Oxygen-Ion and Proton Transport in Sc-Doped Layered Perovskite BaLaInO4

—The effect of isovalent doping Sc 3+ → In 3+ on the transport properties is studied for complex oxide BaLaInO 4 characterized by the Ruddlesden–Popper structure. It is shown that the introduction of scandium increases the oxygen-ionic and protonic conductivity. In the humid air atmosphere at 500°С, both BaLaInO 4 and BaLaIn 0.9 Sc 0.1 O 4 are the protonic conductors with ~90–95% contribution of proton transfer.