Nature of domains in lanthanum calcium cobaltite perovskite revealed by atomic resolution Z-contrast and electron energy loss spectroscopy

Lamella-type planar features in La0.6Ca0.4CoO3 perovskite were investigated in a dedicated scanning transmission electron microscope. Atomic resolution Z-contrast imaging and modelling, along with electron energy loss spectroscopy, gave evidence these features could be Ca-enriched domains of the rock salt structure in the perovskite lattice. Z-contrast of a second type of planar fault, occurring after repeated investigations in the electron microscope, suggests formation of ordered O-vacancy arrangements on Co–O planes.