Structure and ionic diffusivity in an yttria-stabilised zirconia/strontium titanate multilayer.
File(s)
Accepted version
Author(s)
Cheah, WL
McComb, DW
Finnis, MW
Type
Journal Article
Abstract
Enhanced ionic conductivity observed in a heteroepitaxial multilayer of yttria-stabilised zirconia and (YSZ) and strontium titanate (STO) has variously been attributed to lattice dilation or a disordered oxygen sublattice, leading to high interfacial mobility of anions, as compared to those of the constituent bulk oxides. We seek to understand the mechanism of ionic motion in such heterostructures by first simulating the atomic structure assuming coherent interfaces. After investigating possible low-energy interface structures using a genetic algorithm, we perform molecular dynamics simulations on these structures to examine the anionic diffusivity in the system. We find that the extreme biaxial tensile strain in the YSZ layer, as imposed between layers of STO, induces phases that differ from fluorite. The lowest energy structure is an unknown phase, which we refer to as quasi-cubic and whose cation sublattice resembles an extension of the perovskite; this structure does not lead to enhanced ionic conductivity, in contradiction to some reports in the literature.
Date Issued
2017-02-28
Date Acceptance
2017-02-25
Citation
Acta Materialia, 2017, 129, pp.388-397
ISSN
1359-6454
Publisher
Elsevier
Start Page
388
End Page
397
Journal / Book Title
Acta Materialia
Volume
129
Copyright Statement
© 2017 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Sponsor
Department Of Trade & Industry (DTI)
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000400033900038&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
DT/E01013X/1
Subjects
Science & Technology
Technology
Materials Science, Multidisciplinary
Metallurgy & Metallurgical Engineering
Materials Science
Interface
Atomic structure
Strain accommodation
Ionic diffusion
Atomistic simulation
OXIDE FUEL-CELLS
YSZ THIN-FILMS
OXYGEN DIFFUSION
MOLECULAR-DYNAMICS
ZIRCONIA
CONDUCTIVITY
STRAIN
INTERFACES
HETEROSTRUCTURES
TEMPERATURE
Publication Status
Published