An X-Ray Powder and Electron Diffraction Study of Reduced Tantalates with the Perovskite Structure, Na1-xSrxTaO3, 0

An experimental reinterpretation together with a thermodynamic analysis of the twocomponent system (CCl4)+(C(CH3)4) has been performed. The 35-year-old specific heat diagrams obtained by adiabatic calorimetry have been revised in order to remove the inconsistencies of the tentative experimental phase diagram. The fact that the two components of the system do not have the same ODIC form was ignored 30 years ago and, at present, it has been considered. From a thermodynamic point of view the two-component system is a very nice example of crossed isodimorphism: two ODIC+liquid loops crossing each other give rise to a three-phase equilibrium. The thermodynamic information of the excess magnitudes is wide enough to perform a complete and realistic thermodynamic analysis. Likewise, the excess thermodynamic magnitudes in the ODIC states have been well explained by means of the quasi-subregular solution model including a compensation law.