Abstract
Lattice images of Y2O3 are observed by a high resolution electron microscope. Because Y2O3 belongs to the body-centered C-Rare earth Ia\bar3 structure, oxygen vacancies along ⟨111⟩ direction induce a shift of atoms from the CaF2 structure. The periodicity of the obtained lattice images corresponds with that of the projected pattern, where the periodicity is influenced by the shifts Y atoms. For the (001) projection, the images of two neighboring lattice planes make a pair to ⟨100⟩ directions and the 110 spots of the optical diffraction pattern are missing as expected by the projected pattern of the Ia\bar3 structure. For the (111) planes, images of Y atoms make zigzag lines for the shift. For the (110) and (111) planes, the same type of lattice image appears every four layers to the ⟨110⟩ directions. Because the forbidden 110 reflection spots appeared and the fourfold period of lattice image was not clear for very thin area, the structure images of the (110) and (111) planes may include contribution of the double reflection of electron beam.
