Binary phase diagrams from thermodynamics

Binary phase diagrams from thermodynamics Gibbs phase rule... 

As a conclusion to these notes on the assessment and compilation of intermetallic data, we mention a few examples of papers in which criteria to be followed in order to extract from literature data the best version of a phase diagram have been discussed. These are Morral and Gupta (1991) (a figure of merit for predicted phase diagram), Okamoto and Massalski (1991, 1993) (thermodynamically improbable phase diagrams and guidelines for binary phase diagram assessment). See also various comments in several chapters in Cahn (2001). 

Figure 1. Uranium-aluminum phase diagram. (From P. Chiotti, V. V. Akhachinskij, I. Ansara, M. H. Rand, The Chemical Thermodynamics of Actinide Elements and Compounds, Part 5, The Actinide Binary Alloys, International Atomic Energy Agency, Vienna, 1981, Fig. 5.22, with permission.)...

Schematic derivation of the size-dependent FeP04-LiFeP04 binary phase diagram using the XRD data for Lio.6FeP04 is illustrated in Fig. 14.5, which highlights the fact that the solid solubility limits a, jS, in LiaFeP04, and Lii FeP04 systematically increases along with the reduction in particle size. Most probably, these systematic variations originate from the elastic thermodynamic effects on the...

One practical problem of the determinant method is the common unavailability of thermodynamic data and phase diagrams for multiphase compounds. For practical applications, an estimate obtained from data for binary compounds of the multinary system may be useful. 

The implications for films cast from mixtures of enantiomers is that diagrams similar to those obtained for phase changes (i.e., melting point, etc.) versus composition for the bulk surfactant may be obtained if a film property is plotted as a function of composition. In the case of enantiomeric mixtures, these monolayer properties should be symmetric about the racemic mixture, and may help to determine whether the associations in the racemic film are homochiral, heterochiral, or ideal. Monolayers cast from non-enantiomeric chiral surfactant mixtures normally will not exhibit this feature. In addition, a systematic study of binary films cast from a mixture of chiral and achiral surfactants may help to determine the limits for chiral discrimination in monolayers doped with an achiral diluent. However, to our knowledge, there has never been any other systematic investigation of the thermodynamic, rheological and mixing properties of chiral monolayers than those reported below from this laboratory. 

Figure 4.8 (a) Phase diagram of the binary system Y203 Mg0 at 1 bar defining the five temperatures for the Gibbs energy curves shown in (b) T (c) Ty, (d) Ty (e) Ty, (f) T. Thermodynamic data are taken from reference [6]. 

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