Predicting properties of MgO·nAl2O3 by first‐principles calculation combined with bond valence models

Abstract

AbstractSpinel‐type oxides have attracted tremendous attentions owing to their wide applications. However, the complicated composition and structure of spinel‐type solid solution brought about challenge to explore the relationship among composition, structure, and properties. A new approach which combined first‐principles calculation with bond valence models was developed to explore the composition dependence of structure and properties for spinel‐type oxide solid solution. The first‐principles calculation was used to simulate the structural parameters of spinel‐type oxide solid solution. The mechanical and thermal properties of Mg1‐xAl2(1+x/3)O4 spinel‐type solid solution were estimated by bond valence models based on the structure which was reconstructed from the structural parameters determined by the first‐principles calculation. Besides, bond valence arguments were also used to assess the reliability of reconstructed structure. The results suggest that the extremely overbonded or underbonded atoms can be avoided in the reconstructed structure, which improves the stability of reconstructed structure. By comparing the results with experimental values, it can be seen that mechanical and thermal properties could be simulated exactly by the new approach and bulk modulus was used as an example to explore the relationship among composition, structure, and properties of Mg1‐xAl2(1+x/3)O4.