Please use this identifier to cite or link to this item:
Title: Revisiting the cubic crystal structures of Sr4Nb2O9 and Sr5Nb2O10
Authors: Li, JY
Wang, CH
Wang, XM
Avdeev, M
Ling, CD
Kennedy, BJ
Keywords: Crystal structure
Electric conductivity
X-ray diifraction
Neutron diffraction
Temperature dependence
Issue Date: 1-Nov-2021
Publisher: Elsevier
Citation: Li, J.-Y., Wang, C.-H., Wang, X.-M., Avdeev, M., Ling, C. D., & Kennedy, B. J. (2021) Revisiting the cubic crystal structures of Sr4Nb2O9 and Sr5Nb2O10, Journal of Solid State Chemistry, 303, 122502. doi:10.1016/j.jssc.2021.122502
Abstract: We have synthesized polycrystalline and single crystal samples of Sr4Nb2O9 and Sr5Nb2O10 and revisited the crystal structure of the high-temperature cubic phase. By careful analysis of single-crystal X-ray diffraction (SXRD), powder synchrotron X-ray diffraction (Syn-PXRD) and powder neutron diffraction (PND) data, we arrive at a structure model in space group F4¯3m (#216), a subgroup of the reported Fm3¯m (#225) model. The F4¯3m model gives a better fit to the diffraction data, especially the PND data. We observed an interstitial oxide ion (O3) on the 48h site near the typical perovskite 24e site (O1), which gives a Td Nb–O symmetry rather than an Oh one as found in the Fm3¯m model. The temperature-dependent conductivities of Sr4Nb2O9 and Sr5Nb2O10 in dried O2 were studied using impedance spectroscopy. The activation energies of Sr4Nb2O9 and Sr5Nb2O10 were estimated to be 1.18(1) eV and 1.17(4) eV, respectively. This disordered crystallographic arrangement of the O1 and O3 anions is likely a key structural factor behind oxide ionic migration in Sr4Nb2O9 and Sr5Nb2O10. © 2021 Elsevier Inc.
ISSN: 0022-4596
Appears in Collections:Journal Articles

Files in This Item:
There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.