase equilibria of binary salt hydrate mixtures involving ammonium alum

Summary The solid-liquid phase diagrams of binary mixtures of ammonium alum with ammonium iron(III) alum, with aluminum nitrate nonahydrate and with ammonium nitrate and of aluminum sulfate hexadecahydrate with aluminum nitrate nonahydrate are presented. The alum rich branches of the former three-phase diagrams were fitted by the Ott equation. The specific enthalpy of fusion/freezing of some compositions of the former three mixtures was determined by differential drop calorimetry.     

Thermodynamic stability of phases in the Bi−Sr−Cu−(O) system

Journal of Thermal Analysis and Calorimetry - An effort for a better understanding of the phase formation and their stability in the ternary system Bi2O3?SrO?CuO led to investigations...     

Phase diagram investigation and thermodynamic study of Os-B system

The constitution of the Os-B system was investigated in this work. The phase regions were determined by metallographic investigations. The existence of the following borides was confirmed: OsB_1.1 (hex.), Os₂B₃ (hex.) and OsB₂ (orthorh.), while the new high temperature Os₂B₃ compound with a not yet identified structure was observed. OsB_1.1 melts congruently at 1820±15°C and OsB₂ at 1870±15°C, while the solid solubility of B in Os was found to be less than 0.5 at%B. Considering thermodynamic study of this system, the activities and activity coefficients for osmium and boron were determined in temperature interval 3300-3500 K, based on the known liquidus and solidus lines from phase diagram, according to calculation procedure given by Rao and Belton. This revised version was published online in July 2006 with corrections to the Cover Date.     

Factors affecting the general shape of the phase diagram and compound formation in the binary copper(I) halide–alkali-metal halide systems

A set of phase diagrams for the systems CuX–AlkX (where Alk=Li, Na, K, Rb or Cs and X=Cl, Br or I) is given, basing on authors investigation and selected literature data. Sizes and valences of ions involved in Coulombic and polarization interactions were considered as main factors affecting phase equilibria. An increasing tendency for compound formation was noted in series Na→K→Rb→Cs, Na→Li and I→Br→Cl. The most strongly represented are compounds of the formulas AlkCu₂X₃ and Alk₂CuX₃.     

Contribution to the study of the Al-Zn phase diagram

Calorimetric measurements in the AI-Zn system rule out the existence of anα″-phase and of a second monotectoid reaction at 340?.