Investigation of the hydrothermal crystallisation of the perovskite solid solution NaCe1-xLaxTi2O6 and its defect chemistry
Abstract
Perovskites of nominal composition NaCe1−xLaxTi2O6 (0≤x≤1) crystallise directly under hydrothermal conditions at 240 °C. Raman spectroscopy shows distortion from the ideal cubic structure and Rietveld analysis of powder X-ray and neutron diffraction reveals that the materials represent a continuous series in rhombohedral space group R3̄c. Ce LIII-edge X-ray absorption near edge structure spectroscopy shows that while the majority of cerium is present as Ce3+ there is evidence for Ce4+. The paramagnetic Ce3+ affects the chemical shift and line width of 23Na MAS NMR spectra, which also show with no evidence for A-site ordering. 2H MAS NMR of samples prepared in D2O shows the inclusion of deuterium, which IR spectroscopy shows is most likely to be as D2O. The deuterium content is highest for the cerium-rich materials, consistent with oxidation of some cerium to Ce4+ to provide charge balance of A-site water.
Citation
Harunsani , M H , Woodward , D I , Peel , M , Ashbrook , S E & Walton , R I 2013 , ' Investigation of the hydrothermal crystallisation of the perovskite solid solution NaCe 1-x La x Ti 2 O 6 and its defect chemistry ' , Journal of Solid State Chemistry , vol. 207 , pp. 117-125 . https://doi.org/10.1016/j.jssc.2013.09.015
Publication
Journal of Solid State Chemistry
Status
Peer reviewed
ISSN
0022-4596Type
Journal article
Description
MHH thanks the Ministry of Education, Brunei for award of a scholarship. EPSRC are thanked for a DTG studentship to MDP.Collections
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