Electron channeling contrast imaging of anti-phase boundaries in coherently strained La0.7Sr0.3MnO3 thin films on (110)-oriented SrTiO3

Abstract

Electron channeling contrast imaging (ECCI) was used to characterize coherently strained La0.7Sr0.3MnO3 (LSM) films grown on (110)cubic-SrTiO3 (STO) and (100)orthorhombic-NdGaO3 (NGO). We focus on the characterization of a relatively low density (1–3 μm/μm2) of meandering loops (MLs) found in the LSM film on STO and absent in the film on NGO. The MLs exhibit a uniform contrast variation from the background and a strong contrast dependence on the diffraction vector g. The MLs are quantitatively consistent with LSM anti-phase boundaries (APBs) having a displacement vector R=12[001]LSM. These APBs are consistent with a “double positioning” degeneracy of tilted octahedra along [001]LSM on untilted octahedra along [001]STO. The results highlight the non-destructive capacity of ECCI to characterize extended defects in oxide films.