Fig. 6: STEM images showing the structure of lanthanide-based RP nickelates.

Atomic-column-resolved images were acquired in a La2NiO4, La3Ni2O7, and La4Ni3O10, b Nd2NiO4, and c Pr2NiO4, as listed in Supplementary Table 3. Strong local repulsion between [LnO]+ sublayers is illustrated in the left-hand column. Significant elongation of the Ni–O bonds at the shear planes is denoted by yellow arrows in the ABF images, providing quantitative information on the bond lengths. Red arrows in each image indicate substantial displacement of oxygen anions.