Protonic conduction in BaNdInO4 structure achieved by acceptor doping
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
The potential of calcium-doped layered perovskite compounds, BaNd1–xCaxInO4–x/2 (where x is the excess Ca content), as protonic conductors was experimentally investigated. The acceptor-doped ceramics exhibit improved total conductivities that were 1–2 orders of magnitude higher than those of the pristine material, BaNdInO4. The highest total conductivity of 2.6 × 10–3 S cm–1 was obtained in the BaNd0.8Ca0.2InO3.90 sample at a temperature of 750 °C in air. Electrochemical impedance spectroscopy measurements of the x = 0.1 and x = 0.2 substituted samples showed higher total conductivity under humid environments than those measured in a dry environment over a large temperature range (250–750 °C). At 500 °C, the total conductivity of the 20% substituted sample in humid air (∼3% H2O) was 1.3 × 10–4 S cm–1. The incorporation of water vapor decreased the activation energies of the bulk conductivity of the BaNd0.8Ca0.2InO3.90 sample from 0.755(2) to 0.678(2) eV in air. The saturated BaNd0.8Ca0.2InO3.90 sample contained 2.2 mol % protonic defects, which caused an expansion in the lattice according to the high-temperature X-ray diffraction data. Combining the studies of the impedance behavior with four-probe DC conductivity measurements obtained in humid air, which showed a decrease in the resistance of the x = 0.2 sample, we conclude that experimental evidence indicates that BaNd1–xCaxInO4–x/2 is a fast proton conductor.
Date Issued
2021-03-23
Date Acceptance
2021-02-26
Citation
Chemistry of Materials, 2021, 33 (6), pp.2139-2146
ISSN
0897-4756
Publisher
American Chemical Society
Start Page
2139
End Page
2146
Journal / Book Title
Chemistry of Materials
Volume
33
Issue
6
Copyright Statement
© 2021 The Authors. Published by American Chemical Society. CC BY 4.0
License URL
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Identifier
https://pubs.acs.org/doi/10.1021/acs.chemmater.0c04828#
Grant Number
EP/P026478/1
Subjects
Science & Technology
Physical Sciences
Technology
Chemistry, Physical
Materials Science, Multidisciplinary
Chemistry
Materials Science
03 Chemical Sciences
09 Engineering
Materials
Publication Status
Published
Date Publish Online
2021-03-10