Nanodomains Coupled to Ferroelectric Domains Induced by Lattice Distortion in Self-Doped LuMnxO3±δ Hexagonal Ceramics

Abstract

Self-doped h-LuMnxO3±δ multiferroic ceramics with 0.92 ≤ x ≤ 1.12 were studied for the dependence of magnetic properties on x. Interlocking of lattice distortion at the nanoscale with ferroelectric (FE) domains in bulk RMnO3 materials is mostly unknown. Here we report occurrence of nanodomains in transmission electron microscopy (TEM) images with the presence of antiphase boundaries/ferroelectric domain walls separating nano-FE domains. Observed chemical inhomogeneity across the crystalline grains of the ceramics causes distortion in the lattice. Formation of nanostructural domains revealed across particles of Mn deficient or Lu deficient samples includes bands of strained atomic planes, structural antiphase boundaries, and planar defects similar to stacking fault ribbons. Nanotwins exist in the basal plane, the twin boundary representing disorder of the stacking of atomic planes along the [110] direction. Image contrast in high resolution HRTEM images and TEM image simulation confirm the role of planar d...