Atomic scale symmetry and polar nanoclusters in the paraelectric phase of ferroelectric materials
arXiv:2010.10860 · doi:10.1038/s41467-021-23600-3
Abstract
The nature of the "forbidden" local- and long-range polar order in nominally nonpolar paraelectric phases of ferroelectric materials has been an open question since the discovery of ferroelectricity in oxide perovskites (ABO3). A currently considered model suggests locally correlated displacements of B-site atoms along a subset of <111> cubic directions. Such offsite displacements have been confirmed experimentally, however, being essentially dynamic in nature they cannot account for the static nature of the symmetry-forbidden polarization implied by the macroscopic experiments. Here, in an atomically resolved study by aberration corrected scanning transmission electron microscopy (STEM) complemented by Raman spectroscopy, we reveal, directly visualize and quantitatively describe static, 2-4 nm large polar nanoclusters in the nominally nonpolar cubic phases of (Ba,Sr)TiO3 and BaTiO3. These results have implications on understanding of the atomic-scale structure of disordered materials, the origin of precursor states in ferroelectrics, and may help answering ambiguities on the dynamic-versus-static nature of nano-sized clusters.
arXiv commentthe main text and supplementary information
References in corpus (7)
- Breaking of macroscopic centric symmetry in paraelectric phases of ferroelectric materials and implications for flexoelectricity
- Emergence of long-range order in BaTiO3 from local symmetry-breaking distortions
- Concentration phase diagram of Ba(x)Sr(1-x)TiO3 solid solutions
- Room temperature surface piezoelectricity in SrTiO3 ceramics via piezoresponse force microscopy
- Order-Disorder Ferroelectric Transition of Strained SrTiO3
- Dynamic Displacement Disorder of Cubic BaTiO
- Nonlinear dynamics of polar regions in paraelectric phase of (Ba1-x,Srx)TiO3 ceramics