Strain Tuning and Strong Enhancement of Ionic Conductivity in SrZrO3–RE2O3 (RE = Sm, Eu, Gd, Dy, and Er) Nanocomposite Films

Fast ion transport channels at interfaces in thin fi lms have attracted great attention due to a range of potential applications for energy materials and devices, for, solid oxide fuel cells, sensors, and memories. Here, it is shown that in vertical nanocomposite heteroepitaxial fi lms of SrZrO 3 ‐RE 2 O 3 (RE = Sm, Eu, Gd, Dy, and Er) the ionic conductivity of the composite can be tuned and strongly enhanced using embedded, stiff, and vertical nanopillars of RE 2 O 3 . With increasing lattice constant of RE 2 O 3 from Er 2 O 3 to Sm 2 O 3 , it is found that the tensile strain in the SrZrO 3 increases proportionately, and the ionic conductivity of the composite increases accordingly, by an order of magnitude. The results here conclusively show, for the fi rst time, that strain in fican be effectively used to tune the ionic conductivity of the materials.