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Abstract  

An effort for a better understanding of the phase formation and their stability in the ternary system Bi2O3−SrO−CuO led to investigations of the phase equilibria, particularly in the sub-solidus region. To extend this phase region about the respective solid-liquid equilibria the isothermal and pseudobinary cuts of the BiO1.5−SrO−CuO ternary system in the temperature range from 810 to 850°C were determined. A particular attention was also devoted to the thermodynamic stability of the Bi2+xSr2−yCuO6+δ phase.

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Journal of Thermal Analysis and Calorimetry
Authors: Peer Schmidt, Michael Schöneich, Melanie Bawohl, Tom Nilges, and Richard Weihrich

Abstract

Several methods are established in thermal analysis to investigate phase formation, phase transition, and decomposition reactions. The analysis of phase equilibria with volatile components is particularly feasible by using standard method of thermogravimetry. Hardly any investigations of phase formation reactions are possible to realize if one of the components is lost by vaporization. By using the “High-Temperature Gas-Balance” (HTGB), the vapor phase is enclosed in a silica ampoule and thus forms an equilibrium gas phase in permanent contact with the solid phase. The measurement signal Δm meas is caused by change of the leverage of the horizontal balance support during evaporation and condensation. The application of the HTGB allows the analysis of solid–gas equilibria in the working range from 0.01 till 15 bar at temperatures up to 1,100 °C. The first comparison of evaporation reactions determined by standard thermogravimetric analyses and by measurements using the HTGB is given for the inorganic systems: P, As, SeO2, PtI2, and Hg/I.

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Phase equilibria in the V2O5-Ag2O system were investigated at a constant pressure of oxygen (0.2 atm) and the phase diagram found under these conditions was compared with the results of the authors who investigated the same system in vacuum and at an oxygen pressure of 1 atm. On the basis of all these results, an attempt was made to construct the hypothetical diagram of V2O5-Ag2O-O2.

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Differential thermal and phase X-ray analyses have shown that MoO3 and Fe2V4O13 form a solid substitution solution, in which Mo6+ ions are incorporate into the crystal lattice of Fe2V4O13 in place of V5+ ions. The solubility limit of MoO3 in Fe2V4O13 at ambient temperature is 18 mole % of MoO3. The phase equilibria in the system Fe2V4O13-FeVMoO7, were also studied. Results are presented in the form of a phase diagram.

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Letter to the Editor

Comment on the paper “Phase stability study of the pseudobinary system Gd2O3–Nd2O3 (T ≤ 1350 °C)” by G. A. Costa, C. Artini, A. Ubaldini, M. M. Carnasciali, P. Mele, and R. Masini

Journal of Thermal Analysis and Calorimetry
Author: P. P. Fedorov

Gd 2 O 3 –Nd 2 O 3 phase diagram”. Unfortunately, the results of [ 1 ] do not correspond to the thermodynamics of heterogeneous equilibria. Figure 2 form [ 1 ] violates the phase rule. Figure 1 shows the correct scheme of phase equilibria

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reported compounds is still speculative. In this article, we present a new version of phase equilibria in a composition range from 30 to 50 at.% Pt where two new phases have been evidenced. Experimental procedures The samples

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dissolve up to 3(mass%) of NiSb [ 11 ]. The results on phase equilibria of the components of the NiS–Sb section were given by Allazov et al. [ 4 ] together with thermodynamic data on the NiSbS compound, its melting point, type of formation reaction

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Experimental investigation of the Nd–Al–Si system

The isothermal section at 500 °C

Journal of Thermal Analysis and Calorimetry
Authors: Anna Maria Cardinale, Daniele Macciò, Stefano Delfino, and Adriana Saccone

. Literature data Boundary binary systems The Nd–Si phase diagram was assessed by Gokhale [ 3 ] mainly on the basis of a complete investigation of the phase equilibria carried out by Eremenko et al. [ 4 ]. The following intermediate

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Introduction The field of phase equilibria in materials science has become extensive, and a number of review articles have appeared and reported in the literature [ 1 – 6 ] but the nature and liquidus structure of eutectic

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Journal of Thermal Analysis and Calorimetry
Authors: Dragana Živković, Aleksandra Mitovski, Ljubiša Balanović, Dragan Manasijević, and Živan Živković

calculated by FACT [ 4 ], etc.), as presented in Fig. 1 according to Ref. [ 3 ]. Also, there are other literature data concerning phase equilibria investigation of mentioned binary system [ 5 – 8 ]. Fig. 1 Phase

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