Defect chemistry and proton uptake of La2-xSrxNiO4±δ and La2-xBaxNiO4±δ Ruddlesden-Popper phases

Abstract Due to their layered structure, Ruddlesden-Popper oxides possess intriguing properties and appear promising for application in a protonic ceramic fuel cell (PCFC) as an air electrode. In this work, two series of K2NiF4-type oxides, namely La2-xSrxNiO4±δ with 0.75 ≤ x ≤ 1.4 and La 2-xBaxNiO4±δ with 0.25