Fig. 1: Structural analysis of the complex epitaxial stack using scanning transmission electron microscopy.
From: Establishing a pure antiferroelectric PbZrO3 phase through tensile epitaxial strain

a HAADF-STEM image of the carbon-covered PbZrO3/SrPbO3/LaLuO3 orthorhombic perovskite layers grown on the DyScO3(110)o orthorhombic substrate. The layer thicknesses are 30, 19, and 108 nm for PbZrO3, SrPbO3, and LaLuO3, respectively. The SrPbO3 electrode reacts under the electron beam of the microscope. b Colored images obtained by filtering the FFT contributions of the different layers (as displayed on the right panel), showing DyScO3 (DSO), LaLuO3 (LLO), and the two orientations of PbZrO3 (PZO) corresponding to 90° rotation around the co axis. The ½{110} superlattice reflections of DyScO3 and LaLuO3 are emphasized by the yellow circles. The ¼{110} superlattice reflections of PbZrO3 are underlined by the red and green circles. The zone axis is parallel to the co axes of the four orthorhombic layers, giving rise to the following epitaxial relationship: PbZrO3(120)o,(1-20)o \(\parallel\) SrPbO3(110)o \(\parallel\) LaLuO3(110)o \(\parallel\) DyScO3(110)o with PbZrO3[001]o \(\parallel\) SrPbO3[001]o \(\parallel\) LaLuO3[001]o \(\parallel\) DyScO3[001]o. c, d Out-of-plane unit-cell deformation (εzz) (c) and in-plane unit-cell deformation (εxx) (d) obtained from geometrical phase analysis of the bright field STEM image (Supplementary Fig. 4). The uniform lattice expansion observed for the in-plane unit-cell deformation shows that the epitaxial stack is coherently strained to the LaLuO3 buffer layer.