Structural investigation of the cubic perovskite‐type doped lanthanum cobaltite La 0.6 Sr 0.4 CoO 3−δ at 1531 K: possible diffusion path of oxygen ions in an electrode material

The crystal structure of a cubic perovskite‐type doped lanthanum cobaltite, La 0.6 Sr 0.4 CoO 3−δ , has been studied using in situ neutron powder diffraction data measured at 1531 K. The refined occupancy 0.886 (6) of O atoms at the 3 d 1/2, 0, 0 site indicated an oxygen deficiency of δ = 0.34 (2) and an average valence of +2.7 for Co cations in La 0.6 Sr 0.4 CoO 3−δ at 1531 K. Refined anisotropic atomic displacement parameters and nuclear density mapping reveal that the oxygen ions in La 0.6 Sr 0.4 CoO 3−δ exhibit a large thermal motion perpendicular to the Co—O bond. A curved path for oxygen‐ion migration between adjacent anion sites in La 0.6 Sr 0.4 CoO 3−δ is proposed, although it was not observed as a connected density in the experimental mapping.