Surface Atomic imaging of La₂O₃ and La₂CuO₄

Surface profile images from La2O3 and La2CuO4 have been obtained using high resolution electron microscopy. A surface layer of the C-form of La2O3 about 1 nm in thickness coating the bulk of the A-form La2O3 and the movement of atomic columns within this coating were observed; these two structural forms being intergrown with the (001) plane of the A-form parallel to the (111) plane of the C-form. On the (113) surface of a La2CuO4 crystal, a single atomic layer having a different structural arrangement from that of the bulk crystal was visible, and a displacement of some of the La cations on the surface was proven by image simulation. On the (001) surface plane of La2CuO4, the movement of atomic columns in a surface re-arrangement was also observed.