Review and perspective on polyhedron model for estimating thermodynamic properties of oxides

Abstract

Knowledge of thermodynamics and phase equilibria of oxidic materials is crucial for advancement in the field of ceramics and glass. With the development of computational thermodynamics, predicting phase diagrams and chemical reactions of multicomponent systems has become possible. However, there are still plenty of oxides, the thermodynamic properties of which have not been identified due to the challenges in conducting experiments. Therefore, a key to the advancement in thermodynamic modeling would be to develop a universal model that can be used to estimate the thermodynamic properties of oxides with reliable extrapolation capacity. Atomistic (or molecular) scale models are still insufficient in predicting the thermodynamic properties of oxides at any scale. Alternatively, among group contribution–based methods, the polyhedron model has presented its potential in the estimation of the thermodynamic properties of ionic crystals. However, this model still demands improvements that increase the model's accuracy and extrapolation capacity. In this paper, the background and the state‐of‐the‐art of polyhedron model will be presented together with its strengths and shortcomings. Subsequently, it will be briefly discussed how the field of artificial intelligence could be exploited to devise the next generation of the polyhedron model, the modified polyhedron model.

Boron oxide influencing phase transformations in Eu and Dy co‐doped Sr4Al14O25 exhibiting persistent luminescence

“…Coordination polyhedral networks additionally require energy to enable changes in topological connectivity. 16,17 Although all phases of strontium aluminate consist of an Al 3+ scaffolding that defines the crystal structure with Sr 2+ cations providing charge compensation in a sub-lattice of cavities, 15,18,19 the polyhedral networks differ between phases, resulting in differences in structural stability. The energy of formation may involve an energy penalty for a single oxygen bridging of 2 Al 3+ tetrahedra, also known as the Loewenstein rule.…”