Journal article
Crystal structure and electronic properties of bulk and thin film brownmillerite oxides
Physical review. B, v 92(17)
17 Nov 2015
Abstract
The equilibrium structure and functional properties exhibited by brownmillerite oxides, a family of perovskite-derived structures with alternating layers of BO6 octahedra and BO4 tetrahedra, viz., ordered arrangements of oxygen vacancies, is dependent on a variety of competing crystal-chemistry factors. We use electronic structure calculations to disentangle the complex interactions in two ferrates, Sr2Fe2O5 and Ca2Fe2O5, relating the stability of the equilibrium (strain-free) and thin film structures to both previously identified and herein newly proposed descriptors. We show that cation size and intralayer separation of the tetrahedral chains provide key contributions to the preferred ground state. We show the bulk ground-state structure is retained in the ferrates over a range of strain values; however, a change in the orientation of the tetrahedral chains, i.e., a perpendicular orientation of the vacancies relative to the substrate, is stabilized in the compressive region. The structure stability under strain is largely governed by maximizing the intraplane separation of the dipoles generated from rotations of the FeO4 tetrahedra. Lastly, we find that the electronic band gap is strongly influenced by strain, manifesting as an unanticipated asymmetric-vacancy alignment dependent response. This atomistic understanding establishes a practical route for the design of functional electronic materials in thin film geometries.
Metrics
Details
- Title
- Crystal structure and electronic properties of bulk and thin film brownmillerite oxides
- Creators
- Joshua Young - Drexel UniversityJames M. Rondinelli - Argonne National Laboratory
- Publication Details
- Physical review. B, v 92(17)
- Publisher
- Amer Physical Soc
- Number of pages
- 10
- Grant note
- DE-AC02-06CH11357 / U.S. DOE, Office of Basic Energy Sciences (BES); United States Department of Energy (DOE) Drexel's University Research Computing Facility DOE-BES DE-AC02-06CH11357; CNM39812 / CARBON cluster at the Center for Nanoscale Materials (Argonne National Laboratory)
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Materials Science and Engineering
- Web of Science ID
- WOS:000364810200002
- Scopus ID
- 2-s2.0-84948435468
- Other Identifier
- 991019335515004721
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Collaboration types
- Domestic collaboration
- Web of Science research areas
- Materials Science, Multidisciplinary
- Physics, Applied
- Physics, Condensed Matter