Abstract
Structure-property relationships were determined for the family of three-layer Aurivillius materials Bi2Sr(A)TiNb2O12 (A = Ca2+, Sr2+, Ba2+). X-ray and neutron diffraction along with selected area electron diffraction indicate that Bi2SrBaTiNb2O12 crystallizes in the nonpolar I4/mmm space group, whereas the polar B2cb space group best describes Bi2SrCaTiNb2O12 and Bi2Sr2TiNb2O12. Despite the different space groups, all three compositions show relaxor behavior as evidenced through P(E) and dielectric measurements. These relaxor properties are derived from the extensive amount of disorder in each composition that is found at every cationic crystallographic site and do not depend on the space group. This disorder is so extensive that it disrupts the ferroelectric properties allowed by symmetry in the B2cb space group. This work demonstrates the important role of cation substitution and site disorder in these three-layered Aurivillius materials and its significant effect on both ferroelectric and dielectric properties.
| Original language | English |
|---|---|
| Pages (from-to) | 7774-7784 |
| Number of pages | 11 |
| Journal | Chemistry of Materials |
| Volume | 29 |
| Issue number | 18 |
| DOIs | |
| State | Published - Sep 26 2017 |
| Externally published | Yes |
Funding
Michelle Dolgos and Alicia Manjon-Sanź would like to thank the NSF (DMR-1606909) for support. T. Thao Tran would like to thank the NSF (DMR-1503573) for support. Use of the Advanced Photon Source at Argonne National Laboratory was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. We would like to thank Saul Lapidus and Lynn Ribaud of 11-BM at the APS and Ashfia Huq, Pam Whitfield, and Melanie Kirkham of POWGEN at the SNS for their assistance with our experiments. This research used the Oregon State University Electron Microscopy facility, and we would like to thank Peter Eschbach for his help with electron diffraction. We would like to thank May Nyman for the use of her differential thermal analysis equipment. We would like to thank Mas Subramanian at Oregon State University (Chemistry) for his conversations about dielectrics and dielectric anomalies. We would like to thank David Cann at Oregon State University (Materials Science) for use of his equipment for the permittivity measurements and discussion regarding conductivity in Aurivillius phases. We would also like to thank P. Shiv Halasyamani (University of Houston) for SHG measurements and helpful discussion.
| Funders | Funder number |
|---|---|
| Office of Basic Energy Sciences | |
| National Science Foundation | DMR-1503573, DMR-1606909 |
| U.S. Department of Energy | |
| Office of Science |