Structure evolution upon chemical and physical pressure in (Sr1−xBax)2FeSbO6

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Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2017-02-01
Major/Subject
Mcode
Degree programme
Language
en
Pages
7
245-251
Series
Journal of Solid State Chemistry, Volume 246
Abstract
Here we demonstrate the gradual structural transformation from the monoclinic I2/m to tetragonal I4/m, cubic Fm-3m and hexagonal P63/mmc structure upon the isovalent larger-for-smaller A-site cation substitution in the B-site ordered double-perovskite system (Sr1−xBax)2FeSbO6. This is the same transformation sequence previously observed up to Fm-3m upon heating the parent Sr2FeSbO6 phase to high temperatures. High-pressure treatment, on the other hand, transforms the hexagonal P63/mmc structure of the other end member Ba2FeSbO6 back to the cubic Fm-3m structure. Hence we may conclude that chemical pressure, physical pressure and decreasing temperature all work towards the same direction in the (Sr1−xBax)2FeSbO6 system. Also shown is that with increasing Ba-for-Sr substitution level, i.e. with decreasing chemical pressure effect, the degree-of-order among the B-site cations, Fe and Sb, decreases.
Description
Keywords
Cation order, Chemical pressure, Crystal structure, Double perovskite, High-pressure synthesis
Other note
Citation
Tiittanen , T & Karppinen , M 2017 , ' Structure evolution upon chemical and physical pressure in (Sr 1−x Ba x ) 2 FeSbO 6 ' , Journal of Solid State Chemistry , vol. 246 , pp. 245-251 . https://doi.org/10.1016/j.jssc.2016.11.033