Oxygen migration performance of LaFeO<sub>3</sub> perovskite-type oxygen carriers with Sr doping
Yuan Feng, Hanyu Jin, Shuai Wang
Abstract
density functional theory (DFT). The effect of Sr doping on the A-site is considered. The results show that the covalency of the interaction between Fe and O at the surface is higher than that in the bulk, and the Sr doping on the A-site enhances this covalency, leading to a lower oxygen vacancy formation energy. The oxygen migration barrier is also different with the distance from the surface. A smaller deviation of the surrounding lattice atoms from their original place in the crystal at a deeper layer leads to a higher oxygen migration energy. Meanwhile, Sr doping increases the lattice constant, leading to larger migration space thus lowering the migration barrier. In addition, Sr doping can weaken the difference in the oxygen migration barrier between near the surface and in the bulk.