К 125-летию со дня рождения лауреата Нобелевской премии академика Николая Николаевича Семенова Полуэмпирические методы расчета температур ликвидуса в оксидных системах

In the present study, two semi-empirical methods (geometric and polynomial) were proposed to calculate liquidus temperatures in ternary and quaternary systems using the data on the equilibria in the corresponding binary systems. Advantages, limitations, and peculiarities of application of the semi-empirical methods proposed were considered. The reliability of the results of calculating the liquidus temperature values in the Gd2O3-Y2O3-ZrO2 system was illustrated by comparison with the available data on the phase equilibria. The capacity to evaluate the eutectic line position in the temperature-composition coordinates was shown in multicomponent oxide systems. It was mentioned that the semi-empirical approaches proposed may find a further use to evaluate the liquidus temperature values in multicomponent systems with the aim of reducing the amount of experimental investigations of phase equilibria at high temperatures.

Computational Phase Studies of Oxide Ceramics

This paper shows how phase equilibria and thermodynamic properties of various multicomponent oxide systems can be represented with the use of model equations for the Gibbs energies of all phases as functions of temperature and composition. Starting from the stoichiometric phases and random solutions, the complexity of the models increases tremendously when ordering tendencies or certain defects in the lattice of ionic crystals, such as vacancies and/or variable oxidation states have to be taken into account.