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B-cation effects in relaxor and ferroelectric tetragonal tungsten bronzes

Arnold, Donna C., Morrison, Finlay D. (2009) B-cation effects in relaxor and ferroelectric tetragonal tungsten bronzes. Journal of Materials Chemistry, 19 (36). pp. 6485-6488. ISSN 1364-5501. (doi:10.1039/b912535c) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided) (KAR id:40385)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)
Official URL
http://dx.doi.org/10.1039/b912535c

Abstract

The properties of a family of relaxor materials with nominal formula Ba6M3+Nb9O30 (M3+ = Ga3+, Sc3+ and In3+) with the tetragonal tungsten bronze (TTB) structure are reported. The dielectric curves are dramatically shifted (>200 K) to higher temperature with increasing M3+ cation size, in contrast to the opposite effect observed with increasing M4+ ionic radius in Ba6M4+2Nb8O30 TTBs. Previously, variation in dielectric properties with ionic radii in these materials has been discussed in terms of geometry (tolerance factor) arguments as used in perovskite ferroelectrics, however we demonstrate the seeming contradictory results for tri- and tetravalent B-site substitutions can be unified by describing the degree of structural distortion such that polar stability is governed by ‘tetragonality’. Using this approach the observed peaks in dielectric constant with temperature, Tm, are displaced to higher temperatures with increasing tetragonality irrespective of substituting cation valence or absolute unit cell parameters.

Item Type: Article
DOI/Identification number: 10.1039/b912535c
Subjects: Q Science > QC Physics
Divisions: Faculties > Sciences > School of Physical Sciences
Faculties > Sciences > School of Physical Sciences > Functional Materials Group
Depositing User: Stewart Brownrigg
Date Deposited: 07 Mar 2014 00:05 UTC
Last Modified: 29 May 2019 12:24 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/40385 (The current URI for this page, for reference purposes)
Arnold, Donna C.: https://orcid.org/0000-0003-0239-5790
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