The possibility to control oxygen transport in one of the most promising solid oxide fuel cell cathode materials, La_0.6Sr_0.4CoO_3−δ, by controlling lattice strain raises questions regarding the contribution of atomic scale effects. Here, high-resolution transmission electron microscopy revealed the different atomic structures in La_0.6Sr_0.4CoO_3−δ thin films grown under tensile and compressive strain conditions. The atomic structure of the tensile-strained film indicated significant local concentration of the oxygen vacancies, with the average value of the oxygen non-stoichiometry being much larger than for the compressive-strained film. In addition to the vacancy concentration differences that are measured by isotope exchange depth profiling, significant vacancy ordering was found in tensile-strained films. This understanding might be useful for tuning the atomic structure of La_0.6Sr_0.4CoO_3−δ thin films to optimize cathode performance.

通过控制晶格应变来控制最有前途的固体氧化物燃料电池正极材料之一La _0.6 Sr _0.4 CoO3 _-δ中的氧传输的可能性提出了关于原子尺度效应的贡献的问题。在这里，高分辨率透射电子显微镜揭示了La _0.6 Sr _0.4 CoO3 _-δ中不同的原子结构在拉伸和压缩应变条件下生长的薄膜。拉伸应变膜的原子结构表明氧空位的显着局部浓度，氧非化学计量的平均值比压缩应变膜的平均值大得多。除了通过同位素交换深度分布测量的空位浓度差异外，在拉伸应变薄膜中还发现了明显的空位排序。这种理解可能对调整La _0.6 Sr _0.4 CoO3 _-δ薄膜的原子结构以优化阴极性能很有帮助。