Evolution of structure in the incommensurate modulated LaNb1–xWxO4+x/2 (x = 0.04–0.16) oxide ion conductors
File(s)
Accepted version
Supporting information
Author(s)
Type
Journal Article
Abstract
Hyper-stoichiometric CeNbO4+d phases demonstrate remarkable oxygen diffusivity and provide an interesting structural template for oxygen ion conductors. Previously, we have reported the room temperature structure of the incommensurate modulated LaNb0.88W0.12O4.06, a structural analogue of CeNbO4+d. We have confirmed that it is a pure oxygen ion conductor, with anions diffusing via an interstitialcy mechanism. However, the high temperature structural information for the LaNb1–xWxO4+d (x = 0.04–0.16) family, which is key to understanding the structure–property relationship in oxygen ionic conductors with complex structures at operating conditions, is unreported. In this contribution, we address this question by investigating the high temperature structural evolution of the LaNb1–xWxO4+2/x phases using a combination of thermal analysis, scattering techniques, and 17O and 93Nb nuclear magnetic resonance spectroscopy. We reveal a series of phase transitions between a modulated monoclinic phase, a high temperature modulated tetragonal phase, and a high temperature unmodulated tetragonal phase. These findings are correlated with the ion transport and offer insights into the design of new materials for solid state electrochemical devices.
Date Issued
2020-03-24
Date Acceptance
2020-02-20
Citation
Chemistry of Materials, 2020, 32 (6), pp.2292-2303
ISSN
0897-4756
Publisher
American Chemical Society
Start Page
2292
End Page
2303
Journal / Book Title
Chemistry of Materials
Volume
32
Issue
6
Copyright Statement
© 2020 American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Chemistry of Materials, after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.chemmater.9b04255
Subjects
03 Chemical Sciences
09 Engineering
Materials
Publication Status
Published
Date Publish Online
2020-02-20