Electronic structure and O vacancy formation/migration in La0.825(Mg/Ca/Ba)0.125CoO3
1 King Abdullah University of Science and Technology (KAUST), Physical Science and Engineering Division (PSE) - Thuwal 23955-6900, Saudi Arabia
2 Key Laboratory of Advanced Technology of Materials (Ministry Education), Superconductivity and New Energy R and D Center, Southwest Jiaotong University - Chengdu, 610031, China
Received: 16 March 2016
Accepted: 25 April 2016
The effect of A-site hole doping (Mg2+, Ca2+ or Ba2+) on the electronic and magnetic properties as well as the O vacancy formation and migration in perovskite LaCoO3 is studied using first-principles calculations. All three dopants are found to facilitate O vacancy formation. Substitution of La3+ with Ba2+/Mg2+ yields the lowest O vacancy formation energy for low/intermediate spin Co, implying that not only the structure but also the spin state of Co is a key parameter. Only for low spin Co the ionic radius is correlated with the O migration barrier. Enhanced migration for intermediate spin Co is ascribed to the availability of additional space at the transition state.
PACS: 66.30.-h – Diffusion in solids
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