Structural investigation of epitaxial LaFeO_3 thin films on (111) oriented SrTiO_3 by transmission electron microscopy

We report on structural domains in LaFeO3 epitaxial thin films on (111) oriented SrTiO3 observed by transmission electron microscopy using low magnification dark field imaging and high resolution transmission electron microscopy techniques. The films were grown by pulsed laser deposition and had a thickness ≈ 20 nm. Three domain orientations are found, in accordance with the orthorhombic structure of LaFeO3. The domains themselves are of irregular shapes, and vary in size from tens to thousands of nm2. Regions of reduced Bragg scattering are observed as straight lines along , hinting at a complex domain structure.