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Updated: Apr 27, 2026
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Published on: January 16, 2017
Oxygen content, crystal structure and chemical expansion of PrBaCo(2-x)Fe(x)O(6-δ) double perovskites
D S Tsvetkov1, I L Ivanov, D A Malyshkin
1Department of Chemistry, Institute of Natural Sciences, Ural Federal University, Ekaterinburg, 620000, Russia. dmitry.tsvetkov@urfu.ru.
Abstract:
PrBaCo2-xFexO6-δ (x = 0-0.6) double perovskites were shown to have a tetragonal P4/mmm structure in air over the complete temperature range investigated despite the oxygen content reaching a threshold value of 5.5 at temperatures from 850 °C for x = 0 up to 1078 °C for x = 0.6. However the P4/mmm→Pmmm structure transition was found to occur in PrBaCo2O6-δ under reducing conditions at temperatures from 500 °C at pO2 = 10(-3) atm down to 350 °C at pO2 = 10(-4) atm. The lattice chemical expansion along the a-axis and contraction along the c-axis, with decreasing oxygen content, 6 - δ, were found to completely compensate each other in the double perovskites and, therefore, their volume chemical expansion became negligible. As a result the cell volume linearly increases with temperature contrary to simple cubic perovskites.
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