Journal article
Polar Oxides without Inversion Symmetry through Vacancy and Chemical Order
Journal of the American Chemical Society, v 139(7), pp 2833-2841
22 Feb 2017
PMID: 28161942
Abstract
One synthetic modality for materials discovery proceeds by forming mixtures of two or more compounds. In transition metal oxides (TMOs), chemical substitution often obeys Vegard's principle, and the resulting structure and properties of the derived phase follow from its components. A change in the assembly of the components into a digital nanostructure, however, can stabilize new polymorphs and properties not observed in the constituents. Here we formulate and demonstrate a crystal chemistry design approach for realizing digital TMOs without inversion symmetry by combining two centrosymmetric compounds, utilizing periodic anion-vacancy order to generate multiple polyhedra that together with cation order produce a polar structure. We next apply this strategy to two brownmillerite-structured TMOs known to display centrosymmetric crystal structures in their bulk, Ca2Fe2O5 and Sr2Fe2O5. We then realize epitaxial (SrFeO2.5)(1)/(CaFeO2.5)(1) thin film superlattices possessing both anion-vacancy order and Sr and Ca chemical order at the subnanometer scale, confirmed through synchrotron-based diffraction and aberration corrected electron microscopy. Through a detailed symmetry analysis and density functional theory calculations, we show that A-site cation ordering lifts inversion symmetry in the superlattice and produces a polar compound. Our results demonstrate how control of anion and cation order at the nanoscale can be utilized to produce acentric structures markedly different than their constituents and open a path toward novel structure-based property design.
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Details
- Title
- Polar Oxides without Inversion Symmetry through Vacancy and Chemical Order
- Creators
- Joshua Young - Drexel UniversityEun Ju Moon - Drexel UniversityDebangshu Mukherjee - Pennsylvania State UniversityGreg Stone - Pennsylvania State UniversityVenkatraman Gopalan - Pennsylvania State UniversityNasim Alem - Pennsylvania State UniversitySteven J. May - Drexel UniversityJames M. Rondinelli - Northwestern University
- Publication Details
- Journal of the American Chemical Society, v 139(7), pp 2833-2841
- Publisher
- American Chemical Society; Washington, DC
- Number of pages
- 9
- Grant note
- DE-AC02-06CH11357 / DOE Office of Science by Argonne National Laboratory; United States Department of Energy (DOE) NSF DMR-1420620 / Penn State MRSEC, Center for Nanoscale Science DE-AC02-06CH11357 / DOE-BES; United States Department of Energy (DOE) DMR-1420620; DMR-1151649 / National Science Foundation; National Science Foundation (NSF) 1151649 / Direct For Mathematical & Physical Scien; National Science Foundation (NSF); NSF - Directorate for Mathematical & Physical Sciences (MPS) DE-AC02-06CH11357 / U.S. DOE, Office of Basic Energy Sciences; United States Department of Energy (DOE)
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Materials Science and Engineering
- Web of Science ID
- WOS:000394829200043
- Scopus ID
- 2-s2.0-85013377872
- Other Identifier
- 991019167587604721
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Collaboration types
- Domestic collaboration
- Web of Science research areas
- Chemistry, Multidisciplinary