Fig. 3
From: Strain control of oxygen kinetics in the Ruddlesden-Popper oxide La1.85Sr0.15CuO4
Redox sensitivity of lattice. Out-of-plane c lattice constants of 20-nm-thick LSCO films on LAO (tensile strain) and LSAO (compression) substrates. The lattice constants were measured from as-grown films and from films oxygen-annealed and vacuum-annealed for different time intervals at 500 °C. The in-plane lattice is fixed with the substrate in all films, as confirmed by X-ray reciprocal space mapping. Compressive-strained films show little sensitivity to oxygen annealing (closed circles) or vacuum annealing (triangles) for up to 2 h, after which a lattice reduction is observed. Tensile-strained films reveal that oxygen annealing leads to a gradual increase in the lattice parameter, whereas vacuum annealing for 30 min shows a significant lattice contraction, indicating the corresponding redox response of lattice volume changes
