Insights into Oxygen Migration in LaBaCo₂O_6-δ Perovskites from In Situ Neutron Powder Diffraction and Bond Valence Site Energy Calculations.

ABSTRACT: Layered cobalt oxide perovskites are important mixed ionic and electronic conductors. Here, we investigate LaBaCo₂O_6-δ using in situ neutron powder diffraction. This composition is unique because it can be prepared in cubic, layered, and vacancy-ordered forms. Thermogravimetric analysis and diffraction reveal that layered and disordered samples have near-identical oxygen cycling capacities. Migration barriers for oxide ion conduction calculated using the bond valence site energy approach vary from E _b ∼ 2.8 eV for the cubic perovskite to E _b ∼ 1.5 eV for 2D transport in the layered system. Vacancy-ordered superstructures were observed at low temperatures, 350-400 °C for δ = 0.25 and δ = 0.5. The vacancy ordering at δ = 0.5 is

SUBMITTER: Hesse F 

PROVIDER: S-EPMC9007454 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature