A structural consideration of the defect in LaMnO3 phase around stoichiometric composition

Abstract The defect structure of LaMnO 3 phase close to its stoichiometric composition was studied by transmission electron microscopy (TEM). The electron diffraction patterns of this phase showed two series of superlattice spots that are forbidden for Pnma (62), the reported symmetry for stoichiometric LaMnO 3 . 0 0 l ( l = odd) such as 0 0 1 and h k 0 ( h = odd) such as 1 0 0 superlattice spots appeared in [1 1 0] and [0 1 1] zone patterns. The low magnification TEM images in [1 1 0] zone showed coherent twins. The twin plane was (1 1 2).