Phase transition behavior of the layered perovskite CsBi0.6La0.4Nb2O7 : a hybrid improper ferroelectric
MetadataShow full item record
Altmetrics Handle Statistics
Altmetrics DOI Statistics
The phase behavior of the layered perovskite CsBi0.6La0.4Nb2O7, of the Dion-Jacobson family, has been studied by high-resolution powder neutron diffraction between temperatures 25 < T < 850 °C. At ambient temperature this material adopts the polar space group P21am; this represents an example of hybrid improper ferroelectricity caused by the interaction of two distinct octahedral tilt modes. Within the limits of our data resolution the thermal evolution of the crystal structure is consistent with a first-order transition between 725 and 750 °C, with both tilt modes vanishing simultaneously, leading to the aristotype space group P4/mmm. This apparent ‘avalanche transition’ behavior resembles that seen in the related Aurivillius phase SrBi2Nb2O9.
Dixon , C A L , McNulty , J A , Knight , K S , Gibbs , A S & Lightfoot , P 2017 , ' Phase transition behavior of the layered perovskite CsBi 0.6 La 0.4 Nb 2 O 7 : a hybrid improper ferroelectric ' , Crystals , vol. 7 , no. 5 , 135 . https://doi.org/10.3390/cryst7050135
© 2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open accessarticle distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
DescriptionWe thank EPSRC for a PhD studentship to CALD (EP/P505097/1).
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.