Fig. 16
From: Material structure, properties, and dynamics through scanning transmission electron microscopy
Beam-induced oxygen vacancy ordering in a LaCoO 3 /SrTiO 3 superlattice grown on a SrTiO 3 substrate viewed along the [100] direction. a Sequential ADF images overlaid with corresponding maps of the out-of-plane interatomic La-La spacings. b Average spacings in the central V o layer (red curve), the adjacent (black curve), and peripheral (blue curve) layers within the top LCO block as a function of time; green (star) curve gives the overall average, suggesting that the beam primarily induces redistribution of existing vacancies rather than vacancy injection. c Comparison of the evolution of interatomic spacings in the oxygen-depleted planes of the top (T), middle (M), and bottom (B) LaCoO 3 blocks; the differences are attributed to differences in thickness due to the wedge geometry of the sample. d Atomic model of the ordering transition; La atoms are shown in green, CoO 6 octahedra in blue, and CoO 4 tetrahedra in purple. Reproduced from Jang et al. 2017. Copyright 2017 American Chemical Society