Structural Stability of Perovskite Type Composite Oxide LaCrO3-δ
1. State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China;
2. Shanghai Key Laboratory of Multiphase Materials Chemical Engineering, Shanghai 200237, China
Abstract In order to study the effect of oxygen vacancy on the stability of LaCrO3-δ structure, the formation process of oxygen vacancies in LaCrO3 structure was firstly analyzed, and then the structure of LaCrO3-δ (δ=0.125-0.875) under different oxygen vacancies concentrations was established. The vacancies formation energy and the LaCrO3-δ stability were calculated by the first-principles based on the density functional theory. The results indicated that the formation energy of oxygen vacancy in LaCrO3-δ increased and the structural stability of LaCrO3-δ decreased with the increase of δ. In addition, according to the relative size of oxygen vacancy formation energy, it was found that oxygen vacancies were arranged in the CrO2 layer in the most stable LaCrO3-δ (δ = 0.125-0.500) structure.
